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Raya JG, Duarte A, Wang N, Mazzoli V, Jaramillo D, Blamire AM, Dietrich O. Applications of Diffusion-Weighted MRI to the Musculoskeletal System. J Magn Reson Imaging 2024; 59:376-396. [PMID: 37477576 DOI: 10.1002/jmri.28870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 02/22/2023] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 07/22/2023] Open
Abstract
Diffusion-weighted imaging (DWI) is an established MRI technique that can investigate tissue microstructure at the scale of a few micrometers. Musculoskeletal tissues typically have a highly ordered structure to fulfill their functions and therefore represent an optimal application of DWI. Even more since disruption of tissue organization affects its biomechanical properties and may indicate irreversible damage. The application of DWI to the musculoskeletal system faces application-specific challenges on data acquisition including susceptibility effects, the low T2 relaxation time of most musculoskeletal tissues (2-70 msec) and the need for sub-millimetric resolution. Thus, musculoskeletal applications have been an area of development of new DWI methods. In this review, we provide an overview of the technical aspects of DWI acquisition including diffusion-weighting, MRI pulse sequences and different diffusion regimes to study tissue microstructure. For each tissue type (growth plate, articular cartilage, muscle, bone marrow, intervertebral discs, ligaments, tendons, menisci, and synovium), the rationale for the use of DWI and clinical studies in support of its use as a biomarker are presented. The review describes studies showing that DTI of the growth plate has predictive value for child growth and that DTI of articular cartilage has potential to predict the radiographic progression of joint damage in early stages of osteoarthritis. DTI has been used extensively in skeletal muscle where it has shown potential to detect microstructural and functional changes in a wide range of muscle pathologies. DWI of bone marrow showed to be a valuable tool for the diagnosis of benign and malignant acute vertebral fractures and bone metastases. DTI and diffusion kurtosis have been investigated as markers of early intervertebral disc degeneration and lower back pain. Finally, promising new applications of DTI to anterior cruciate ligament grafts and synovium are presented. The review ends with an overview of the use of DWI in clinical routine. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.
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Affiliation(s)
- José G Raya
- Department of Radiology, NYU Langone Health, New York, New York, USA
| | - Alejandra Duarte
- Division of Musculoskeletal Radiology, Department of Radiology, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - Nian Wang
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
| | - Valentina Mazzoli
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Diego Jaramillo
- Department of Radiology, Columbia University Medical Center, New York, New York, USA
| | - Andrew M Blamire
- Magnetic Resonance Centre, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Olaf Dietrich
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
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2
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He J, Blazeski A, Nilanthi U, Menéndez J, Pirani SC, Levic DS, Bagnat M, Singh MK, Raya JG, García-Cardeña G, Torres-Vázquez J. Plxnd1-mediated mechanosensing of blood flow controls the caliber of the Dorsal Aorta via the transcription factor Klf2. bioRxiv 2024:2024.01.24.576555. [PMID: 38328196 PMCID: PMC10849625 DOI: 10.1101/2024.01.24.576555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The cardiovascular system generates and responds to mechanical forces. The heartbeat pumps blood through a network of vascular tubes, which adjust their caliber in response to the hemodynamic environment. However, how endothelial cells in the developing vascular system integrate inputs from circulatory forces into signaling pathways to define vessel caliber is poorly understood. Using vertebrate embryos and in vitro-assembled microvascular networks of human endothelial cells as models, flow and genetic manipulations, and custom software, we reveal that Plexin-D1, an endothelial Semaphorin receptor critical for angiogenic guidance, employs its mechanosensing activity to serve as a crucial positive regulator of the Dorsal Aorta's (DA) caliber. We also uncover that the flow-responsive transcription factor KLF2 acts as a paramount mechanosensitive effector of Plexin-D1 that enlarges endothelial cells to widen the vessel. These findings illuminate the molecular and cellular mechanisms orchestrating the interplay between cardiovascular development and hemodynamic forces.
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Affiliation(s)
- Jia He
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Adriana Blazeski
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA and Harvard Medical School, Boston, MA, USA
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Uthayanan Nilanthi
- Programme in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857
| | - Javier Menéndez
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Samuel C. Pirani
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Daniel S. Levic
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Michel Bagnat
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Manvendra K. Singh
- Programme in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857
- National Heart Research Institute Singapore, National Heart Centre Singapore, 5 Hospital Drive, Singapore, 169609
| | - José G Raya
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Guillermo García-Cardeña
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA and Harvard Medical School, Boston, MA, USA
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jesús Torres-Vázquez
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
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3
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Ruiz A, Adler RS, Raya JG. Reply to Aytekin et al.: Comment on "Accuracy of Ultrasound-Guided versus Landmark-Guided Intra-articular Injection for Rat Knee Joints". Ultrasound Med Biol 2022; 48:1164. [PMID: 35287995 DOI: 10.1016/j.ultrasmedbio.2022.02.004] [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] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Amparo Ruiz
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, New York, New York, USA.
| | - Ronald S Adler
- Division of Musculoskeletal Radiology, Department of Radiology, New York University Langone Health, New York, New York, USA
| | - José G Raya
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, New York, New York, USA
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4
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Jaramillo D, Duong P, Nguyen JC, Mostoufi-Moab S, Nguyen MK, Moreau A, Barrera CA, Hong S, Raya JG. Diffusion Tensor Imaging of the Knee to Predict Childhood Growth. Radiology 2022; 303:655-663. [PMID: 35315716 PMCID: PMC9131176 DOI: 10.1148/radiol.210484] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 12/15/2021] [Accepted: 01/19/2022] [Indexed: 01/16/2023]
Abstract
Background Accurate and precise methods to predict growth remain lacking. Diffusion tensor imaging (DTI) depicts the columnar structure of the physis and metaphyseal spongiosa and provides measures of tract volume and length that may help predict growth. Purpose To validate physeal DTI metrics as predictors of height velocity (1-year height gain from time of MRI examination) and total height gain (height gain from time of MRI examination until growth stops) and compare the prediction accuracy with bone age-based models. Materials and Methods Femoral DTI studies (b values = 0 and 600 sec/mm2; directions = 20) of healthy children who underwent MRI of the knee between February 2012 and December 2016 were retrospectively analyzed. Children with height measured at MRI and either 1 year later (height velocity) or after growth cessation (total height gain, mean = 34 months from MRI) were included. Physeal DTI tract volume and length were correlated with height velocity and total height gain. Multilinear regression was used to assess the potential of DTI metrics in the prediction of both parameters. Bland-Altman plots were used to compare root mean square error (RMSE) and bias in height prediction using DTI versus bone age methods. Results Eighty-nine children (mean age, 13 years ± 3 [SD]; 47 boys) had height velocity measured, and 70 (mean age, 14 years ± 1; 36 girls) had total height gain measured. Tract volumes correlated with height velocity (r2 = 0.49) and total height gain (r2 = 0.46) (P < .001 for both) after controlling for age and sex. Tract volume was the strongest predictor for height velocity and total height gain. An optimal multilinear model including tract volume improved prediction of height velocity (R2 = 0.63, RMSE = 1.7 cm) and total height gain (R2 = 0.59, RMSE = 1.8 cm) compared with bone age-based methods (height velocity: R2 = 0.32, RMSE = 2.9 cm; total height gain: R2 = 0.42, RMSE = 5.0 cm). Conclusion Models using tract volume derived from diffusion tensor imaging may perform better than bone age-based models in children for the prediction of height velocity and total height gain. © RSNA, 2022.
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Affiliation(s)
- Diego Jaramillo
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Phuong Duong
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Jie C. Nguyen
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Sogol Mostoufi-Moab
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Michael K. Nguyen
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Andrew Moreau
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Christian A. Barrera
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - Shijie Hong
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
| | - José G. Raya
- From the Department of Radiology, Columbia University Medical Center,
630 W 168th St, MC 28, New York, NY 10032 (D.J., P.D.); Department of Radiology
(J.C.N., M.K.N., S.H.) and Division of Oncology (S.M.M., A.M.),
Children’s Hospital of Philadelphia, Philadelphia, Pa; Department of
Radiology, Massachusetts General Hospital, Boston, Mass (C.A.B.); and Department
of Radiology, NYU Grossman School of Medicine, New York, NY (J.G.R.)
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Ruiz A, Duarte A, Bravo D, Ramos E, Zhang C, Cowman MK, Kirsch T, Milne M, Luyt LG, Raya JG. In vivo multimodal imaging of hyaluronan-mediated inflammatory response in articular cartilage. Osteoarthritis Cartilage 2022; 30:329-340. [PMID: 34774790 PMCID: PMC8792232 DOI: 10.1016/j.joca.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 02/19/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVE One driving factor in the progression to posttraumatic osteoarthritis (PTOA) is the perpetuation of the inflammatory response to injury into chronic inflammation. Molecular imaging offers many opportunities to complement the sensitivity of current imaging modalities with molecular specificity. The goal of this study was to develop and characterize agents to image hyaluronan (HA)-mediated inflammatory signaling. DESIGN We developed optical (Cy5.5-P15-1) and magnetic resonance contrast agents (Gd-DOTA-P15-1) based in a hyaluronan-binding peptide (P15-1) that has shown anti-inflammatory effects on human chondrocytes, and validated them in vitro and in vivo in two animal models of PTOA. RESULTS In vitro studies with a near infrared (NIR) Cy5.5-P15-1 imaging agent showed a fast and stable localization of Cy5.5-P15-1 on chondrocytes, but not in synovial cells. In vivo NIR showed significantly higher retention of imaging agent in PTOA knees between 12 and 72 h (n = 8, Cohen's d > 2 after 24 h). NIR fluorescence accumulation correlated with histologic severity in cartilage and meniscus (ρ between 0.37 and 0.57, P < 0.001). By using in vivo magnetic resonance imaging with a Gd-DOTA-P15-1 contrast agent in 12 rats, we detected a significant decrease of T1 on injured knees in all cartilage plates at 48 h (-15%, 95%-confidence interval (CI) = [-18%,-11%]) while no change was observed in the controls (-2%, 95%-CI = [-5%,+1%]). CONCLUSIONS This study provides the first in vivo evidence that hyaluronan-related inflammatory response in cartilage after injury is a common finding. Beyond P15-1, we have demonstrated that molecular imaging can provide a versatile technology to investigate and phenotype PTOA pathogenesis, as well as study therapeutic interventions.
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Affiliation(s)
- Amparo Ruiz
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.,Tech4Health Institute, New York University Langone Health, New York, NY, USA
| | - Alejandra Duarte
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Dalibel Bravo
- Musculoskeletal Research Center, Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA
| | - Elisa Ramos
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Chongda Zhang
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Mary K. Cowman
- Musculoskeletal Research Center, Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA.,Department of Biomedical Engineering, New York University Tandon School of Engineering, New York, NY, USA
| | - Thorsten Kirsch
- Musculoskeletal Research Center, Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA.,Department of Biomedical Engineering, New York University Tandon School of Engineering, New York, NY, USA
| | - Mark Milne
- The University of Western Ontario, London, ON, Canada.,London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada
| | - Leonard G. Luyt
- The University of Western Ontario, London, ON, Canada.,London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada
| | - José G. Raya
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.,Tech4Health Institute, New York University Langone Health, New York, NY, USA
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Ben-Eliezer N, Raya JG, Babb JS, Youm T, Sodickson DK, Lattanzi R. A New Method for Cartilage Evaluation in Femoroacetabular Impingement Using Quantitative T2 Magnetic Resonance Imaging: Preliminary Validation against Arthroscopic Findings. Cartilage 2021; 13:1315S-1323S. [PMID: 31455091 PMCID: PMC8808928 DOI: 10.1177/1947603519870852] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 12/19/2022] Open
Abstract
OBJECTIVE The outcome of arthroscopic treatment for femoroacetabular impingement (FAI) depends on the preoperative status of the hip cartilage. Quantitative T2 can detect early biochemical cartilage changes, but its routine implementation is challenging. Furthermore, intrinsic T2 variability between patients makes it difficult to define a threshold to identify cartilage lesions. To address this, we propose a normalized T2-index as a new method to evaluate cartilage in FAI. DESIGN We retrospectively analyzed magnetic resonance imaging (MRI) data of 18 FAI patients with arthroscopically confirmed cartilage defects. Cartilage T2 maps were reconstructed from multi-spin-echo 3-T data using the echo-modulation-curve (EMC) model-based technique. The central femoral cartilage, assumed healthy in early-stage FAI, was used as the normalization reference to define a T2-index. We investigated the ability of the T2-index to detect surgically confirmed cartilage lesions. RESULTS The average T2-index was 1.14 ± 0.1 and 1.13 ± 0.1 for 2 separated segmentations. Using T2-index >1 as the threshold for damaged cartilage, accuracy was 88% and 100% for the 2 segmentations. We found moderate intraobserver repeatability, although separate segmentations yielded comparable accuracy. Damaged cartilage could not be identified using nonnormalized average T2 values. CONCLUSIONS This preliminary study confirms the importance of normalizing T2 values to account for interpatient variability and suggests that the T2-index is a promising biomarker for the detection of cartilage lesions in FAI. Future work is needed to confirm that combining T2-index with morphologic MRI and other quantitative biomarkers could improve cartilage assessment in FAI.
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Affiliation(s)
- Noam Ben-Eliezer
- Center for Advanced Imaging Innovation
and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging,
Department of Radiology, New York University School of Medicine, New York, NY,
USA
| | - José G. Raya
- Center for Advanced Imaging Innovation
and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging,
Department of Radiology, New York University School of Medicine, New York, NY,
USA,The Sackler Institute of Graduate
Biomedical Sciences, New York University School of Medicine, New York, NY, USA
| | - James S. Babb
- Center for Advanced Imaging Innovation
and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging,
Department of Radiology, New York University School of Medicine, New York, NY,
USA
| | - Thomas Youm
- Department of Orthopedic Surgery, New
York University Hospital for Joint Diseases, New York, NY, USA
| | - Daniel K. Sodickson
- Center for Advanced Imaging Innovation
and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging,
Department of Radiology, New York University School of Medicine, New York, NY,
USA,The Sackler Institute of Graduate
Biomedical Sciences, New York University School of Medicine, New York, NY, USA
| | - Riccardo Lattanzi
- Center for Advanced Imaging Innovation
and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging,
Department of Radiology, New York University School of Medicine, New York, NY,
USA,The Sackler Institute of Graduate
Biomedical Sciences, New York University School of Medicine, New York, NY, USA,Riccardo Lattanzi, The Bernard and Irene
Schwartz Center for Biomedical Imaging, New York University Langone Health, 660
First Avenue Room 203, New York, NY 10016, USA.
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7
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Duong P, Mostoufi-Moab S, Raya JG, Jaimes C, Delgado J, Jaramillo D. Imaging Biomarkers of the Physis: Cartilage Volume on MRI vs. Tract Volume and Length on Diffusion Tensor Imaging. J Magn Reson Imaging 2020; 52:544-551. [PMID: 32039525 DOI: 10.1002/jmri.27076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 11/23/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Current methods to predict height and growth failure are imprecise. MRI measures of physeal cartilage are promising biomarkers for growth. PURPOSE In the physis, to assess how 3D MRI volume measurements, and diffusion tensor imaging (DTI) measurements (tract volume and length) correlate with growth parameters and detect differences in growth. We compared patients exposed to cis-retinoic acid, which causes physeal damage and growth failure, with normal subjects. STUDY TYPE Case-control. POPULATION Twenty pediatric neuroblastoma survivors treated with cis-retinoic acid and 20 age- and sex-matched controls. FIELD STRENGTH/SEQUENCE 3T; DTI and 3D double-echo steady-state (DESS) sequences. ASSESSMENT On distal femoral MR studies, physeal 3D volume and DTI tract measurements were calculated and compared to height. STATISTICAL TESTS We used partial Spearman correlation, analysis of covariance, logistic regression, Wald test, and the intraclass correlation coefficient (ICC). RESULTS The height percentile correlated most strongly with DTI tract volumes (r = 0.74), followed by mean tract length (r = 0.53) and 3D volume (r = 0.40) (all P < 0.02). Only tract volumes and lengths correlated with annualized growth velocity. Relative to controls, patients showed smaller tract volumes (8.00 cc vs. 13.71 cc, P < 0.01), shorter tract lengths (5.92 mm vs 6.99 mm, P = 0.03), and smaller ratios of 3D cartilage volume to tract length; but no difference (4.51 cc vs 4.85 cc) in 3D MRI volumes. The 10 patients with the lowest height percentiles had smaller tract volumes (5.07 cc vs. 10.93 cc, P < 0.01), but not significantly different 3D MRI volumes. Tract volume is associated with abnormal growth, with an accuracy of 75%. DATA CONCLUSION DTI tract volume of the physis/metaphysis predicts abnormal growth better than physeal cartilage volumetric measurement and correlates best with height percentile and growth velocity. EVIDENCE LEVEL 2 TECHNICAL EFFICACY: Stage 2 J. Magn. Reson. Imaging 2020;52:544-551.
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Affiliation(s)
- Phuong Duong
- Department of Radiology, Columbia University Medical Center, New York, New York, USA
| | - Sogol Mostoufi-Moab
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - José G Raya
- Department of Radiology, NYU Langone Medical Center, New York, New York, USA
| | - Camilo Jaimes
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Jorge Delgado
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Diego Jaramillo
- Department of Radiology, Columbia University Medical Center, New York, New York, USA
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8
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Ruiz A, Bravo D, Duarte A, Adler RS, Raya JG. Accuracy of Ultrasound-Guided versus Landmark-Guided Intra-articular Injection for Rat Knee Joints. Ultrasound Med Biol 2019; 45:2787-2796. [PMID: 31327492 PMCID: PMC6718332 DOI: 10.1016/j.ultrasmedbio.2019.06.403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 02/11/2019] [Revised: 05/15/2019] [Accepted: 06/10/2019] [Indexed: 06/10/2023]
Abstract
Our aim was to test the effectiveness of ultrasound-guided intra-articular (IA) injection into the knee joint of rodents by an inexperienced operator compared with standard landmark-guided IA injections by a trained injector. Fifty landmark-guided and 46 ultrasound-guided IA injections in 49 rats were analyzed. Animal positioning and injection protocol were designed for use with the ultrasound system. Injection delivery was verified with a secondary imaging modality. We compared the success of IA injections by method (landmark and ultrasound-guided), adjusting for all other confounding factors (age, weight, experience, laterality and presence of surgery). Ultrasound-guided injections had higher success rates overall (89% vs. 58%) and helped to reduce the number of failed attempts per injection. None of the cofounding factors influenced the success of injection. In conclusion, we found higher accuracy for ultrasound-guided IA injection delivery than the traditional landmark-based injection method and also the technical feasibility for untrained personnel.
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Affiliation(s)
- Amparo Ruiz
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, New York, NY, USA.
| | - Dalibel Bravo
- Department of Orthopedic Surgery, New York University School of Medicine, New York, NY, USA
| | - Alejandra Duarte
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, New York, NY, USA
| | - Ronald S Adler
- Division of Musculoskeletal Radiology, Department of Radiology, New York University Langone Health, New York, NY, USA
| | - José G Raya
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, New York, NY, USA
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9
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Duarte A, Ruiz A, Ferizi U, Bencardino J, Abramson SB, Samuels J, Krasnokutsky-Samuels S, Raya JG. Diffusion tensor imaging of articular cartilage using a navigated radial imaging spin-echo diffusion (RAISED) sequence. Eur Radiol 2018; 29:2598-2607. [PMID: 30382348 DOI: 10.1007/s00330-018-5780-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 05/16/2018] [Revised: 08/27/2018] [Accepted: 09/19/2018] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To validate a radial imaging spin-echo diffusion tensor (RAISED) sequence for high-resolution diffusion tensor imaging (DTI) of articular cartilage at 3 T. METHODS The RAISED sequence implementation is described, including the used non-linear motion correction algorithm. The robustness to eddy currents was tested on phantoms, and accuracy of measurement was assessed with measurements of temperature-dependent diffusion of free water. Motion correction was validated by comparing RAISED with single-shot diffusion-weighted echo-planar imaging (EPI) measures. DTI was acquired in asymptomatic subjects (n = 6) and subjects with doubtful (Kellgren-Lawrence [KL] grade 1, n = 9) and mild (KL = 2, n = 9) symptomatic knee osteoarthritis (OA). MD and FA values without correction, and after all corrections, were calculated. A test-retest evaluation of the DTI acquisition on three asymptomatic and three OA subjects was also performed. RESULTS The root mean squared coefficient of variation of the global test-restest reproducibility was 3.54% for MD and 5.34% for FA. MD was significantly increased in both femoral condyles (7-9%) of KL 1 and in the medial (11-17%) and lateral (10-12%) compartments of KL 2 subjects. Averaged FA presented a trend of lower values with increasing KL grade, which was significant for the medial femoral condyle (-11%) of KL 1 and all three compartments in KL 2 subjects (-18 to -11%). Group differences in MD and FA were only significant after motion correction. CONCLUSION The RAISED sequence with the proposed reconstruction framework provides reproducible assessment of DTI parameters in vivo at 3 T and potentially the early stages of the disease in large regions of interest. KEY POINTS • DTI of articular cartilage is feasible at 3T with a multi-shot RAISED sequence with non-linear motion correction. • RAISED sequence allows estimation of the diffusion indices MD and FA with test-retest errors below 4% (MD) and 6% (FA). • RAISED-based measurement of DTI of articular cartilage with non-linear motion correction holds potential to differentiate healthy from OA subjects.
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Affiliation(s)
- Alejandra Duarte
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, 660 First avenue, 4th Floor, New York, NY, 10016, USA
| | - Amparo Ruiz
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, 660 First avenue, 4th Floor, New York, NY, 10016, USA
| | - Uran Ferizi
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, 660 First avenue, 4th Floor, New York, NY, 10016, USA
| | - Jenny Bencardino
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, 660 First avenue, 4th Floor, New York, NY, 10016, USA
| | - Steven B Abramson
- Division of Rheumatology, Department of Medicine, New York University Langone Health, New York, NY, USA
| | - Jonathan Samuels
- Division of Rheumatology, Department of Medicine, New York University Langone Health, New York, NY, USA
| | | | - José G Raya
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Health, 660 First avenue, 4th Floor, New York, NY, 10016, USA.
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Ferizi U, Scherrer B, Schneider T, Alipoor M, Eufracio O, Fick RH, Deriche R, Nilsson M, Loya‐Olivas AK, Rivera M, Poot DH, Ramirez‐Manzanares A, Marroquin JL, Rokem A, Pötter C, Dougherty RF, Sakaie K, Wheeler‐Kingshott C, Warfield SK, Witzel T, Wald LL, Raya JG, Alexander DC. Diffusion MRI microstructure models with in vivo human brain Connectome data: results from a multi-group comparison. NMR Biomed 2017. [PMID: 28643354 PMCID: PMC5563694 DOI: 10.1002/nbm.3734] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A large number of mathematical models have been proposed to describe the measured signal in diffusion-weighted (DW) magnetic resonance imaging (MRI). However, model comparison to date focuses only on specific subclasses, e.g. compartment models or signal models, and little or no information is available in the literature on how performance varies among the different types of models. To address this deficiency, we organized the 'White Matter Modeling Challenge' during the International Symposium on Biomedical Imaging (ISBI) 2015 conference. This competition aimed to compare a range of different kinds of models in their ability to explain a large range of measurable in vivo DW human brain data. Specifically, we assessed the ability of models to predict the DW signal accurately for new diffusion gradients and b values. We did not evaluate the accuracy of estimated model parameters, as a ground truth is hard to obtain. We used the Connectome scanner at the Massachusetts General Hospital, using gradient strengths of up to 300 mT/m and a broad set of diffusion times. We focused on assessing the DW signal prediction in two regions: the genu in the corpus callosum, where the fibres are relatively straight and parallel, and the fornix, where the configuration of fibres is more complex. The challenge participants had access to three-quarters of the dataset and their models were ranked on their ability to predict the remaining unseen quarter of the data. The challenge provided a unique opportunity for a quantitative comparison of diverse methods from multiple groups worldwide. The comparison of the challenge entries reveals interesting trends that could potentially influence the next generation of diffusion-based quantitative MRI techniques. The first is that signal models do not necessarily outperform tissue models; in fact, of those tested, tissue models rank highest on average. The second is that assuming a non-Gaussian (rather than purely Gaussian) noise model provides little improvement in prediction of unseen data, although it is possible that this may still have a beneficial effect on estimated parameter values. The third is that preprocessing the training data, here by omitting signal outliers, and using signal-predicting strategies, such as bootstrapping or cross-validation, could benefit the model fitting. The analysis in this study provides a benchmark for other models and the data remain available to build up a more complete comparison in the future.
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Affiliation(s)
- Uran Ferizi
- Centre for Medical Image ComputingDepartment of Computer Science, University College LondonUK
- Department of RadiologyNew York University School of MedicineUSA
- Department of Neuroinflammation, Institute of NeurologyUniversity College LondonUK
| | - Benoit Scherrer
- Computational Radiology Laboratory, Boston Children's Hosp.Harvard UniversityUSA
| | - Torben Schneider
- Department of Neuroinflammation, Institute of NeurologyUniversity College LondonUK
- Philips HealthcareGuildfordSurreyUK
| | | | - Odin Eufracio
- Centro de Investigacion en Matematicas ACGuanajuatoMexico
| | | | - Rachid Deriche
- Athena Project‐TeamINRIA Sophia Antipolis ‐ MéditerranéeFrance
| | | | | | - Mariano Rivera
- Centro de Investigacion en Matematicas ACGuanajuatoMexico
| | - Dirk H.J. Poot
- Erasmus Medical Center and Delft University of Technologythe Netherlands
| | | | | | - Ariel Rokem
- eScience InstituteUniversity of WashingtonUSA
- Center for Cognitive and Neurobiological ImagingStanford UniversityUSA
| | - Christian Pötter
- Center for Cognitive and Neurobiological ImagingStanford UniversityUSA
| | | | - Ken Sakaie
- Imaging InstituteThe Cleveland ClinicClevelandUSA
| | | | - Simon K. Warfield
- Computational Radiology Laboratory, Boston Children's Hosp.Harvard UniversityUSA
| | - Thomas Witzel
- A.A. Martinos Center for Biomedical Imaging, MGHHarvard UniversityUSA
| | - Lawrence L. Wald
- A.A. Martinos Center for Biomedical Imaging, MGHHarvard UniversityUSA
| | - José G. Raya
- Department of RadiologyNew York University School of MedicineUSA
| | - Daniel C. Alexander
- Centre for Medical Image ComputingDepartment of Computer Science, University College LondonUK
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11
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Ferizi U, Rossi I, Lee Y, Lendhey M, Teplensky J, Kennedy OD, Kirsch T, Bencardino J, Raya JG. Diffusion tensor imaging of articular cartilage at 3T correlates with histology and biomechanics in a mechanical injury model. Magn Reson Med 2017; 78:69-78. [PMID: 27455389 PMCID: PMC9175493 DOI: 10.1002/mrm.26336] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/01/2016] [Accepted: 06/20/2016] [Indexed: 01/23/2024]
Abstract
PURPOSE We establish a mechanical injury model for articular cartilage to assess the sensitivity of diffusion tensor imaging (DTI) in detecting cartilage damage early in time. Mechanical injury provides a more realistic model of cartilage degradation compared with commonly used enzymatic degradation. METHODS Nine cartilage-on-bone samples were obtained from patients undergoing knee replacement. The 3 Tesla DTI (0.18 × 0.18 × 1 mm3 ) was performed before, 1 week, and 2 weeks after (zero, mild, and severe) injury, with a clinical radial spin-echo DTI (RAISED) sequence used in our hospital. We performed stress-relaxation tests and used a quasilinear-viscoelastic (QLV) model to characterize cartilage mechanical properties. Serial histology sections were dyed with Safranin-O and given an OARSI grade. We then correlated the changes in DTI parameters with the changes in QLV-parameters and OARSI grades. RESULTS After severe injury the mean diffusivity increased after 1 and 2 weeks, whereas the fractional anisotropy decreased after 2 weeks (P < 0.05). The QLV-parameters and OARSI grades of the severe injury group differed from the baseline with statistical significance. The changes in mean diffusivity across all the samples correlated with the changes in the OARSI grade (r = 0.72) and QLV-parameters (r = -0.75). CONCLUSION DTI is sensitive in tracking early changes after mechanical injury, and its changes correlate with changes in biomechanics and histology. Magn Reson Med 78:69-78, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Uran Ferizi
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ignacio Rossi
- Department of Radiology, New York University School of Medicine, New York, New York, USA
- Centro de Diagnostico Dr. Enrique Rossi, Buenos Aires, Argentina
| | - Youjin Lee
- Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA
| | - Matin Lendhey
- Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA
| | - Jason Teplensky
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Oran D Kennedy
- Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA
| | - Thorsten Kirsch
- Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA
| | - Jenny Bencardino
- Department of Radiology, New York University School of Medicine, New York, New York, USA
- Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA
| | - José G Raya
- Department of Radiology, New York University School of Medicine, New York, New York, USA
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12
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Ferizi U, Ruiz A, Rossi I, Bencardino J, Raya JG. A robust diffusion tensor model for clinical applications of MRI to cartilage. Magn Reson Med 2017; 79:1157-1164. [PMID: 28556394 DOI: 10.1002/mrm.26702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 10/17/2016] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 01/06/2023]
Abstract
PURPOSE Diffusion tensor imaging (DTI) of articular cartilage is a promising technique for the early diagnosis of osteoarthritis (OA). However, in vivo diffusion tensor (DT) measurements suffer from low signal-to-noise ratio (SNR) that can result in bias when estimating the six parameters of the full DT, thus reducing sensitivity. This study seeks to validate a simplified four-parameter DT model (zeppelin) for obtaining more robust and sensitive in vivo DTI biomarkers of cartilage. METHODS We use simulations in a substrate to mimic changes during OA; and analytic simulations of the DT drawn from a range of fractional anisotropies (FA) measured with high-quality DT data from ex vivo human cartilage. We also use in vivo data from the knees of a healthy subject and two OA patients with Kellgren-Lawrence (KL) grades 1 and 2. RESULTS For simulated in vivo cartilage SNR (∼25) and anisotropy levels, the estimated mean values of MD from the DT and zeppelin models were identical to the ground truth values. However, zeppelin's FA is more accurate in measuring water restriction. More specifically, the FA estimations of the DT model were additionally biased by between +2% and +48% with respect to zeppelin values. Additionally, both mean diffusivity (MD) and FA of the zeppelin had lower parameter variance compared to the full DT (F-test, P < 0.05). We observe the same trends from in vivo values of patient data. CONCLUSION The zeppelin is more robust than the full DT for cartilage diffusion anisotropy and SNR at levels typically encountered in clinical applications of articular cartilage. Magn Reson Med 79:1157-1164, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Uran Ferizi
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Amparo Ruiz
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ignacio Rossi
- Centro de Diagnostico Dr. Enrique Rossi, Buenos Aires, Argentina
| | - Jenny Bencardino
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - José G Raya
- Department of Radiology, New York University School of Medicine, New York, New York, USA
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13
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Krepkin K, Bruno M, Raya JG, Adler RS, Gyftopoulos S. Quantitative assessment of the supraspinatus tendon on MRI using T2/T2* mapping and shear-wave ultrasound elastography: a pilot study. Skeletal Radiol 2017; 46:191-199. [PMID: 27896400 DOI: 10.1007/s00256-016-2534-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [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: 07/19/2016] [Revised: 10/05/2016] [Accepted: 11/10/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether there is an association between T2/T2* mapping and supraspinatus tendon mechanical properties as assessed by shear-wave ultrasound elastography (SWE). MATERIALS AND METHODS This HIPAA-compliant prospective pilot study received approval from our hospital's institutional review board. Eight patients (3 males/5 females; age range 44-72 years) and nine shoulders underwent conventional shoulder MRI, T2/T2* mapping on a 3-T scanner, and SWE. Two musculoskeletal radiologists reviewed the MRI examinations in consensus for evidence of supraspinatus tendon pathology, with tear size measured for full-thickness tears. T2/T2* values and ultrasound shear-wave velocities (SWV) were calculated in three corresponding equidistant regions of interest (ROIs) within the insertional 1-2 cm of the supraspinatus tendon (medial, middle, lateral). Pearson correlation coefficients between T2/T2* values and SWV, as well as among T2, T2*, SWV and tear size, were calculated. RESULTS There was a significant negative correlation between T2* and SWV in the lateral ROI (r = -0.86, p = 0.013) and overall mean ROI (r = -0.90, p = 0.006). There was significant positive correlation between T2 and measures of tear size in the lateral and mean ROIs (r range 0.71-0.77, p range 0.016-0.034). There was significant negative correlation between SWV and tear size in the middle and mean ROIs (r range -0.79--0.68, p range 0.011-0.046). CONCLUSION Our pilot study demonstrated a potential relationship between T2* values and shear wave velocity values in the supraspinatus tendon, a finding that could lead to an improved, more quantitative evaluation of the rotator cuff tendons.
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Affiliation(s)
- Konstantin Krepkin
- Department of Radiology, NYU Langone Medical Center/Hospital for Joint Diseases, 301 E 17th Street, New York, NY, 10003, USA
| | - Mary Bruno
- Department of Radiology, NYU Langone Medical Center, Center for Biomedical Imaging, 660 First Avenue, New York, NY, 10016, USA
| | - José G Raya
- Department of Radiology, NYU Langone Medical Center, Center for Biomedical Imaging, 660 First Avenue, New York, NY, 10016, USA
| | - Ronald S Adler
- Department of Radiology, NYU Langone Medical Center/Hospital for Joint Diseases, 301 E 17th Street, New York, NY, 10003, USA
| | - Soterios Gyftopoulos
- Department of Radiology, NYU Langone Medical Center/Hospital for Joint Diseases, 301 E 17th Street, New York, NY, 10003, USA.
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14
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Ramme AJ, Lendhey M, Raya JG, Kirsch T, Kennedy OD. A novel rat model for subchondral microdamage in acute knee injury: a potential mechanism in post-traumatic osteoarthritis. Osteoarthritis Cartilage 2016; 24:1776-1785. [PMID: 27235904 DOI: 10.1016/j.joca.2016.05.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [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: 11/24/2015] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Subchondral microdamage may play an important role in post-traumatic osteoarthritis (PTOA) development following anterior cruciate ligament (ACL) rupture. It remains unknown whether this injury mechanism causes subchondral microdamage, or whether its repair occurs by targeted osteoclast-mediated remodeling. If so these events may represent a mechanism by which subchondral bone is involved in PTOA. Our objective was to test the hypothesis that subchondral microdamage occurs, and is co-localized with remodeling, in a novel rat model of ACL rupture. DESIGN We developed a novel non-invasive rat animal model for ACL rupture and subchondral microdamage generation. By inducing ACL rupture noninvasively rather than surgically, this more closely mimics the clinical injury. MicroCT, MRI and histological methods were used to measure microstructural changes, ligament damage, and cellular/matrix degeneration, respectively. RESULTS We reproducibly generated ACL rupture without damage to other soft joint tissues. Immediately after injury, increased microdamage was found in the postero-medial aspect of the tibia. Microstructural parameters showed increased resorption at 2 weeks, which returned to baseline. Dynamic histomorphometry showed increased calcein label uptake in the same region at 4 and 8 weeks. Chondrocyte death and protease activity in cartilage was also noted, however whether this was directly linked to subchondral changes is not yet known. Similarly, cartilage scoring showed degradation at 4 and 8 weeks post-injury. CONCLUSIONS This study shows that our novel model can be used to study subchondral microdamage after ACL-rupture, and its association with localized remodeling. Cartilage degeneration, on a similar time-scale to other models, is also a feature of this system.
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Affiliation(s)
- A J Ramme
- Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA.
| | - M Lendhey
- Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA.
| | - J G Raya
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - T Kirsch
- Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA.
| | - O D Kennedy
- Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, USA; Department of Mechanical and Aerospace Engineering, New York University Tandon School of Engineering, New York, NY, USA.
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15
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Raya JG. Techniques and applications of in vivo diffusion imaging of articular cartilage. J Magn Reson Imaging 2015. [DOI: 10.1002/jmri.24949] [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: 11/11/2022] Open
Affiliation(s)
- José G. Raya
- Department Radiology; New York University Langone Medical Center; New York New York USA
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16
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Raya JG. Techniques and applications of in vivo diffusion imaging of articular cartilage. J Magn Reson Imaging 2015; 41:1487-504. [PMID: 25865215 DOI: 10.1002/jmri.24767] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [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: 07/01/2014] [Accepted: 09/11/2014] [Indexed: 01/07/2023] Open
Abstract
Early in the process of osteoarthritis (OA) the composition (water, proteoglycan [PG], and collagen) and structure of articular cartilage is altered leading to changes in its mechanical properties. A technique that can assess the composition and structure of the cartilage in vivo can provide insight in the mechanical integrity of articular cartilage and become a powerful tool for the early diagnosis of OA. Diffusion tensor imaging (DTI) has been proposed as a biomarker for cartilage composition and structure. DTI is sensitive to the PG content through the mean diffusivity and to the collagen architecture through the fractional anisotropy. However, the acquisition of DTI of articular cartilage in vivo is challenging due to the short T2 of articular cartilage (∼40 ms at 3 Tesla) and the high resolution needed (0.5-0.7 mm in plane) to depict the cartilage anatomy. We describe the pulse sequences used for in vivo DTI of articular cartilage and discus general strategies for protocol optimization. We provide a comprehensive review of measurements of DTI of articular cartilage from ex vivo validation experiments to its recent clinical applications.
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Affiliation(s)
- José G Raya
- Department Radiology, New York University Langone Medical Center, New York, New York, USA
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17
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Knoll F, Raya JG, Halloran RO, Baete S, Sigmund E, Bammer R, Block T, Otazo R, Sodickson DK. A model-based reconstruction for undersampled radial spin-echo DTI with variational penalties on the diffusion tensor. NMR Biomed 2015; 28:353-66. [PMID: 25594167 PMCID: PMC4339452 DOI: 10.1002/nbm.3258] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [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: 05/09/2014] [Revised: 12/08/2014] [Accepted: 12/17/2014] [Indexed: 05/04/2023]
Abstract
Radial spin-echo diffusion imaging allows motion-robust imaging of tissues with very low T2 values like articular cartilage with high spatial resolution and signal-to-noise ratio (SNR). However, in vivo measurements are challenging, due to the significantly slower data acquisition speed of spin-echo sequences and the less efficient k-space coverage of radial sampling, which raises the demand for accelerated protocols by means of undersampling. This work introduces a new reconstruction approach for undersampled diffusion-tensor imaging (DTI). A model-based reconstruction implicitly exploits redundancies in the diffusion-weighted images by reducing the number of unknowns in the optimization problem and compressed sensing is performed directly in the target quantitative domain by imposing a total variation (TV) constraint on the elements of the diffusion tensor. Experiments were performed for an anisotropic phantom and the knee and brain of healthy volunteers (three and two volunteers, respectively). Evaluation of the new approach was conducted by comparing the results with reconstructions performed with gridding, combined parallel imaging and compressed sensing and a recently proposed model-based approach. The experiments demonstrated improvements in terms of reduction of noise and streaking artifacts in the quantitative parameter maps, as well as a reduction of angular dispersion of the primary eigenvector when using the proposed method, without introducing systematic errors into the maps. This may enable an essential reduction of the acquisition time in radial spin-echo diffusion-tensor imaging without degrading parameter quantification and/or SNR.
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Affiliation(s)
- Florian Knoll
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
- Correspondence to: Florian Knoll, PhD, New York University School of Medicine, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, Phone: 212-263-0335,
| | - José G Raya
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
| | - Rafael O Halloran
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Steven Baete
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
| | - Eric Sigmund
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
| | - Roland Bammer
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Tobias Block
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
| | - Ricardo Otazo
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
| | - Daniel K Sodickson
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA
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18
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Raya JG, Dettmann E, Notohamiprodjo M, Krasnokutsky S, Abramson S, Glaser C. Feasibility of in vivo diffusion tensor imaging of articular cartilage with coverage of all cartilage regions. Eur Radiol 2014; 24:1700-6. [PMID: 24816930 DOI: 10.1007/s00330-014-3155-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 03/04/2014] [Accepted: 03/18/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To investigate the value of diffusion tensor imaging (DTI) of articular cartilage to differentiate healthy from osteoarthritis (OA) subjects in all cartilage regions. METHODS DTI was acquired sagittally at 7 T in ten healthy and five OA (Kellgren-Lawrence grade 2) subjects with a line scan diffusion tensor sequence (LSDTI). Three healthy volunteers and two OA subjects were examined twice to assess the test-retest reproducibility. Averaged mean diffusivity (MD) and fractional anisotropy (FA) were calculated in each cartilage region (femoral trochlea, lateral and medial femoral condyles, patella, and lateral and medial tibia). RESULTS The test-retest reproducibility was 2.9% for MD and 5.6% for FA. Averaged MD was significantly increased (+20%, p < 0.05) in the OA subjects in the lateral femoral condyle, lateral tibia and the femoral trochlea compartments. Averaged FA presented a trend of lower values in the OA subjects (-12%), which was only significant for the lateral tibia. CONCLUSIONS In vivo DTI of articular cartilage with coverage of all cartilage regions using an LSDTI sequence is feasible, shows excellent reproducibility for MD and FA, and holds potential for the diagnosis of OA. KEY POINTS • DTI of articular cartilage is feasible at 7 T in all cartilage regions • DTI of articular cartilage can potentially differentiate healthy and OA subjects.
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Affiliation(s)
- José G Raya
- Department Radiology, New York University Langone Medical Center, 660 First Avenue, 4th Floor, 10016, New York, NY, USA,
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Notohamiprodjo M, Chandarana H, Mikheev A, Rusinek H, Grinstead J, Feiweier T, Raya JG, Lee VS, Sigmund EE. Combined intravoxel incoherent motion and diffusion tensor imaging of renal diffusion and flow anisotropy. Magn Reson Med 2014; 73:1526-32. [PMID: 24752998 DOI: 10.1002/mrm.25245] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [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: 07/22/2013] [Revised: 02/19/2014] [Accepted: 03/17/2014] [Indexed: 12/27/2022]
Abstract
PURPOSE We used a combined intravoxel incoherent motion-diffusion tensor imaging (IVIM-DTI) methodology to distinguish structural from flow effects on renal diffusion anisotropy. METHODS Eight volunteers were examined with IVIM-DTI at 3T with 20 diffusion directions and 10 b-values. Mean diffusivity (MD) and fractional anisotropy (FA) from DTI analysis were calculated for low (b ≤ 200 s/mm(2) ), high (b > 200 s/mm(2) ), and full b-value ranges. IVIM-parameters perfusion-fraction fP , pseudo-diffusivity Dp , and tissue-diffusivity Dt were first calculated independently on a voxelwise basis for all directions. After estimating a fixed isotropic fp from these data, global anisotropies of Dt and Dp in the cortex and medulla were determined in a constrained cylindrical description and visualized using polar plots and cosine scatterplots. RESULTS For all b-value ranges, medullary FA was significantly higher than that of the cortex. The corticomedullary difference was smaller for the high b-value range. Significantly higher fp and Dt were determined for the cortex and showed a significantly higher directional variance in the medulla. Polar plot analysis displayed nearly isotropic Dp and Dt in the cortex and anisotropy in the medulla. CONCLUSION Both flow and microstructure apparently contribute to the medullary diffusion anisotropy. The described novel method may be useful in separating decreased tubular flow from irreversible structural tubular damage, for example, in diabetic nephropathy or during allograft rejection.
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Affiliation(s)
- Mike Notohamiprodjo
- Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, New York, USA; Department of Clinical Radiology, University Hospitals Munich, Munich, Germany; Department of Radiology, University Hospital Tuebingen, Tuebingen, Germany
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Raya JG, Melkus G, Adam-Neumair S, Dietrich O, Mützel E, Reiser MF, Putz R, Kirsch T, Jakob PM, Glaser C. Diffusion-tensor imaging of human articular cartilage specimens with early signs of cartilage damage. Radiology 2012; 266:831-41. [PMID: 23238155 DOI: 10.1148/radiol.12120954] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess the use of diffusion-tensor (DT) imaging of articular cartilage to detect and grade early cartilage damage in human specimens with early signs of cartilage damage. MATERIALS AND METHODS This study was approved by the institutional review board. Forty-three cartilage-on-bone samples drilled from 21 human patellae were examined with 17.6-T magnetic resonance (MR) imaging and a diffusion-weighted spin-echo sequence (spatial resolution, 50 × 100 × 800 μm). Subsequently, samples underwent histologic analysis with safranin O staining. Cartilage damage on safranin O histologic slides was quantified with Osteoarthritis Research Society International (OARSI) grades; grades ranged from 0 (healthy) to 6 (bone remodeling). Maps of longitudinal diffusivity (λ(l)), transverse diffusivity (λ(t)), mean diffusivity (MD), and fractional anisotropy (FA) were calculated. Cartilage was segmented, and region of interest (ROI) analysis was performed and compared with histologic findings. Significant differences in MR parameters between the OARSI groups were assessed with the Tukey test. The value of DT imaging in the diagnosis and grading of cartilage damage was assessed with logistic regression analysis. RESULTS Samples had OARSI grades of 0 (n = 14), 1 (n = 11), 2 (n = 12), 3 (n = 4), and 4 (n = 2). Samples with an OARSI grade greater than 0 had significantly increased λ(l), λ(t), and MD (7%-25% increase) in the superficial cartilage growing deeper into cartilage with increasing OARSI grade. Samples with an OARSI grade greater than 0 showed significantly decreased FA in the deep cartilage (-25% to -35% decrease), suggesting that changes in the collagen architecture may occur early in cartilage degradation. DTI showed excellent performance in the detection of cartilage damage (accuracy, 0.95; 41 of 43 samples) and good performance in the grading of cartilage damage (accuracy, 0.74; 32 of 43 samples). CONCLUSION DT imaging of articular cartilage can enable physicians to detect and grade early cartilage damage.
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Affiliation(s)
- José G Raya
- Department of Radiology, New York University Langone Medical Center, 660 First Ave, 4th Floor, New York, NY 10016, USA.
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Raya JG, Horng A, Dietrich O, Krasnokutsky S, Beltran LS, Storey P, Reiser MF, Recht MP, Sodickson DK, Glaser C. Articular cartilage: in vivo diffusion-tensor imaging. Radiology 2011; 262:550-9. [PMID: 22106350 DOI: 10.1148/radiol.11110821] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE To investigate technical feasibility, test-retest reproducibility, and the ability to differentiate healthy subjects from subjects with osteoarthritis (OA) with diffusion-tensor (DT) imaging parameters and T2 relaxation time. MATERIALS AND METHODS This study was approved by the institutional review board and was HIPAA compliant. All subjects provided written informed consent. DT imaging parameters and T2 (resolution=0.6×0.6×2 mm) of patellar cartilage were measured at 7.0 T in 16 healthy volunteers and 10 patients with OA with subtle inhomogeneous signal intensity but no signs of cartilage erosion at clinical magnetic resonance (MR) imaging. Ten volunteers were imaged twice to determine test-retest reproducibility. After cartilage segmentation, maps of mean apparent diffusion coefficient (ADC), fractional anisotropy (FA), and T2 relaxation time were calculated. Differences for ADC, FA, and T2 between the healthy and OA populations were assessed with nonparametric tests. The ability of each MR imaging parameter to help discriminate healthy subjects from subjects with OA was assessed by using receiver operating characteristic curve analysis. RESULTS Test-retest reproducibility was better than 10% for mean ADC (8.1%), FA (9.7%), and T2 (5.9%). Mean ADC and FA differed significantly (P<.01) between the OA and healthy populations, but T2 did not. For ADC, the optimal threshold to differentiate both populations was 1.2×10(-3) mm2/sec, achieving specificity of 1.0 (16 of 16) and sensitivity of 0.80 (eight of 10). For FA, the optimal threshold was 0.25, yielding specificity of 0.88 (14 of 16) and sensitivity of 0.80 (eight of 10). T2 showed poor differentiation between groups (optimal threshold=22.9 msec, specificity=0.69 [11 of 16], sensitivity=0.60 [six of 10]). CONCLUSION In vivo DT imaging of patellar cartilage is feasible, has good test-retest reproducibility, and may be accurate in discriminating healthy subjects from subjects with OA. ADC and FA are two promising biomarkers for early OA.
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Affiliation(s)
- José G Raya
- Department of Radiology, New York University Langone Medical Center, 660 First Ave, 4th Floor, New York, NY 10016, USA.
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Pierce DM, Trobin W, Raya JG, Trattnig S, Bischof H, Glaser C, Holzapfel GA. DT-MRI based computation of collagen fiber deformation in human articular cartilage: a feasibility study. Ann Biomed Eng 2010; 38:2447-63. [PMID: 20225124 DOI: 10.1007/s10439-010-9990-9] [Citation(s) in RCA: 50] [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: 11/16/2009] [Accepted: 02/25/2010] [Indexed: 01/25/2023]
Abstract
Accurate techniques for simulating the deformation of soft biological tissues are an increasingly valuable tool in many areas of biomechanical analysis and medical image computing. To model the complex morphology and response of articular cartilage, a hyperviscoelastic (dispersed) fiber-reinforced constitutive model is employed to complete two specimen-specific finite element (FE) simulations of an indentation experiment, with and without considering fiber dispersion. Ultra-high field Diffusion Tensor Magnetic Resonance Imaging (17.6 T DT-MRI) is performed on a specimen of human articular cartilage before and after indentation to approximately 20% compression. Based on this DT-MRI data, we detail a novel FE approach to determine the geometry (edge detection from first eigenvalue), the meshing (semi-automated smoothing of DTI measurement voxels), and the fiber structural input (estimated principal fiber direction and dispersion). The global and fiber fabric deformations of both the un-dispersed and dispersed fiber models provide a satisfactory match to that estimated experimentally. In both simulations, the fiber fabric in the superficial and middle zones becomes more aligned with the articular surface, although the dispersed model appears more consistent with the literature. In the future, a multi-disciplinary combination of DT-MRI and numerical simulation will allow the functional state of articular cartilage to be determined in vivo.
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Affiliation(s)
- David M Pierce
- Institute of Biomechanics, Center of Biomedical Engineering, Graz University of Technology, Kronesgasse 5-I, Graz, Austria
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Raya JG, Dietrich O, Horng A, Weber J, Reiser MF, Glaser C. T2 measurement in articular cartilage: impact of the fitting method on accuracy and precision at low SNR. Magn Reson Med 2010; 63:181-93. [PMID: 19859960 DOI: 10.1002/mrm.22178] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
T2 relaxation time is a promising MRI parameter for the detection of cartilage degeneration in osteoarthritis. However, the accuracy and precision of the measured T2 may be substantially impaired by the low signal-to-noise ratio of images available from clinical examinations. The purpose of this work was to assess the accuracy and precision of the traditional fit methods (linear least-squares regression and nonlinear fit to an exponential) and two new noise-corrected fit methods: fit to a noise-corrected exponential and fit of the noise-corrected squared signal intensity to an exponential. Accuracy and precision have been analyzed in simulations, in phantom measurements, and in seven repetitive acquisitions of the patellar cartilage in six healthy volunteers. Traditional fit methods lead to a poor accuracy for low T2, with overestimations of the exact T2 up to 500%. The noise-corrected fit methods demonstrate a very good accuracy for all T2 values and signal-to-noise ratio. Even more, the fit to a noise-corrected exponential results in precisions comparable to the best achievable precisions (Cramér-Rao lower bound). For in vivo images, the traditional fit methods considerably overestimate T2 near the bone-cartilage interface. Therefore, using an adequate fit method may substantially improve the sensitivity of T2 to detect pathology in cartilage and change in T2 follow-up examinations.
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Affiliation(s)
- José G Raya
- Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology-Grosshadern, Ludwig Maximilian University of Munich, Munich, Germany.
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Raya JG, Horng A, Dietrich O, Weber J, Dinges J, Mützel E, Reiser MF, Glaser C. Voxel-based reproducibility of T2 relaxation time in patellar cartilage at 1.5 T with a new validated 3D rigid registration algorithm. Magn Reson Mater Phy 2009; 22:229-39. [DOI: 10.1007/s10334-009-0168-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 03/03/2009] [Accepted: 03/11/2009] [Indexed: 11/29/2022]
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Raya JG, Melkus G, Dietrich O, Reiser MF, Jakob P, Glaser C. Multiparametrische Charakterisierung des gesunden und kranken Knorpels unter Druck bei 17.6 T. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221579] [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: 10/20/2022]
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Notohamiprodjo M, Horng A, Pietschmann M, Horger W, Park J, Crispin A, Herrmann KA, Raya JG, Reiser MF, Glaser C. Technische und klinische Evaluierung einer fettgesättigten (fs) Protonendichte-gewichteten (PDw) 3D-TSE-Sequenz für Knie-MRT bei 3T. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221472] [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: 10/20/2022]
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Weckbach S, Pforte G, Horng A, Raya JG, Eckstein F, Reiser MF, Glaser C. Entwicklung von T-Scores für die Diagnose der Retropatellararthrose. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221346] [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: 10/20/2022]
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Glaser C, Filidoro L, Raya JG, Weber D, Horng A, Arnoldi A, Kellerer A, Weber J, Jakob P, Putz R, Muetzel E, Reiser MF. Hochaufgelöste Diffusions-Tensor-MRT der Kollagenfaserarchitektur im Gelenkknorpel: Korrelation mit der Rasterelektronenmikroskopie. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221578] [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: 10/20/2022]
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Horng A, Raya JG, Zscharn M, Hoehne-Hückstädt U, Hermanns I, Glitsch U, Ellegast R, Reiser MF, Glaser C. Darstellung von Knorpeldeformationsmuster des Kniegelenkknorpels nach knieender Belastung durch die hochauflösende 3D-MR-Volumetrie bei 3T. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221577] [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: 10/20/2022]
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Abstract
The well-known noise distributions of magnetic resonance imaging (MRI) data (Rayleigh, Rician, or non-central chi-distribution) describe the probability density of real-valued (i.e., floating-point) signal intensities. MR image data, however, is typically quantized to integers before visualization or archiving. Depending on the scaling factors applied before the quantization and the signal-to-noise ratio (SNR), very low noise levels with substantial artifacts due to the quantization process can occur. The purpose of this study was to analyze the consequences of the signal quantization, to determine the theoretical absolute lower limit for noise measurements in discrete data, and to evaluate an improved method for noise and SNR measurements in the presence of very low noise levels. Image data were simulated with original noise levels of between 0.02 and 2.00. Noise measurements were performed based on the properties of background and foreground data using the conventional approach, which exploits the standard deviation or mean value of the signal, and a maximum-likelihood approach based on the relative frequencies of the observed discrete signal intensities. Substantial deviations were found for the conventionally determined noise levels, while noise levels comparable to or lower than the quantization error can be accurately estimated with the proposed maximum-likelihood approach.
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Affiliation(s)
- Olaf Dietrich
- Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology-Grosshadern, LMU Ludwig Maximilian University of Munich, Munich Germany.
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Saam T, Cyran CC, Sourbon S, Raya JG, Bochmann K, Hacker M, Rominger A, Pfefferkorn T, Dichgans M, Reiser MF, Nikolaou K. Die kontrastverstärkte, dynamische MRT zur Quantifikation der Entzündung von Arterienwänden in Korrelation zur 18F-FDG PET-CT. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1208337] [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: 10/21/2022]
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Dietrich O, Raya JG, Reeder SB, Ingrisch M, Reiser MF, Schoenberg SO. Influence of multichannel combination, parallel imaging and other reconstruction techniques on MRI noise characteristics. Magn Reson Imaging 2008; 26:754-62. [PMID: 18440746 DOI: 10.1016/j.mri.2008.02.001] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 01/15/2008] [Accepted: 02/24/2008] [Indexed: 11/25/2022]
Abstract
The statistical properties of background noise such as its standard deviation and mean value are frequently used to estimate the original noise level of the acquired data. This requires the knowledge of the statistical intensity distribution of the background signal, that is, the probability density of the occurrence of a certain signal intensity. The influence of many new MRI techniques and, in particular, of various parallel-imaging methods on the noise statistics has neither been rigorously investigated nor experimentally demonstrated yet. In this study, the statistical distribution of background noise was analyzed for MR acquisitions with a single-channel and a 32-channel coil, with sum-of-squares (SoS) and spatial-matched-filter (SMF) data combination, with and without parallel imaging using k-space and image-domain algorithms, with real-part and conventional magnitude reconstruction and with several reconstruction filters. Depending on the imaging technique, the background noise could be described by a Rayleigh distribution, a noncentral chi-distribution or the positive half of a Gaussian distribution. In particular, the noise characteristics of SoS-reconstructed multichannel acquisitions (with k-space-based parallel imaging or without parallel imaging) differ substantially from those with image-domain parallel imaging or SMF combination. These effects must be taken into account if mean values or standard deviations of background noise are employed for data analysis such as determination of local noise levels. Assuming a Rayleigh distribution as in conventional MR images or a noncentral chi-distribution for all multichannel acquisitions is invalid in general and may lead to erroneous estimates of the signal-to-noise ratio or the contrast-to-noise ratio.
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Affiliation(s)
- Olaf Dietrich
- Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology-Grosshadern, Ludwig Maximilian University of Munich, 81377 Munich, Germany.
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Notohamiprodjo M, Horng A, Horger W, Park J, Trumm C, Raya JG, Reiser M, Glaser C. Hochaufgelöste Knie-MRT bei 3 Tesla mit einer 3D- moderat T2-gewichteten TSE-Sequenz (SPACE). ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073697] [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: 10/21/2022]
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Weckbach S, Sourbron SP, Raya JG, Notohamiprodjo M, Horng A, Reiser M, Glaser C. Quantifizierung von kapillärem Fluss und endothelialer Permeabilität bei entzündlichen Gelenkerkrankungen: erste Ergebnisse aus MR-Perfusionsmessungen. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073664] [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: 10/21/2022]
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Horng A, Raya JG, Weber J, Weckbach S, Nixdorf K, Reiser M, Glaser C. Reproduzierbarkeit der T2 Relaxationszeit in gesundem und degenerativ verändertem Tibiaknorpel des Menschen. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073696] [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: 10/21/2022]
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Dietrich O, Raya JG, Reeder SB, Reiser MF, Schoenberg SO. Measurement of signal-to-noise ratios in MR images: influence of multichannel coils, parallel imaging, and reconstruction filters. J Magn Reson Imaging 2007; 26:375-85. [PMID: 17622966 DOI: 10.1002/jmri.20969] [Citation(s) in RCA: 682] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To evaluate the validity of different approaches to determine the signal-to-noise ratio (SNR) in MRI experiments with multi-element surface coils, parallel imaging, and different reconstruction filters. MATERIALS AND METHODS Four different approaches of SNR calculation were compared in phantom measurements and in vivo based on: 1) the pixel-by-pixel standard deviation (SD) in multiple repeated acquisitions; 2) the signal statistics in a difference image; and 3) and 4) the statistics in two separate regions of a single image employing either the mean value or the SD of background noise. Different receiver coil systems (with one and eight channels), acquisitions with and without parallel imaging, and five different reconstruction filters were compared. RESULTS Averaged over all phantom measurements, the deviations from the reference value provided by the multiple-acquisitions method are 2.7% (SD 1.6%) for the difference method, 37.7% (25.9%) for the evaluation of the mean value of background noise, and 34.0% (38.1%) for the evaluation of the SD of background noise. CONCLUSION The conventionally determined SNR based on separate signal and noise regions in a single image will in general not agree with the true SNR measured in images after the application of certain reconstruction filters, multichannel reconstruction, or parallel imaging.
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Affiliation(s)
- Olaf Dietrich
- Department of Clinical Radiology-Grosshadern, Ludwig Maximilian University of Munich, Munich, Germany.
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Raya JG, Dietrich O, Birkenmaier C, Sommer J, Reiser MF, Baur-Melnyk A. Feasibility of a RARE-based sequence for quantitative diffusion-weighted MRI of the spine. Eur Radiol 2007; 17:2872-9. [PMID: 17356841 DOI: 10.1007/s00330-007-0618-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 01/24/2007] [Accepted: 02/13/2007] [Indexed: 10/23/2022]
Abstract
The feasibility of a diffusion-weighted single-shot fast-spin-echo sequence for the diagnostic work-up of bone marrow diseases was assessed. Twenty healthy controls and 16 patients with various bone marrow pathologies of the spine (bone marrow edema, tumor and inflammation) were examined with a diffusion-weighted single-shot sequence based on a modified rapid acquisition with relaxation enhancement (mRARE) technique; four diffusion weightings (b-values: 50, 250, 500 and 750 s/mm(2)) in three orthogonal orientations were applied. Apparent diffusion coefficients (ADCs) were determined in the bone marrow and in the intervertebral discs of healthy volunteers and in diseased bone marrow. Ten of the 20 volunteers were repeatedly scanned within 30 min to examine short-time reproducibility. Spatial reproducibility was assessed by measuring ADCs in two different slices including the same lesion in 12 patients. The ADCs of the lesions exhibited significantly higher values, (1.27 +/- 0.32)x10(-3) mm(2)/s, compared with healthy bone marrow, (0.21 +/- 0.10)x10(-3) mm(2)/s. Short-time and spatial reproducibility had a mean coefficient of variation of 2.1% and 6.4%, respectively. The diffusion-weighted mRARE sequence provides a reliable tool for determining quantitative ADCs in vertebral bone marrow with adequate image quality.
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Affiliation(s)
- J G Raya
- Department of Clinical Radiology, University of Munich-Grosshadern, Marchioninistr. 15, 81377, Munich, Germany.
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Abstract
Diffusion-weighted imaging (DWI) is an MRI technique that is sensitive to random water movements at spatial scales far below typical MRI voxel dimensions. DWI is a valuable tool for the diagnoses of diseases that involve alterations in water mobility. In the spine, DWI has proven to be a highly useful method for the differential diagnosis of benign and malignant compression fractures. In these pathologies, the microscopic structure of bone marrow is altered in a very different ways, leading to different water mobility, which can be depicted by DWI. Most of the pulse sequences developed for MRI can be adapted for DWI. However, these DWI-adapted sequences are frequently affected by artifacts, mostly caused by physiological motion. Therefore, the introduction of additional correction techniques, or even the development of new sequences is necessary. The first part of this article describes the principles of DWI and the sequences used for DWI of the spine: spin echo (SE), turbo spin echo (TSE), single-shot echo planar imaging (EPI), and steady-state free precession (SSFP) sequences. In the second part, clinical applications of DWI of the spinal bone marrow are extensively discussed.
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Affiliation(s)
- José G Raya
- Department of Clinical Radiology-Grosshadern, Ludwig Maximilian University of Munich, Munich, Germany.
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Glaser C, Horng A, Mendlik T, Weckbach S, Hoffmann RT, Wagner S, Raya JG, Horger W, Reiser M. T2-Relaxationszeit am Patellaknorpel - Globale und regionale Reproduzierbarkeit bei 1,5 Tesla und 3 Tesla. ROFO-FORTSCHR RONTG 2007; 179:146-52. [PMID: 17262244 DOI: 10.1055/s-2006-927203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Evaluation of the global and regional reproducibility of T2 relaxation time in patellar cartilage at 1.5 T and 3 T. MATERIALS AND METHODS 6 left patellae of 6 healthy volunteers (aged 25 - 30, 3 female, 3 male) were examined using a fat-saturated multiecho sequence and a T1-w 3D-FLASH sequence with water excitation at 1.5 Tesla and 3 Tesla. Three consecutive data sets were acquired within one MRI session with the examined knee being repositioned in the coil and scanner between each data set. The segmented cartilage (FLASH sequence) was overlaid on the multiecho data and T2 values were calculated for the total cartilage, 3 horizontal layers consisting of a superficial, intermedial and deep layer, 3 facets consisting of a medial, median (ridge) and lateral facet (global T2 values) and 27 ROIs/MRI slices (regional T2 value). The reproducibility (precision error) was calculated as the root mean square average of the individual standard deviations [ms] and coefficients of variation (COV) [%]. RESULTS The mean global reproducibility error for T2 was 3.53 % (+/- 0.38 %) at 1.5 Tesla and 3.25 % (+/- 0.61 %) at 3 Tesla. The mean regional reproducibility error for T2 was 8.62 % (+/- 2.61 %) at 1.5 Tesla and 9.66 % (+/- 3.37 %) at 3 Tesla. There was no significant difference with respect to absolute reproducibility errors between 1.5 Tesla and 3 Tesla at a constant spatial resolution. However, different reproducibility errors were found between the cartilage layers. One third of the data variability could be attributed to the influence of the different cartilage layers, and another 10 % to the influence of the separate MRI slices. CONCLUSION Our data provides an estimation of the global and regional reproducibility errors of T2 in healthy cartilage. In the analysis of small subregions, an increase in the regional reproducibility error must be accepted. The data may serve as a basis for sample size calculations of study populations and may contribute to the decision regarding the level of detail of an evaluation of study data.
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Affiliation(s)
- C Glaser
- Institut für Klinische Radiologie, Klinikum der Universität München Grosshadern
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Raya JG, Dietrich O, Reiser MF, Baur-Melnyk A. Techniques for diffusion-weighted imaging of bone marrow. Eur J Radiol 2005; 55:64-73. [PMID: 15950102 DOI: 10.1016/j.ejrad.2005.01.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 01/20/2005] [Accepted: 01/26/2005] [Indexed: 10/25/2022]
Abstract
Diffusion-weighted magnetic resonance imaging (DWI) is an imaging technique which is sensitive to random water movements in spatial scales far below those typically accessible by magnetic resonance imaging (MRI). This property makes DWI a powerful tool for diagnosis of diseases which involve alterations in water mobility, such as acute stroke. In bone marrow, DWI has been proven to be a highly useful method for the differential diagnosis of benign and malignant compression fractures. Unfortunately, the application of DWI sequences to the bone marrow frequently suffers from artifacts, which in some cases seriously restrict the diagnostic utility of the image. This requires the introduction of additional correction techniques, or even the development of new sequences. Thus, the selection of an adequate imaging technique for DWI of the bone marrow is a very important issue. In this article the most important sequences for DWI of the bone marrow are reviewed. Special attention is paid to the problems associated with these sequences, as well as their possible solutions.
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Affiliation(s)
- J G Raya
- Department of Clinical Radiology, Grosshadern, Ludwig Maximilian University, Marchioninistr. 15, 81377 Munich, Germany.
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Dietrich O, Raya JG, Sommer J, Deimling M, Reiser MF, Baur-Melnyk A. A comparative evaluation of a RARE-based single-shot pulse sequence for diffusion-weighted MRI of musculoskeletal soft-tissue tumors. Eur Radiol 2004; 15:772-83. [PMID: 15627173 DOI: 10.1007/s00330-004-2619-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 11/29/2004] [Accepted: 12/02/2004] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to evaluate the feasibility of a centric-reordered modified rapid acquisition with relaxation enhancement (mRARE) sequence for single-shot diffusion-weighted magnetic resonance imaging (DWI) of soft-tissue tumors in the musculoskeletal system. In the evaluation of this sequence, DWI was performed in a liquid phantom, in excised human tumor samples embedded in bovine muscle, and in nine patients suffering from different types of soft-tissue tumors. The measurements were compared to DWI using a spin-echo sequence and a single-shot echo planar imaging (EPI) sequence. The phantom measurements in water and dimethyl sulfoxide showed a difference of less than 5% when comparing the apparent diffusion coefficients (ADCs) determined by the mRARE sequence and the two other techniques. Comparing mRARE and EPI, the differences in the ADCs were about 10% in the excised tumor tissue and, typically, about 15% in vivo. ADCs between 0.8 x 10(-3) mm2/s and 1.4 x 10(-3) mm2/s, depending on the tumor type, were found in solid tumor tissue; in cystic tumor areas, ADCs greater than 2.0 x 10(-3) mm2/s were determined with the mRARE and the EPI sequences. Diffusion-weighted images of the mRARE sequence were less distorted than those acquired with the single-shot EPI sequence, and provided more anatomic information, since the muscle and fat signals were considerably higher.
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Affiliation(s)
- Olaf Dietrich
- Department of Clinical Radiology--Grosshadern, Ludwig Maximilian University of Munich, Marchioninistrasse 15, 81377 Munich, Germany.
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Cueva-Rolón R, Delgado-Lezama R, Raya JG, Raya M, Tecuanhuey R, Muñoz-Martínez EJ. Sustained firing of alpha and gamma hind limb motoneurons induced by stimulation of the pudendal nerve. J Neurophysiol 2002; 88:3232-42. [PMID: 12466443 DOI: 10.1152/jn.00157.2002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Axons from receptors in the cat vaginal wall run in the sensory pudendal nerve (SPN), and brief (<10 s) vaginal probing (VP) in the decerebrate cat produces a long-lasting (>1 min) contraction of the triceps surae (TS) muscles. The aim of the present project was to find out whether brief SPN stimulation also produces sustained TS response and, eventually, to study the mechanisms involved in it. Decerebrate female cats were used. In some cats, TS electromyography (EMG) and tension response were recorded; stimulation of left SPN with single or repetitive trains of shocks produced a bilateral TS response that outlasted the stimulus >1 min as VP did. In paralyzed cats (pancuronium; Panc), intracellular recordings were made from hind limb motoneurons (MNs). SPN stimulation produced a depolarization <or=5 s long and occasional cell firing only lasting <2.5 s; this is in contrast with the prolonged TS postdischarge seen in nonparalyzed cats. If MNs were depolarized below the firing threshold by current injection, about half of them showed bistable firing that could last several minutes in response to SPN train. It is suggested that MNs might hyperpolarize after Panc injection. Before Panc injection, SPN train produced long-lasting (>1 min) electroneurographic (ENG) postdischarge in a small filament of the medial gastrocnemius (MG) nerve; the MG EMG postdischarge was also recorded. Large spikes (LS) and small spikes (SS) were distinguished in the ENG. During the postdischarge, LS frequency and the integrated EMG activity correlated well (r > 0.9); no correlation was found between SS and EMG. After Panc injection, LS postdischarge was absent but the SS postdischarge remained. LS followed by EMG potential were also evoked by brief TS stretch (reflex LS); single shocks to SPN only elicited SS that were not followed by EMG potential. It is concluded that alpha axons and gamma axons produced LS and SS, respectively, and that SPN activates gamma axons. It is proposed that, in the nonparalyzed cats, the stimulation of SPN with trains of shocks might cause an increase in the afferent inflow from muscle spindles to alpha MNs through the sustained firing of gamma MNs. The increased excitatory inflow would depolarize alpha MNs and allow bistable MN firing; Panc would decrease this inflow by blocking transmission to the spindle fibers.
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Affiliation(s)
- Rafael Cueva-Rolón
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, 07000-México D. F., Mexico
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Abstract
A method to measure small movements of living tissues either large or small is presented. The method is based on the detection of changes in reflected infrared light. An optocoupler (coupled photodiode and photodetector) and a small (< 1 cm2) mirror were used. The optocoupler (OC) has a low cost and it can be calibrated easily. It can be also used as the transducer of a strain-gage. Three different uses are shown: (a) as a strain-gage transducer; (b) detection of tendon and aponeurosis movements in large muscles (cat soleus); (c) detection of the onset of muscle contraction. Movements of less than 1 microm can be detected with the aid of automatic averaging of the signals. Concerning the second use (b), it permits the estimation of tendon stretch. Concerning the third use, the onset of muscle movement precedes by at least 2 ms that of the force recorded at the tendon.
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Affiliation(s)
- R Delgado-Lezama
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN. Apdo., México, D.F., México
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Cueva-Rolón R, Muñoz-Martínez EJ, Delgado-Lezama R, Raya JG. The cat pudendal nerve: afferent fibers responding to mechanical stimulation of the perineal skin, the vagina or the uterine cervix. Brain Res 1994; 655:1-6. [PMID: 7812760 DOI: 10.1016/0006-8993(94)91589-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Some afferent fibers from the pudendal nerve of the female cat were stimulated by pressing on the perineal skin, the vagina or the uterine cervix. Three different types of skin mechanoreceptors were found: (1) with low threshold (< 20 mg) and slow-adapting discharges; (2) with high threshold (0.1-0.5 g) and slow-adapting discharges; and (3) with low threshold and fast-adapting discharges. Most of these receptors increased their firing frequency as the velocity of skin indentation was increased (velocity detectors). The average conduction velocity of the skin afferents was 29 +/- 9 m/s. The receptors located at the vagina showed a fast-adapting response to probing and were sensitive to the velocity of the probe movement. Most of these receptors, however, showed a slow adaptation when the vaginal wall was distended with a balloon. The conduction velocity in vaginal afferents was 37 +/- 16 m/s. Those receptors responding to pressure on the uterine cervix adapted slowly to constant pressure but were sensitive to the velocity of the pressure pulses. The conduction velocity in the afferents from the uterine cervix was 31 +/- 9 m/s.
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Affiliation(s)
- R Cueva-Rolón
- Departamento de Fisiología, Biofísica y Neurociencias, CINVESTAV, México, DF, México
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Cueva-Rolón R, Múñoz-Martínez EJ, Delgado-Lezama R, Raya JG, González-Santos G. Sustained activation of the triceps surae muscles produced by mechanical stimulation of the genital tract of the female cat. Brain Res 1993; 600:33-8. [PMID: 8422588 DOI: 10.1016/0006-8993(93)90398-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In decerebrate cats, controlled mechanical stimulation of the perivulvar skin, the vaginal wall or the cervix uteri induced visible hind limb extension. Pressing on the cervix uteri produced the greater response. To quantify these responses, the EMG activity and the tension developed by the normally inserted triceps surae muscles were recorded. The activity induced in these muscles by stimulation of the genital canal outlasted the stimulus by many seconds or a few minutes. These effects disappeared after spinalization at the T12 level. We propose that stimulation of the vaginal canal in the female cat may induce bistability of triceps surae motoneurones.
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Affiliation(s)
- R Cueva-Rolón
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del IPN, México DF, Mexico
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