ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Cartilage & Basic Science: Emerging Techniques
Wednesday 24 April 2013
Room 355 BC  10:00 - 12:00 Moderators: Xiaojuan Li, Miika T. Nieminen

10:00 0429.   
Susceptibility Weighted Imaging of Cartilage Canals of the Distal Femur ex Vivo and in Vivo
Mikko J. Nissi1,2, Ferenc Toth3, Jinjin Zhang1,2, Sebastian Schmitter1, Michael Benson1, Bruce Hammer1, Cathy Carlson3, and Jutta Maria Ellermann1
1CMRR and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States,3Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States

Visualization of cartilage canals of epiphyseal growth cartilage has been limited to gadolinium-enhanced imaging. Susceptibility weighted imaging (SWI) is a method that is sensitive to minute differences in magnetic susceptibility, such as those between deoxygenated blood and surrounding tissue. In the present study, the feasibility of SWI for visualizing the cartilage canals was demonstrated ex vivo at 9.4T, 7T and 3T and in vivo at 7T, using a porcine animal model.

10:12 0430.   
Regional Analysis of Hip Cartilage MR Relaxation Times in Subjects with and Without Femoroacetabular Impingement
Karupppasamy Subburaj1, Alexander Valentinitsch1, Alexander B. Dillon1, Xiaojuan Li1, Thomas M. Link1, Thomas P. Vail2, and Sharmila Majumdar1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, United States

Conditions such as femoroacetabular impingement (FAI) characterized by an anatomic deformity at the femoral head-neck junction, is known to affect the pathogenesis of hip osteoarthritis (OA) and have been identified as pertinent causes of premature OA of the hip joint in young and middle-aged patients. Early detection of cartilage degeneration could help identify patients with hip pain who may benefit from early intervention The objective of this study was to perform a sub-regional analysis of cartilage magnetic resonance (MR) relaxation times (T1ρ and T2) measurements in the hip joint for early assessment of cartilage defects in patients with FAI.

10:24 0431.   
Factors Influencing Quantitative Magnetization Transfer (QMT) Parameters of Articular Cartilage
Pouria Mossahebi1, Rajeev Chaudhary2, Nade Sritanyaratana1, Walter F. Block2,3, Alexey A. Samsonov4, and Richard Kijowski4
1Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 3Medical Physics, University of Wisconsin, Madison, WI, United States, 4Radiology, University of Wisconsin, Madison, WI, United States

This study was performed to investigate the factors leading to changes in qMT measures of cartilage in controlled conditions including phantom experiments and an ex-vivo bovine cartilage degradation model. Bound pool fraction (f) and exchange rate (k) increased significantly with increasing concentration of collagen solution but changed only minimally with increasing concentration of proteoglycan solution. Thermal denaturation of collagen solution resulted in a decrease in f and k and increase in T2 relaxation time of bound protons (T2B). Trypsin degradation of bovine cartilage resulted in a decrease in k and increase in T2B but no change in f. Our results support strong association of f with collagen content. The observed trends and unique sensitivity of qMT measures to macromolecules, however, suggest that a multivariate analysis involving all qMT parameters may be the most specific method to analyze the complex changes which occur during cartilage degeneration.

10:36 0432.   
Assessment of Degradation of Proteoglycans and Matrix Proteins in Intervertebral Disc Degeneration by Diffusion Weighted MRS
Anna M. WANG1,2, Peng Cao1,2, Jian Yang3, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China, 3Department of Radiology, Xi'an Jiaotong University, Xi'an, Shanxi, China

This study investigated the capability of diffusion weighted magnetic resonance spectroscopy (DW-MRS) for assessing the changes in carbohydrates region (3.5-4.2ppm) during intervertebral disc degeneration (IVDD). Our experimental results demonstrated that spectral contamination of carbohydrate resonances by overlapping water peak could be effectively suppressed by diffusion weighting due to the fast water diffusion (compared to macromolecules). More importantly, we demonstrated that non-water diffusion measurement could detect proteoglycan and disc matrix protein breakdowns during disc degeneration. Such diffusion spectroscopy approval can constitute a new and useful tool for early IVDD detection and mechanistic understanding of IVDD.

10:48 0433.   Classification of OARSI Scored Human Articular Cartilage Explants Through Multiparametric MRI Analysis at 3T
Vanessa A. Lukas1, Kenneth W. Fishbein1, Ping-Chang Lin2, Michael Schär3, Corey P. Neu4, Richard G. Spencer1, and David A. Reiter5
1Magnetic Resonance Imaging and Spectroscopy Section, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States, 2Department of Radiology, Howard University College of Medicine, Washington, District of Columbia, United States, 3Philips Healthcare, Highland Heights, Ohio, United States, 4Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, United States, 5Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States

In this study, we extend our previous work on classification of degradation of bovine nasal cartilage, performed at 9.4T and 4 °C, to the problem of classification of osteoarthritic human articular cartilage explants at physiological temperature (37 °C) and at the clinical field strength of 3T. We compared the conventional univariate classification scheme to multiparametric classification according to multivariage Gaussian models. Using the MRI parameters T1, T2, T2*, and ADC, multiparametric classification showed substantially improved accuracy in discriminating between normal and OA cartilage, as determined based on OARSI histological scores. These initial results represent a promising step towards diagnosis of cartilage matrix degradation during early OA using acquisition schemes that are readily available on clinical MRI systems.

11:00 0434.   
Assessment of Human Tibial Cartilage-Bone Interface in Osteoarthritis Using SWIFT
Jari Rautiainen1,2, Elli-Noora Salo3, Virpi Tiitu4, Mikko A.J. Finnilä5, Olli-Matti Aho6, Simo Saarakkala5, Petri Lehenkari6, Jutta Maria Ellermann7, Mikko J. Nissi7,8, and Miika T. Nieminen2,3
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 2Department of Radiology, University of Oulu, Oulu, Finland, 3Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 4Institute of Biomedicine, Anatomy, University of Eastern Finland, Kuopio, Finland, 5Department of Medical Technology, University of Oulu, Oulu, Finland, 6Department of Anatomy and Cell Biology, University of Oulu, Oulu, Finland, 7Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States,8Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States

The purpose of this study was to evaluate cartilage-bone interface in osteochondral samples from human tibia with varying degrees of degeneration using SWIFT. For reference, micro-computed tomography (micro-CT) imaging, histopathological scoring (OARSI) and histological evaluation were used. Differences in the appearance of the calcified cartilage and subchondral bone were detected with SWIFT, depending on the degree of OA. SWIFT was capable of elucidating tissue changes associated to the degree of OA.

11:12 0435.   
Validation of a Clinical Protocol for DTI of Articular Cartilage in Whole Knee Specimen Using a New Method for One-To-One Correlation of DTI with Histology
Jose G. Raya1, Tony Wong1, You Jin Lee2, Christian Glaser1, and Thorsten Kirsch2
1Radiology, New York University Langone Medical Center, New York, NY, United States, 2Orthopaedic Surgery, New York University Langone Medical Center, New York, NY, United States

In vivo diffusion tensor imaging (DTI) of the articular cartilage has demonstrated high accuracy (90%) for the early diagnosis of osteoarthritis (OA). However, DTI data acquired with a clinical scanner needs further histological validation in conditions mimicking the in vivo acquisition. The aim of this work is to introduce a new method for one to one correlation of DTI and histology on whole knee specimens measured in the same conditions as in vivo acquisition. Our data indicate potential of DTI to detect damaged cartilage with OARSI grade 2 or higher.

11:24 0436.   CubeQuant T1rho, QDESS T2, and Cones Sodium Measurements Are Sufficiently Reproducible for In Vivo Cartilage Studies
Caroline D. Jordan1,2, Uche D. Monu1,3, Emily J. McWalter1, Ronald D. Watkins1, Weitian Chen4, Neal K. Bangerter5, Brian Andrew Hargreaves1, and Garry E. Gold1,6
1Radiology, Stanford University, Stanford, CA, United States, 2Bioengineering, Stanford University, Stanford, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States, 4Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 5Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States, 6Orthopaedic Surgery, Stanford University, Stanford, CA, United States

Quantitative MRI parameters such as T1lower case Greek rho, T2 and sodium have been shown to vary in osteoarthritis patients. We measured the reproducibility of the 3D quantitative MRI techniques of CubeQuant T1lower case Greek rho, qDESS T2 and cones sodium measurements in knee cartilage. Intra-observer, inter-observer, adjacent slice, and short-term/long-term intra-subject variability were measured by computing the coefficient of variation (CV). The short-term and long-term intra-subject reproducibility amongst different regions of cartilage, expressed by the root-mean-square CV, ranged between 2.7-8.6% and 4.6-9.0% for CubeQuant T1lower case Greek rho, between 2.4-9.8% and 4.4-13.8% for qDESS T2, and between 5.2-13.8% and 4.6-16.0% for 3D cones sodium MRI, respectively.

11:36 0437.   Magic Angle Effect Plays a Significant Role in T1rho Relaxation in Articular Cartilage
Pedram Golnari1, Jiang Du1, Won C. Bae1, Reni Biswas1, Sheronda Statum1, Eric Chang1, and Christine Chung1
1Radiology, University of California, San Diego, San Diego, CA, United States

In recent years quantitative imaging of the joint tissues has focused on two particular biomarkers: T1rho and T2. T1rho has been shown to be sensitive to proteoglycan depletion . T2 has been shown to be sensitive to collagen matrix degradation. The magic angle effect is a potential confounding factor in T2 and T1rho evaluation of joint tissue degeneration. However, the literature regarding T1rho relaxation is inconsistent, with some groups finding strong residual dipolar interaction, and other groups reporting a much reduced magic angle effect. In this study we aimed to evaluate the effect of sample orientation on T2 and T1rho values of cadaveric human patellae.

11:48 0438.   Numerical Validation of Two-Component T2* Mapping for Cartilages in Human Knee
Yongxian Qian1, Tiejun Zhao2, and Fernando Emilio Boada3
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2MR R&D Collaborations, Siemens Healthcare USA, Pittsburgh, PA, United States, 3Radiology, University of Pittsburgh, New York, NY, United States

A numerical approach was used in this work to simulate the T2* relaxation of two components in cartilages of human knee and to validate the accuracy of two-component T2* mapping on the knee cartilages.