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Shin SH, Moazamian D, Suprana A, Zeng C, Athertya JS, Carl M, Ma Y, Jang H, Du J. Yet more evidence that non-aqueous myelin lipids can be directly imaged with ultrashort echo time (UTE) MRI on a clinical 3T scanner: a lyophilized red blood cell membrane lipid study. Neuroimage 2024; 296:120666. [PMID: 38830440 DOI: 10.1016/j.neuroimage.2024.120666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 05/16/2024] [Accepted: 05/31/2024] [Indexed: 06/05/2024] Open
Abstract
Direct imaging of semi-solid lipids, such as myelin, is of great interest as a noninvasive biomarker of neurodegenerative diseases. Yet, the short T2 relaxation times of semi-solid lipid protons hamper direct detection through conventional magnetic resonance imaging (MRI) pulse sequences. In this study, we examined whether a three-dimensional ultrashort echo time (3D UTE) sequence can directly acquire signals from membrane lipids. Membrane lipids from red blood cells (RBC) were collected from commercially available blood as a general model of the myelin lipid bilayer and subjected to D2O exchange and freeze-drying for complete water removal. Sufficiently high MR signals were detected with the 3D UTE sequence, which showed an ultrashort T2* of ∼77-271 µs and a short T1 of ∼189 ms for semi-solid RBC membrane lipids. These measurements can guide designing UTE-based sequences for direct in vivo imaging of membrane lipids.
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Affiliation(s)
- Soo Hyun Shin
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Dina Moazamian
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Arya Suprana
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Chun Zeng
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Jiyo S Athertya
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | | | - Yajun Ma
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Jiang Du
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA.
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Jerban S, Jang H, Chang EY, Bukata S, Du J, Chung CB. Bone Biomarkers Based on Magnetic Resonance Imaging. Semin Musculoskelet Radiol 2024; 28:62-77. [PMID: 38330971 DOI: 10.1055/s-0043-1776431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Magnetic resonance imaging (MRI) is increasingly used to evaluate the microstructural and compositional properties of bone. MRI-based biomarkers can characterize all major compartments of bone: organic, water, fat, and mineral components. However, with a short apparent spin-spin relaxation time (T2*), bone is invisible to conventional MRI sequences that use long echo times. To address this shortcoming, ultrashort echo time MRI sequences have been developed to provide direct imaging of bone and establish a set of MRI-based biomarkers sensitive to the structural and compositional changes of bone. This review article describes the MRI-based bone biomarkers representing total water, pore water, bound water, fat fraction, macromolecular fraction in the organic matrix, and surrogates for mineral density. MRI-based morphological bone imaging techniques are also briefly described.
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Affiliation(s)
- Saeed Jerban
- Department of Radiology, University of California, San Diego, La Jolla, California
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, La Jolla, California
| | - Eric Y Chang
- Department of Radiology, University of California, San Diego, La Jolla, California
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Susan Bukata
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Jiang Du
- Department of Radiology, University of California, San Diego, La Jolla, California
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Bioengineering, University of California, San Diego, La Jolla, California
| | - Christine B Chung
- Department of Radiology, University of California, San Diego, La Jolla, California
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California
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Surowiec RK, Does MD, Nyman JS. In Vivo Assessment of Bone Quality Without X-rays. Curr Osteoporos Rep 2024; 22:56-68. [PMID: 38227178 PMCID: PMC11050740 DOI: 10.1007/s11914-023-00856-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/22/2023] [Indexed: 01/17/2024]
Abstract
PURPOSE OF REVIEW This review summarizes recent advances in the assessment of bone quality using non-X-ray techniques. RECENT FINDINGS Quantitative ultrasound (QUS) provides multiple measurements of bone characteristics based on the propagation of sound through bone, the attenuation of that sound, and different processing techniques. QUS parameters and model predictions based on backscattered signals can discriminate non-fracture from fracture cases with accuracy comparable to standard bone mineral density (BMD). With advances in magnetic resonance imaging (MRI), bound water and pore water, or a porosity index, can be quantified in several long bones in vivo. Since such imaging-derived measurements correlate with the fracture resistance of bone, they potentially provide new BMD-independent predictors of fracture risk. While numerous measurements of mineral, organic matrix, and bound water by Raman spectroscopy correlate with the strength and toughness of cortical bone, the clinical assessment of person's bone quality using spatially offset Raman spectroscopy (SORS) requires advanced spectral processing techniques that minimize contaminating signals from fat, skin, and blood. Limiting exposure of patients to ionizing radiation, QUS, MRI, and SORS has the potential to improve the assessment of fracture risk and track changes of new therapies that target bone matrix and micro-structure.
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Affiliation(s)
- Rachel K Surowiec
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN, 47907, USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N. University Blvd., Indianapolis, IN, 46202, USA
| | - Mark D Does
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN, 37232, USA
- Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN, 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN, 37232, USA
- Department of Electrical Engineering and Computer Science, Vanderbilt University, 400 24th Ave. S., Nashville, TN, 37212, USA
| | - Jeffry S Nyman
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN, 37232, USA.
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, 1215 21st Ave. S., Suite 4200, Nashville, TN, 37232, USA.
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, 1211 Medical Center Dr., Nashville, TN, 37212, USA.
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.
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Fujisaki A, Tsukamoto J, Narimatsu H, Hayashida Y, Todoroki Y, Hirano N, Takeda K, Shin S, Ota S, Anai K, Fukumitsu S, Yoshimatsu Y, Kono Y, Ueno M, Ide S, Murakami Y, Aoki T. Zero Echo Time Magnetic Resonance Imaging; Techniques and Clinical Utility in Musculoskeletal System. J Magn Reson Imaging 2024; 59:32-42. [PMID: 37288953 DOI: 10.1002/jmri.28843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/23/2023] [Accepted: 05/23/2023] [Indexed: 06/09/2023] Open
Abstract
Zero echo time (ZTE) sequence is recent advanced magnetic resonance technique that utilizes ultrafast readouts to capture signals from short-T2 tissues. This sequence enables T2- and T2* weighted imaging of tissues with short intrinsic relaxation times by using an extremely short TE, and are increasingly used in the musculoskeletal system. We review the imaging physics of these sequences, practical limitations, and image reconstruction, and then discuss the clinical utilities in various disorders of the musculoskeletal system. ZTE can be readily incorporated into the clinical workflow, and is a promising technique to avoid unnecessary radiation exposure, cost, and time-consuming by computed tomography in some cases. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Akitaka Fujisaki
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Jun Tsukamoto
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Hidekuni Narimatsu
- Department of Radiology, Hospital of University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yoshiko Hayashida
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yo Todoroki
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Natsumi Hirano
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Kazuki Takeda
- Department of Radiology, Hospital of University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Sho Shin
- Department of Radiology, Hospital of University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Satoru Ota
- Department of Radiology, Hospital of University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Kenta Anai
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Satoshi Fukumitsu
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yuta Yoshimatsu
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yuichiro Kono
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Midori Ueno
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Satoru Ide
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yu Murakami
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Takatoshi Aoki
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
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Zhang X, Zhou B, Chen Y, Cai Z, Guo Y, Wei Z, Li S, Feng Y, Sedaghat S, Jang H. Evaluation of gadolinium deposition in cortical bone using three-dimensional ultrashort echo time quantitative susceptibility mapping: A preliminary study. NMR IN BIOMEDICINE 2024; 37:e5035. [PMID: 37721094 PMCID: PMC10726698 DOI: 10.1002/nbm.5035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 09/19/2023]
Abstract
The aim of the current study was to investigate the feasibility of three-dimensional ultrashort echo time quantitative susceptibility mapping (3D UTE-QSM) for the assessment of gadolinium (Gd) deposition in cortical bone. To this end, 40 tibial bovine cortical bone specimens were divided into five groups then soaked in phosphate-buffered saline (PBS) solutions with five different Gd concentrations of 0, 0.4, 0.8, 1.2, and 1.6 mmol/L for 48 h. Additionally, eight rabbits were randomly allocated into three groups, consisting of a normal-dose macrocyclic gadolinium-based contrast agent (GBCA) group (n = 3), a high-dose macrocyclic GBCA group (n = 3), and a control group (n = 2). All bovine and rabbit tibial bone samples underwent magnetic resonance imaging (MRI) on a 3-T clinical MR system. A 3D UTE-Cones sequence was utilized to acquire images with five different echo times (i.e., 0.032, 0.2, 0.4, 0.8, and 1.2 ms). The UTE images were subsequently processed with the morphology-enabled dipole inversion algorithm to yield a susceptibility map. The average susceptibility was calculated in three regions of interest in the middle of each specimen, and the Pearson's correlation between the estimated susceptibility and Gd concentration was calculated. The bone samples soaked in PBS with higher Gd concentrations exhibited elevated susceptibility values. A mean susceptibility value of -2.47 ± 0.23 ppm was observed for bovine bone soaked in regular PBS, while the mean QSM value increased to -1.75 ± 0.24 ppm for bone soaked in PBS with the highest Gd concentration of 1.6 mmol/L. A strong positive correlation was observed between Gd concentrations and QSM values. The mean susceptibility values of rabbit tibial specimens in the control group, normal-dose GBCA group, and high-dose GBCA group were -4.11 ± 1.52, -3.85 ± 1.33, and -3.39 ± 1.35 ppm, respectively. In conclusion, a significant linear correlation between Gd in cortical bone and QSM values was observed. The preliminary results suggest that 3D UTE-QSM may provide sensitive noninvasive assessment of Gd deposition in cortical bone.
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Affiliation(s)
- Xiaodong Zhang
- Department of Radiology, Third Affiliated Hospital of Southern Medical University, Guangzhou, China
- University of California, San Diego, San Diego, CA, United States
| | - Beibei Zhou
- The Third School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Yanjun Chen
- Department of Radiology, Third Affiliated Hospital of Southern Medical University, Guangzhou, China
- University of California, San Diego, San Diego, CA, United States
| | - Zhenyu Cai
- University of California, San Diego, San Diego, CA, United States
| | - Yihao Guo
- School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Zhao Wei
- University of California, San Diego, San Diego, CA, United States
| | - Shisi Li
- Department of Radiology, Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Yanqiu Feng
- School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Sam Sedaghat
- University of California, San Diego, San Diego, CA, United States
| | - Hyungseok Jang
- University of California, San Diego, San Diego, CA, United States
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Cui L, McWalter EJ, Moran G, Venugopal N. Design and development of a novel flexible ultra-short echo time (FUSE) sequence. Magn Reson Med 2023; 90:1905-1918. [PMID: 37392415 DOI: 10.1002/mrm.29784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 05/28/2023] [Accepted: 06/13/2023] [Indexed: 07/03/2023]
Abstract
PURPOSE To present the validation of a new Flexible Ultra-Short Echo time (FUSE) pulse sequence using a short-T2 phantom. METHODS FUSE was developed to include a range of RF excitation pulses, trajectories, dimensionalities, and long-T2 suppression techniques, enabling real-time interchangeability of acquisition parameters. Additionally, we developed an improved 3D deblurring algorithm to correct for off-resonance artifacts. Several experiments were conducted to validate the efficacy of FUSE, by comparing different approaches for off-resonance artifact correction, variations in RF pulse and trajectory combinations, and long-T2 suppression techniques. All scans were performed on a 3 T system using an in-house short-T2 phantom. The evaluation of results included qualitative comparisons and quantitative assessments of the SNR and contrast-to-noise ratio. RESULTS Using the capabilities of FUSE, we demonstrated that we could combine a shorter readout duration with our improved deblurring algorithm to effectively reduce off-resonance artifacts. Among the different RF and trajectory combinations, the spiral trajectory with the regular half-inc pulse achieves the highest SNRs. The dual-echo subtraction technique delivers better short-T2 contrast and superior suppression of water and agar signals, whereas the off-resonance saturation method successfully suppresses water and lipid signals simultaneously. CONCLUSION In this work, we have validated the use of our new FUSE sequence using a short T2 phantom, demonstrating that multiple UTE acquisitions can be achieved within a single sequence. This new sequence may be useful for acquiring improved UTE images and the development of UTE imaging protocols.
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Affiliation(s)
- Lumeng Cui
- Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Emily J McWalter
- Department of Mechanical Engineering and Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Gerald Moran
- Siemens Healthcare Limited, Oakville, Ontario, Canada
| | - Niranjan Venugopal
- Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada
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Tsuchiya K, Gomyo M, Katase S, Hiraoka S, Tateishi H. Magnetic resonance bone imaging: applications to vertebral lesions. Jpn J Radiol 2023; 41:1173-1185. [PMID: 37209299 PMCID: PMC10613598 DOI: 10.1007/s11604-023-01449-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023]
Abstract
MR bone imaging is a recently introduced technique, that allows visualization of bony structures in good contrast against adjacent structures, like CT. Although CT has long been considered the modality of choice for bone imaging, MR bone imaging allows visualization of the bone without radiation exposure while simultaneously allowing conventional MR images to be obtained. Accordingly, MR bone imaging is expected as a new imaging technique for the diagnosis of miscellaneous spinal diseases. This review presents several sequences used in MR bone imaging including black bone imaging, ultrashort/zero echo time (UTE/ZTE) sequences, and T1-weighted 3D gradient-echo sequence. We also illustrate clinical cases in which spinal lesions could be effectively demonstrated on MR bone imaging, performed in most cases using a 3D gradient-echo sequence at our institution. The lesions presented herein include degenerative diseases, tumors and similar diseases, fractures, infectious diseases, and hemangioma. Finally, we discuss the differences between MR bone imaging and previously reported techniques, and the limitations and future perspectives of MR bone imaging.
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Affiliation(s)
- Kazuhiro Tsuchiya
- Department of Radiology, JR Tokyo General Hospital, 2-1-3 Yoyogi, Shibuya-ku, Tokyo, 151-8528, Japan.
- Department of Radiology, Faculty of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka City, Tokyo, 181-8611, Japan.
| | - Miho Gomyo
- Department of Radiology, Faculty of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka City, Tokyo, 181-8611, Japan
| | - Shichiro Katase
- Department of Radiology, Faculty of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka City, Tokyo, 181-8611, Japan
| | - Sayuki Hiraoka
- Department of Radiology, JR Tokyo General Hospital, 2-1-3 Yoyogi, Shibuya-ku, Tokyo, 151-8528, Japan
| | - Hidekatsu Tateishi
- Department of Radiology, JR Tokyo General Hospital, 2-1-3 Yoyogi, Shibuya-ku, Tokyo, 151-8528, Japan
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8
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Nyman JS, Ketsiri T, Louie EA, Harkins KD, Manhard MK, Gochberg DF, Lee DH, Desai MJ, Maslow J, Tanner SB, Does MD. Toward the use of MRI measurements of bound and pore water in fracture risk assessment. Bone 2023; 176:116863. [PMID: 37527697 PMCID: PMC10528882 DOI: 10.1016/j.bone.2023.116863] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/03/2023]
Abstract
The current clinical assessment of fracture risk lacks information about the inherent quality of a person's bone tissue. Working toward an imaging-based approach to quantify both a bone tissue quality marker (tissue hydration as water bound to the matrix) and a bone microstructure marker (porosity as water in pores), we hypothesized that the concentrations of bound water (Cbw) are lower and concentrations of pore water (Cpw) are higher in patients with osteoporosis (OP) than in age- and sex-matched adults without the disease. Using recent developments in ultrashort echo time (UTE) magnetic resonance imaging (MRI), maps of Cbw and Cpw were acquired from the uninjured distal third radius (Study 1) of 20 patients who experienced a fragility fracture of the distal radius (Fx) and 20 healthy controls (Non-Fx) and from the tibia mid-diaphysis (Study 2) of 30 women with clinical OP (low T-scores) and 15 women without OP (normal T-scores). In Study 1, Cbw was significantly lower (p = 0.0018) and Cpw was higher (p = 0.0022) in the Fx than in the Non-Fx group. In forward stepwise, logistic regression models using Bayesian Information Criterion for selecting the best set of predictors (from imaging parameters, age, BMI, and DXA scanner type), the area-under-the-receiver operator characteristics-curve (AUC with 95 % confidence intervals) was 0.73 (0.56, 0.86) for hip aBMD (best predictors without MRI) and 0.86 (0.70, 0.95) for the combination of Cbw and Cpw (best predictors overall). In Study 2, Cbw was significantly lower (p = 0.0005) in women with OP (23.8 ± 4.3 1H mol/L) than in women without OP (29.9 ± 6.4 1H mol/L); Cpw was significantly higher by estimate of 2.9 1H mol/L (p = 0.0298) with clinical OP, but only when accounting for the type of UTE-MRI scan with 3D providing higher values than 2D (p < 0.0001). Lastly, Cbw, but not Cpw, was sensitive to bone forming osteoporosis medications over 12-months. UTE-MRI-derived measurements of bound and pore water concentrations are potential, aBMD-independent predictors of fracture risk.
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Affiliation(s)
- Jeffry S Nyman
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, 1215 21st Ave. S., Suite 4200, Nashville, TN 37232, USA; Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN 37232, USA; Department of Veterans Affairs, Tennessee Valley Healthcare System, 1310 24th Ave. S., Nashville, TN 37212, USA; Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center,1211 Medical Center Dr., Nashville, TN 37212, USA.
| | - Thammathida Ketsiri
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN 37232, USA; Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Elizabeth A Louie
- Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Kevin D Harkins
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN 37232, USA; Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Mary Kate Manhard
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA
| | - Daniel F Gochberg
- Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Donald H Lee
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, 1215 21st Ave. S., Suite 4200, Nashville, TN 37232, USA
| | - Mihir J Desai
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, 1215 21st Ave. S., Suite 4200, Nashville, TN 37232, USA
| | - Jed Maslow
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, 1215 21st Ave. S., Suite 4200, Nashville, TN 37232, USA
| | - S Bobo Tanner
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center,1211 Medical Center Dr., Nashville, TN 37212, USA; Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA
| | - Mark D Does
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN 37232, USA; Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S., Nashville, TN 37232, USA; Department of Electrical Engineering and Computer Science, Vanderbilt University, 400 24th Ave. S., Nashville, TN 37212, USA.
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Abrahamsen BS, Knudtsen IS, Eikenes L, Bathen TF, Elschot M. Pelvic PET/MR attenuation correction in the image space using deep learning. Front Oncol 2023; 13:1220009. [PMID: 37692851 PMCID: PMC10484800 DOI: 10.3389/fonc.2023.1220009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction The five-class Dixon-based PET/MR attenuation correction (AC) model, which adds bone information to the four-class model by registering major bones from a bone atlas, has been shown to be error-prone. In this study, we introduce a novel method of accounting for bone in pelvic PET/MR AC by directly predicting the errors in the PET image space caused by the lack of bone in four-class Dixon-based attenuation correction. Methods A convolutional neural network was trained to predict the four-class AC error map relative to CT-based attenuation correction. Dixon MR images and the four-class attenuation correction µ-map were used as input to the models. CT and PET/MR examinations for 22 patients ([18F]FDG) were used for training and validation, and 17 patients were used for testing (6 [18F]PSMA-1007 and 11 [68Ga]Ga-PSMA-11). A quantitative analysis of PSMA uptake using voxel- and lesion-based error metrics was used to assess performance. Results In the voxel-based analysis, the proposed model reduced the median root mean squared percentage error from 12.1% and 8.6% for the four- and five-class Dixon-based AC methods, respectively, to 6.2%. The median absolute percentage error in the maximum standardized uptake value (SUVmax) in bone lesions improved from 20.0% and 7.0% for four- and five-class Dixon-based AC methods to 3.8%. Conclusion The proposed method reduces the voxel-based error and SUVmax errors in bone lesions when compared to the four- and five-class Dixon-based AC models.
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Affiliation(s)
- Bendik Skarre Abrahamsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ingerid Skjei Knudtsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Live Eikenes
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tone Frost Bathen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Mattijs Elschot
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
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10
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He T, Pang Z, Yin Y, Xue H, Pang Y, Song H, Li J, Bai R, Qin A, Kong X. Micron-resolution Imaging of Cortical Bone under 14 T Ultrahigh Magnetic Field. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300959. [PMID: 37339792 PMCID: PMC10460861 DOI: 10.1002/advs.202300959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 05/11/2023] [Indexed: 06/22/2023]
Abstract
Compact, mineralized cortical bone tissues are often concealed on magnetic resonance (MR) images. Recent development of MR instruments and pulse techniques has yielded significant advances in acquiring anatomical and physiological information from cortical bone despite its poor 1 H signals. This work demonstrates the first MR research on cortical bones under an ultrahigh magnetic field of 14 T. The 1 H signals of different mammalian species exhibit multi-exponential decays of three characteristic T2 or T2 * values: 0.1-0.5 ms, 1-4 ms, and 4-8 ms. Systematic sample comparisons attribute these T2 /T2 * value ranges to collagen-bound water, pore water, and lipids, respectively. Ultrashort echo time (UTE) imaging under 14 T yielded spatial resolutions of 20-80 microns, which resolves the 3D anatomy of the Haversian canals. The T2 * relaxation characteristics further allow spatial classifications of collagen, pore water and lipids in human specimens. The study achieves a record of the spatial resolution for MR imaging in bone and shows that ultrahigh-field MR has the unique ability to differentiate the soft and organic compartments in bone tissues.
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Affiliation(s)
- Tian He
- Department of ChemistryZhejiang UniversityHangzhou310027China
| | - Zhenfeng Pang
- Department of ChemistryZhejiang UniversityHangzhou310027China
| | - Yu Yin
- Department of ChemistryZhejiang UniversityHangzhou310027China
| | - Huadong Xue
- Department of ChemistryZhejiang UniversityHangzhou310027China
- Department of RehabilitationSir Run Run Shaw HospitalCollege of MedicineZhejiang UniversityHangzhou310016China
| | - Yichuan Pang
- Shanghai Key Laboratory of Orthopedic ImplantsDepartment of OrthopaedicsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai200011China
| | - Haixin Song
- Department of RehabilitationSir Run Run Shaw HospitalCollege of MedicineZhejiang UniversityHangzhou310016China
| | - Jianhua Li
- Department of RehabilitationSir Run Run Shaw HospitalCollege of MedicineZhejiang UniversityHangzhou310016China
| | - Ruiliang Bai
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT)College of Biomedical Engineering and Instrument ScienceZhejiang UniversityHangzhou310027China
- School of MedicineZhejiang UniversityHangzhou310058China
| | - An Qin
- Shanghai Key Laboratory of Orthopedic ImplantsDepartment of OrthopaedicsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai200011China
| | - Xueqian Kong
- Department of ChemistryZhejiang UniversityHangzhou310027China
- Department of RehabilitationSir Run Run Shaw HospitalCollege of MedicineZhejiang UniversityHangzhou310016China
- Institute of Translational MedicineShanghai Jiaotong UniversityShanghai200240China
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11
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Inoue A, Watanabe H, Suehiro S, Nishida N, Shiraishi Y, Furumochi T, Takimoto Y, Ohnishi T, Shigekawa S, Kunieda T. Clinical utility of new bone imaging using zero-echo-time sequence in neurosurgical procedures: Can zero-echo-time be used in clinical practice in neurosurgery? Neuroradiol J 2023; 36:289-296. [PMID: 37259240 PMCID: PMC10268098 DOI: 10.1177/19714009221114447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2024] Open
Abstract
PURPOSE The purpose of this study was to evaluate the clinical usefulness of zero-echo-time (ZTE)-based magnetic resonance imaging (MRI) in planning the optimum surgical approach and applying ZTE for anatomical guidance during transcranial surgery. METHODS Eleven of 26 patients who underwent transcranial surgery and carotid endarterectomy and in whom ZTE-based MRI and magnetic resonance angiography (MRA) data were obtained were analyzed by creating ZTE/MRA fusion images and 3D ZTE-based MRI models. We examined whether these images and models can be substituted for computed tomography imaging for neurosurgical procedures. Furthermore, the clinical usability of the 3D ZTE-based MRI models was evaluated by comparing them with actual surgical views. RESULTS Zero-echo-time/MRA fusion images and 3D ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of iodinated contrast medium. The models allowed determination of the optimum surgical approach to cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship of lesions with adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions such as vestibular schwannoma because bone structures of the skull base often include air components, which cause signal disturbance in MRI. CONCLUSIONS Zero-echo-time sequences on MRI allowed distinct visualization of not only bone but also vital structures around the lesion. This technology has low invasiveness for patients and was useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.
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Affiliation(s)
- Akihiro Inoue
- Department of Neurosurgery, Ehime University School of
Medicine, Japan
| | - Hideaki Watanabe
- Department of Neurosurgery, Ehime University School of
Medicine, Japan
| | - Satoshi Suehiro
- Department of Neurosurgery, Ehime University School of
Medicine, Japan
| | - Naoya Nishida
- Department of Otolaryngology, Ehime University School of
Medicine, Japan
| | | | | | | | | | - Seiji Shigekawa
- Department of Neurosurgery, Ehime University School of
Medicine, Japan
| | - Takeharu Kunieda
- Department of Neurosurgery, Ehime University School of
Medicine, Japan
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12
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Lin C, Liu D, Wen H, Liu B, Tu L, Gu J. Zero echo time MRI improved detection of erosions and sclerosis in the sacroiliac joint in comparison with LAVA-flex. Front Endocrinol (Lausanne) 2023; 14:1167334. [PMID: 37313443 PMCID: PMC10258343 DOI: 10.3389/fendo.2023.1167334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 05/05/2023] [Indexed: 06/15/2023] Open
Abstract
Background T1-weighted spoiled 3D Gradient Recalled Echo pulse sequences, exemplified by Liver Acquisition with Volume Acceleration-flexible MRI (LAVA-Flex), are currently the preferred MR sequence for detecting erosions of the sacroiliac joint (SIJ). However, zero echo time MRI (ZTE) is recently reported to provide excellent visualization of the cortical bone. Purpose To directly compare the diagnostic accuracy of ZTE and LAVA-Flex in the detection of structural lesions of the SIJ, including erosions, sclerosis and joint space changes. Materials and methods Two readers independently reviewed the ldCT, ZTE and LAVA-Flex images of 53 patients diagnosed as axSpA and scored the erosions, sclerosis and joint space changes. Sensitivity, specificity and Cohen's kappa (κ) of ZTE and LAVA-Flex were calculated, while McNemar's test was employed to compare the two sequences for the positivity of detecting the structural lesions. Results Analysis of diagnostic accuracy showed a higher sensitivity of ZTE in comparison with LAVA-Flex in the depiction of erosions (92.5% vs 81.5%, p<0.001), especially first-degree erosions (p<0.001) and second-degree erosions (p<0.001), as well as sclerosis (90.6% vs 71.2%, p<0.001), but not joint space changes (95.2% vs 93.8%, p=0.332). Agreement with ldCT was also higher in ZTE in the detection of erosions than LAVA-Flex as indicated by the κ values (0.73 vs 0.47), as well as in the detection of sclerosis (0.92 vs 0.22). Conclusion With ldCT as the reference standard, ZTE could improve diagnostic accuracy of erosions and sclerosis of the SIJ in patients suspected of axSpA, in comparison with LAVA-Flex.
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Affiliation(s)
- Churong Lin
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Dong Liu
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Huiquan Wen
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Budian Liu
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Liudan Tu
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Jieruo Gu
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
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13
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Chen Y, Mei X, Liang X, Cao Y, Peng C, Fu Y, Zhang Y, Liu C, Liu Y. Application of magnetic resonance image compilation (MAGiC) in the diagnosis of middle-aged and elderly women with osteoporosis. BMC Med Imaging 2023; 23:63. [PMID: 37189019 DOI: 10.1186/s12880-023-01010-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 03/30/2023] [Indexed: 05/17/2023] Open
Abstract
OBJECTIVE To investigate the feasibility of diagnosing osteoporosis (OP) in women through magnetic resonance image compilation (MAGiC). METHODS A total of 110 patients who underwent lumbar magnetic resonance imaging and dual X-ray absorptiometry examinations were collected and divided into two groups according bone mineral density: osteoporotic group (OP) and non-osteoporotic group (non-OP). The variation trends of T1 (longitudinal relaxation time), T2 (transverse relaxation time) and BMD (bone mineral density) with the increase of age, and the correlation of T1 and T2 with BMD were examined by establishing a clinical mathematical model. RESULTS With the increase of age, BMD and T1 value decreased gradually, while T2 value increased. T1 and T2 had statistical significance in diagnosing OP (P < 0.001), and there is moderate positive correlation between T1 and BMD values (R = 0.636, P < 0.001), while moderate negative correlation between T2 and BMD values (R=-0.694, P < 0.001). Receiver characteristic curve test showed that T1 and T2 had high accuracy in diagnosing OP (T1 AUC = 0.982, T2 AUC = 0.978), and the critical values of T1 and T2 for evaluating osteoporosis were 0.625s and 0.095s, respectively. Besides, the combined utilization of T1 and T2 had higher diagnostic efficiency (AUC = 0.985). Combined T1 and T2 had higher diagnostic efficiency (AUC = 0.985). Function fitting results of OP group: BMD=-0.0037* age - 0.0015*T1 + 0.0037*T2 + 0.86, sum of squared error (SSE) = 0.0392, and non-OP group: BMD = 0.0024* age - 0.0071*T1 + 0.0007*T2 + 1.41, SSE = 0.1007. CONCLUSION T1 and T2 value of MAGiC have high efficiency in diagnosing OP by establishing a function fitting formula of BMD with T1, T2 and age.
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Affiliation(s)
- Yiming Chen
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China.
| | - Xiuting Mei
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Xuqian Liang
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Yi Cao
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Cong Peng
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Yang Fu
- Rehabilitation Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Yulong Zhang
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Cuifang Liu
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China.
| | - Yang Liu
- Radiology Department of Chongqing Traditional Chinese Medicine Hospital, Chongqing, China.
- School of Pharmacy, Chongqing Medical and Pharmaceutical College, Chongqing, China.
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14
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Jerban S, Ma Y, Alenezi S, Moazamian D, Athertya J, Jang H, Dorthe E, Dlima D, Woods G, Chung CB, Chang EY, Du J. Ultrashort Echo Time (UTE) MRI porosity index (PI) and suppression ratio (SR) correlate with the cortical bone microstructural and mechanical properties: Ex vivo study. Bone 2023; 169:116676. [PMID: 36657630 PMCID: PMC9987215 DOI: 10.1016/j.bone.2023.116676] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/19/2022] [Accepted: 01/08/2023] [Indexed: 01/18/2023]
Abstract
Ultrashort echo time (UTE) MRI can image and consequently enable quantitative assessment of cortical bone. UTE-MRI-based evaluation of bone is largely underutilized due to the high cost and time demands of MRI in general. The signal ratio in dual-echo UTE imaging, known as porosity index (PI), as well as the signal ratio between UTE and inversion recovery UTE (IR-UTE) imaging, known as the suppression ratio (SR), are two rapid UTE-based bone evaluation techniques (∼ 5 mins scan time each), which can potentially reduce the time demand and cost in future clinical studies. This study aimed to investigate the correlations of PI and SR measures with cortical bone microstructural and mechanical properties. Cortical bone strips (n = 135) from tibial and femoral midshafts of 37 donors (61 ± 24 years old) were scanned using a dual-echo 3D Cones UTE sequence and a 3D Cones IR-UTE sequence for PI and SR calculations, respectively. Average bone mineral density, porosity, and pore size were measured using microcomputed tomography (μCT). Bone mechanical properties were measured using 4-point bending tests. The μCT measures showed significant correlations with PI (moderate to strong, R = 0.68-0.71) and SR (moderate, R = 0.58-0.68). Young's modulus, yield stress, and ultimate stress demonstrated significant moderate correlations with PI and SR (R = 0.52-0.62) while significant strong correlations with μCT measures (R > 0.7). PI and SR can potentially serve as fast and noninvasive (non-ionizing radiation) biomarkers for evaluating cortical bone in various bone diseases.
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Affiliation(s)
- Saeed Jerban
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA; Department of Orthopedic Surgery, University of California, San Diego, La Jolla, CA, USA.
| | - Yajun Ma
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA
| | - Salem Alenezi
- Research and Laboratories Sector, Saudi Food and Drug Authority, Riyadh, Kingdom of Saudi Arabia
| | - Dina Moazamian
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Jiyo Athertya
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA
| | - Erik Dorthe
- Shiley Center for Orthopedic Research and Education at Scripps Clinic, La Jolla, CA, USA
| | - Darryl Dlima
- Shiley Center for Orthopedic Research and Education at Scripps Clinic, La Jolla, CA, USA
| | - Gina Woods
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Christine B Chung
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA
| | - Eric Y Chang
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA
| | - Jiang Du
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA; Radiology Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, USA.
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15
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Lombardi AF, Ma YJ, Jang H, Jerban S, Du J, Chang EY, Chung CB. Synthetic CT in Musculoskeletal Disorders: A Systematic Review. Invest Radiol 2023; 58:43-59. [PMID: 36070535 PMCID: PMC9742139 DOI: 10.1097/rli.0000000000000916] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT Repeated computed tomography (CT) examinations increase patients' ionizing radiation exposure and health costs, making an alternative method desirable. Cortical and trabecular bone, however, have short T2 relaxation times, causing low signal intensity on conventional magnetic resonance (MR) sequences. Different techniques are available to create a "CT-like" contrast of bone, such as ultrashort echo time, zero echo time, gradient-echo, and susceptibility-weighted image MR sequences, and artificial intelligence. This systematic review summarizes the essential technical background and developments of ultrashort echo time, zero echo time, gradient-echo, susceptibility-weighted image MR imaging sequences and artificial intelligence; presents studies on research and clinical applications of "CT-like" MR imaging; and describes their main advantages and limitations. We also discuss future opportunities in research, which patients would benefit the most, the most appropriate situations for using the technique, and the potential to replace CT in the clinical workflow.
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Affiliation(s)
- Alecio F Lombardi
- From the Department of Radiology, University of California San Diego, La Jolla, and the Research Service, Veterans Affairs San Diego Healthcare System, California
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16
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Ma Y, Jang H, Jerban S, Chang EY, Chung CB, Bydder GM, Du J. Making the invisible visible-ultrashort echo time magnetic resonance imaging: Technical developments and applications. APPLIED PHYSICS REVIEWS 2022; 9:041303. [PMID: 36467869 PMCID: PMC9677812 DOI: 10.1063/5.0086459] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 09/12/2022] [Indexed: 05/25/2023]
Abstract
Magnetic resonance imaging (MRI) uses a large magnetic field and radio waves to generate images of tissues in the body. Conventional MRI techniques have been developed to image and quantify tissues and fluids with long transverse relaxation times (T2s), such as muscle, cartilage, liver, white matter, gray matter, spinal cord, and cerebrospinal fluid. However, the body also contains many tissues and tissue components such as the osteochondral junction, menisci, ligaments, tendons, bone, lung parenchyma, and myelin, which have short or ultrashort T2s. After radio frequency excitation, their transverse magnetizations typically decay to zero or near zero before the receiving mode is enabled for spatial encoding with conventional MR imaging. As a result, these tissues appear dark, and their MR properties are inaccessible. However, when ultrashort echo times (UTEs) are used, signals can be detected from these tissues before they decay to zero. This review summarizes recent technical developments in UTE MRI of tissues with short and ultrashort T2 relaxation times. A series of UTE MRI techniques for high-resolution morphological and quantitative imaging of these short-T2 tissues are discussed. Applications of UTE imaging in the musculoskeletal, nervous, respiratory, gastrointestinal, and cardiovascular systems of the body are included.
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Affiliation(s)
- Yajun Ma
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Saeed Jerban
- Department of Radiology, University of California, San Diego, California 92037, USA
| | | | | | - Graeme M Bydder
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Jiang Du
- Author to whom correspondence should be addressed:. Tel.: (858) 246-2248, Fax: (858) 246-2221
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17
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Bharadwaj UU, Coy A, Motamedi D, Sun D, Joseph GB, Krug R, Link TM. CT-like MRI: a qualitative assessment of ZTE sequences for knee osseous abnormalities. Skeletal Radiol 2022; 51:1585-1594. [PMID: 35088162 PMCID: PMC9198000 DOI: 10.1007/s00256-021-03987-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/15/2021] [Accepted: 12/29/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To qualitatively evaluate the utility of zero echo-time (ZTE) MRI sequences in identifying osseous findings and to compare ZTE with optimized spoiled gradient echo (SPGR) sequences in detecting knee osseous abnormalities. MATERIALS AND METHODS ZTE and standard knee MRI sequences were acquired at 3T in 100 consecutive patients. Three radiologists rated confidence in evaluating osseous abnormalities and image quality on a 5-grade Likert scale in ZTE compared to standard sequences. In a subset of knees (n = 57) SPGR sequences were also obtained, and diagnostic confidence in identifying osseous structures was assessed, comparing ZTE and SPGR sequences. Statistical significance of using ZTE over SPGR was characterized with a paired t-test. RESULTS Image quality of the ZTE sequences was rated high by all reviewers with 278 out of 299 (100 studies, 3 radiologists) scores ≥ 4 on the Likert scale. Diagnostic confidence in using ZTE sequences was rated "very high confidence" in 97%, 85%, 71%, and 73% of the cases for osteophytosis, subchondral cysts, fractures, and soft tissue calcifications/ossifications, respectively. In 74% of cases with osseous findings, reviewer scores indicated confidence levels (score ≥ 3) that ZTE sequences improved diagnostic certainty over standard sequences. The diagnostic confidence in using ZTE over SPGR sequences for osseous structures as well as abnormalities was favorable and statistically significant (p < 0.01). CONCLUSION Incorporating ZTE sequences in the standard knee MRI protocol was technically feasible and improved diagnostic confidence for osseous findings in relation to standard MR sequences. In comparison to SPGR sequences, ZTE improved assessment of osseous abnormalities.
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Affiliation(s)
- Upasana Upadhyay Bharadwaj
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA.
| | - Adam Coy
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
- Musculoskeletal Radiology, Vision Radiology, Dallas, TX, USA
| | - Daria Motamedi
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
| | - Dong Sun
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gabby B Joseph
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
| | - Roland Krug
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
| | - Thomas M Link
- Musculoskeletal Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA
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18
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Wiesinger F, Ho ML. Zero-TE MRI: principles and applications in the head and neck. Br J Radiol 2022; 95:20220059. [PMID: 35616709 PMCID: PMC10162052 DOI: 10.1259/bjr.20220059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Zero echo-time (ZTE) MRI is a novel imaging technique that utilizes ultrafast readouts to capture signal from short-T2 tissues. Additional sequence advantages include rapid imaging times, silent scanning, and artifact resistance. A robust application of this technology is imaging of cortical bone without the use of ionizing radiation, thus representing a viable alternative to CT for both rapid screening and "one-stop-shop" MRI. Although ZTE is increasingly used in musculoskeletal and body imaging, neuroimaging applications have historically been limited by complex anatomy and pathology. In this article, we review the imaging physics of ZTE including pulse sequence options, practical limitations, and image reconstruction. We then discuss optimization of settings for ZTE bone neuroimaging including acquisition, processing, segmentation, synthetic CT generation, and artifacts. Finally, we examine clinical utility of ZTE in the head and neck with imaging examples including malformations, trauma, tumors, and interventional procedures.
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Affiliation(s)
- Florian Wiesinger
- Department for Neuroimaging, Institute of Psychiatry & Neuroscience, King's College London, London, UK.,Principal Scientist at GE Healthcare, Munich, Germany
| | - Mai-Lan Ho
- Nationwide Children's Hospital and The Ohio State University, Columbus, USA
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19
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Aydıngöz Ü, Yıldız AE, Ergen FB. Zero Echo Time Musculoskeletal MRI: Technique, Optimization, Applications, and Pitfalls. Radiographics 2022; 42:1398-1414. [PMID: 35904982 DOI: 10.1148/rg.220029] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Zero echo time (ZTE) imaging is an MRI technique that produces images similar to those obtained with radiography or CT. In ZTE MRI, the very short T2 signal from the mineralized trabecular bone matrix and especially cortical bone-both of which have a low proton density (PD)-is sampled in a unique sequence setup. Additionally, the PD weighting of the ZTE sequence results in less contrast between soft tissues. Therefore, along with gray-scale inversion from black to white and vice versa, ZTE imaging provides excellent contrast between cortical bone and soft tissues similar to that of radiography and CT. However, despite isotropic or near-isotropic three-dimensional (3D) imaging capabilities of the ZTE sequence, spatial resolution in this technique is still inferior to that of radiography and CT, and 3D volume renderings are currently time-consuming and require postprocessing software that features segmentation and manual contouring. Optimization of ZTE MRI mostly entails adjustments of bandwidth, flip angle, field of view, and image matrix. A wide range of structural abnormalities and disease or healing processes in the musculoskeletal system are well delineated with ZTE MRI, including conditions that involve bone-based morphometric analyses (which aid diagnosis, help prognostication, and guide surgery), impaction, avulsion and stress fractures, loose bodies or erosions in and around joints, soft-tissue calcifications and ossifications, and bone tumors (including treatment response). The pitfalls of ZTE imaging include mimics of foci of calcification or ossification such as intra-articular gas and susceptibility artifacts from surgical materials and hemosiderin deposition, which can be avoided in many instances by cross-referencing images obtained with other MRI sequences. Online supplemental material is available for this article. ©RSNA, 2022.
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Affiliation(s)
- Üstün Aydıngöz
- From the Department of Radiology, Hacettepe University School of Medicine, 06230 Ankara, Turkey
| | - Adalet Elçin Yıldız
- From the Department of Radiology, Hacettepe University School of Medicine, 06230 Ankara, Turkey
| | - F Bilge Ergen
- From the Department of Radiology, Hacettepe University School of Medicine, 06230 Ankara, Turkey
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Surowiec RK, Allen MR, Wallace JM. Bone hydration: How we can evaluate it, what can it tell us, and is it an effective therapeutic target? Bone Rep 2022; 16:101161. [PMID: 35005101 PMCID: PMC8718737 DOI: 10.1016/j.bonr.2021.101161] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 12/22/2022] Open
Abstract
Water constitutes roughly a quarter of the cortical bone by volume yet can greatly influence mechanical properties and tissue quality. There is a growing appreciation for how water can dynamically change due to age, disease, and treatment. A key emerging area related to bone mechanical and tissue properties lies in differentiating the role of water in its four different compartments, including free/pore water, water loosely bound at the collagen/mineral interfaces, water tightly bound within collagen triple helices, and structural water within the mineral. This review summarizes our current knowledge of bone water across the four functional compartments and discusses how alterations in each compartment relate to mechanical changes. It provides an overview on the advent of- and improvements to- imaging and spectroscopic techniques able to probe nano-and molecular scales of bone water. These technical advances have led to an emerging understanding of how bone water changes in various conditions, of which aging, chronic kidney disease, diabetes, osteoporosis, and osteogenesis imperfecta are reviewed. Finally, it summarizes work focused on therapeutically targeting water to improve mechanical properties.
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Affiliation(s)
- Rachel K. Surowiec
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Biomedical Engineering, Indiana University Purdue University of Indianapolis, Indianapolis, IN, United States
| | - Matthew R. Allen
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Biomedical Engineering, Indiana University Purdue University of Indianapolis, Indianapolis, IN, United States
- Roudebush Veterans Administration Medical Center, Indianapolis, IN, United States
| | - Joseph M. Wallace
- Department of Biomedical Engineering, Indiana University Purdue University of Indianapolis, Indianapolis, IN, United States
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21
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Jerban S, Ma Y, Afsahi AM, Lombardi A, Wei Z, Shen M, Wu M, Le N, Chang DG, Chung CB, Du J, Chang EY. Lower Macromolecular Content in Tendons of Female Patients with Osteoporosis versus Patients with Osteopenia Detected by Ultrashort Echo Time (UTE) MRI. Diagnostics (Basel) 2022; 12:1061. [PMID: 35626217 PMCID: PMC9140093 DOI: 10.3390/diagnostics12051061] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 01/30/2023] Open
Abstract
Tendons and bones comprise a special interacting unit where mechanical, biochemical, and metabolic interplays are continuously in effect. Bone loss in osteoporosis (OPo) and its earlier stage disease, osteopenia (OPe), may be coupled with a reduction in tendon quality. Noninvasive means for quantitatively evaluating tendon quality during disease progression may be critically important for the improvement of characterization and treatment optimization in patients with bone mineral density disorders. Though clinical magnetic resonance imaging (MRI) sequences are not typically capable of directly visualizing tendons, ultrashort echo time MRI (UTE-MRI) is able to acquire a high signal from tendons. Magnetization transfer (MT) modeling combined with UTE-MRI (i.e., UTE-MT-modeling) can indirectly assess macromolecular proton content in tendons. This study aimed to determine whether UTE-MT-modeling could detect differences in tendon quality across a spectrum of bone health. The lower legs of 14 OPe (72 ± 6 years) and 31 OPo (73 ± 6 years) female patients, as well as 30 female participants with normal bone (Normal-Bone, 36 ± 19 years), are imaged using UTE sequences on a 3T MRI scanner. Institutional review board approval is obtained for the study, and all recruited subjects provided written informed consent. A T1 measurement and UTE-MT-modeling are performed on the anterior tibialis tendon (ATT), posterior tibialis tendon (PTT), and the proximal Achilles tendon (PAT) of all subjects. The macromolecular fraction (MMF) is estimated as the main measure from UTE-MT-modeling. The mean MMF in all the investigated tendons was significantly lower in OPo patients compared with the Normal-Bone cohort (mean difference of 24.2%, p < 0.01), with the largest Normal-Bone vs. OPo difference observed in the ATT (mean difference of 32.1%, p < 0.01). Average MMF values of all the studied tendons are significantly lower in the OPo cohort compared with the OPe cohort (mean difference 16.8%, p = 0.02). Only the PPT shows significantly higher T1 values in OPo patients compared with the Normal-Bone cohort (mean difference 17.6%, p < 0.01). Considering the differences between OPo and OPe groups with similar age ranges, tendon deterioration associated with declining bone health was found to be larger than a priori detected differences caused purely by aging, highlighting UTE-MT MRI techniques as useful methods in assessing tendon quality over the course of progressive bone weakening.
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Affiliation(s)
- Saeed Jerban
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Yajun Ma
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Amir Masoud Afsahi
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Alecio Lombardi
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Zhao Wei
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Meghan Shen
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Mei Wu
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
| | - Nicole Le
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Douglas G. Chang
- Department of Orthopaedic Surgery, University of California, San Diego, CA 92093, USA;
| | - Christine B. Chung
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Jiang Du
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego, CA 92093, USA; (Y.M.); (A.M.A.); (A.L.); (Z.W.); (M.S.); (M.W.); (N.L.); (C.B.C.); (J.D.)
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
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22
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Li W, Li Y, Gao Q, Liu J, Wen Q, Jia S, Tang F, Mo L, Zhang Y, Zhai M, Chen Y, Guo Y, Gong W. Change in knee cartilage components in stroke patients with genu recurvatum analysed by zero TE MR imaging. Sci Rep 2022; 12:3751. [PMID: 35260668 PMCID: PMC8904817 DOI: 10.1038/s41598-022-07817-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/25/2022] [Indexed: 11/23/2022] Open
Abstract
Genu recurvatum in stroke patients with hemiplegia causes readily cumulative damage and degenerative changes in the knee cartilage. It is important to detect early cartilage lesions for appropriate treatment and rehabilitation. The purpose of this cross-sectional study was to provide a theoretical basis for the early rehabilitation of hemiplegia patients. We used a zero TE double-echo imaging sequence to analyse the water content in knee joint cartilage at 12 different sites of 39 stroke patients with genu recurvatum and 9 healthy volunteers using a metric similar to the porosity index. When comparing the hemiplegic limb vs. the nonhemiplegic limb in patients, the ratios of the deep/shallow free water content of the femur cartilages at the anterior horn (1.16 vs. 1.06) and posterior horn (1.13 vs. 1.25) of the lateral meniscus were significantly different. Genu recurvatum in stroke patients with hemiplegia can cause changes in the moisture content of knee cartilage, and the changes in knee cartilage are more obvious as the genu recurvatum increases. The "healthy limb" can no longer be considered truly healthy and should be considered simultaneously with the affected limb in the development of a rehabilitation treatment plan.
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Affiliation(s)
- Wenshan Li
- Beijing Rehabilitation Medicine Academy, Capital Medical University, Beijing, 100144, China
| | - Youwei Li
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Qiang Gao
- Scientific Research Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Jingxin Liu
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Qiping Wen
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Shiqi Jia
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Fen Tang
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Linhong Mo
- Department of Neurological Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Yuanfang Zhang
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Mingchun Zhai
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Yukun Chen
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Yue Guo
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China
| | - Weijun Gong
- Department of Neurological Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, 100144, China.
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23
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Evaluation of the degenerative lumbar osseous morphology using zero echo time magnetic resonance imaging (ZTE-MRI). EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2022; 31:792-800. [PMID: 35015138 DOI: 10.1007/s00586-021-07099-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/16/2021] [Accepted: 12/18/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE To determine and compare the performance of zero echo imaging (ZTE) with conventional MRI sequences on lumbar osseous morphology in patients suspected with lumbar degeneration with multi-slice computed tomography (MSCT) as standard reference. METHODS 22 subjects with concerned lumbar degeneration were recruited. All subjects were scanned with ZTE sequence after routine conventional MR sequences on a 3.0 T system and also received MSCT examination. Image quality was assessed. The quantitative and qualitative parameters of lumbar osseous morphology on MSCT, ZTE and MRI images were evaluated by three musculoskeletal radiologists independently. Inter-reader and inter-modality reliability and the difference between the modalities were calculated. RESULTS There was no difference for the osseous parameters between modalities, including axial orientation (p = 0.444), IAD (p = 0.381), lateral recess (p = 0.370), pedicle width (p = 0.067), pedicle height (p = 0.056), and osteophyte grade (p = 0.052). The measurement of the foramina diameter was statistically different between conventional MRI and MSCT (p < 0.05) but not between the MSCT and ZTE (p = 0.660). Conventional MRI was more likely to miss cortical bone abnormalities. ZTE appeared blurrier in cortical bone than MSCT, especially in cases with severe lumbar degeneration. The inter-reader agreement between MSCT and ZTE-MRI was higher than between MSCT and conventional MRI. CONCLUSIONS ZTE-MRI could offer more cortical bone details than conventional MRI images and might be a valid alternative to CT for lumbar osseous morphology assessment to some extent.
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24
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Florkow MC, Willemsen K, Mascarenhas VV, Oei EHG, van Stralen M, Seevinck PR. Magnetic Resonance Imaging Versus Computed Tomography for Three-Dimensional Bone Imaging of Musculoskeletal Pathologies: A Review. J Magn Reson Imaging 2022; 56:11-34. [PMID: 35044717 PMCID: PMC9305220 DOI: 10.1002/jmri.28067] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/31/2021] [Accepted: 01/05/2022] [Indexed: 12/18/2022] Open
Abstract
Magnetic resonance imaging (MRI) is increasingly utilized as a radiation‐free alternative to computed tomography (CT) for the diagnosis and treatment planning of musculoskeletal pathologies. MR imaging of hard tissues such as cortical bone remains challenging due to their low proton density and short transverse relaxation times, rendering bone tissues as nonspecific low signal structures on MR images obtained from most sequences. Developments in MR image acquisition and post‐processing have opened the path for enhanced MR‐based bone visualization aiming to provide a CT‐like contrast and, as such, ease clinical interpretation. The purpose of this review is to provide an overview of studies comparing MR and CT imaging for diagnostic and treatment planning purposes in orthopedic care, with a special focus on selective bone visualization, bone segmentation, and three‐dimensional (3D) modeling. This review discusses conventional gradient‐echo derived techniques as well as dedicated short echo time acquisition techniques and post‐processing techniques, including the generation of synthetic CT, in the context of 3D and specific bone visualization. Based on the reviewed literature, it may be concluded that the recent developments in MRI‐based bone visualization are promising. MRI alone provides valuable information on both bone and soft tissues for a broad range of applications including diagnostics, 3D modeling, and treatment planning in multiple anatomical regions, including the skull, spine, shoulder, pelvis, and long bones.
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Affiliation(s)
- Mateusz C Florkow
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Koen Willemsen
- Department of Orthopedics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Vasco V Mascarenhas
- Musculoskeletal Imaging Unit, Imaging Center, Hospital da Luz, Lisbon, Portugal
| | - Edwin H G Oei
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marijn van Stralen
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands.,MRIguidance BV, Utrecht, The Netherlands
| | - Peter R Seevinck
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands.,MRIguidance BV, Utrecht, The Netherlands
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25
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Liu J, Liao JW, Li W, Chen XJ, Feng JX, Yao L, Huang PH, Su ZH, Lu H, Liao YT, Li SL, Ma YJ. Assessment of Osteoporosis in Lumbar Spine: In Vivo Quantitative MR Imaging of Collagen Bound Water in Trabecular Bone. Front Endocrinol (Lausanne) 2022; 13:801930. [PMID: 35250862 PMCID: PMC8888676 DOI: 10.3389/fendo.2022.801930] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/21/2022] [Indexed: 11/17/2022] Open
Abstract
AIM Bone collagen matrix makes a crucial contribution to the mechanical properties of bone by imparting tensile strength and elasticity. The collagen content of bone is accessible via quantification of collagen bound water (CBW) indirectly. We prospectively study the performance of the CBW proton density (CBWPD) measured by a 3D short repetition time adiabatic inversion recovery prepared ultrashort echo time (STAIR-UTE) magnetic resonance imaging (MRI) sequence in the diagnosis of osteoporosis in human lumbar spine. METHODS A total of 189 participants with a mean age of 56 (ranged from 50 to 86) years old were underwent MRI, quantitative computed tomography (QCT), and dual-energy X-ray absorptiometry (DXA) in lumbar spine. Major fracture risk was also evaluated for all participants using Fracture Risk Assessment Tool (FRAX). Lumbar CBWPD, bone marrow fat fraction (BMFF), bone mineral density (BMD) and T score values were calculated in three vertebrae (L2-L4) for each subject. Both the CBWPD and BMFF were correlated with BMD, T score, and FRAX score for comparison. The abilities of the CBWPD and BMFF to discriminate between three different cohorts, which included normal subjects, patients with osteopenia, and patients with osteoporosis, were also evaluated and compared using receiver operator characteristic (ROC) analysis. RESULTS The CBWPD showed strong correlation with standard BMD (R2 = 0.75, P < 0.001) and T score (R2 = 0.59, P < 0.001), as well as a moderate correlation with FRAX score (R2 = 0.48, P < 0.001). High area under the curve (AUC) values (≥ 0.84 using QCT as reference; ≥ 0.76 using DXA as reference) obtained from ROC analysis demonstrated that the CBWPD was capable of well differentiating between the three different subject cohorts. Moreover, the CBWPD had better correlations with BMD, T score, and FRAX score than BMFF, and also performed better in cohort discrimination. CONCLUSION The STAIR-UTE-measured CBWPD is a promising biomarker in the assessment of bone quality and fracture risk.
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Affiliation(s)
- Jin Liu
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Jian-Wei Liao
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Wei Li
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Xiao-Jun Chen
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Jia-Xin Feng
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Lin Yao
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Pan-Hui Huang
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Zhi-Hai Su
- Department of Spinal Surgery, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - Hai Lu
- Department of Spinal Surgery, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | | | - Shao-Lin Li
- Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
- *Correspondence: Shao-Lin Li,
| | - Ya-Jun Ma
- Department of Radiology, University of California San Diego, La Jolla, CA, United States
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26
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Afsahi AM, Ma Y, Jang H, Jerban S, Chung CB, Chang EY, Du J. Ultrashort Echo Time Magnetic Resonance Imaging Techniques: Met and Unmet Needs in Musculoskeletal Imaging. J Magn Reson Imaging 2021; 55:1597-1612. [PMID: 34962335 DOI: 10.1002/jmri.28032] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 12/14/2022] Open
Abstract
This review article summarizes recent technical developments in ultrashort echo time (UTE) magnetic resonance imaging of musculoskeletal (MSK) tissues with short-T2 relaxation times. A series of contrast mechanisms are discussed for high-contrast morphological imaging of short-T2 MSK tissues including the osteochondral junction, menisci, ligaments, tendons, and bone. Quantitative UTE mapping of T1, T2*, T1ρ, adiabatic T1ρ, magnetization transfer ratio, MT modeling of macromolecular proton fraction, quantitative susceptibility mapping, and water content is also introduced. Met and unmet needs in MSK imaging are discussed. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.
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Affiliation(s)
- Amir Masoud Afsahi
- Department of Radiology, University of California, San Diego, California, USA
| | - Yajun Ma
- Department of Radiology, University of California, San Diego, California, USA
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, California, USA
| | - Saeed Jerban
- Department of Radiology, University of California, San Diego, California, USA
| | - Christine B Chung
- Department of Radiology, University of California, San Diego, California, USA.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
| | - Eric Y Chang
- Department of Radiology, University of California, San Diego, California, USA.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
| | - Jiang Du
- Department of Radiology, University of California, San Diego, California, USA.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
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27
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Müller M, Egger N, Sommer S, Wilferth T, Meixner CR, Laun FB, Mennecke A, Schmidt M, Huhn K, Rothhammer V, Uder M, Dörfler A, Nagel AM. Direct imaging of white matter ultrashort T 2∗ components at 7 Tesla. Magn Reson Imaging 2021; 86:107-117. [PMID: 34906631 DOI: 10.1016/j.mri.2021.11.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/02/2021] [Accepted: 11/29/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To demonstrate direct imaging of the white matter ultrashort T2∗ components at 7 Tesla using inversion recovery (IR)-enhanced ultrashort echo time (UTE) MRI. To investigate its characteristics, potentials and limitations, and to establish a clinical protocol. MATERIAL AND METHODS The IR UTE technique suppresses long T2∗ signals within white matter by using adiabatic inversion in combination with dual-echo difference imaging. Artifacts arising at 7 T from long T2∗ scalp fat components were reduced by frequency shifting the IR pulse such that those frequencies were inverted likewise. For 8 healthy volunteers, the T2∗ relaxation times of white matter were then quantified. In 20 healthy volunteers, the UTE difference and fraction contrast were evaluated. Finally, in 6 patients with multiple sclerosis (MS), the performance of the technique was assessed. RESULTS A frequency shift of -1.2 ppm of the IR pulse (i.e. towards the fat frequency) provided a good suppression of artifacts. With this, an ultrashort compartment of (68 ± 6) % with a T2∗ time of (147 ± 58) μs was quantified with a chemical shift of (-3.6 ± 0.5) ppm from water. Within healthy volunteers' white matter, a stable ultrashort T2∗ fraction contrast was calculated. For the MS patients, a significant fraction reduction in the identified lesions as well as in the normal-appearing white matter was observed. CONCLUSIONS The quantification results indicate that the observed ultrashort components arise primarily from myelin tissue. Direct IR UTE imaging of the white matter ultrashort T2∗ components is thus feasible at 7 T with high quantitative inter-subject repeatability and good detection of signal loss in MS.
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Affiliation(s)
- Max Müller
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Nico Egger
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stefan Sommer
- Siemens Healthcare, Zurich, Switzerland; Swiss Center for Musculoskeletal Imaging (SCMI), Balgrist Campus, Zurich, Switzerland
| | - Tobias Wilferth
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christian R Meixner
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Frederik Bernd Laun
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Angelika Mennecke
- Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Manuel Schmidt
- Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Konstantin Huhn
- Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Veit Rothhammer
- Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Arnd Dörfler
- Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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28
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Zhao Q, Ridout RP, Shen J, Wang N. Effects of Angular Resolution and b Value on Diffusion Tensor Imaging in Knee Joint. Cartilage 2021; 13:295S-303S. [PMID: 33843284 PMCID: PMC8804734 DOI: 10.1177/19476035211007909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE To investigate the influences of the diffusion gradient directions (angular resolution) and the strength of the diffusion gradient (b value) on diffusion tensor imaging (DTI) metrics and tractography of various connective tissues in knee joint. DESIGN Two rat knee joints were scanned on a preclinical 9.4-T system using a 3-dimensional diffusion-weighted spin echo pulse sequence. One protocol with b value of 500, 1500, and 2500 s/mm2 were acquired separately using 43 diffusion gradient directions. The other protocol with b value of 1000 s/mm2 was performed using 147 diffusion gradient directions. The in-plane resolution was 45 µm isotropic. Fractional anisotropy (FA) and mean diffusivity (MD) were compared at different angular resolution. Tractography was quantitatively evaluated at different b values and angular resolutions in cartilage, ligament, meniscus, and growth plate. RESULTS The ligament showed higher FA value compared with growth plate and cartilage. The FA values were largely overestimated at the angular resolution of 6. Compared with FA, MD showed less sensitivity to the angular resolution. The fiber tracking was failed at low angular resolution (6 diffusion gradient directions) or high b value (2500 s/mm2). The quantitative measurements of tract length and track volume were strongly dependent on angular resolution and b value. CONCLUSIONS To obtain consistent DTI outputs and tractography in knee joint, the scan may require a proper b value (ranging from 500 to 1500 s/mm2) and sufficient angular resolution (>14) with signal-to-noise ratio >10.
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Affiliation(s)
- Qi Zhao
- School of Psychology, Shanghai
University of Sport, Shanghai, China
| | - Rees P. Ridout
- Pratt School of Engineering, Duke
University, Durham, NC, USA
| | - Jikai Shen
- Pratt School of Engineering, Duke
University, Durham, NC, USA
| | - Nian Wang
- Department of Radiology, Duke
University School of Medicine, Durham, NC, USA,Department of Radiology and Imaging
Sciences, Indiana University School of Medicine, Indianapolis, IN, USA,Nian Wang, Department of Radiology and
Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202,
USA.
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29
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Macromolecular fraction (MMF) from 3D ultrashort echo time cones magnetization transfer (3D UTE-Cones-MT) imaging predicts meniscal degeneration and knee osteoarthritis. Osteoarthritis Cartilage 2021; 29:1173-1180. [PMID: 33882334 PMCID: PMC8971054 DOI: 10.1016/j.joca.2021.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 03/15/2021] [Accepted: 04/07/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Meniscal degeneration is strongly associated with osteoarthritis (OA). We aimed to evaluate a 3D ultrashort-echo-time Cones magnetization transfer (UTE-Cones-MT) sequence for quantification of macromolecular fraction (MMF) and MT ratio (MTR) in menisci of healthy volunteers and patients with different degrees of OA. METHODS Patients with mild OA (n = 19; 37-86 years; 10 males) or advanced OA (n = 12; 52-88 years; 4 males) and healthy volunteers (n = 17; 20-49 years; 7 males) were scanned with T2-FSE and UTE-Cones-MT sequences at 3T. Morphological assessment was performed using meniscal whole-organ magnetic resonance imaging score (WORMS). MMF and MTR were calculated for menisci, and correlated with age and meniscal WORMS scores. The diagnostic efficiency was performed by using receiver operating characteristic (ROC) curve and the area under the curve (AUC) analyses. RESULTS Decreased MMF and MTR were observed in menisci of patients with mild or advanced OA compared with healthy subjects, and in menisci with tears (Grade 2-4) compared with normal menisci (Grade 0). Significant negative correlations were observed between MMF (r = -0.769, P < 0.01), MTR (r = -0.320, P < 0.01), and meniscal WORMS score. There was a mild negative correlation between MMF (r = -0.438, P < 0.01), MTR (r = -0.289, P < 0.01), and age. The AUC values of MMF and MTR in the four horns of meniscus and the posterior horn medial meniscus for differentiating OA patients from healthy volunteers were 0.762 and 0.699, and 0.835 and 0.883, respectively. CONCLUSION The 3D UTE-Cones-MT biomarkers of MTR and especially MMF can detect compositional changes in meniscus and differentiate healthy subjects from patients with mild or advanced knee OA.
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Low XZ, Lim MC, Nga V, Sundar G, Tan AP. Clinical application of "black bone" imaging in paediatric craniofacial disorders. Br J Radiol 2021; 94:20200061. [PMID: 34233472 DOI: 10.1259/bjr.20200061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
For decades, CT has been the primary imaging modality for the diagnosis and surveillance of paediatric craniofacial disorders. However, the deleterious effects of ionising radiation in the paediatric population are well established and remain an ongoing concern. This is especially so in the head and neck region, which has relatively poor soft tissue shielding with many radiosensitive organs. The development of "black bone" imaging utilising low flip angles and short echo time (TE) has shown considerable promise in alleviating the use of ionising radiation in many cases of craniofacial disorders. In this review article, we share our experience of utilising "black bone" sequence in children with craniofacial pathologies, ranging from traumatic injuries to craniosynostosis and focal osseous/fibro-osseous lesions such as fibrous dysplasia and Langerhans cell histiocytosis (LCH). A detailed discussion on the technical aspects of "black bone" sequence, including its potential pitfalls and limitations, will also be included.
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Affiliation(s)
- Xi Zhen Low
- Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | - Mei Chin Lim
- Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | - Vincent Nga
- Division of Neurosurgery, Department of Surgery, National University Hospital, Singapore, Singapore
| | - Gangadhara Sundar
- Dept of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Ai Peng Tan
- Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
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Na S, Wang LV. Photoacoustic computed tomography for functional human brain imaging [Invited]. BIOMEDICAL OPTICS EXPRESS 2021; 12:4056-4083. [PMID: 34457399 PMCID: PMC8367226 DOI: 10.1364/boe.423707] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/05/2021] [Accepted: 06/08/2021] [Indexed: 05/02/2023]
Abstract
The successes of magnetic resonance imaging and modern optical imaging of human brain function have stimulated the development of complementary modalities that offer molecular specificity, fine spatiotemporal resolution, and sufficient penetration simultaneously. By virtue of its rich optical contrast, acoustic resolution, and imaging depth far beyond the optical transport mean free path (∼1 mm in biological tissues), photoacoustic computed tomography (PACT) offers a promising complementary modality. In this article, PACT for functional human brain imaging is reviewed in its hardware, reconstruction algorithms, in vivo demonstration, and potential roadmap.
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Affiliation(s)
- Shuai Na
- Caltech Optical Imaging Laboratory, Andrew
and Peggy Cherng Department of Medical Engineering,
California Institute of Technology, 1200
East California Boulevard, Pasadena, CA 91125, USA
| | - Lihong V. Wang
- Caltech Optical Imaging Laboratory, Andrew
and Peggy Cherng Department of Medical Engineering,
California Institute of Technology, 1200
East California Boulevard, Pasadena, CA 91125, USA
- Caltech Optical Imaging Laboratory,
Department of Electrical Engineering, California
Institute of Technology, 1200 East California Boulevard,
Pasadena, CA 91125, USA
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Zhu X, Tan F, Johnson K, Larson P. Optimizing trajectory ordering for fast radial ultra-short TE (UTE) acquisitions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 327:106977. [PMID: 33873091 PMCID: PMC8164474 DOI: 10.1016/j.jmr.2021.106977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
PURPOSE Additional spoiler gradients are required in 3D UTE sequences with random view ordering to suppress magnetization refocusing. By leveraging the encoding gradient induced spoiling effect, the spoiler gradients could potentially be reduced or removed to shorten the TR and increase encoding efficiency. An analysis framework is built that models the gradient spoiling effects and a new ordering scheme is proposed for fast 3D UTE acquisition. THEORY AND METHODS UTE signal evolution and spatial encoding gradient induced spoiling effect are derived from the Bloch equations. And the concept is validated in 2D radial UTE simulation. Then an optimized ordering scheme, named reordered 2D golden angle (r2DGA) scheme, for 3D UTE acquisition is proposed. The r2DGA scheme is compared to the sequential and 3D golden angle schemes in both phantom and volunteer studies. RESULTS The proposed r2DGA ordering scheme was applied to two applications, single breath-holding and free breathing 3D lung MRI. With r2DGA ordering scheme, breath-holding lung MRI scan increased 60% scan efficiency by removing the spoiler gradients and the free breathing scan reduced 20% scan time compared to the 3D golden angle scheme by reducing the spoiler gradients. CONCLUSIONS The proposed r2DGA ordering scheme UTE acquisition reduces the need of spoiler gradients and increases the encoding efficiency, and shows improvements in both breath-holding and free breathing lung MRI applications.
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Affiliation(s)
- Xucheng Zhu
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, United States; Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; GE Healthcare, Menlo Park, CA, United States
| | - Fei Tan
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, United States; Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States
| | - Kevin Johnson
- Medical Physics, University of Wisconsin, Madison, WI, United States; Radiology, University of Wisconsin, Madison, WI, United States
| | - Peder Larson
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, United States; Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States.
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Lee JS. A Review of Deep-Learning-Based Approaches for Attenuation Correction in Positron Emission Tomography. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2020.3009269] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wei Z, Jang H, Bydder GM, Yang W, Ma YJ. Fast T 1 measurement of cortical bone using 3D UTE actual flip angle imaging and single-TR acquisition (3D UTE-AFI-STR). Magn Reson Med 2021; 85:3290-3298. [PMID: 33404142 DOI: 10.1002/mrm.28655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE To describe a new method for accurate T1 measurement of cortical bone that fits the data sets of both 3D UTE actual flip angle imaging (UTE-AFI) and UTE with a single TR (UTE-STR) simultaneously (UTE-AFI-STR). THEORY AND METHODS To make both the constant values and longitudinal mapping functions in the signal equations for UTE-AFI and UTE-STR identical, the same RF pulses and flip angles were used. Therefore, there were three unknowns in the three equations. This was sufficient to fit the data. Numerical simulation as well as ex vivo and in vivo cortical bone studies were performed to validate the T1 measurement accuracy with the UTE-AFI-STR method. The original UTE-AFI variable TR (VTR) (ie, combined UTE-AFI and UTE with VTR) and simultaneous fitting (sf) of UTE-AFI and UTE-VTR (sf-UTE-AFI-VTR) methods were performed for comparison. RESULTS The numerical simulation study showed that the UTE-AFI-STR method provided accurate value of T1 when the SNR of the UTE-STR image was higher than 40. The ex vivo study showed that the UTE-AFI-STR method measured the T1 of cortical bone accurately, with difference ratios ranging from -5.0% to 0.4%. The in vivo study showed a mean T1 of 246 ms with the UTE-AFI-STR method, and mean difference ratios of 2.4% and 5.0%, respectively, compared with the other two methods. CONCLUSION The 3D UTE-AFI-STR method provides accurate mapping of the T1 of cortical bone with improved time efficiency compared with the UTE-AFI-VTR/sf-UTE-AFI-VTR methods.
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Affiliation(s)
- Zhao Wei
- Department of Radiology, University of California San Diego, San Diego, California, USA
- Institute of Electrical Engineering Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hyungseok Jang
- Department of Radiology, University of California San Diego, San Diego, California, USA
| | - Graeme M Bydder
- Department of Radiology, University of California San Diego, San Diego, California, USA
| | - Wenhui Yang
- Institute of Electrical Engineering Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ya-Jun Ma
- Department of Radiology, University of California San Diego, San Diego, California, USA
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Afsahi AM, Lombardi AF, Wei Z, Carl M, Athertya J, Masuda K, Wallace M, Lee RR, Ma YJ. High-Contrast Lumbar Spinal Bone Imaging Using a 3D Slab-Selective UTE Sequence. Front Endocrinol (Lausanne) 2021; 12:800398. [PMID: 35069448 PMCID: PMC8777294 DOI: 10.3389/fendo.2021.800398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 12/13/2021] [Indexed: 01/11/2023] Open
Abstract
Ultra-short echo time (UTE) MRI with post-processing is a promising technique in bone imaging that produces a similar contrast to computed tomography (CT). Here, we propose a 3D slab-selective ultrashort echo time (UTE) sequence together with image post-processing to image bone structures in the lumbar spine. We also explore the intermodality agreement between the UTE and CT images. The lumbar spines of two healthy volunteers were imaged with 3D UTE using five different resolutions to determine the best imaging protocol. Then, four patients with low back pain were imaged with both the 3D UTE sequence and CT to investigate agreement between the imaging methods. Two other patients with low back pain were then imaged with the 3D UTE sequence and clinical conventional T1-weighted and T2-weighted fast spin-echo (FSE) MRI sequences for qualitative comparison. The 3D UTE sequence together with post-processing showed high contrast images of bone and high intermodality agreement with CT images. In conclusion, post-processed slab-selective UTE imaging is a feasible approach for highlighting bone structures in the lumbar spine and demonstrates significant anatomical correlation with CT images.
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Affiliation(s)
- Amir Masoud Afsahi
- Department of Radiology, University of California San Diego, San Diego, CA, United States
| | - Alecio F. Lombardi
- Department of Radiology, University of California San Diego, San Diego, CA, United States
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA, United States
| | - Zhao Wei
- Department of Radiology, University of California San Diego, San Diego, CA, United States
| | | | - Jiyo Athertya
- Department of Radiology, University of California San Diego, San Diego, CA, United States
| | - Koichi Masuda
- Department of Orthopedic Surgery, University of California San Diego, San Diego, CA, United States
| | - Mark Wallace
- Department of Anesthesiology, University of California San Diego, San Diego, CA, United States
| | - Roland R. Lee
- Department of Radiology, University of California San Diego, San Diego, CA, United States
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA, United States
| | - Ya-Jun Ma
- Department of Radiology, University of California San Diego, San Diego, CA, United States
- *Correspondence: Ya-Jun Ma,
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Jang H, Ma Y, Carl M, Lombardi AF, Chang EY, Du J. Feasibility of an Inversion Recovery-Prepared Fat-Saturated Zero Echo Time Sequence for High Contrast Imaging of the Osteochondral Junction. Front Endocrinol (Lausanne) 2021; 12:777080. [PMID: 35002964 PMCID: PMC8739813 DOI: 10.3389/fendo.2021.777080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/02/2021] [Indexed: 12/11/2022] Open
Abstract
PURPOSE The osteochondral junction (OCJ) region-commonly defined to include the deep radial uncalcified cartilage, tidemark, calcified cartilage, and subchondral bone plate-functions to absorb mechanical stress and is commonly associated with the pathogenesis of osteoarthritis. However, magnetic resonance imaging of the OCJ region is difficult due to the tissues' short transverse relaxation times (i.e., short T2 or T2*), which result in little or no signal with conventional MRI. The goal of this study is to develop a 3D adiabatic inversion recovery prepared fat saturated zero echo time (IR-FS-ZTE) sequence for high-contrast imaging of the OCJ. METHOD An IR-FS-ZTE MR sequence was developed to image the OCJ on a clinical 3T MRI scanner. The IR-FS-ZTE sequence employed an adiabatic inversion pulse followed by a fat saturation pulse that suppressed signals from the articular cartilage and fat. At an inversion time (TI) that was matched to the nulling point of the articular cartilage, continuous ZTE imaging was performed with a smoothly rotating readout gradient, which enabled time-efficient encoding of the OCJ region's short T2 signal with a minimal echo time (TE) of 12 μs. An ex vivo experiment with six cadaveric knee joints, and an in vivo experiment with six healthy volunteers and three patients with OA were performed to evaluate the feasibility of the proposed approach for high contrast imaging of the OCJ. Contrast-to-noise ratios (CNRs) between the OCJ and its neighboring femoral and tibial cartilage were measured. RESULTS In the ex vivo experiment, IR-FS-ZTE produced improved imaging of the OCJ region over the clinical sequences, and significantly improved the contrast compared to FS-ZTE without IR preparation (p = 0.0022 for tibial cartilage and p = 0.0019 for femoral cartilage with t-test). We also demonstrated the feasibility of high contrast imaging of the OCJ region in vivo using the proposed IR-FS-ZTE sequence, thereby providing more direct information on lesions in the OCJ. Clinical MRI did not detect signal from OCJ due to the long TE (>20 ms). CONCLUSION IR-FS-ZTE allows direct imaging of the OCJ region of the human knee and may help in elucidating the role of the OCJ in cartilage degeneration.
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Affiliation(s)
- Hyungseok Jang
- Department of Radiology, University of California, San Diego, CA, United States
| | - Yajun Ma
- Department of Radiology, University of California, San Diego, CA, United States
| | | | - Alecio F. Lombardi
- Department of Radiology, University of California, San Diego, CA, United States
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego, CA, United States
- Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States
| | - Jiang Du
- Department of Radiology, University of California, San Diego, CA, United States
- *Correspondence: Jiang Du,
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Park H, Nam IC, Baek HJ, Ryu KH, Cho E, Kim SS, An HJ. Chronic Intradiploic Organizing Hematoma of the Skull Mimicking Calvarial Tumor Diagnosed Using Zero TE MRI: A Case Report and Review of Literature. ACTA ACUST UNITED AC 2020; 57:medicina57010018. [PMID: 33379265 PMCID: PMC7824157 DOI: 10.3390/medicina57010018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022]
Abstract
Chronic intradiploic organizing hematoma of the skull is a rare lesion that usually presents as a progressively growing mass after head trauma, thus making it difficult to diagnose. To date, only nine cases that have been histopathologically confirmed as organizing hematoma of the skull have been reported in the literature. Herein, we describe a case of a chronic organizing hematoma involving the right parietal bone, presenting as a slowly growing mass in a 54-year-old man. The lesion was also visualized on magnetic resonance imaging (MRI) with a zero echo time sequence. In this case report, we emphasize that chronic intradiploic organizing hematoma should be considered in the differential diagnosis of a palpable scalp mass. We also highlight the importance of meticulous radiological review in the context of appropriate clinical suspicion and the usefulness of the zero TE sequence in evaluating calvarial lesions.
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Affiliation(s)
- Hyun Park
- Department of Neurosurgery, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea; (H.P.); (S.S.K.)
| | - In Chul Nam
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea;
| | - Hye Jin Baek
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea; (K.H.R.); (E.C.)
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, 816-15 Jinju-daero, Jinju 52727, Korea
- Correspondence: ; Tel.: +82-55-214-3140
| | - Kyeong Hwa Ryu
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea; (K.H.R.); (E.C.)
| | - Eun Cho
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea; (K.H.R.); (E.C.)
| | - Seung Soo Kim
- Department of Neurosurgery, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea; (H.P.); (S.S.K.)
| | - Hyo Jung An
- Department of Pathology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, 11 Samjeongja-ro, Seongsan-gu, Changwon 51472, Korea;
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Zhang R, Lee H, Zhao X, Song HK, Vossough A, Wehrli FW, Bartlett SP. Bone-Selective MRI as a Nonradiative Alternative to CT for Craniofacial Imaging. Acad Radiol 2020; 27:1515-1522. [PMID: 32299762 DOI: 10.1016/j.acra.2020.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/17/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
Abstract
RATIONAL AND OBJECTIVES Computed tomography (CT) is the clinical gold-standard for high-resolution 3D visualization of cortical bone structures. However, ionizing radiation is of concern, particularly for pediatric patients. This study evaluates the feasibility of producing 3D human skull renderings using a novel bone-selective magnetic resonance imaging technique. MATERIALS AND METHODS A dual-radiofrequency pulse, dual-echo, 3D ultrashort echo time sequence was applied for scanning of a cadaver skull and five healthy adult subjects. Scans were each completed within 6 minutes. Semiautomatic segmentation of bone voxels was performed using ITK-SNAP software, leading to 3D renderings of the skulls. For comparison, thin-slice head CT scans were performed. Mimics software was used to measure eight anatomic distances from 3D renderings. Lin's Concordance Correlation test was applied to assess agreement between measurements from MR-based and CT-based 3D skull renderings. RESULTS The 3D rendered MR images depict most craniofacial features (e.g., zygomatic arch), although some voxels were erroneously included or excluded in the renderings. MR-based measurements differed from CT-based measurements by mean percent difference ranging from 2.3%-5.0%. Lin's Concordance Correlation Coefficients for MR-based vs CT-based measurements ranged from 0.998-1.000. CONCLUSION The proposed dual-radiofrequency dual-echo 3D ultrashort echo time imaging technique produces high-resolution bone-specific images within a clinically feasible imaging time, leading to clear visualization of craniofacial skeletal structures. Concordance coefficients suggest good reliability of the method compared to CT. The method is currently limited by time and manual input necessary for segmentation correction. Further investigation is needed for more accurate 3D renderings and for scanning of pediatric patients.
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Affiliation(s)
- Rosaline Zhang
- Division of Plastic Surgery, Children's Hospital of Philadelphia, University of Pennsylvania, Buerger Center, 3500 Civic Center Boulevard, Philadelphia, PA 19104
| | - Hyunyeol Lee
- Department of Radiology, University of Pennsylvania, Philadelphia, PA
| | - Xia Zhao
- Department of Radiology, University of Pennsylvania, Philadelphia, PA
| | - Hee Kwon Song
- Department of Radiology, University of Pennsylvania, Philadelphia, PA
| | - Arastoo Vossough
- Department of Radiology, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA
| | - Felix W Wehrli
- Department of Radiology, University of Pennsylvania, Philadelphia, PA
| | - Scott P Bartlett
- Division of Plastic Surgery, Children's Hospital of Philadelphia, University of Pennsylvania, Buerger Center, 3500 Civic Center Boulevard, Philadelphia, PA 19104.
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Ma YJ, Jerban S, Jang H, Chang D, Chang EY, Du J. Quantitative Ultrashort Echo Time (UTE) Magnetic Resonance Imaging of Bone: An Update. Front Endocrinol (Lausanne) 2020; 11:567417. [PMID: 33071975 PMCID: PMC7531487 DOI: 10.3389/fendo.2020.567417] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/17/2020] [Indexed: 12/24/2022] Open
Abstract
Bone possesses a highly complex hierarchical structure comprised of mineral (~45% by volume), organic matrix (~35%) and water (~20%). Water exists in bone in two forms: as bound water (BW), which is bound to bone mineral and organic matrix, or as pore water (PW), which resides in Haversian canals as well as in lacunae and canaliculi. Magnetic resonance (MR) imaging has been increasingly used for assessment of cortical and trabecular bone. However, bone appears as a signal void on conventional MR sequences because of its short T2*. Ultrashort echo time (UTE) sequences with echo times (TEs) 100-1,000 times shorter than those of conventional sequences allow direct imaging of BW and PW in bone. A series of quantitative UTE MRI techniques has been developed for bone evaluation. UTE and adiabatic inversion recovery prepared UTE (IR-UTE) sequences have been developed to quantify BW and PW. UTE magnetization transfer (UTE-MT) sequences have been developed to quantify collagen backbone protons, and UTE quantitative susceptibility mapping (UTE-QSM) sequences have been developed to assess bone mineral.
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Affiliation(s)
- Ya-Jun Ma
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Saeed Jerban
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Douglas Chang
- Department of Orthopedic Surgery, University of California, San Diego, San Diego, CA, United States
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA, United States
| | - Jiang Du
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
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Yunker BE, Stupic KF, Wagner JL, Huddle S, Shandas R, Weir RF, Russek SE, Keenan KE. Characterization of 3-Dimensional Printing and Casting Materials for use in Magnetic Resonance Imaging Phantoms at 3 T. JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 2020; vol:vol125.028. [PMID: 35573857 PMCID: PMC9097953 DOI: 10.6028/jres.125.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/16/2020] [Indexed: 06/14/2023]
Abstract
Imaging phantoms are used to calibrate and validate the performance of magnetic resonance imaging (MRI) systems. Many new materials have been developed for additive manufacturing (three-dimensional [3D] printing) processes that may be useful in the direct printing or casting of dimensionally accurate, anatomically accurate, patient-specific, and/or biomimetic MRI phantoms. The T1, T2, and T2* spin relaxation times of polymer samples were tested to discover materials for use as tissue mimics and structures in MRI phantoms. This study included a cohort of polymer compounds that was tested in cured form. The cohort consisted of 101 standardized polymer samples fabricated from: two-part silicones and polyurethanes used in commercial casting processes; one-part optically cured polyurethanes used in 3D printing; and fused deposition thermoplastics used in 3D printing. The testing was performed at 3 T using inversion recovery, spin echo, and gradient echo sequences for T1, T2, and T2*, respectively. T1, T2, and T2* values were plotted with error bars to allow the reader to assess how well a polymer matches a tissue for a specific application. A correlation was performed between T1, T2, T2* values and material density, elongation, tensile strength, and hardness. Two silicones, SI_XP-643 and SI_P-45, may be usable mimics for reported liver values; one silicone, SI_XP-643, may be a useful mimic for muscle; one silicone, SI_XP-738, may be a useful mimic for white matter; and four silicones, SI_P-15, SI_GI-1000, SI_GI-1040, and SI_GI-1110, may be usable mimics for spinal cord. Elongation correlated to T2 (p = 0.0007), tensile strength correlated to T1 (p = 0.002), T2 (p = 0.0003), and T2* (p = 0.003). The 80 samples not providing measurable signal with T1, T2, T2* relaxation values too short to measure with the standard sequences, may be useful for MRI-invisible fixturing and medical devices at 3 T.
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Affiliation(s)
- B. E. Yunker
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
- University of Colorado-Denver/Anschutz, Aurora, CO 80045,
USA
| | - K. F. Stupic
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
| | - J. L. Wagner
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
| | - S. Huddle
- University of Colorado-Denver/Anschutz, Aurora, CO 80045,
USA
| | - R. Shandas
- University of Colorado-Denver/Anschutz, Aurora, CO 80045,
USA
| | - R. F. Weir
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
| | - S. E. Russek
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
| | - K. E. Keenan
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305,
USA
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41
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Zhao K, Li S, Yi P, Guo Y, Yu Q, Zhu C, Feng Q, Du J, Zhang X, Feng Y. Detection of gadolinium deposition in cortical bone with ultrashort echo time T 1 mapping: an ex vivo study in a rabbit model. Eur Radiol 2020; 31:1569-1577. [PMID: 32929642 DOI: 10.1007/s00330-020-07258-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 07/27/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To investigate the capacity of ultrashort echo time (UTE) T1 mapping to non-invasively assess gadolinium deposition in cortical bone after gadolinium-based contrast agent (GBCA) administration. METHODS Twenty-eight New Zealand rabbits (male, 3.0-3.5 kg) were randomly allocated into control, macrocyclic, high-dose macrocyclic, and linear GBCA groups (n = 7 for each group), and respectively given daily doses of 0.9 ml/kg bodyweight saline, 0.3 mmol/kg bodyweight gadobutrol, 0.9 mmol/kg bodyweight gadobutrol, and 0.3 mmol/kg bodyweight gadopentetate dimeglumine for five consecutive days per week over a period of 4 weeks. After a subsequent 4 weeks of recovery, the rabbits were sacrificed and their tibiae harvested. T1 value of cortical bone was measured using a combination of UTE actual flip angle imaging and variable repetition time on a 7T animal scanner. Gadolinium concentration in cortical bone was measured using inductively coupled plasma mass spectrometry (ICP-MS). Pearson's correlation between R1 value (R1 = 1/T1) and gadolinium concentration in cortical bone was assessed. RESULTS Bone T1 values were significantly lower in the lower-dose macrocyclic (329.2 ± 21.0 ms, p < 0.05), higher-dose macrocyclic (316.8 ± 21.7 ms, p < 0.01), and linear (296.8 ± 24.1 ms, p < 0.001) GBCA groups compared with the control group (356.3 ± 19.4 ms). Gadolinium concentrations measured by ICP-MS in the control, lower-dose macrocyclic, higher-dose macrocyclic, and linear GBCA groups were 0.04 ± 0.02 μg/g, 2.60 ± 0.48 μg/g, 4.95 ± 1.17 μg/g, and 13.62 ± 1.55 μg/g, respectively. There was a strong positive correlation between R1 values and gadolinium concentrations in cortical bone (r = 0.73, p < 0.001). CONCLUSIONS These results suggest that UTE T1 mapping has the potential to provide a non-invasive assessment of gadolinium deposition in cortical bone following GBCA administration. KEY POINTS • Changes in T1 value related to gadolinium deposition were found in bone after both linear and macrocyclic GBCA administrations. • R1 relaxometry correlates strongly with gadolinium concentration in cortical bone. • UTE T1 mapping provides a potential tool for non-invasively monitoring gadolinium deposition in cortical bone.
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Affiliation(s)
- Kaixuan Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Shisi Li
- Department of Medical Imaging, Third Affiliated Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Peiwei Yi
- School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Yihao Guo
- School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Qinqin Yu
- Department of Medical Imaging, Third Affiliated Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Cuiling Zhu
- Department of Medical Imaging, Third Affiliated Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Jiang Du
- Department of Radiology, University of California, San Diego, CA, USA
| | - Xiaodong Zhang
- Department of Medical Imaging, Third Affiliated Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, China. .,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China.
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42
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Jerban S, Ma Y, Wei Z, Jang H, Chang EY, Du J. Quantitative Magnetic Resonance Imaging of Cortical and Trabecular Bone. Semin Musculoskelet Radiol 2020; 24:386-401. [PMID: 32992367 DOI: 10.1055/s-0040-1710355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bone is a composite material consisting of mineral, organic matrix, and water. Water in bone can be categorized as bound water (BW), which is bound to bone mineral and organic matrix, or as pore water (PW), which resides in Haversian canals as well as in lacunae and canaliculi. Bone is generally classified into two types: cortical bone and trabecular bone. Cortical bone is much denser than trabecular bone that is surrounded by marrow and fat. Magnetic resonance (MR) imaging has been increasingly used for noninvasive assessment of both cortical bone and trabecular bone. Bone typically appears as a signal void with conventional MR sequences because of its short T2*. Ultrashort echo time (UTE) sequences with echo times 100 to 1,000 times shorter than those of conventional sequences allow direct imaging of BW and PW in bone. This article summarizes several quantitative MR techniques recently developed for bone evaluation. Specifically, we discuss the use of UTE and adiabatic inversion recovery prepared UTE sequences to quantify BW and PW, UTE magnetization transfer sequences to quantify collagen backbone protons, UTE quantitative susceptibility mapping sequences to assess bone mineral, and conventional sequences for high-resolution imaging of PW as well as the evaluation of trabecular bone architecture.
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Affiliation(s)
- Saeed Jerban
- Department of Radiology, University of California, San Diego, California
| | - Yajun Ma
- Department of Radiology, University of California, San Diego, California
| | - Zhao Wei
- Department of Radiology, University of California, San Diego, California
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, California
| | - Eric Y Chang
- Department of Radiology, University of California, San Diego, California.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Jiang Du
- Department of Radiology, University of California, San Diego, California
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Abstract
Deep learning methods have shown promising results for accelerating quantitative musculoskeletal (MSK) magnetic resonance imaging (MRI) for T2 and T1ρ relaxometry. These methods have been shown to improve musculoskeletal tissue segmentation on parametric maps, allowing efficient and accurate T2 and T1ρ relaxometry analysis for monitoring and predicting MSK diseases. Deep learning methods have shown promising results for disease detection on quantitative MRI with diagnostic performance superior to conventional machine-learning methods for identifying knee osteoarthritis.
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Affiliation(s)
- Fang Liu
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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44
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Sollmann N, Löffler MT, Kronthaler S, Böhm C, Dieckmeyer M, Ruschke S, Kirschke JS, Carballido-Gamio J, Karampinos DC, Krug R, Baum T. MRI-Based Quantitative Osteoporosis Imaging at the Spine and Femur. J Magn Reson Imaging 2020; 54:12-35. [PMID: 32584496 DOI: 10.1002/jmri.27260] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/31/2020] [Accepted: 06/01/2020] [Indexed: 12/27/2022] Open
Abstract
Osteoporosis is a systemic skeletal disease with a high prevalence worldwide, characterized by low bone mass and microarchitectural deterioration, predisposing an individual to fragility fractures. Dual-energy X-ray absorptiometry (DXA) has been the clinical reference standard for diagnosing osteoporosis and for assessing fracture risk for decades. However, other imaging modalities are of increasing importance to investigate the etiology, treatment, and fracture risk. The purpose of this work is to review the available literature on quantitative magnetic resonance imaging (MRI) methods and related findings in osteoporosis at the spine and proximal femur as the clinically most important fracture sites. Trabecular bone microstructure analysis at the proximal femur based on high-resolution MRI allows for a better prediction of osteoporotic fracture risk than DXA-based bone mineral density (BMD) alone. In the 1990s, T2 * mapping was shown to correlate with the density and orientation of the trabecular bone. Recently, quantitative susceptibility mapping (QSM), which overcomes some of the limitations of T2 * mapping, has been applied for trabecular bone quantifications at the spine, whereas ultrashort echo time (UTE) imaging provides valuable surrogate markers of cortical bone quantity and quality. Magnetic resonance spectroscopy (MRS) and chemical shift encoding-based water-fat MRI (CSE-MRI) enable the quantitative assessment of the nonmineralized bone compartment through extraction of the bone marrow fat fraction (BMFF). Furthermore, CSE-MRI allows for the differentiation of osteoporotic vs. pathologic fractures, which is of high clinical relevance. Lastly, advanced postprocessing and image analysis tools, particularly considering statistical parametric mapping and region-specific BMFF distributions, have high potential to further improve MRI-based fracture risk assessments at the spine and hip. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Nico Sollmann
- Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Maximilian T Löffler
- Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Sophia Kronthaler
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christof Böhm
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Michael Dieckmeyer
- Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefan Ruschke
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Jan S Kirschke
- Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Julio Carballido-Gamio
- Department of Radiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Roland Krug
- Department of Radiology and Biomedical Imaging, School of Medicine, University of California San Francisco, San Francisco, California, USA
| | - Thomas Baum
- Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
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45
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Li S, Huang X, Li G, Zhang Y, Li Z, Liu L, Gao S. Exponential subtraction in 3D ultrashort echo time imaging to visualize short T2 tissues in tibia. Acta Radiol 2020; 61:760-767. [PMID: 31569946 DOI: 10.1177/0284185119877797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Short T2 tissues can be directly visualized by dual-echo ultrashort echo time imaging with weighted subtraction. As a type of post-processing method, exponential subtraction of ultrashort echo time images with an optimal exponential factor is expected to provide improved positive short T2 contrast. PURPOSE To test the feasibility and effectiveness of exponential subtraction in three-dimensional ultrashort echo time imaging and to determine the optimal exponential factor. MATERIAL AND METHODS A dual-echo three-dimensional ultrashort echo time sequence was implemented on a 3-T MRI system. Exponential subtraction was performed on dual three-dimensional ultrashort echo time images of the tibia of seven healthy volunteers with exponential factors in the range of 1.00-3.00 in increments of 0.01. The regions of interest, including cortical bone, marrow, and muscle, were depicted on subtracted images of different exponential factors. Contrast-to-noise ratio values were calculated from these regions of interest and then used to assess the optimal exponential factor. To determine intra-observer agreement regarding region of interest selection, paired intra-observer measurements of regions of interest in all direct subtraction images were conducted with a one-week interval and the paired measurements were assessed using Bland-Altman analysis and paired-samples t-test. RESULTS Cortical bone can be better visualized by using exponential subtraction in three-dimensional ultrashort echo time imaging; the suggested optimal exponential factor is 1.99-2.03 in the tibia. Paired measurements showed excellent intra-observer agreement. CONCLUSION It is feasible to visualize cortical bone of the tibia using exponential subtraction in three-dimensional ultrashort echo time imaging. Compared with weighted subtraction images, exponential subtraction images with an optimal exponential factor provide enhanced visualization of short T2 tissues.
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Affiliation(s)
- Sha Li
- Department of Medical Physics, Institute of Medical Humanities, Peking University, Beijing, PR China
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing Cancer Hospital & Institute, Beijing, PR China
| | - Xinrui Huang
- Department of Biophysics, School of basic medical sciences, Peking University, Beijing, PR China
| | - Guozhen Li
- Department of Precision Instrument, Tsinghua University, Beijing, PR China
| | - Yibao Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing Cancer Hospital & Institute, Beijing, PR China
| | - Zhaotong Li
- Department of Medical Physics, Institute of Medical Humanities, Peking University, Beijing, PR China
| | - Liangyou Liu
- Department of Medical Physics, Institute of Medical Humanities, Peking University, Beijing, PR China
| | - Song Gao
- Department of Medical Physics, Institute of Medical Humanities, Peking University, Beijing, PR China
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46
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Mastrogiacomo S, Dou W, Jansen JA, Walboomers XF. Magnetic Resonance Imaging of Hard Tissues and Hard Tissue Engineered Bio-substitutes. Mol Imaging Biol 2020; 21:1003-1019. [PMID: 30989438 DOI: 10.1007/s11307-019-01345-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Magnetic resonance imaging (MRI) is a non-invasive diagnostic imaging tool based on the detection of protons into the tissues. This imaging technique is remarkable because of high spatial resolution, strong soft tissue contrast and specificity, and good depth penetration. However, MR imaging of hard tissues, such as bone and teeth, remains challenging due to low proton content in such tissues as well as to very short transverse relaxation times (T2). To overcome these issues, new MRI techniques, such as sweep imaging with Fourier transformation (SWIFT), ultrashort echo time (UTE) imaging, and zero echo time (ZTE) imaging, have been developed for hard tissues imaging with promising results reported. Within this article, MRI techniques developed for the detection of hard tissues, such as bone and dental tissues, have been reviewed. The main goal was thus to give a comprehensive overview on the corresponding (pre-) clinical applications and on the potential future directions with such techniques applied. In addition, a section dedicated to MR imaging of novel biomaterials developed for hard tissue applications was given as well.
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Affiliation(s)
- Simone Mastrogiacomo
- Department of Biomaterials, Radboud University Medical Center, Philips van Leijdenlaan 25, 6525 EX, Nijmegen, The Netherlands.
- Laboratory of Functional and Molecular Imaging, NINDS, National Institutes of Health, Building 10, 5S261, Bethesda, MD, 20892, USA.
| | - Weiqiang Dou
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
- GE Healthcare, MR Research, Beijing, People's Republic of China
| | - John A Jansen
- Department of Biomaterials, Radboud University Medical Center, Philips van Leijdenlaan 25, 6525 EX, Nijmegen, The Netherlands
| | - X Frank Walboomers
- Department of Biomaterials, Radboud University Medical Center, Philips van Leijdenlaan 25, 6525 EX, Nijmegen, The Netherlands
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47
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Huang J, Chen L, Chan KWY, Cai C, Cai S, Chen Z. Super-resolved water/fat image reconstruction based on single-shot spatiotemporally encoded MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 314:106736. [PMID: 32361511 DOI: 10.1016/j.jmr.2020.106736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/11/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
Single-shot spatiotemporally encoded (SPEN) MRI has been validated to possess considerable performance in both spatial and temporal resolution. Water/fat separation is essential for MRI applications in which only water signal is needed. In this article, a super-resolved water/fat image reconstruction method (dubbed SWAF) combined prior knowledge was developed based on single-shot SPEN MRI. The point spread function of spatiotemporal encoding under multiple chemical shifts situation was derived and used for constructing an equation for SWAF image reconstruction. By processing the prior chemical shift information with filtering operation, an initial spin density profile of water/fat and a weighting matrix for water/fat residual artifacts suppression were obtained to guide the reconstruction process. A l1 norm minimization problem with regularization was exploited to reconstruct separated water/fat images with high spatial resolution and less residual/aliasing artifacts. Numeric simulation and experiments on water-oil phantom and rat abdomen/neck imaging demonstrated the effectiveness and robustness of this new method. The SWAF method proposed herein would promote the application of SPEN MRI in the cases where water/fat separation is required.
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Affiliation(s)
- Jianpan Huang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China; Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Lin Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China
| | - Kannie W Y Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Congbo Cai
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China.
| | - Shuhui Cai
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China.
| | - Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China
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48
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Wei Z, Ma YJ, Jang H, Yang W, Du J. To measure T 1 of short T 2 species using an inversion recovery prepared three-dimensional ultrashort echo time (3D IR-UTE) method: A phantom study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 314:106725. [PMID: 32320926 PMCID: PMC7307614 DOI: 10.1016/j.jmr.2020.106725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/20/2020] [Accepted: 04/02/2020] [Indexed: 05/04/2023]
Abstract
PURPOSE To demonstrate the feasibility of a new method for measuring T1 of short T2 species based on an adiabatic inversion recovery-prepared three-dimensional ultrashort echo time Cones (3D IR-UTE-Cones) sequence. METHODS T1 values for short T2 species were quantified using 3D IR-UTE-Cones data acquired with different repetition times (TRs) and inversion times (TIs). An inversion efficiency factor Q was introduced into the fitting model to accurately calculate T1 values for short T2 species. Experiments were performed on twelve MnCl2 aqueous solution phantoms with a wide range of T1 values and T2* values on a 3 T clinical MR system to verify the efficacy of the proposed method. For comparison, a variable flip angle UTE (VFA-UTE) sequence, a variable TR UTE (VTR-UTE) sequence, and a conventional 2D IR fast spin echo (IR-FSE) sequence were also used to quantify T1 values of those phantoms. T1 values were compared between all performed sequences. RESULTS The proposed 3D IR-UTE-Cones method provided higher contrast images of short T2 phantoms and measured much shorter T1 values than the VFA-UTE, VTR-UTE and 2D IR-FSE methods. T1 values as short as 2.95 ms could be measured by the 3D IR-UTE-Cones sequence. The 3D IR-UTE-Cones methods with different TRs were applied to different ranges of T1 measurement, and the scan time was significantly decreased by using 5 TIs along the recovery curves to perform fitting with comparable accuracy. CONCLUSION The 3D IR-UTE-Cones sequence could accurately measure short T1 values while providing high contrast images of short T2 species.
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Affiliation(s)
- Zhao Wei
- Department of Radiology, University of California San Diego, CA, United States; University of Chinese Academy of Sciences, Beijing, China; Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China.
| | - Ya-Jun Ma
- Department of Radiology, University of California San Diego, CA, United States.
| | - Hyungseok Jang
- Department of Radiology, University of California San Diego, CA, United States.
| | - Wenhui Yang
- University of Chinese Academy of Sciences, Beijing, China; Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China.
| | - Jiang Du
- Department of Radiology, University of California San Diego, CA, United States.
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49
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Latta P, Starčuk Z, Kojan M, Gruwel MLH, Tomanek B, Trattnig S, Juras V. Simple compensation method for improved half-pulse excitation profile with rephasing gradient. Magn Reson Med 2020; 84:1796-1805. [PMID: 32129544 DOI: 10.1002/mrm.28233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/14/2020] [Accepted: 02/07/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE To improve the slice profile quality obtained by RF half-pulse excitation for 2D-UTE applications. METHODS The overall first-order and zero-order phase errors along the slice-selection direction were obtained with the help of an optimization task to minimize the out-of-slice signal contamination from the calibration 1-dimenisonal (1D) profile data. The time-phase-error evolution was approximated from the k-space readout data, which were acquired primarily for correction of the readout trajectories during data regridding to the rectilinear grids. The correction of the slice profile was achieved by rephasing gradient pulses applied immediately after the end of excitation. The total prescan calibration typically took less than 2 minutes. RESULTS The improved image quality using the proposed calibration method was demonstrated both on phantoms and on ankle images obtained from healthy volunteers. It was demonstrated that calibration can be performed either as a separate water phantom measurement or directly as a prescan procedure. CONCLUSION The slice-profile distortion from the half-pulse excitation could substantially affect the overall fidelity of 2D-UTE images. The presented experiments proved that the image quality could be substantially increased by application of the proposed slice-correction method.
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Affiliation(s)
- Peter Latta
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Zenon Starčuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Martin Kojan
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Marco L H Gruwel
- Biological Resources Imaging Laboratory, Mark Wainwright Analytical Centre, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Boguslaw Tomanek
- Department of Oncology, Division of Medical Physics, University of Alberta, Edmonton, AB, Canada
| | - Siegfried Trattnig
- High-Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Vladimir Juras
- High-Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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50
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Clinical utility of new three-dimensional model using a zero-echo-time sequence in endoscopic endonasal transsphenoidal surgery. Clin Neurol Neurosurg 2020; 190:105743. [PMID: 32113079 DOI: 10.1016/j.clineuro.2020.105743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/11/2020] [Accepted: 02/16/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Recognizing the anatomical orientation surrounding the sellar floor is crucial in endoscopic endonasal transsphenoidal surgery (ETSS). Zero-echo-time (ZTE) sequences were recently suggested for a new bone identification technique on magnetic resonance imaging (MRI). This study aimed to evaluate the clinical usefulness of three-dimensional (3D)-ZTE-based MRI models in providing anatomical guidance for ETSS. PATIENTS AND METHODS ZTE-based MRI and magnetic resonance angiography (MRA) data from 15 consecutive patients with pituitary tumor treated between September 2018 and May 2019 were used to create 3D-MRI models. From these, the architecture surrounding the sellar floor, particularly anatomical relationships between tumors and internal carotid arteries (ICAs), was visualized to preoperatively plan surgical procedures. In addition, 3D-ZTE-based MRI models were compared to actual surgical views during ETSS to evaluate model applicability. RESULTS These 3D-ZTE-based MRI models clearly demonstrated the morphology of the sellar floor and matched well with intraoperative views, including pituitary tumor, by successively eliminating sphenoidal structures. The models also permitted determination of the maximum marginal line of the opening of the sellar floor by presenting vital structures such as ICAs and tumors. With such 3D-MRI models, the surgeon could access the intracranial area through the sellar floor more safely, and resect the pituitary tumor maximally without complications. CONCLUSION Our 3D-MRI models based on ZTE sequences allowed distinct visualization of vital structures and pituitary tumor around the sellar floor. This new method using 3D-ZTE-based MRI models showed low invasiveness for patients and was useful in preoperative planning for ETSS, facilitating maximum tumor resection without complications.
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