51
|
Abstract
Purpose to create a custom-shaped graft through 3D tissue shape reconstruction and rapid-prototype molding methods using MRI data, and to test the accuracy of the custom-shaped graft against the original anatomical defect. Methods An iatrogenic defect on the distal femur was identified with a 1.5 Tesla MRI and its shape was reconstructed into a three-dimensional (3D) computer model by processing the 3D MRI data. First, the accuracy of the MRI-derived 3D model was tested against a laser-scan based 3D model of the defect. A custom-shaped polyurethane graft was fabricated from the laser-scan based 3D model by creating custom molds through computer aided design and rapid-prototyping methods. The polyurethane tissue was laser-scanned again to calculate the accuracy of this process compared to the original defect. Results The volumes of the defect models from MRI and laser-scan were 537 mm3 and 405 mm3, respectively, implying that the MRI model was 33% larger than the laser-scan model. The average (±SD) distance deviation of the exterior surface of the MRI model from the laser-scan model was 0.4±0.4 mm. The custom-shaped tissue created from the molds was qualitatively very similar to the original shape of the defect. The volume of the custom-shaped cartilage tissue was 463 mm3 which was 15% larger than the laser-scan model. The average (±SD) distance deviation between the two models was 0.04±0.19 mm. Conclusions This investigation proves the concept that custom-shaped engineered grafts can be fabricated from standard sequence 3-D MRI data with the use of CAD and rapid-prototyping technology. The accuracy of this technology may help solve the interfacial problem between native cartilage and graft, if the grafts are custom made for the specific defect. The major source of error in fabricating a 3D custom-shaped cartilage graft appears to be the accuracy of a MRI data itself; however, the precision of the model is expected to increase by the utilization of advanced MR sequences with higher magnet strengths.
Collapse
Affiliation(s)
- Seungbum Koo
- School of Mechanical Engineering, Chung-Ang University, Seoul - South Korea
| | | | - Garry E. Gold
- Department of Radiology, Stanford University, Stanford, California - USA
| | - Jason L. Dragoo
- Department of Orthopedic Surgery, Stanford University, Stanford, California - USA
| |
Collapse
|
52
|
Titchenal MR, Williams AA, Chehab EF, Asay JL, Dragoo JL, Gold GE, McAdams TR, Andriacchi TP, Chu CR. Cartilage Subsurface Changes to Magnetic Resonance Imaging UTE-T2* 2 Years After Anterior Cruciate Ligament Reconstruction Correlate With Walking Mechanics Associated With Knee Osteoarthritis. Am J Sports Med 2018; 46:565-572. [PMID: 29293364 PMCID: PMC6548433 DOI: 10.1177/0363546517743969] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Anterior cruciate ligament (ACL) injury increases risk for posttraumatic knee osteoarthritis (OA). Quantitative ultrashort echo time enhanced T2* (UTE-T2*) mapping shows promise for early detection of potentially reversible subsurface cartilage abnormalities after ACL reconstruction (ACLR) but needs further validation against established clinical metrics of OA risk such as knee adduction moment (KAM) and mechanical alignment. HYPOTHESIS Elevated UTE-T2* values in medial knee cartilage 2 years after ACLR correlate with varus alignment and higher KAM during walking. STUDY DESIGN Cohort study (diagnosis); Level of evidence, 2. METHODS Twenty patients (mean age, 33.1 ± 10.5 years; 11 female) 2 years after ACLR underwent 3.0-T knee magnetic resonance imaging (MRI), radiography, and gait analysis, after which mechanical alignment was measured, KAM during walking was calculated, and UTE-T2* maps were generated. The mechanical axis and the first and second peaks of KAM (KAM1 and KAM2, respectively) were tested using linear regressions for correlations with deep UTE-T2* values in the central and posterior medial femoral condyle (cMFC and pMFC, respectively) and central medial tibial plateau (cMTP). UTE-T2* values from ACL-reconstructed patients were additionally compared with those of 14 uninjured participants (mean age, 30.9 ± 8.9 years; 6 female) using Mann-Whitney U and standard t tests. RESULTS Central weightbearing medial compartment cartilage of ACL-reconstructed knees was intact on morphological MRI. Mean UTE-T2* values were elevated in both the cMFC and pMFC of ACL-reconstructed knees compared with those of uninjured knees ( P = .003 and P = .012, respectively). In ACL-reconstructed knees, UTE-T2* values of cMFC cartilage positively correlated with increasing varus alignment ( R = 0.568). Higher UTE-T2* values in cMFC and cMTP cartilage of ACL-reconstructed knees also correlated with greater KAM1 ( R = 0.452 and R = 0.463, respectively) and KAM2 ( R = 0.465 and R = 0.764, respectively) and with KAM2 in pMFC cartilage ( R = 0.602). CONCLUSION Elevated deep UTE-T2* values of medial knee cartilage 2 years after ACLR correlate with 2 clinical markers of increased risk of medial knee OA. These results support the clinical utility of MRI UTE-T2* for early diagnosis of subsurface cartilage abnormalities. Longitudinal follow-up of larger cohorts is needed to determine the predictive and staging potential of UTE-T2* for posttraumatic OA.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Constance R. Chu
- Address correspondence to Constance R. Chu, MD, Stanford University, 450 Broadway Street, MC 6342, Redwood City, CA 94061, USA ()
| |
Collapse
|
53
|
Kogan F, Levine E, Chaudhari AS, Monu UD, Epperson K, Oei EHG, Gold GE, Hargreaves BA. Simultaneous bilateral-knee MR imaging. Magn Reson Med 2017; 80:529-537. [PMID: 29250856 DOI: 10.1002/mrm.27045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/19/2017] [Accepted: 11/21/2017] [Indexed: 12/23/2022]
Abstract
PURPOSE To demonstrate and evaluate the scan time and quantitative accuracy of simultaneous bilateral-knee imaging compared with single-knee acquisitions. METHODS Hardware modifications and safety testing was performed to enable MR imaging with two 16-channel flexible coil arrays. Noise covariance and sensitivity-encoding g-factor maps for the dual-coil-array configuration were computed to evaluate coil cross-talk and noise amplification. Ten healthy volunteers were imaged on a 3T MRI scanner with both dual-coil-array bilateral-knee and single-coil-array single-knee configurations. Two experienced musculoskeletal radiologists compared the relative image quality between blinded image pairs acquired with each configuration. Differences in T2 relaxation time measurements between dual-coil-array and single-coil-array acquisitions were compared with the standard repeatability of single-coil-array measurements using a Bland-Altman analysis. RESULTS The mean g-factors for the dual-coil-array configuration were low for accelerations up to 6 in the right-left direction, and minimal cross-talk was observed between the two coil arrays. Image quality ratings of various joint tissues showed no difference in 89% (95% confidence interval: 85-93%) of rated image pairs, with only small differences ("slightly better" or "slightly worse") in image quality observed. The T2 relaxation time measurements between the dual-coil-array configuration and the single-coil configuration showed similar limits of agreement and concordance correlation coefficients (limits of agreement: -0.93 to 1.99 ms; CCC: 0.97 (95% confidence interval: 0.96-0.98)), to the repeatability of single-coil-array measurements (limits of agreement: -2.07 to 1.96 ms; CCC: 0.97 (95% confidence interval: 0.95-0.98)). CONCLUSION A bilateral coil-array setup can image both knees simultaneously in similar scan times as conventional unilateral knee scans, with comparable image quality and quantitative accuracy. This has the potential to improve the value of MRI knee evaluations. Magn Reson Med 80:529-537, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Evan Levine
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Akshay S Chaudhari
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Uchechukwuka D Monu
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Kevin Epperson
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Edwin H G Oei
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Orthopedic Surgery, Stanford University, Stanford, California, USA
| | - Brian A Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| |
Collapse
|
54
|
Favre J, Erhart-Hledik JC, Blazek K, Fasel B, Gold GE, Andriacchi TP. Anatomically Standardized Maps Reveal Distinct Patterns of Cartilage Thickness With Increasing Severity of Medial Compartment Knee Osteoarthritis. J Orthop Res 2017; 35:2442-2451. [PMID: 28233332 DOI: 10.1002/jor.23548] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 02/10/2017] [Indexed: 02/04/2023]
Abstract
While cartilage thickness alterations are a central element of knee osteoarthritis (OA), differences among disease stages are still incompletely understood. This study aimed to quantify the spatial-variations in cartilage thickness using anatomically standardized thickness maps and test if there are characteristic patterns in patients with different stages of medial compartment knee OA. Magnetic resonance images were acquired for 75 non-OA and 100 OA knees of varying severities (Kellgren and Lawrence (KL) scores 1-4). Three-dimensional cartilage models were reconstructed and a shape matching technique was applied to convert the models into two-dimensional anatomically standardized thickness maps. Difference thickness maps and statistical parametric mapping were used to compare the four OA and the non-OA subgroups. This analysis showed distinct thickness patterns for each clinical stage that formed a coherent succession from the non-OA to the KL 4 subgroups. Interestingly, the only significant difference for early stage (KL 1) was thicker femoral cartilage. With increase in disease severity, typical patterns developed, including thinner cartilage in the anterior area of the medial condyle (significant for KL 3 and 4) and thicker cartilage in the posterior area of the medial and lateral condyles (significant for all OA subgroups). The tibial patterns mainly consisted of thinner cartilage for both medial and lateral compartments (significant for KL 2-4). Comparing anatomically standardized maps allowed identifying patterns of thickening and thinning over the entire cartilage surface, consequently improving the characterization of thickness differences associated with OA. The results also highlighted the value of anatomically standardized maps to analyze spatial variations in cartilage thickness. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2442-2451, 2017.
Collapse
Affiliation(s)
- Julien Favre
- Department of Musculoskeletal Medicine, Centre Hospitalier Universiatire Vaudois, University of Lausanne, Lausanne, Switzerland.,Department of Mechanical Engineering, Stanford University, Stanford, California
| | - Jennifer C Erhart-Hledik
- Department of Mechanical Engineering, Stanford University, Stanford, California.,Palo Alto VA, Palo Alto, California
| | - Katerina Blazek
- Department of Mechanical Engineering, Stanford University, Stanford, California.,Palo Alto VA, Palo Alto, California
| | - Benedikt Fasel
- Department of Mechanical Engineering, Stanford University, Stanford, California
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California.,Department of Bioengineering, Stanford University, Stanford, California.,Department of Orthopaedic Surgery, Stanford University, Stanford, California
| | - Thomas P Andriacchi
- Department of Mechanical Engineering, Stanford University, Stanford, California.,Palo Alto VA, Palo Alto, California.,Department of Orthopaedic Surgery, Stanford University, Stanford, California
| |
Collapse
|
55
|
Affiliation(s)
- Sachin Sharma
- Radiology, and (by courtesy) Bioengineering and Orthopedic Surgery, 1201 Welch Road P263, Stanford, CA 94305
| | - Garry E Gold
- Radiology, and (by courtesy) Bioengineering and Orthopedic Surgery, 1201 Welch Road P263, Stanford, CA 94305.
| |
Collapse
|
56
|
Chaudhari AS, Black MS, Eijgenraam S, Wirth W, Maschek S, Sveinsson B, Eckstein F, Oei EHG, Gold GE, Hargreaves BA. Five-minute knee MRI for simultaneous morphometry and T 2 relaxometry of cartilage and meniscus and for semiquantitative radiological assessment using double-echo in steady-state at 3T. J Magn Reson Imaging 2017; 47:1328-1341. [PMID: 29090500 DOI: 10.1002/jmri.25883] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 10/14/2017] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Biomarkers for assessing osteoarthritis activity necessitate multiple MRI sequences with long acquisition times. PURPOSE To perform 5-minute simultaneous morphometry (thickness/volume measurements) and T2 relaxometry of both cartilage and meniscus, and semiquantitative MRI Osteoarthritis Knee Scoring (MOAKS). STUDY TYPE Prospective. SUBJECTS Fifteen healthy volunteers for morphometry and T2 measurements, and 15 patients (five each Kellgren-Lawrence grades 0/2/3) for MOAKS assessment. FIELD STRENGTH/SEQUENCE A 5-minute double-echo steady-state (DESS) sequence was evaluated for generating quantitative and semiquantitative osteoarthritis biomarkers at 3T. ASSESSMENT Flip angle simulations evaluated tissue signals and sensitivity of T2 measurements. Morphometry and T2 reproducibility was compared against morphometry-optimized and relaxometry-optimized sequences. Repeatability was assessed by scanning five volunteers twice. MOAKS reproducibility was compared to MOAKS derived from a clinical knee MRI protocol by two readers. STATISTICAL TESTS Coefficients of variation (CVs), concordance confidence intervals (CCI), and Wilcoxon signed-rank tests compared morphometry and relaxometry measurements with their reference standards. DESS MOAKS positive percent agreement (PPA), negative percentage agreement (NPA), and interreader agreement was calculated using the clinical protocol as a reference. Biomarker variations between Kellgren-Lawrence groups were evaluated using Wilcoxon rank-sum tests. RESULTS Cartilage thickness (P = 0.65), cartilage T2 (P = 0.69), and meniscus T2 (P = 0.06) did not significantly differ from their reference standard (with a 20° DESS flip angle). DESS slightly overestimated meniscus volume (P < 0.001). Accuracy and repeatability CVs were <3.3%, except the meniscus T2 accuracy (7.6%). DESS MOAKS had substantial interreader agreement and high PPA/NPA values of 87%/90%. Bone marrow lesions and menisci had slightly lower PPAs. Cartilage and meniscus T2 , and MOAKS (cartilage surface area, osteophytes, cysts, and total score) was higher in Kellgren-Lawrence groups 2 and 3 than group 0 (P < 0.05). DATA CONCLUSION The 5-minute DESS sequence permits MOAKS assessment for a majority of tissues, along with repeatable and reproducible simultaneous cartilage and meniscus T2 relaxometry and morphometry measurements. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1328-1341.
Collapse
Affiliation(s)
- Akshay S Chaudhari
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Marianne S Black
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Mechanical Engineering, Stanford University, Stanford, California, USA
| | - Susanne Eijgenraam
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Wolfgang Wirth
- Institute of Anatomy, Paracelsus Medical University Salzburg and Nuremberg, Salzburg, Austria.,Chondrometrics GmbH, Ainring, Germany
| | - Susanne Maschek
- Institute of Anatomy, Paracelsus Medical University Salzburg and Nuremberg, Salzburg, Austria.,Chondrometrics GmbH, Ainring, Germany
| | - Bragi Sveinsson
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Felix Eckstein
- Institute of Anatomy, Paracelsus Medical University Salzburg and Nuremberg, Salzburg, Austria.,Chondrometrics GmbH, Ainring, Germany
| | - Edwin H G Oei
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Brian A Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| |
Collapse
|
57
|
Kogan F, Fan AP, McWalter E, Oei E, Quon A, Gold GE. PET/MRI of metabolic activity in osteoarthritis: A feasibility study. J Magn Reson Imaging 2017; 45:1736-1745. [PMID: 27796082 PMCID: PMC5761655 DOI: 10.1002/jmri.25529] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 10/10/2016] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To evaluate positron emission tomography / magnetic resonance imaging (PET/MRI) knee imaging to detect and characterize osseous metabolic abnormalities and correlate PET radiotracer uptake with osseous abnormalities and cartilage degeneration observed on MRI. MATERIALS AND METHODS Both knees of 22 subjects with knee pain or injury were scanned at one timepoint, without gadolinium, on a hybrid 3.0T PET-MRI system following injection of 18 F-fluoride or 18 F-fluorodeoxyglucose (FDG). A musculoskeletal radiologist identified volumes of interest (VOIs) around bone abnormalities on MR images and scored bone marrow lesions (BMLs) and osteophytes using a MOAKS scoring system. Cartilage appearance adjacent to bone abnormalities was graded with MRI-modified Outerbridge classifications. On PET standardized uptake values (SUV) maps, VOIs with SUV greater than 5 times the SUV in normal-appearing bone were identified as high-uptake VOI (VOIHigh ). Differences in 18 F-fluoride uptake between bone abnormalities, BML, and osteophyte grades and adjacent cartilage grades on MRI were identified using Mann-Whitney U-tests. RESULTS SUVmax in all subchondral bone lesions (BML, osteophytes, sclerosis) was significantly higher than that of normal-appearing bone on MRI (P < 0.001 for all). Of the 172 high-uptake regions on 18 F-fluoride PET, 63 (37%) corresponded to normal-appearing subchondral bone on MRI. Furthermore, many small grade 1 osteophytes (40 of 82 [49%]), often described as the earliest signs of osteoarthritis (OA), did not show high uptake. Lastly, PET SUVmax in subchondral bone adjacent to grade 0 cartilage was significantly lower compared to that of grades 1-2 (P < 0.05) and grades 3-4 cartilage (P < 0.001). CONCLUSION PET/MRI can simultaneously assess multiple early metabolic and morphologic markers of knee OA across multiple tissues in the joint. Our findings suggest that PET/MR may detect metabolic abnormalities in subchondral bone, which appear normal on MRI. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;45:1736-1745.
Collapse
Affiliation(s)
- Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Audrey P. Fan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Emily McWalter
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Edwin Oei
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Andrew Quon
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Garry E. Gold
- Department of Radiology, Stanford University, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Department of Orthopaedic Surgery, Stanford University, Stanford, California, USA
| |
Collapse
|
58
|
Müller K, Datta S, Ahmad M, Choi JH, Moore T, Pung L, Niebler C, Gold GE, Maier A, Fahrig R. Interventional dual-energy imaging-Feasibility of rapid kV-switching on a C-arm CT system. Med Phys 2017; 43:5537. [PMID: 27782692 DOI: 10.1118/1.4962929] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
PURPOSE In the last years, dual-energy CT imaging has shown clinical value, thanks to its ability to differentiate materials based on their atomic number and to exploit different properties of images acquired at two different energies. C-arm CT systems are used to guide procedures in the interventional suite. Until now, there are no commercially available systems that employ dual-energy material decomposition. This paper explores the feasibility of implementing a fast kV-switching technique on a clinically available angiographic system for acquiring dual-energy C-arm CT images. METHODS As an initial proof of concept, a fast kV-switching approach was implemented on an angiographic C-arm system and the peak tube voltage during 3D rotational scans was measured. The tube voltage measurements during fast kV-switching scans were compared to corresponding measurements on kV-constant scans. Additionally, to prove stability of the requested exposure parameters, the accuracy of the delivered tube current and pulse width were also recorded and compared. In a first phantom experiment, the voxel intensity values of the individual tube voltage components of the fast kV-switching scans were compared to their corresponding kV-constant scans. The same phantom was used for a simple material decomposition between different iodine concentrations and pure water using a fast kV-switching protocol of 81 and 125 kV. In the last experiment, the same kV-switching protocol as in the phantom scan was used in an in vivo pig study to demonstrate the clinical feasibility. RESULTS During rapid kV-switching acquisitions, the measured tube voltage of the x-ray tube during fast switching scans has an absolute deviation of 0.23 ± 0.13 kV compared to the measured tube voltage produced during kV-constant acquisitions. The stability of the peak tube voltage over different scan requests was about 0.10 kV for the low and 0.46 for the high energy kV-switching scans and less than 0.1 kV for kV-constant scans, indicating slightly lower stability for kV-switching scans. The tube current resulted in a relative deviation of -1.6% for the low and 6.6% overestimation for the high tube voltage of the kV-switching scans compared to the kV-constant scans. The pulse width showed no deviation for the longer pulse width and only minor deviations (0.02 ± 0.02 ms) for the shorter pulse widths compared to the kV-constant scans. The phantom experiment using different iodine concentrations showed an accurate correlation (R2 > 0.99) between the extracted intensity values in the kV-switching and kV-constant reconstructed volumes, and allows for an automatic differentiation between contrast concentration down to 10% (350 mg/ml iodine) and pure water under low-noise conditions. Preliminary results of iodine and soft tissue separation showed also promising results in the first in vivo pig study. CONCLUSIONS The feasibility of dual-energy imaging using a fast kV-switching method on an angiographic C-arm CT system was investigated. Direct measurements of beam quality in the x-ray field demonstrate the stability of the kV-switching method. Phantom and in vivo experiments showed that images did not deviate from those of corresponding kV-constant scans. All performed experiments confirmed the capability of performing fast kV-switching scans on a clinically available C-arm CT system. More complex material decomposition tasks and postprocessing steps will be part of future investigations.
Collapse
Affiliation(s)
- K Müller
- Radiological Sciences Lab, Stanford University, Stanford, California 94305
| | - S Datta
- Siemens Medical Solutions, Inc., Malvern, Pennsylvania 19355
| | - M Ahmad
- Radiological Sciences Lab, Stanford University, Stanford, California 94305
| | - J-H Choi
- Radiological Sciences Lab, Stanford University, Stanford, California 94305
| | - T Moore
- Siemens Medical Solutions, Inc., Malvern, Pennsylvania 19355
| | - L Pung
- Siemens Medical Solutions, Inc., Malvern, Pennsylvania 19355
| | - C Niebler
- Department of Electrical Engineering, Technische Hochschule Nürnberg, Nürnberg 90489, Germany
| | - G E Gold
- Department of Radiology, Stanford University Stanford, California 94305; Department of Orthopaedic Surgery, Stanford University, Stanford, California 94305; and Department of Bioengineering, Stanford University, Stanford, California 94305
| | - A Maier
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91058, Germany
| | - R Fahrig
- Radiological Sciences Lab, Stanford University, Stanford, California 94305
| |
Collapse
|
59
|
Chaudhari AS, Sveinsson B, Moran CJ, McWalter EJ, Johnson EM, Zhang T, Gold GE, Hargreaves BA. Imaging and T 2 relaxometry of short-T 2 connective tissues in the knee using ultrashort echo-time double-echo steady-state (UTEDESS). Magn Reson Med 2017; 78:2136-2148. [PMID: 28074498 DOI: 10.1002/mrm.26577] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/26/2016] [Accepted: 11/19/2016] [Indexed: 12/15/2022]
Abstract
PURPOSE To develop a radial, double-echo steady-state (DESS) sequence with ultra-short echo-time (UTE) capabilities for T2 measurement of short-T2 tissues along with simultaneous rapid, signal-to-noise ratio (SNR)-efficient, and high-isotropic-resolution morphological knee imaging. METHODS THe 3D radial UTE readouts were incorporated into DESS, termed UTEDESS. Multiple-echo-time UTEDESS was used for performing T2 relaxometry for short-T2 tendons, ligaments, and menisci; and for Dixon water-fat imaging. In vivo T2 estimate repeatability and SNR efficiency for UTEDESS and Cartesian DESS were compared. The impact of coil combination methods on short-T2 measurements was evaluated by means of simulations. UTEDESS T2 measurements were compared with T2 measurements from Cartesian DESS, multi-echo spin-echo (MESE), and fast spin-echo (FSE). RESULTS UTEDESS produced isotropic resolution images with high SNR efficiency in all short-T2 tissues. Simulations and experiments demonstrated that sum-of-squares coil combinations overestimated short-T2 measurements. UTEDESS measurements of meniscal T2 were comparable to DESS, MESE, and FSE measurements while the tendon and ligament measurements were less biased than those from Cartesian DESS. Average UTEDESS T2 repeatability variation was under 10% in all tissues. CONCLUSION The T2 measurements of short-T2 tissues and high-resolution morphological imaging provided by UTEDESS makes it promising for studying the whole knee, both in routine clinical examinations and longitudinal studies. Magn Reson Med 78:2136-2148, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Akshay S Chaudhari
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Bragi Sveinsson
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Catherine J Moran
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Emily J McWalter
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ethan M Johnson
- Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Tao Zhang
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Brian A Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| |
Collapse
|
60
|
Kogan F, Stafford RB, Englund EK, Gold GE, Hariharan H, Detre JA, Reddy R. Perfusion has no effect on the in vivo CEST effect from Cr (CrCEST) in skeletal muscle. NMR Biomed 2017; 30:10.1002/nbm.3673. [PMID: 27898185 PMCID: PMC5518925 DOI: 10.1002/nbm.3673] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 05/08/2023]
Abstract
Creatine, a key component of muscle energy metabolism, exhibits a chemical exchange saturation transfer (CEST) effect between its amine group and bulk water, which has been exploited to spatially and temporally map creatine changes in skeletal muscle before and after exercise. In addition, exercise leads to an increase in muscle perfusion. In this work, we determined the effects of perfused blood on the CEST effects from creatine in skeletal muscle. Experiments were performed on healthy human subjects (n = 5) on a whole-body Siemens 7T magnetic resonance imaging (MRI) scanner with a 28-channel radiofrequency (RF) coil. Reactive hyperemia, induced by inflation and subsequent deflation of a pressure cuff secured around the thigh, was used to increase tissue perfusion whilst maintaining the levels of creatine kinase metabolites. CEST, arterial spin labeling (ASL) and 31 P MRS data were acquired at baseline and for 6 min after cuff deflation. Reactive hyperemia resulted in substantial increases in perfusion in human skeletal muscle of the lower leg as measured by the ASL mean percentage difference. However, no significant changes in CrCEST asymmetry (CrCESTasym ) or 31 P MRS-derived PCr levels of skeletal muscle were observed following cuff deflation. This work demonstrates that perfusion changes do not have a major confounding effect on CrCEST measurements.
Collapse
Affiliation(s)
- Feliks Kogan
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Randall B. Stafford
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Erin K. Englund
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Garry E. Gold
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, B1 Stellar-Chance Labs, 422 Curie Boulevard, Philadelphia, PA 19104
| | - John A. Detre
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, B1 Stellar-Chance Labs, 422 Curie Boulevard, Philadelphia, PA 19104
- Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, B1 Stellar-Chance Labs, 422 Curie Boulevard, Philadelphia, PA 19104
| |
Collapse
|
61
|
Sveinsson B, Chaudhari AS, Gold GE, Hargreaves BA. A simple analytic method for estimating T2 in the knee from DESS. Magn Reson Imaging 2016; 38:63-70. [PMID: 28017730 DOI: 10.1016/j.mri.2016.12.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 11/16/2022]
Abstract
PURPOSE To introduce a simple analytical formula for estimating T2 from a single Double-Echo in Steady-State (DESS) scan. METHODS Extended Phase Graph (EPG) modeling was used to develop a straightforward linear approximation of the relationship between the two DESS signals, enabling accurate T2 estimation from one DESS scan. Simulations were performed to demonstrate cancellation of different echo pathways to validate this simple model. The resulting analytic formula was compared to previous methods for T2 estimation using DESS and fast spin-echo scans in agar phantoms and knee cartilage in three volunteers and three patients. The DESS approach allows 3D (256×256×44) T2-mapping with fat suppression in scan times of 3-4min. RESULTS The simulations demonstrated that the model approximates the true signal very well. If the T1 is within 20% of the assumed T1, the T2 estimation error was shown to be less than 5% for typical scans. The inherent residual error in the model was demonstrated to be small both due to signal decay and opposing signal contributions. The estimated T2 from the linear relationship agrees well with reference scans, both for the phantoms and in vivo. The method resulted in less underestimation of T2 than previous single-scan approaches, with processing times 60 times faster than using a numerical fit. CONCLUSION A simplified relationship between the two DESS signals allows for rapid 3D T2 quantification with DESS that is accurate, yet also simple. The simplicity of the method allows for immediate T2 estimation in cartilage during the MRI examination.
Collapse
Affiliation(s)
- B Sveinsson
- Department of Radiology, Stanford University, Stanford, CA, United States.
| | - A S Chaudhari
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - G E Gold
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - B A Hargreaves
- Department of Radiology, Stanford University, Stanford, CA, United States
| |
Collapse
|
62
|
Abstract
Early detection of musculoskeletal disease leads to improved therapies and patient outcomes, and would benefit greatly from imaging at the cellular and molecular level. As it becomes clear that assessment of multiple tissues and functional processes are often necessary to study the complex pathogenesis of musculoskeletal disorders, the role of multi-modality molecular imaging becomes increasingly important. New positron emission tomography-magnetic resonance imaging (PET-MRI) systems offer to combine high-resolution MRI with simultaneous molecular information from PET to study the multifaceted processes involved in numerous musculoskeletal disorders. In this article, we aim to outline the potential clinical utility of hybrid PET-MRI to these non-oncologic musculoskeletal diseases. We summarize current applications of PET molecular imaging in osteoarthritis (OA), rheumatoid arthritis (RA), metabolic bone diseases and neuropathic peripheral pain. Advanced MRI approaches that reveal biochemical and functional information offer complementary assessment in soft tissues. Additionally, we discuss technical considerations for hybrid PET-MR imaging including MR attenuation correction, workflow, radiation dose, and quantification.
Collapse
Affiliation(s)
- Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Audrey P Fan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California, USA; Department of Bioengineering, Stanford University, Stanford, California, USA; Department of Orthopaedic Surgery, Stanford University, Stanford, California, USA
| |
Collapse
|
63
|
Pappas GP, Vogelsong MA, Staroswiecki E, Gold GE, Safran MR. Magnetic Resonance Imaging of Asymptomatic Knees in Collegiate Basketball Players: The Effect of One Season of Play. Clin J Sport Med 2016; 26:483-489. [PMID: 27347867 PMCID: PMC5083196 DOI: 10.1097/jsm.0000000000000283] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the prevalence of abnormal structural findings using 3.0-T magnetic resonance imaging (MRI) in the asymptomatic knees of male and female collegiate basketball players before and after a season of high-intensity basketball. DESIGN Institutional review board-approved prospective case series. PARTICIPANTS Asymptomatic knees of 24 NCAA Division I collegiate basketball players (12 male, 12 female) were imaged using a 3.0-T MRI scanner before and after the end of the competitive season. Three subjects did not undergo scanning after the season. MAIN OUTCOME MEASURES Images were evaluated for prepatellar bursitis, fat pad edema, patellar and quadriceps tendinopathy, bone marrow edema, and articular cartilage and meniscal injury. RESULTS Every knee imaged had at least 1 structural abnormality both preseason and postseason. A high preseason and postseason prevalence of fat pad edema (75% and 81%), patellar tendinopathy (83% and 90%), and quadriceps tendinopathy (75% and 90%) was seen. Intrameniscal signal change was observed in 50% preseason knees and 62% of postseason knees, but no discrete tears were found. Bone marrow edema was seen in 75% and 86% of knees in the preseason and postseason, respectively. Cartilage findings were observed in 71% and 81% of knees in the preseason and postseason, respectively. The cartilage injury score increased significantly in the postseason compared with the preseason (P = 0.0009). CONCLUSIONS A high prevalence of abnormal knee MRI findings was observed in a population of asymptomatic young elite athletes. These preliminary data suggest that high-intensity basketball may have potentially deleterious effects on articular cartilage.
Collapse
|
64
|
Abstract
PURPOSE Elevated cartilage stress has been identified as a potential mechanism for retropatellar pain; however, there are limited data in the literature to support this mechanism. Females are more likely to develop patellofemoral pain than males, yet the causes of this dimorphism are unclear. We used experimental data and computational modeling to determine whether patients with patellofemoral pain had elevated cartilage stress compared with pain-free controls and test the hypothesis that females exhibit greater cartilage stress than males. METHODS We created finite element models of 24 patients with patellofemoral pain (11 males and 13 females) and 16 pain-free controls (8 males and 8 females) to estimate peak patellar cartilage stress (strain energy density) during a stair climb activity. Simulations took into account cartilage morphology from magnetic resonance imaging, joint posture from weight-bearing magnetic resonance imaging, and muscle forces from an EMG-driven model. RESULTS We found no difference in peak patellar strain energy density between those with patellofemoral pain (1.9 ± 1.23 J·m(-3)) and control subjects (1.66 ± 0.75 J·m(-3), P = 0.52). Females exhibited greater cartilage stress compared with males (2.2 vs 1.3 J·m(-3), respectively; P = 0.0075), with large quadriceps muscle forces (3.7 body weight in females vs 3.3 body weight in males) and 23% smaller joint contact area (females, 467 ± 59 mm2, vs males, 608 ± 95 mm2). CONCLUSIONS Patients with patellofemoral pain did not display significantly greater patellar cartilage stress compared with pain-free controls; however, there was a great deal of subject variation. Females exhibited greater peak cartilage stress compared with males, which might explain the greater prevalence of patellofemoral pain in females compared with that in males, but other mechanical and biological factors are clearly involved in this complex pathway to pain.
Collapse
Affiliation(s)
- Thor F Besier
- 1Auckland Bioengineering Institute, University of Auckland, Auckland, NEW ZEALAND; 2Department of Engineering Science, University of Auckland, Auckland, NEW ZEALAND; 3College of Engineering, California Polytechnic State University, San Luis Obispo, CA; 4Department of Bioengineering, Stanford University, Stanford, CA; 5Department of Orthopaedics, Stanford University, Stanford, CA; 6Department of Radiology, Stanford University, Stanford, CA; and 7VA Palo Alto Rehabilitation Research and Development Center, Palo Alto, CA
| | | | | | | | | | | | | |
Collapse
|
65
|
Silder A, Gold GE, Bae SK, Ko BH, Jang DG, Delp SL. Evaluation of an Algorithm to Detect the First Ventilatory Threshold from Heart Rate. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000487019.84069.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
66
|
Kogan F, Hargreaves BA, Gold GE. Volumetric multislice gagCEST imaging of articular cartilage: Optimization and comparison with T1rho. Magn Reson Med 2016; 77:1134-1141. [PMID: 26923108 DOI: 10.1002/mrm.26200] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/12/2016] [Accepted: 02/12/2016] [Indexed: 12/28/2022]
Abstract
PURPOSE To develop and optimize a multislice glycosaminoglycan (GAG) chemical exchange saturation transfer (GagCEST) sequence for volumetric imaging of articular cartilage, and to validate the sequence against T1ρ relaxation times in whole joint imaging of tibiotalar cartilage. METHODS Ex vivo experiments were used to observe the effect of the number of partitions and shot TR on signal-to-noise ratio and measured GagCESTasym . GagCEST imaging of the entire tibiotalar joint was also performed on 10 healthy subjects. The measured GagCESTasym was compared and correlated with T1ρ relaxation times. RESULTS Ex vivo studies showed a higher average GagCESTasym from articular cartilage on multislice acquisitions acquired with two or more partitions than observed with a single-slice acquisition. In healthy human subjects, an average GagCESTasym of 8.8 ± 0.7% was observed. A coefficient of variation of GagCESTasym across slices of less than 15% was seen for all subjects. Across subjects, a Pearson correlation coefficient of -0.58 was observed between the measured gagCESTasym and T1ρ relaxation times. CONCLUSIONS We demonstrated the feasibility and optimization of multislice GagCEST mapping of articular cartilage. Volumetric analysis and decreased scan times will help to advance the clinical utility of GagCEST imaging of articular cartilage. Magn Reson Med 77:1134-1141, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Brian A Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Orthopedic Surgery, Stanford University, Stanford, California, USA
| |
Collapse
|
67
|
Wentland AL, McWalter EJ, Pal S, Delp SL, Gold GE. Muscle velocity and inertial force from phase contrast MRI. J Magn Reson Imaging 2015. [DOI: 10.1002/jmri.25013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Andrew L. Wentland
- Department of Medical Physics; University of Wisconsin School of Medicine & Public Health; Madison Wisconsin USA
| | - Emily J. McWalter
- Department of Radiology; Stanford University School of Medicine; Stanford California USA
| | - Saikat Pal
- Department of Biomedical Engineering; California Polytechnic State University; San Luis Obispo California USA
| | - Scott L. Delp
- Department of Bioengineering; Stanford University School of Medicine; Stanford California USA
| | - Garry E. Gold
- Department of Radiology; Stanford University School of Medicine; Stanford California USA
- Department of Bioengineering; Stanford University School of Medicine; Stanford California USA
| |
Collapse
|
68
|
Matzat SJ, McWalter EJ, Kogan F, Chen W, Gold GE. T2 Relaxation time quantitation differs between pulse sequences in articular cartilage. J Magn Reson Imaging 2015; 42:105-13. [PMID: 25244647 PMCID: PMC4369475 DOI: 10.1002/jmri.24757] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/28/2014] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND To compare T2 relaxation time measurements between MR pulse sequences at 3 Tesla in agar phantoms and in vivo patellar, femoral, and tibial articular cartilage. METHODS T2 relaxation times were quantified in phantoms and knee articular cartilage of eight healthy individuals using a single echo spin echo (SE) as a reference standard and five other pulse sequences: multi-echo SE (MESE), fast SE (2D-FSE), magnetization-prepared spoiled gradient echo (3D-MAPSS), three-dimensional (3D) 3D-FSE with variable refocusing flip angle schedules (3D vfl-FSE), and quantitative double echo steady state (qDESS). Cartilage was manually segmented and average regional T2 relaxation times were obtained for each sequence. A regression analysis was carried out between each sequence and the reference standard, and root-mean-square error (RMSE) was calculated. RESULTS Phantom measurements from all sequences demonstrated strong fits (R(2) > 0.8; P < 0.05). For in vivo cartilage measurements, R(2) values, slope, and RMSE were: MESE: 0.25/0.42/5.0 ms, 2D-FSE: 0.64/1.31/9.3 ms, 3D-MAPSS: 0.51/0.66/3.8 ms, 3D vfl-FSE: 0.30/0.414.2 ms, qDESS: 0.60/0.90/4.6 ms. CONCLUSION 2D-FSE, qDESS, and 3D-MAPSS demonstrated the best fits with SE measurements as well as the greatest dynamic ranges. The 3D-MAPSS, 3D vfl-FSE, and qDESS demonstrated the closest average measurements to SE. Discrepancies in T2 relaxation time quantitation between sequences suggest that care should be taken when comparing results between studies.
Collapse
Affiliation(s)
| | | | - Feliks Kogan
- Radiology, Stanford University, Stanford, California, USA
| | - Weitian Chen
- MR Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA
| | - Garry E. Gold
- Radiology, Stanford University, Stanford, California, USA
- Bioengineering, Stanford University, Stanford, California, USA
| |
Collapse
|
69
|
Abstract
Efforts to reduce the ever-increasing rates of osteoarthritis (OA) in the developed world require the ability to non-invasively detect the degradation of joint tissues before advanced damage has occurred. This is particularly relevant for damage to articular cartilage because this soft tissue lacks the capacity to repair itself following major damage and is essential to proper joint function. While conventional magnetic resonance imaging (MRI) provides sufficient contrast to visualize articular cartilage morphology, more advanced imaging strategies are necessary for understanding the underlying biochemical composition of cartilage that begins to break down in the earliest stages of OA. This review discusses the biochemical basis and the advantages and disadvantages associated with each of these techniques. Recent implementations for these techniques are touched upon, and future considerations for improving the research and clinical power of these imaging technologies are also discussed.
Collapse
|
70
|
Hunter DJ, Altman RD, Cicuttini F, Crema MD, Duryea J, Eckstein F, Guermazi A, Kijowski R, Link TM, Martel-Pelletier J, Miller CG, Mosher TJ, Ochoa-Albíztegui RE, Pelletier JP, Peterfy C, Raynauld JP, Roemer FW, Totterman SM, Gold GE. OARSI Clinical Trials Recommendations: Knee imaging in clinical trials in osteoarthritis. Osteoarthritis Cartilage 2015; 23:698-715. [PMID: 25952343 DOI: 10.1016/j.joca.2015.03.012] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 02/02/2023]
Abstract
Significant advances have occurred in our understanding of the pathogenesis of knee osteoarthritis (OA) and some recent trials have demonstrated the potential for modification of the disease course. The purpose of this expert opinion, consensus driven exercise is to provide detail on how one might use and apply knee imaging in knee OA trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, sequences artifacts); quality assurance (QA)/control procedures; measurement methods; measurement performance (reliability, responsiveness, validity); recommendations for trials; and research recommendations.
Collapse
Affiliation(s)
- D J Hunter
- Institute of Bone and Joint Research, Kolling Institute, University of Sydney, Sydney, NSW, Australia; Rheumatology Department, Royal North Shore Hospital, University of Sydney, Sydney, NSW, Australia.
| | - R D Altman
- Department of Medicine, Division of Rheumatology and Immunology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - F Cicuttini
- School of Public health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne 3004, Australia
| | - M D Crema
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, Hospital do Coração (HCor) and Teleimagem, São Paulo, SP, Brazil
| | - J Duryea
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Brazil
| | - F Eckstein
- Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany
| | - A Guermazi
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA
| | - R Kijowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - T M Link
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, USA
| | - J Martel-Pelletier
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | | | - T J Mosher
- Department of Radiology, Penn State University, Hershey, PA, USA; Department of Orthopaedic Surgery, Penn State University, Hershey, PA, USA
| | - R E Ochoa-Albíztegui
- Department of Radiology, The American British Cowdray Medical Center, Mexico City, Mexico
| | - J-P Pelletier
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - C Peterfy
- Spire Sciences, Inc., Boca Raton, Florida, USA
| | - J-P Raynauld
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - F W Roemer
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - G E Gold
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA; Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| |
Collapse
|
71
|
Keenan KE, Besier TF, Pauly JM, Smith RL, Delp SL, Beaupre GS, Gold GE. T1ρ Dispersion in Articular Cartilage: Relationship to Material Properties and Macromolecular Content. Cartilage 2015; 6:113-22. [PMID: 26069714 PMCID: PMC4462251 DOI: 10.1177/1947603515569529] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE This study assessed T1ρ relaxation dispersion, measured by magnetic resonance imaging (MRI), as a tool to noninvasively evaluate cartilage material and biochemical properties. The specific objective was to answer two questions: (1) does cartilage initial elastic modulus (E 0) correlate with T1ρ dispersion effects and (2) does collagen or proteoglycan content correlate with T1ρ dispersion effects? DESIGN Cadaveric patellae with and without visible cartilage damage on conventional MR were included. T2 and T1ρ relaxation times at 500 and 1000 Hz spin-lock field amplitudes were measured. We estimated T1ρ dispersion effects by measuring T1ρ relaxation time at 500 and 1000 Hz and T2 relaxation time and using a new tool, the ratio T1ρ/T2. Cartilage initial elastic modulus, E 0, was measured from initial response of mechanical indentation creep tests. Collagen and proteoglycan contents were measured at the indentation test sites; proteoglycan content was measured by their covalently linked sulfated glycosaminoglycans (sGAG). Pearson correlation coefficients were determined, taking into account the clustering of multiple samples within a single patella specimen. RESULTS Cartilage initial elastic modulus, E 0, increased with decreasing values of T1ρ/T2 measurements at both 500 Hz (P = 0.034) and 1000 Hz (P = 0.022). 1/T1ρ relaxation time (500 Hz) increased with increasing sGAG content (P = 0.041). CONCLUSIONS T1ρ/T2 ratio, a new tool, and cartilage initial elastic modulus are both measures of water-protein interactions, are dependent on the cartilage structure, and were correlated in this study.
Collapse
Affiliation(s)
- Kathryn E. Keenan
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Thor F. Besier
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - John M. Pauly
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - R. Lane Smith
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA,Rehabilitation R&D Musculoskeletal Research Laboratory, Department of Veterans Affairs, Palo Alto, CA, USA
| | - Scott L. Delp
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA,Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Gary S. Beaupre
- Rehabilitation R&D Musculoskeletal Research Laboratory, Department of Veterans Affairs, Palo Alto, CA, USA
| | - Garry E. Gold
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA,Department of Bioengineering, Stanford University, Stanford, CA, USA,Department of Radiology, Stanford University, Stanford, CA, USA
| |
Collapse
|
72
|
Riley GM, McWalter EJ, Stevens KJ, Safran MR, Lattanzi R, Gold GE. MRI of the Hip for the evaluation of femoroacetabular impingement; past, present, and future. J Magn Reson Imaging 2015. [DOI: 10.1002/jmri.24868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Geoffrey M. Riley
- Department of Radiology; Stanford University; Stanford California USA
| | - Emily J. McWalter
- Department of Radiology; Stanford University; Stanford California USA
| | | | - Marc R. Safran
- Department of Orthopaedic Surgery; Stanford University; Redwood City California USA
| | - Riccardo Lattanzi
- Department of Radiology, The Bernard and Irene Schwartz Center for Biomedical Imaging; New York University School of Medicine; New York New York USA
| | - Garry E. Gold
- Department of Radiology; Stanford University; Stanford California USA
| |
Collapse
|
73
|
Del Grande F, Santini F, Herzka DA, Aro MR, Dean CW, Gold GE, Carrino JA. Fat-suppression techniques for 3-T MR imaging of the musculoskeletal system. Radiographics 2015; 34:217-33. [PMID: 24428292 DOI: 10.1148/rg.341135130] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fat suppression is an important technique in musculoskeletal imaging to improve the visibility of bone-marrow lesions; evaluate fat in soft-tissue masses; optimize the contrast-to-noise ratio in magnetic resonance (MR) arthrography; better define lesions after administration of contrast material; and avoid chemical shift artifacts, primarily at 3-T MR imaging. High-field-strength (eg, 3-T) MR imaging has specific technical characteristics compared with lower-field-strength MR imaging that influence the use and outcome of various fat-suppression techniques. The most commonly used fat-suppression techniques for musculoskeletal 3-T MR imaging include chemical shift (spectral) selective (CHESS) fat saturation, inversion recovery pulse sequences (eg, short inversion time inversion recovery [STIR]), hybrid pulse sequences with spectral and inversion-recovery (eg, spectral adiabatic inversion recovery and spectral attenuated inversion recovery [SPAIR]), spatial-spectral pulse sequences (ie, water excitation), and the Dixon techniques. Understanding the different fat-suppression options allows radiologists to adopt the most appropriate technique for their clinical practice.
Collapse
Affiliation(s)
- Filippo Del Grande
- From the Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, Md (F.D.G., M.R.A., J.A.C.); Division of Radiological Physics, Department of Radiology, Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland (F.S.); Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Md (D.A.H.); Department of Radiology, University of Florida College of Medicine, Gainesville, Fla (C.W.D.); and Departments of Radiology, Bioengineering, and Orthopaedic Surgery, Stanford University School of Medicine, Stanford, Calif (G.E.G.). Recipient of a Certificate of Merit award for an education exhibit at the 2012 RSNA Annual Meeting
| | | | | | | | | | | | | |
Collapse
|
74
|
Choi JH, Maier A, Keil A, Pal S, McWalter EJ, Beaupré GS, Gold GE, Fahrig R. Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. II. Experiment. Med Phys 2015; 41:061902. [PMID: 24877813 DOI: 10.1118/1.4873675] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE A C-arm CT system has been shown to be capable of scanning a single cadaver leg under loaded conditions by virtue of its highly flexible acquisition trajectories. In Part I of this study, using the 4D XCAT-based numerical simulation, the authors predicted that the involuntary motion in the lower body of subjects in weight-bearing positions would seriously degrade image quality and the authors suggested three motion compensation methods by which the reconstructions could be corrected to provide diagnostic image quality. Here, the authors demonstrate that a flat-panel angiography system is appropriate for scanning both legs of subjects in vivo under weight-bearing conditions and further evaluate the three motion-correction algorithms using in vivo data. METHODS The geometry of a C-arm CT system for a horizontal scan trajectory was calibrated using the PDS-2 phantom. The authors acquired images of two healthy volunteers while lying supine on a table, standing, and squatting at several knee flexion angles. In order to identify the involuntary motion of the lower body, nine 1-mm-diameter tantalum fiducial markers were attached around the knee. The static mean marker position in 3D, a reference for motion compensation, was estimated by back-projecting detected markers in multiple projections using calibrated projection matrices and identifying the intersection points in 3D of the back-projected rays. Motion was corrected using three different methods (described in detail previously): (1) 2D projection shifting, (2) 2D deformable projection warping, and (3) 3D rigid body warping. For quantitative image quality analysis, SSIM indices for the three methods were compared using the supine data as a ground truth. RESULTS A 2D Euclidean distance-based metric of subjects' motion ranged from 0.85 mm (±0.49 mm) to 3.82 mm (±2.91 mm) (corresponding to 2.76 to 12.41 pixels) resulting in severe motion artifacts in 3D reconstructions. Shifting in 2D, 2D warping, and 3D warping improved the SSIM in the central slice by 20.22%, 16.83%, and 25.77% in the data with the largest motion among the five datasets (SCAN5); improvement in off-center slices was 18.94%, 29.14%, and 36.08%, respectively. CONCLUSIONS The authors showed that C-arm CT control can be implemented for nonstandard horizontal trajectories which enabled us to scan and successfully reconstruct both legs of volunteers in weight-bearing positions. As predicted using theoretical models, the proposed motion correction methods improved image quality by reducing motion artifacts in reconstructions; 3D warping performed better than the 2D methods, especially in off-center slices.
Collapse
Affiliation(s)
- Jang-Hwan Choi
- Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305
| | - Andreas Maier
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Andreas Keil
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Saikat Pal
- Biomedical Engineering Department, California Polytechnic State University, San Luis Obispo, California 93407
| | - Emily J McWalter
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Gary S Beaupré
- Musculoskeletal Research Laboratory, VA Palo Alto Health Care System, Palo Alto, California 94304
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Rebecca Fahrig
- Department of Radiology, Stanford University, Stanford, California 94305
| |
Collapse
|
75
|
Li CQ, Chen W, Rosenberg JK, Beatty PJ, Kijowski R, Hargreaves BA, Busse RF, Gold GE. Optimizing isotropic three-dimensional fast spin-echo methods for imaging the knee. J Magn Reson Imaging 2015; 39:1417-25. [PMID: 24987753 DOI: 10.1002/jmri.24315] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To optimize acquisition parameters for three dimensional fast spin-echo (3D FSE) imaging of the knee. MATERIALS AND METHODS The knees of eight healthy volunteers were imaged in a 3 Tesla MRI scanner using an eight-channel knee coil. A total of 146 intermediate weighted isotropic resolution 3D FSE (3D-FSE-Cube)images with varied acquisition parameter settings were acquired with an additional reference scan performed for subjective image quality assessment. Images were graded for overall quality, parallel imaging artifact severity and blurring. Cartilage, muscle, and fluid signal-to-noise ratios and fluid-cartilage contrast-to-noise ratios were quantified by acquiring scans without radio frequency excitation and custom-reconstructing the k-space data.Mixed effects regression modeling was used to determine statistically significant effects of different parameters on image quality. RESULTS Changes in receiver bandwidth, repetition time and echo train length significantly affected all measurements of image quality (P < 0.05). Reducing band width improved all metrics of image quality with the exception of blurring. Reader agreement was slight to fair for subjective metrics, but overall trends in quality ratings were apparent. CONCLUSION We used a systematic approach to optimize 3D-FSE-Cube parameters for knee imaging. Image quality was overall improved using a receiver bandwidth of 631.25 kHz, and blurring increased with lower band width and longer echo trains.
Collapse
Affiliation(s)
- Charles Q Li
- Department of Radiology, University of California, San Diego, San Diego, California, USA
| | | | | | | | | | | | | | | |
Collapse
|
76
|
Shapiro LM, Matzat SJ, Gold GE. Functional magnetic resonance imaging. Rheumatology (Oxford) 2015. [DOI: 10.1016/b978-0-323-09138-1.00041-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
77
|
Wentland AL, McWalter EJ, Pal S, Delp SL, Gold GE. Muscle velocity and inertial force from phase contrast MRI. J Magn Reson Imaging 2014; 42:526-32. [PMID: 25425185 DOI: 10.1002/jmri.24807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/04/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To evaluate velocity waveforms in muscle and to create a tool and algorithm for computing and analyzing muscle inertial forces derived from 2D phase contrast (PC) magnetic resonance imaging (MRI). MATERIALS AND METHODS PC MRI was performed in the forearm of four healthy volunteers during 1 Hz cycles of wrist flexion-extension as well as in the lower leg of six healthy volunteers during 1 Hz cycles of plantarflexion-dorsiflexion. Inertial forces (F) were derived via the equation F = ma. The mass, m, was derived by multiplying voxel volume by voxel-by-voxel estimates of density via fat-water separation techniques. Acceleration, a, was obtained via the derivative of the PC MRI velocity waveform. RESULTS Mean velocities in the flexors of the forearm and lower leg were 1.94 ± 0.97 cm/s and 5.57 ± 2.72 cm/s, respectively, as averaged across all subjects; the inertial forces in the flexors of the forearm and lower leg were 1.9 × 10(-3) ± 1.3 × 10(-3) N and 1.1 × 10(-2) ± 6.1 × 10(-3) N, respectively, as averaged across all subjects. CONCLUSION PC MRI provided a promising means of computing muscle velocities and inertial forces-providing the first method for quantifying inertial forces.
Collapse
Affiliation(s)
- Andrew L Wentland
- Department of Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, USA
| | - Emily J McWalter
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Saikat Pal
- Department of Biomedical Engineering, California Polytechnic State University, San Luis Obispo, California, USA
| | - Scott L Delp
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
| | - Garry E Gold
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA.,Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
| |
Collapse
|
78
|
Zöllner AM, Pok JM, McWalter EJ, Gold GE, Kuhl E. On high heels and short muscles: a multiscale model for sarcomere loss in the gastrocnemius muscle. J Theor Biol 2014; 365:301-10. [PMID: 25451524 DOI: 10.1016/j.jtbi.2014.10.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 10/28/2014] [Accepted: 10/29/2014] [Indexed: 11/29/2022]
Abstract
High heels are a major source of chronic lower limb pain. Yet, more than one third of all women compromise health for looks and wear high heels on a daily basis. Changing from flat footwear to high heels induces chronic muscle shortening associated with discomfort, fatigue, reduced shock absorption, and increased injury risk. However, the long-term effects of high-heeled footwear on the musculoskeletal kinematics of the lower extremities remain poorly understood. Here we create a multiscale computational model for chronic muscle adaptation to characterize the acute and chronic effects of global muscle shortening on local sarcomere lengths. We perform a case study of a healthy female subject and show that raising the heel by 13cm shortens the gastrocnemius muscle by 5% while the Achilles tendon remains virtually unaffected. Our computational simulation indicates that muscle shortening displays significant regional variations with extreme values of 22% in the central gastrocnemius. Our model suggests that the muscle gradually adjusts to its new functional length by a chronic loss of sarcomeres in series. Sarcomere loss varies significantly across the muscle with an average loss of 9%, virtually no loss at the proximal and distal ends, and a maximum loss of 39% in the central region. These changes reposition the remaining sarcomeres back into their optimal operating regime. Computational modeling of chronic muscle shortening provides a valuable tool to shape our understanding of the underlying mechanisms of muscle adaptation. Our study could open new avenues in orthopedic surgery and enhance treatment for patients with muscle contracture caused by other conditions than high heel wear such as paralysis, muscular atrophy, and muscular dystrophy.
Collapse
Affiliation(s)
- Alexander M Zöllner
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Jacquelynn M Pok
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Emily J McWalter
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Garry E Gold
- Department of Radiology, Stanford University, Stanford, CA 94305, USA; Department of Orthopaedics, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Ellen Kuhl
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
79
|
Jordan CD, Monu UD, McWalter EJ, Watkins RD, Chen W, Bangerter NK, Hargreaves BA, Gold GE. Variability of CubeQuant T1ρ, quantitative DESS T2, and cones sodium MRI in knee cartilage. Osteoarthritis Cartilage 2014; 22:1559-67. [PMID: 25278065 PMCID: PMC4185151 DOI: 10.1016/j.joca.2014.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 05/20/2014] [Accepted: 06/03/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To measure the variability of T1ρ relaxation times using CubeQuant, T2 relaxation times using quantitative double echo in steady state (DESS), and normalized sodium signals using 3D cones sodium magnetic resonance imaging (MRI) of knee cartilage in vivo at 3 T. DESIGN Eight healthy subjects were scanned at 3 T at baseline, 1 day, 5 months, and 1 year. Ten regions of interest (ROIs) of knee cartilage were segmented in the medial and lateral compartments of each subject's knee. T1ρ and T2 relaxation times and normalized sodium signals were measured and the root-mean-square coefficient of variation (CVRMS) was calculated. Intra-subject variability was measured over short, moderate and long-term, as well as intra-observer and inter-observer variability. RESULTS The average intra-subject CVRMS measurements over short, moderate, and long-term time periods were 4.6%, 6.1%, and 6.0% for the T1ρ measurements, 6.4%, 9.3%, and 10.7% for the T2 measurements and 11.3%, 11.6%, and 12.9% for the sodium measurements, respectively. The average CVRMS measurements for intra-observer and inter-observer segmentation were 3.8% and 5.7% for the T1ρ measurements, 4.7% and 6.7% for the T2 measurements, and 8.1% and 11.4% for the sodium measurements, respectively. CONCLUSIONS These CVRMS measurements are substantially lower than previously measured changes expected in patients with advanced osteoarthritis compared to healthy volunteers, suggesting that CubeQuant T1ρ, quantitative DESS T2 and 3D cones sodium measurements are sufficiently sensitive for in vivo cartilage studies.
Collapse
Affiliation(s)
- Caroline D. Jordan
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States
| | - Uchechukwuka D. Monu
- Radiology, Stanford University, Stanford, CA, United States,Electrical Engineering, Stanford University, Stanford CA, United States
| | | | | | - Weitian Chen
- GE Applied Science Laboratory, Menlo Park, CA, United States
| | - Neal K. Bangerter
- Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States
| | - Brian A. Hargreaves
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States,Electrical Engineering, Stanford University, Stanford CA, United States
| | - Garry E. Gold
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States,Orthopaedic Surgery, Stanford University, Stanford, CA, United States
| |
Collapse
|
80
|
Oei EHG, van Tiel J, Robinson WH, Gold GE. Quantitative radiologic imaging techniques for articular cartilage composition: toward early diagnosis and development of disease-modifying therapeutics for osteoarthritis. Arthritis Care Res (Hoboken) 2014; 66:1129-41. [PMID: 24578345 DOI: 10.1002/acr.22316] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 02/18/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Edwin H G Oei
- Stanford University, Stanford, California; Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | | | | | | |
Collapse
|
81
|
Riley GM, McWalter EJ, Stevens KJ, Safran MR, Lattanzi R, Gold GE. MRI of the hip for the evaluation of femoroacetabular impingement; past, present, and future. J Magn Reson Imaging 2014; 41:558-72. [PMID: 25155435 DOI: 10.1002/jmri.24725] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/21/2014] [Indexed: 11/07/2022] Open
Abstract
The concept of femoroacetabular impingement (FAI) has, in a relatively short time, come to the forefront of orthopedic imaging. In just a few short years MRI findings that were in the past ascribed to degenerative change, normal variation, or other pathologies must now be described and included in radiology reports, as they have been shown, or are suspected to be related to, FAI. Crucial questions have come up in this time, including: what is the relationship of bony morphology to subsequent cartilage and labral damage, and most importantly, how is this morphology related to the development of osteoarthritis? In this review, we attempt to place a historical perspective on the controversy, provide guidelines for interpretation of MRI examinations of patients with suspected FAI, and offer a glimpse into the future of MRI of this complex condition.
Collapse
Affiliation(s)
- Geoffrey M Riley
- Department of Radiology, Stanford University, Stanford, California, USA
| | | | | | | | | | | |
Collapse
|
82
|
Shapiro LM, McWalter EJ, Son MS, Levenston M, Hargreaves BA, Gold GE. Mechanisms of osteoarthritis in the knee: MR imaging appearance. J Magn Reson Imaging 2014; 39:1346-56. [PMID: 24677706 DOI: 10.1002/jmri.24562] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 07/14/2013] [Indexed: 01/15/2023] Open
Abstract
Osteoarthritis has grown to become a widely prevalent disease that has major implications in both individual and public health. Although originally considered to be a degenerative disease driven by "wear and tear" of the articular cartilage, recent evidence has led to a consensus that osteoarthritis pathophysiology should be perceived in the context of the entire joint and multiple tissues. MRI is becoming an increasingly more important modality for imaging osteoarthritis, due to its excellent soft tissue contrast and ability to acquire morphological and biochemical data. This review will describe the pathophysiology of osteoarthritis as it is associated with various tissue types, highlight several promising MR imaging techniques for osteoarthritis and illustrate the expected appearance of osteoarthritis with each technique.
Collapse
Affiliation(s)
- Lauren M Shapiro
- Department of Radiology, Stanford University, Stanford, California, USA
| | | | | | | | | | | |
Collapse
|
83
|
Sveinsson B, Worters PW, Gold GE, Hargreaves BA. Hexagonal undersampling for faster MRI near metallic implants. Magn Reson Med 2014; 73:662-8. [PMID: 24549782 DOI: 10.1002/mrm.25132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/20/2013] [Accepted: 12/21/2013] [Indexed: 12/22/2022]
Abstract
PURPOSE Slice encoding for metal artifact correction acquires a three-dimensional image of each excited slice with view-angle tilting to reduce slice and readout direction artifacts respectively, but requires additional imaging time. The purpose of this study was to provide a technique for faster imaging around metallic implants by undersampling k-space. METHODS Assuming that areas of slice distortion are localized, hexagonal sampling can reduce imaging time by 50% compared with conventional scans. This work demonstrates this technique by comparisons of fully sampled images with undersampled images, either from simulations from fully acquired data or from data actually undersampled during acquisition, in patients and phantoms. Hexagonal sampling is also shown to be compatible with parallel imaging and partial Fourier acquisitions. Image quality was evaluated using a structural similarity (SSIM) index. RESULTS Images acquired with hexagonal undersampling had no visible difference in artifact suppression from fully sampled images. The SSIM index indicated high similarity to fully sampled images in all cases. CONCLUSION The study demonstrates the ability to reduce scan time by undersampling without compromising image quality.
Collapse
Affiliation(s)
- Bragi Sveinsson
- Department of Radiology, Stanford University, Stanford, California, USA; Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | | | | | | |
Collapse
|
84
|
Newbould RD, Miller SR, Upadhyay N, Rao AW, Swann P, Gold GE, Strachan RK, Matthews PM, Taylor PC, Brown AP. T1-weighted sodium MRI of the articulator cartilage in osteoarthritis: a cross sectional and longitudinal study. PLoS One 2013; 8:e73067. [PMID: 23940822 PMCID: PMC3733834 DOI: 10.1371/journal.pone.0073067] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/16/2013] [Indexed: 11/23/2022] Open
Abstract
Structural magnetic resonance imaging (MRI) has shown great utility in diagnosing soft tissue burden in osteoarthritis (OA), though MRI measures of cartilage integrity have proven more elusive. Sodium MRI can reflect the proteoglycan content of cartilage; however, it requires specialized hardware, acquisition sequences, and long imaging times. This study was designed to assess the potential of a clinically feasible sodium MRI acquisition to detect differences in the knee cartilage of subjects with OA versus healthy controls (HC), and to determine whether longitudinal changes in sodium content are observed at 3 and 6 months. 28 subjects with primary knee OA and 19 HC subjects age and gender matched were enrolled in this ethically-approved study. At baseline, 3 and 6 months subjects underwent structural MRI and a 0.4ms echo time 3D T1-weighted sodium scan as well as the knee injury and osteoarthritis outcome score (KOOS) and knee pain by visual analogue score (VAS). A standing radiograph of the knee was taken for Kellgren-Lawrence (K-L) scoring. A blinded reader outlined the cartilage on the structural images which was used to determine median T1-weighted sodium concentrations in each region of interest on the co-registered sodium scans. VAS, K-L, and KOOS all significantly separated the OA and HC groups. OA subjects had higher T1-weighted sodium concentrations, most strongly observed in the lateral tibial, lateral femoral and medial patella ROIs. There were no significant changes in cartilage volume or sodium concentration over 6 months. This study has shown that a clinically-feasible sodium MRI at a moderate 3T field strength and imaging time with fluid attenuation by T1 weighting significantly separated HCs from OA subjects.
Collapse
Affiliation(s)
- Rexford D Newbould
- Imanova Centre for Imaging Sciences, Hammersmith Hospital, Imperial College London, London, United Kingdom.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
85
|
Matzat SJ, van Tiel J, Gold GE, Oei EHG. Quantitative MRI techniques of cartilage composition. Quant Imaging Med Surg 2013; 3:162-74. [PMID: 23833729 DOI: 10.3978/j.issn.2223-4292.2013.06.04] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 06/24/2013] [Indexed: 12/15/2022]
Abstract
Due to aging populations and increasing rates of obesity in the developed world, the prevalence of osteoarthritis (OA) is continually increasing. Decreasing the societal and patient burden of this disease motivates research in prevention, early detection of OA, and novel treatment strategies against OA. One key facet of this effort is the need to track the degradation of tissues within joints, especially cartilage. Currently, conventional imaging techniques provide accurate means to detect morphological deterioration of cartilage in the later stages of OA, but these methods are not sensitive to the subtle biochemical changes during early disease stages. Novel quantitative techniques with magnetic resonance imaging (MRI) provide direct and indirect assessments of cartilage composition, and thus allow for earlier detection and tracking of OA. This review describes the most prominent quantitative MRI techniques to date-dGEMRIC, T2 mapping, T1rho mapping, and sodium imaging. Other, less-validated methods for quantifying cartilage composition are also described-Ultrashort echo time (UTE), gagCEST, and diffusion-weighted imaging (DWI). For each technique, this article discusses the proposed biochemical correlates, as well its advantages and limitations for clinical and research use. The article concludes with a detailed discussion of how the field of quantitative MRI has progressed to provide information regarding two specific patient populations through clinical research-patients with anterior cruciate ligament rupture and patients with impingement in the hip. While quantitative imaging techniques continue to rapidly evolve, specific challenges for each technique as well as challenges to clinical applications remain.
Collapse
|
86
|
Sharma B, Fermanian S, Gibson M, Unterman S, Herzka DA, Cascio B, Coburn J, Hui AY, Marcus N, Gold GE, Elisseeff JH. Human cartilage repair with a photoreactive adhesive-hydrogel composite. Sci Transl Med 2013; 5:167ra6. [PMID: 23303605 DOI: 10.1126/scitranslmed.3004838] [Citation(s) in RCA: 229] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Surgical options for cartilage resurfacing may be significantly improved by advances and application of biomaterials that direct tissue repair. A poly(ethylene glycol) diacrylate (PEGDA) hydrogel was designed to support cartilage matrix production, with easy surgical application. A model in vitro system demonstrated deposition of cartilage-specific extracellular matrix in the hydrogel biomaterial and stimulation of adjacent cartilage tissue development by mesenchymal stem cells. For translation to the joint environment, a chondroitin sulfate adhesive was applied to covalently bond and adhere the hydrogel to cartilage and bone tissue in articular defects. After preclinical testing in a caprine model, a pilot clinical study was initiated where the biomaterials system was combined with standard microfracture surgery in 15 patients with focal cartilage defects on the medial femoral condyle. Control patients were treated with microfracture alone. Magnetic resonance imaging showed that treated patients achieved significantly higher levels of tissue fill compared to controls. Magnetic resonance spin-spin relaxation times (T(2)) showed decreasing water content and increased tissue organization over time. Treated patients had less pain compared with controls, whereas knee function [International Knee Documentation Committee (IKDC)] scores increased to similar levels between the groups over the 6 months evaluated. No major adverse events were observed over the study period. With further clinical testing, this practical biomaterials strategy has the potential to improve the treatment of articular cartilage defects.
Collapse
Affiliation(s)
- Blanka Sharma
- Translational Tissue Engineering Center, Wilmer Eye Institute and the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
87
|
Braun HJ, Dragoo JL, Hargreaves BA, Levenston ME, Gold GE. Application of advanced magnetic resonance imaging techniques in evaluation of the lower extremity. Radiol Clin North Am 2013; 51:529-45. [PMID: 23622097 PMCID: PMC3639445 DOI: 10.1016/j.rcl.2012.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This article reviews current magnetic resonance imaging (MR imaging) techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MR imaging include imaging at 7 T, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphologic changes within articular cartilage, and imaging around orthopedic hardware.
Collapse
Affiliation(s)
- Hillary J. Braun
- Department of Radiology, Stanford University
- Department of Orthopaedic Surgery, Stanford University
| | | | - Brian A. Hargreaves
- Department of Radiology, Stanford University
- Department of Bioengineering, Stanford University
| | | | - Garry E. Gold
- Department of Radiology, Stanford University
- Department of Orthopaedic Surgery, Stanford University
- Department of Bioengineering, Stanford University
| |
Collapse
|
88
|
Pal S, Besier TF, Beaupre GS, Fredericson M, Delp SL, Gold GE. Patellar maltracking is prevalent among patellofemoral pain subjects with patella alta: an upright, weightbearing MRI study. J Orthop Res 2013; 31:448-57. [PMID: 23165335 PMCID: PMC3562698 DOI: 10.1002/jor.22256] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 10/05/2012] [Indexed: 02/04/2023]
Abstract
The purpose of this study is to determine if patellar maltracking is more prevalent among patellofemoral (PF) pain subjects with patella alta compared to subjects with normal patella height. We imaged 37 PF pain and 15 pain free subjects in an open-configuration magnetic resonance imaging scanner while they stood in a weightbearing posture. We measured patella height using the Caton-Deschamps, Blackburne-Peel, Insall-Salvati, Modified Insall-Salvati, and Patellotrochlear indices, and classified the subjects into patella alta and normal patella height groups. We measured patella tilt and bisect offset from oblique-axial plane images, and classified the subjects into maltracking and normal tracking groups. Patellar maltracking was more prevalent among PF pain subjects with patella alta compared to PF pain subjects with normal patella height (two-tailed Fisher's exact test, p<0.050). Using the Caton-Deschamps index, 67% (8/12) of PF pain subjects with patella alta were maltrackers, whereas only 16% (4/25) of PF pain subjects with normal patella height were maltrackers. Patellofemoral pain subjects classified as maltrackers displayed a greater patella height compared to the pain free and PF pain subjects classified as normal trackers (two-tailed unpaired t-tests with Bonferroni correction, p<0.017). This study adds to our understanding of PF pain in two ways-(1) we demonstrate that patellar maltracking is more prevalent in PF pain subjects with patella alta compared to subjects with normal patella height; and (2) we show greater patella height in PF pain subjects compared to pain free subjects using four indices commonly used in clinics.
Collapse
Affiliation(s)
- Saikat Pal
- Department of Bioengineering, Stanford University, Stanford, CA
| | - Thor F. Besier
- Auckland Bioengineering Institute, University of Auckland, New Zealand
| | - Gary S. Beaupre
- Bone & Joint Rehabilitation R&D Center, VA Palo Alto Health Care System, Palo Alto, CA,Mechanical Engineering Department, Stanford University, Stanford, CA
| | | | - Scott L. Delp
- Department of Bioengineering, Stanford University, Stanford, CA,Mechanical Engineering Department, Stanford University, Stanford, CA,Department of Orthopaedic Surgery, Stanford University, Stanford, CA
| | - Garry E. Gold
- Department of Bioengineering, Stanford University, Stanford, CA,Department of Orthopaedic Surgery, Stanford University, Stanford, CA,Department of Radiology, Stanford University, Stanford, CA
| |
Collapse
|
89
|
Abstract
Osteoarthritis (OA) is a chronic, debilitating joint disease characterized by degenerative changes to the bones, cartilage, menisci, ligaments, and synovial tissue. Imaging modalities such as radiography, magnetic resonance imaging (MRI), optical coherence tomography (OCT), and ultrasound (US) permit visualization of these structures and can evaluate disease onset and progression. Radiography is primarily useful for the assessment of bony structures, while OCT is used for evaluation of articular cartilage and US for ligaments and the synovium. MRI permits visualization of all intraarticular structures and pathologies, though US or OCT may be preferential in some circumstances. As OA is a disease of the whole joint, a combination of imaging techniques may be necessary in order to gain the most comprehensive picture of the disease state. This article is part of a Special Issue entitled "Osteoarthritis".
Collapse
|
90
|
Pal S, Besier TF, Draper CE, Fredericson M, Gold GE, Beaupre GS, Delp SL. Patellar tilt correlates with vastus lateralis: vastus medialis activation ratio in maltracking patellofemoral pain patients. J Orthop Res 2012; 30:927-33. [PMID: 22086708 PMCID: PMC3303943 DOI: 10.1002/jor.22008] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/27/2011] [Accepted: 10/17/2011] [Indexed: 02/04/2023]
Abstract
Patellofemoral (PF) pain is a common ailment of the lower extremity. A theorized cause for pain is patellar maltracking due to vasti muscle activation imbalance, represented as large vastus lateralis:vastus medialis (VL:VM) activation ratios. However, evidence relating vasti muscle activation imbalance to patellar maltracking is limited. The purpose of this study was to investigate the relationship between VL:VM activation ratio and patellar tracking measures, patellar tilt and bisect offset, in PF pain subjects and pain-free controls. We evaluated VL:VM activation ratio and VM activation delay relative to VL activation in 39 PF pain subjects and 15 pain-free controls during walking. We classified the PF pain subjects into normal tracking and maltracking groups based on patellar tilt and bisect offset measured from weight-bearing magnetic resonance imaging. Patellar tilt correlated with VL:VM activation ratio only in PF pain subjects classified as maltrackers. This suggests that a clinical intervention targeting vasti muscle activation imbalance may be effective only in PF pain subjects classified as maltrackers.
Collapse
Affiliation(s)
- Saikat Pal
- Department of Bioengineering, Stanford University, Stanford, CA
| | - Thor F. Besier
- Auckland Bioengineering Institute, University of Auckland, New Zealand
| | | | | | - Garry E. Gold
- Department of Bioengineering, Stanford University, Stanford, CA,Department of Radiology, Stanford University, Stanford, CA,Department of Orthopaedic Surgery, Stanford University, Stanford, CA
| | - Gary S. Beaupre
- Bone & Joint Rehabilitation R&D Center, VA Palo Alto Health Care System, Palo Alto, CA
| | - Scott L. Delp
- Department of Bioengineering, Stanford University, Stanford, CA,Department of Orthopaedic Surgery, Stanford University, Stanford, CA
| |
Collapse
|
91
|
Draper CE, Quon A, Fredericson M, Besier TF, Delp SL, Beaupre GS, Gold GE. Comparison of MRI and ¹⁸F-NaF PET/CT in patients with patellofemoral pain. J Magn Reson Imaging 2012; 36:928-32. [PMID: 22549985 DOI: 10.1002/jmri.23682] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 03/16/2012] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To determine whether bone metabolic activity corresponds to bone and cartilage damage in patients with patellofemoral pain. MATERIALS AND METHODS We acquired magnetic resonance imaging (MRI) and (18) F-NaF positron emission tomography (PET) / computed tomography (CT) scans of the knees of 22 subjects. We compared locations of increased tracer uptake on the (18) F-NaF PET images to bone marrow edema and cartilage damage visualized on MRI. RESULTS We found that increased bone activity on (18) F-NaF PET does not always correspond to structural damage in the bone or cartilage as seen on MRI. CONCLUSION Our results suggest that (18) F-NaF PET/CT may provide additional information in patellofemoral pain patients compared to MRI.
Collapse
|
92
|
Newbould RD, Miller SR, Toms LD, Swann P, Tielbeek JAW, Gold GE, Strachan RK, Taylor PC, Matthews PM, Brown AP. T2* measurement of the knee articular cartilage in osteoarthritis at 3T. J Magn Reson Imaging 2012; 35:1422-9. [PMID: 22314961 DOI: 10.1002/jmri.23598] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 12/28/2011] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To measure reproducibility, longitudinal and cross-sectional differences in T2* maps at 3 Tesla (T) in the articular cartilage of the knee in subjects with osteoarthritis (OA) and healthy matched controls. MATERIALS AND METHODS MRI data and standing radiographs were acquired from 33 subjects with OA and 21 healthy controls matched for age and gender. Reproducibility was determined by two sessions in the same day, while longitudinal and cross-sectional group differences used visits at baseline, 3 and 6 months. Each visit contained symptomological assessments and an MRI session consisting of high resolution three-dimensional double-echo-steady-state (DESS) and co-registered T2* maps of the most diseased knee. A blinded reader delineated the articular cartilage on the DESS images and median T2* values were reported. RESULTS T2* values showed an intra-visit reproducibility of 2.0% over the whole cartilage. No longitudinal effects were measured in either group over 6 months. T2* maps revealed a 5.8% longer T2* in the medial tibial cartilage and 7.6% and 6.5% shorter T2* in the patellar and lateral tibial cartilage, respectively, in OA subjects versus controls (P < 0.02). CONCLUSION T2* mapping is a repeatable process that showed differences between the OA subject and control groups.
Collapse
Affiliation(s)
- Rexford D Newbould
- GSK Clinical Imaging Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
93
|
Abstract
Conventional, static magnetic resonance imaging (MRI) is able to provide a vast amount of information regarding the anatomy and pathology of the musculoskeletal system. However, patients, especially those whose pain is position dependent or elucidated by movement, may benefit from more advanced imaging techniques that allow for the acquisition of functional information. This manuscript reviews a variety of advancements in MRI techniques that are used to image the musculoskeletal system dynamically, while in motion or under load. The methodologies, advantages and drawbacks of stress MRI, cine-phase contrast MRI and real-time MRI are discussed as each has helped to advance the field by providing a scientific basis for understanding normal and pathological musculoskeletal anatomy and function. Advancements in dynamic MR imaging will certainly lead to improvements in the understanding, prevention, diagnosis and treatment of musculoskeletal disorders. It is difficult to anticipate that dynamic MRI will replace conventional MRI, however, dynamic MRI may provide additional valuable information to findings of conventional MRI.
Collapse
Affiliation(s)
- Lauren M. Shapiro
- Department of Radiology, Grant Building Room S068B, Stanford, CA 94305
| | - Garry E. Gold
- Department of Radiology, Grant Building Room S068B, Stanford, CA 94305
- Department of Bioengineering, Grant Building Room S068B, Stanford, CA 94305
- Orthopaedic Surgery, Stanford University, Stanford, California, USA
| |
Collapse
|
94
|
Draper CE, Fredericson M, Gold GE, Besier TF, Delp SL, Beaupre GS, Quon A. Patients with patellofemoral pain exhibit elevated bone metabolic activity at the patellofemoral joint. J Orthop Res 2012; 30:209-13. [PMID: 21812024 PMCID: PMC3219799 DOI: 10.1002/jor.21523] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 07/14/2011] [Indexed: 02/04/2023]
Abstract
Patellofemoral pain is characterized by pain behind the kneecap and is often thought to be due to high stress at the patellofemoral joint. While we cannot measure bone stress in vivo, we can visualize bone metabolic activity using (18) F NaF PET/CT, which may be related to bone stress. Our goals were to use (18) F NaF PET/CT to evaluate whether subjects with patellofemoral pain exhibit elevated bone metabolic activity and to determine whether bone metabolic activity correlates with pain intensity. We examined 20 subjects diagnosed with patellofemoral pain. All subjects received an (18) F NaF PET/CT scan of their knees. Uptake of (18) F NaF in the patella and trochlea was quantified by computing the standardized uptake value and normalizing by the background tracer uptake in bone. We detected increased tracer uptake in 85% of the painful knees examined. We found that the painful knees exhibited increased tracer uptake compared to the pain-free knees of four subjects with unilateral pain (P = 0.0006). We also found a correlation between increasing tracer uptake and increasing pain intensity (r(2) = 0.55; P = 0.0005). The implication of these results is that patellofemoral pain may be related to bone metabolic activity at the patellofemoral joint.
Collapse
Affiliation(s)
| | | | - Garry E. Gold
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Thor F. Besier
- Department of Orthopedics, Stanford University, Stanford, CA, USA
| | - Scott L. Delp
- Department of Orthopedics, Stanford University, Stanford, CA, USA,Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Gary S. Beaupre
- Rehabilitation R&D Center, VA Palo Alto Health Care System, Palo Alto, CA, USA
| | - Andrew Quon
- Department of Radiology, Stanford University, Stanford, CA, USA
| |
Collapse
|
95
|
Staroswiecki E, Granlund KL, Alley MT, Gold GE, Hargreaves BA. Simultaneous estimation of T(2) and apparent diffusion coefficient in human articular cartilage in vivo with a modified three-dimensional double echo steady state (DESS) sequence at 3 T. Magn Reson Med 2011; 67:1086-96. [PMID: 22179942 DOI: 10.1002/mrm.23090] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/11/2011] [Accepted: 06/19/2011] [Indexed: 11/12/2022]
Abstract
T(2) mapping and diffusion-weighted imaging complement morphological imaging for assessing cartilage disease and injury. The double echo steady state sequence has been used for morphological imaging and generates two echoes with markedly different T(2) and diffusion weighting. Modifying the spoiler gradient area and flip angle of the double echo steady state sequence allows greater control of the diffusion weighting of both echoes. Data from two acquisitions with different spoiler gradient areas and flip angles are used to simultaneously estimate the T(2) and apparent diffusion coefficient of each voxel. This method is verified in phantoms and validated in vivo in the knee; estimates from different regions of interest in the phantoms and cartilage are compared to those obtained using standard spin-echo methods. The Pearson correlations were 0.984 for T(2) (∼2% relative difference between spin-echo and double echo steady state estimates) and 0.997 for apparent diffusion coefficient (˜1% relative difference between spin-echo and double echo steady state estimates) for the phantom study and 0.989 for T(2) and 0.987 for apparent diffusion coefficient in regions of interest in the human knee in vivo. High accuracy for simultaneous three-dimensional T(2) and apparent diffusion coefficient measurements are demonstrated, while also providing morphologic three-dimensional images without blurring or distortion in reasonable scan times.
Collapse
|
96
|
Jordan CD, Saranathan M, Bangerter NK, Hargreaves BA, Gold GE. Musculoskeletal MRI at 3.0 T and 7.0 T: a comparison of relaxation times and image contrast. Eur J Radiol 2011; 82:734-9. [PMID: 22172536 DOI: 10.1016/j.ejrad.2011.09.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 09/19/2011] [Indexed: 10/14/2022]
Abstract
OBJECTIVE The purpose of this study was to measure and compare the relaxation times of musculoskeletal tissues at 3.0 T and 7.0 T, and to use these measurements to select appropriate parameters for musculoskeletal protocols at 7.0 T. MATERIALS AND METHODS We measured the T₁ and T₂ relaxation times of cartilage, muscle, synovial fluid, bone marrow and subcutaneous fat at both 3.0 T and 7.0 T in the knees of five healthy volunteers. The T₁ relaxation times were measured using a spin-echo inversion recovery sequence with six inversion times. The T₂ relaxation times were measured using a spin-echo sequence with seven echo times. The accuracy of both the T₁ and T₂ measurement techniques was verified in phantoms at both magnetic field strengths. We used the measured relaxation times to help design 7.0 T musculoskeletal protocols that preserve the favorable contrast characteristics of our 3.0 T protocols, while achieving significantly higher resolution at higher SNR efficiency. RESULTS The T₁ relaxation times in all tissues at 7.0 T were consistently higher than those measured at 3.0 T, while the T₂ relaxation times at 7.0 T were consistently lower than those measured at 3.0 T. The measured relaxation times were used to help develop high resolution 7.0 T protocols that had similar fluid-to-cartilage contrast to that of the standard clinical 3.0 T protocols for the following sequences: proton-density-weighted fast spin-echo (FSE), T₂-weighted FSE, and 3D-FSE-Cube. CONCLUSION The T₁ and T₂ changes were within the expected ranges. Parameters for musculoskeletal protocols at 7.0 T can be optimized based on these values, yielding improved resolution in musculoskeletal imaging with similar contrast to that of standard 3.0 T clinical protocols.
Collapse
Affiliation(s)
- Caroline D Jordan
- Department of Radiology, The Richard M. Lucas Center for Imaging, Stanford University, Stanford, CA 94305-5488, United States.
| | | | | | | | | |
Collapse
|
97
|
Quist B, Hargreaves BA, Cukur T, Morrell GR, Gold GE, Bangerter NK. Simultaneous fat suppression and band reduction with large-angle multiple-acquisition balanced steady-state free precession. Magn Reson Med 2011; 67:1004-12. [PMID: 22038883 DOI: 10.1002/mrm.23076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 05/01/2011] [Accepted: 06/08/2011] [Indexed: 01/13/2023]
Abstract
Balanced steady-state free precession (bSSFP) MRI is a rapid and signal-to-noise ratio-efficient imaging method, but suffers from characteristic bands of signal loss in regions of large field inhomogeneity. Several methods have been developed to reduce the severity of these banding artifacts, typically involving the acquisition of multiple bSSFP datasets (and the accompanying increase in scan time). Fat suppression with bSSFP is also challenging; most existing methods require an additional increase in scan time, and some are incompatible with bSSFP band-reduction techniques. This work was motivated by the need for both robust fat suppression and band reduction in the presence of field inhomogeneity when using bSSFP for flow-independent peripheral angiography. The large flip angles used in this application to improve vessel conspicuity and contrast lead to specific absorption rate considerations, longer repetition times, and increased severity of banding artifacts. In this work, a novel method that simultaneously suppresses fat and reduces bSSFP banding artifact with the acquisition of only two phase-cycled bSSFP datasets is presented. A weighted sum of the two bSSFP acquisitions is taken on a voxel-by-voxel basis, effectively synthesizing an off-resonance profile at each voxel that puts fat in the stop band while keeping water in the pass band. The technique exploits the near-sinusoidal shape of the bSSFP off-resonance spectrum for many tissues at large (>50°) flip angles.
Collapse
Affiliation(s)
- Brady Quist
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
| | | | | | | | | | | |
Collapse
|
98
|
Chen CA, Chen W, Goodman SB, Hargreaves BA, Koch KM, Lu W, Brau AC, Draper CE, Delp SL, Gold GE. New MR imaging methods for metallic implants in the knee: artifact correction and clinical impact. J Magn Reson Imaging 2011; 33:1121-7. [PMID: 21509870 DOI: 10.1002/jmri.22534] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To evaluate two magnetic resonance imaging (MRI) techniques, slice encoding for metal artifact correction (SEMAC) and multiacquisition variable-resonance image combination (MAVRIC), for their ability to correct for artifacts in postoperative knees with metal. MATERIALS AND METHODS A total of 25 knees were imaged in this study. Fourteen total knee replacements (TKRs) in volunteers were scanned with SEMAC, MAVRIC, and 2D fast spin-echo (FSE) to measure artifact extent and implant rotation. The ability of the sequences to measure implant rotation and dimensions was compared in a TKR knee model. Eleven patients with a variety of metallic hardware were imaged with SEMAC and FSE to compare artifact extent and subsequent patient management was recorded. RESULTS SEMAC and MAVRIC significantly reduced artifact extent compared to FSE (P < 0.0001) and were similar to each other (P = 0.58), allowing accurate measurement of implant dimensions and rotation. The TKRs were properly aligned in the volunteers. Clinical imaging with SEMAC in symptomatic knees significantly reduced artifact (P < 0.05) and showed findings that were on the majority confirmed by subsequent noninvasive or invasive patient studies. CONCLUSION SEMAC and MAVRIC correct for metal artifact, noninvasively providing high-resolution images with superb bone and soft tissue contrast.
Collapse
Affiliation(s)
- Christina A Chen
- Department of Radiology, Stanford University, Stanford, California, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
99
|
Abstract
Musculoskeletal MRI is advancing rapidly, with innovative technology and significant potential for immediate clinical impact. In particular, cartilage imaging has become a topic of increasing interest as our aging population develops diseases such as osteoarthritis. Advances in MRI hardware and software have led to increased image quality and tissue contrast. Additional developments have allowed the assessment of cartilage macromolecular content, which may be crucial to the early detection of musculoskeletal diseases. This comprehensive article considers current morphological and physiological cartilage imaging techniques, their clinical applications, and their potential to contribute to future improvements in the imaging of cartilage.
Collapse
|
100
|
Stevens KJ, Wallace CG, Chen W, Rosenberg JK, Gold GE. Imaging of the wrist at 1.5 Tesla using isotropic three-dimensional fast spin echo cube. J Magn Reson Imaging 2011; 33:908-15. [PMID: 21448957 DOI: 10.1002/jmri.22494] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To compare three-dimensional fast spin echo Cube (3D-FSE-Cube) with conventional 2D-FSE in MR imaging of the wrist. MATERIALS AND METHODS The wrists of 10 volunteers were imaged in a 1.5 Tesla MRI scanner using an eight-channel wrist coil. The 3D-FSE-Cube images were acquired in the coronal plane with 0.5-mm isotropic resolution. The 2D-FSE images were acquired in both coronal and axial planes for comparison. An ROI was placed in fluid, cartilage, and muscle for SNR analysis. Comparable coronal and axial images were selected for each sequence, and paired images were randomized and graded for blurring, artifact, anatomic details, and overall image quality by three blinded musculoskeletal radiologists. RESULTS SNR of fluid, cartilage and muscle at prescribed locations were higher using 3D-FSE-Cube, without reaching statistical significance. Fluid-cartilage CNR was also higher with 3D-FSE-Cube, but not statistically significant. Blurring, artifact, anatomic details, and overall image quality were significantly better on coronal 3D-FSE-Cube images (P < 0.001), but significantly better on axial 2D-FSE images compared with axial 3D-FSE-Cube reformats (P < 0.01). CONCLUSION Isotropic data from 3D-FSE-Cube allows reformations in arbitrary scan planes, which may make multiple 2D acquisitions unnecessary, and improve depiction of complex wrist anatomy. However, axial reformations suffer from blurring, likely due to T2 decay during the long echo train, limiting overall image quality in this plane.
Collapse
|