Valentina Pedoia¹, Drew Lansdown², Paul Jung¹, C. Benjamin Ma², and Xiaojuan Li^1
1Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, United States, ²Department of Orthopedic Surgery, UCSF, San Francisco, California, United States

This study presents a novel 3D MRI-based method to analyze the knee bones shape and for the first time applied the technique to knees with ACL-injuries. A shape modeling is extracted for tibia and femur using a set of matched landmarks. Significant shape differences were found between ACL-injured and control knees at baseline, and significant differences are detected in longitudinal shape changes between ACL-injured and control knees. Bone shape quantification has the potential to identify specific risk factors for injuries and to describe novel imaging markers for the development of post-traumatic OA after an acute injury.

Yu Zhang^1,2, Michael Hoppe¹, Samuel Wu³, Martin Kretzschmar³, Richard Souza³, Benjamin Ma³, and Xiaojuan Li^3
1Radiology, University of California San Francisco, San Francisco, CA, United States, ²Department of Orthopaedic Surgery, The First Hospital of Jilin University, Changchun, Jllin, China, ³University of California San Francisco, CA, United States

Our study is to evaluate the relationship between cartilage MRI quantification, WORMS (Whole-Organ Magnetic Resonance Imaging Score) and patient-reported outcomes after acute ACL injuries. forty-two subjects with ACL acute ruptured were enrolled. T1ρ and T2 MRI scan were performed at baseline. Osteoarthritis Outcome Score (KOOS) questionnaire was filled in by each patient during the MR visit and WORMS score was graded by experienced msk radiologists. KOOS has significantly correlations with T1ρ and T2 quantification in some compartments of cartilage in tibia and Femoral condyle, and with several sub-scores in WORMS, such as cartilage lesion and bone marrow edema. Significant correlations were observed between KOOS and cartilage T1ρ and T2 after adjusted for age, BMI and time to injury, indicating an independent relationship between cartilage damage and patient outcomes after acute injuries. Higher WORMS scores on cartilage lesion and bone marrow edema, especially on lateral side of knee joint, are obviously related with worse patient’s outcome. It revealed that the recovery of lateral focal lesion potentially greatly affected the patient’s daily living quality.

Vanessa A. Lukas¹, Beth G. Ashinsky¹, Christopher E. Coletta², Julianne M. Boyle¹, David A. Reiter¹, Corey P. Neu³, Richard G. Spencer¹, and Ilya G. Goldberg^2
1Magnetic Resonance Imaging and Spectroscopy Section, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States,²Image Informatics and Computational Biology Unit, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States,³Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, United States

An important limitation in the application of MRI to the early detection and monitoring of osteoarthritis (OA) is the substantial overlap in parameter values between different degrees of cartilage degradation. In several studies, multiparametric analysis as been shown to markedly improve discrimination ability. We extend this through application of an established pattern recognition algorithm, wndchrm, to T₁, T₂, T₂*, ADC and MT weighted images obtained on OARSI-graded human cartilage explants. We found that wndchrm, which detects differences in textures and intensity patterns between images through examination of multiple image transforms, results in substantially higher classification performance than conventional univariate analysis.

Aditi Guha¹, Cory Wyatt¹, Dimitrios Karampinos^1,2, Lorenzo Nardo¹, Thomas M Link¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Radiology, Technische Universität München, Germany

Osteoarthritis (OA) is a common degenerative disorder, which occurs due to wear and tear of the joint. Research has shown that subtle changes in tissue microstructure correlate with changes in restricted diffusion of water, which manifest in signal changes on diffusion-weighted MR images. A new pulse sequence for diffusion weighted imaging of the knee combining stimulated echo diffusion preparation with magnetization prepared angle modulated partitioned k-space spoiled gradient echo snapshots (MAPSS) acquisition for diffusion imaging of short T2 tissues like cartilage at 3T is investigated. We also look at the correlation between two potential biomarkers for OA: diffusion and T1ρ.

Gerd Melkus¹, Kawan S Rakhra¹, Arturo Cardenas-Blanco², Andrew Speirs³, Ian Cameron¹, Mark E Schweitzer⁴, and Paul E Beaulé^5
1Department of Medical Imaging, The Ottawa Hospital, Ottawa, Ontario, Canada, ²German Center for Neurodegenerative Diseases, Magdeburg, Germany, ³Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Ontario, Canada, ⁴Department of Radiology, Stony Brook University, Brookhaven, New York, United States, ⁵Division of Orthopedic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada

In this study T1rho MRI of hip cartilage was performed in three different subject groups: Controls, asymptomatic subjects with cam deformities (Bumps) and symptomatic (Surgical) cam-type femoroacetabular impingement (FAI) patients. The ratio of T1rho of the anterior to the posterior hip hyaline cartilage in the peripheral weight-bearing region of the joint resulted in statistically significant differences between the Control and the Bump group, the Control and the Surgical group, but not between the Bump and the Surgical group. Quantitative T1rho imaging and T1rho ratio analysis has the potential to detect cartilage proteoglycan loss in subjects with symptomatic cam deformities, prior to development of symptomatic cam-FAI.

Martin Brix^1,2, Vladimir Mlynarik², Benjamin Schmitt³, Pavol Szomolanyi², Gerhard Hobusch¹, Florian Sevelda¹, Stephan Puchner¹, Sonja Walzer¹, Reinhard Windhager¹, Stephan Domayer⁴, and Siegfried Trattnig^2
1Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, ²High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ³Siemens Australia, Australia, ⁴Sonderkrankenanstalt Zicksee, Austria

The purpose of this study was the comparison of biochemically determined GAG content in knee joints of human cadavers to gagCEST values. Therefore, the condyles of four human cadavers were measured using gagCEST. From each condyle, nine biopsies were taken from a medial and lateral compartment and the GAG content was measured in the lab. Regions of interest were drawn manually corresponding to the biopsy areas. A correlation coefficient of r = 0.863 was observed (p < 0.001). The excellent correlation between the MTRasym and cartilage GAG content demonstrates the feasibility of the technique.

Mikko Johannes Nissi^1,2, Ferenc Toth³, Cathy S Carlson³, and Jutta M Ellermann^1
1CMRR, 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

Recently, visualization of the cartilage canal vessels of epiphyseal growth cartilage in the developing skeleton was demonstrated using susceptibility weighted imaging (SWI). A visualization artifact (doubling of the vessels along B0 direction) due to the dipolar phase was also reported. At high enough resolution, the dipolar appearance of the phase accumulation around venous vessels can be detected, with the resulting artifact if simple phase mask, as in standard SWI post-processing is used. In the present study, simplified semi-quantitative susceptibility mapping (sQSM) approach was utilized to resolve the dipolar phase pattern to improve the visualization of cartilage canal vessels.

Fang Liu¹, Richard G. Spencer², Wally Block^1,3, and Richard Kijowski^4
1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Magnetic Resonance Imaging and Spectroscopy Section, National Institutes on Health, Baltimore, Maryland, United States, ³Department of Biomedical Engineering, University of Wisconsin-Madison, madison, Wisconsin, United States, ⁴Department of Radiology, University of Wisconsin-Madison, Wisconsin, United States

Multi-Component T2 mapping using mcDESPOT two pool model was performed for ten asymptomatic volunteers and fourteen patients with varying degrees of osteoarthritis. The water fraction for water tightly bound to proteoglycan (FPG ) was significantly lower on all articular surfaces of the knee joint in patients with osteoarthritis than asymptomatic volunteers which likely reflect the decreased proteoglycan content of degenerative cartilage. FPG had greater statistical power than single component T2 (T2single ) for distinguishing between asymptomatic volunteers and patients with osteoarthritis especially on articular surfaces with early cartilage degeneration.

Cory Wyatt¹, Martin Kretzschmar¹, Deepak Kumar¹, Karupppasamy Subburaj², Thomas Link¹, Richard Souza¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CALIFORNIA, United States, ²Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States

In clinical images, the presence of bright infiltrating fluid in the dark labrum is used to diagnose labral tears. Quantitative imaging with shorter echo times may provide greater sensitivity to early labral damage than is possible with standard clinical MRI. In this pilot study, a VTE sequence is used to determine the feasibility of acquiring quantitative T2* maps of the labrum in healthy volunteers and those with labral injury. While no correlations with clinical score were seen, this technique may allow for investigation into the nature of labral injury and its effect on the biochemical nature of the labral tissue.

Alan C. Seifert¹, Suzanne L. Wehrli², Henry H. Ong¹, and Felix W. Wehrli^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²NMR Core Facility, Children's Hospital of Philadelphia, Philadelphia, PA, United States

The very shortest-T2 (~20-50 µs) component of bone 1H signal arises from the collagen backbone of bone matrix. We present images of bone matrix collagen from lamb tibial cortical bone (fully D2O-exchanged, air-dried to remove pore water, and fully H2O-hydrated) at 9.4T using a zero echo-time sequence. NMR spectroscopy confirms the removal of the narrow-line signal from the D2O-exchanged bone, and presence of the collagen-associated 40-kHz splitting in all three bones. Although collagen 1H signal is visible at 9.4T with 245-mT/m gradients, this signal may still be beyond the reach of clinical scanners with more limited gradient strengths.

Alexandra Hotca^1,2, Chamith S. Rajapakse, PhD³, Henry Rusinek, PhD⁴, Stephen Honig, MD⁵, Ryan Brown, PhD⁶, Cem M. Deniz, PhD⁶, Ravinder R. Regatte, PhD⁶, and Gregory Chang, MD^1
1Department of Radiology, NYU Langone Medical Center, Center for Musculoskeletal Care, New York, NY, United States, ²Department of Biological Sciences, CUNY-Hunter College, New York, NY, United States, ³Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States, ⁴Department of Radiology, New York University School of Medicine, New York, NY, United States, ⁵Osteoporosis Center, Hospital for Joint Diseases, NYU Langone Medical Center, New York, NY, United States, ⁶Department of Radiology, NYU Langone Medical Center, Center for Biomedical Imaging, New York, NY, United States

In this study, micro-finite element analysis (μFEA) is applied to high-resolution 3T MR images of proximal femur microarchitecture to quantitatively assess the mechanical competence (stiffness) of the whole proximal femur in vivo. Bone microarchitecture is understood to be a critical determinant of bone strength. The results of this study show that μFEA can be used to detect reduced whole proximal femur stiffness in subjects with osteoporotic fractures compared to controls without fracture who do not differ by bone mineral density. This warrants a larger study to confirm these trends.

Song Gao¹, Yanchun Zhu¹, Huailing Zhang², Shanglian Bao¹, Xiaoguang Cheng³, Graeme Bydder⁴, and Jiang Du^4
1Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing, Beijing, China, ²Guangdong Medical College, Dongguan, Guangdong, China,³Radiology Department, Jishuitan Hospital, Beijing, China, ⁴Department of Radiology, University of California, San Diego, CA, United States

Suppression of signals from surrounding long T2 tissues is important in achieving high contrast for cortical bone in UTE MRI. In IR-UTE,the data acquisition is begun at a delay time (TI) after an adiabatic fast passage inversion pulse designed to allow the inverted water and fat magnetization to approach the null point. Appropriate selection of TI allows robust and efficient suppression of water and fat signals. In this study, the effect of TI on cortical bone imaging was evaluated. We acquired the data using different degrees of undersampling to investigate the feasibility to improve the temporal resolution of IR-UTE.

Alan C. Seifert¹, Cheng Li¹, Chamith S. Rajapakse¹, Mahdieh Bashoor-Zadeh¹, Yusuf A. Bhagat¹, Alexander C. Wright¹, Babette Zemel², Antonios Zavaliangos³, and Felix W. Wehrli^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²GI, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, United States, ³Materials Science and Engineering, Drexel University, Philadelphia, PA, United States

Osteoporosis and osteomalacia both manifest as reduced apparent bone mineral density. The differentiating factor is mineral per volume of matrix. Advances in solid-state MRI have led to the possibility of quantitative bone mineral 31P and collagen-bound water 1H density measurement. Sixteen fully-mineralized human bone specimens were scanned with 31P ZTE and 1H Adiabatic Inversion-Recovery ZTE, and 31P and bound water densities were quantified relative to reference phantoms. Both densities correlate negatively with age and porosity, and positively with pQCT density, and as expected, the ratio of 31P to bound water density does not correlate with age, porosity, or pQCT density.

Mahdieh Bashoor-Zadeh¹, Chamith S. Rajapakse¹, Cheng Li¹, Wenli Sun¹, Alexander C. Wright¹, and Felix W. Wehrli^1
1Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States

Cortical bone porosity is underestimated even with the current state of the art human bone imaging modalities due to resolution limitations. Here, we pursue an UTE imaging approach by collecting only two echoes (TE=50µs and 2000µs) as part of a single scan based on the notion that the first echo contains total bone water, the second predominantly pore water yielding a porosity index as the ratio of the two signal amplitudes. In cadaveric human cortical bone, porosity index was found to correlate strongly with µCT-derived porosity and pore volume fraction obtained by laborious Laplace inversion of multi-echo UTE signal.

Yanchun Zhu^1,2, Jiang Du³, Song Gao⁴, Qun He³, Dandan Zheng⁵, Christine B. Chung³, Graeme M. Bydder³, and Shanglian Bao^1
1Beijing Key Laboratory of Medical Physics and Engineering, Peking University, Beijing, Beijing, China, ²Beijing Top Grade Healthcare, Beijing, Beijing, China, ³Radiology, University of California, San Diego, United States, ⁴Medical Imaging Physics Laboratory, Peking University, Beijing, Beijing, China,⁵Peking University, Beijing, Beijing, China

Dynamic Ultrashort TE (UTE) Imaging of the Temporomandibular Joint (TMJ)

Khaoula Bouazizi-Verdier¹ and Geneviève Guillot^1
1IR4M - UMR8081 - CNRS - Univ. Paris Sud, Orsay, France

Cortical bone porosity can be determined by UTE-MRI. Magnetization Transfer has been already observed between collagen-bound water and free water. Since porosity depends on T1 value, the method used for T1 measurement should be critically assessed. T1 values deduced from UTE experiments at different TR and flip angles in bovine cortical bone increased with TR. Cross-relaxation parameters in agreement with an off-resonance experiment with a long saturation pulse allowed us to simulate the TR-dependent effect of the variable flip angle (VFA) acquisition. The uncertainty on the two-pool parameters was lower when simulating VFA experiment than when fitting off-resonance saturation.

Olgica Zaric¹, Pavol Szomolanyi¹, Vladimir Mlynarik¹, Mark Schurz², Stefanie Syre², Thomas Tiefenböck², Manuela Karner¹, and Siegfried Trattnig^1
1Department of Biomedical Imaging and Image-guided Therapy, Medical University in Vienna, Vienna, Austria, Austria, ²Trauma Surgery Department, Medical University in Vienna, Vienna, Austria, Austria

The aim of this study was to investigate the feasibility of gagCEST imaging and T2* mapping in post-surgery follow-up of biochemical and morphological properties of reconstructed tissue in the patients with anterior cruciate ligament substitution. Results showed an increase of gagCEST effect (related to total glycosaminoglycan content in the tissue) from early to late post-surgery period, while T2* (related to collagen architecture network) showed a significant decrease. Based on this initial results, we conclude that gagCEST has a great potential as biomarker in investigation of properties of newly developed ligament tissue in patients after ACL reconstruction.

Michael Carl¹, Jiang Du², Nikolaus M Szeverenyi², Sheronda Statum², Christine B Chung², and Graeme M Bydder^2
1Global MR Applications & Workflow, General Electric, San Diego, CA, United States, ²University of California, San Diego, CA, United States

Distinction between the red and white zones of the meniscus of the knee is of considerable clinical importance. In this study we employed a 3D Cones sequence to allow display of images in any plane, and followed the subjects for over two hours post injection to determine the time course of enhancement. Demonstration of the red and white zones was dramatic, as was the progression of the extent of the enhancement over time.

Fang Liu¹, Wally Block^1,2, and Richard Kijowski^3
1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³Department of Radiology, University of Wisconsin-Madison, Wisconsin, United States

In-vivo multi-component T2 mapping of menisci using mcDESPOT was performed on asymptomatic volunteers and patients with osteoarthritis at 3.0T. Meniscus has a slowly relaxing water component with a T2 relaxation time of 30.9 ms and a rapidly relaxing water component with a T2 relaxation time of 10.3 ms. Our study has documented a decreased rapid relaxing water component fraction and an increased T2 relaxation time of meniscus in patients with OA when compared to healthy volunteers with greater changes associated with more severe meniscal degeneration (i.e. tearing) and more severe joint degeneration (i.e. higher WORM score).

Christina Hopfgarten¹, Stefan Kirsch¹, Gregor Reisig², Michael Kreinest², and Lothar R. Schad^1
1Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, ²Experimental Orthopaedics and Trauma Surgery, Orthopaedic and Trauma Center Mannheim, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

The aim of the experiments was to check, to which extend the MTR is affected by residual dipole-dipole couplings. Five porcine medial menisci were investigated. The transverse relaxation time shows a distinct variation of T2 values with the orientation of the imaged slice. In contrast, the MTR values are approximately constant over the all orientations. The observed absence of the magic angle (MA) effect in MTR maps may provide a useful tool for diagnosis of meniscal tissue degeneration since it prevents misinterpretation due to MA-artifacts.

Vladimir Juras^1,2, Sebastian Apprich¹, Pavol Szomolanyi^1,2, Stefan Zbyn¹, Marek Chmelik¹, and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

In this study we found moderate correlation between normalized sodium signal which is believed to be related to glycosaminoglycan content in cartilage and Achilles tendon and quantitative morphological VIMAT Score. Relative low correlations suggest that sodium MRI and VIMATS are complementary markers - VIMATS for macroscopic changes and the normalized sodium signal as a marker of GAG content increase due to accompanying or preceding degeneration Sodium imaging may have the potential to detect early stages of Achilles tendon degeneration and partial tear.

L.Tugan Muftuler¹, Joshua J. Jarman², Hon J. Yu³, Dennis J. Maiman⁴, and Vance O. Gardner^5
1Department of Neurosurgery and Center for Imaging Research, Medical College of Wisconsin, Milwaukee, WI, United States, ²Medical college of Wisconsin, WI, United States, ³Radiological Sciences, University of California, Irvine, CA, United States, ⁴Department of Neurosurgery, Medical college of Wisconsin, Milwaukee, WI, United States, ⁵Orthopedic Research Institute of California, CA, United States

Disruption of nutrient delivery through the endplates of intervertebral discs could be a factor initiating or accelerating the degeneration processes. Thus, our goal was to develop a high spatial resolution Dynamic Contrast Enhanced MRI (DCE-MRI) protocol to study solute transport mechanisms in the cartilaginous endplates and subchondral bone of degenerating discs. Results indicate that the cracks and fissures developing in the subchondral bone of degenerating discs lead to increased DCE-MRI enhancement. Furthermore, caudal endplates showed higher enhancement than cranial endplates and the difference increased at lower lumbar levels.

Ephraim I Ben-Abraham¹, Jun Chen, Ph.D.¹, and Richard L Ehman, M.D.^1
1Radiology, Mayo Clinic, Rochester, MN, United States

Low back pain (LBP) is a very costly and prevalent health disorder in the U.S. One of the most common causes of LBP is degenerative disc disease (DDD). It is known that the stiffness of the disc changes substantially with degeneration. MRE has been demonstrated for estimating the shear stiffness of the nucleus in the intervertebral disc in vitro. In this study, we investigate the change in nucleus stiffness caused by an in vitro, enzymatically-induced animal model for disc degeneration using MRE. Our results showed a substantial increase in the nucleus shear stiffness with the induced disc degeneration.

RAYMOND LEE¹, GLADYS LO GOH¹, KA FAT JOHN CHAN¹, Wing Wa Li¹, PO LUNG CHAN¹, CHI WAI LIU¹, KA MAN CHAN¹, and MEI LEE HUNG^1
1DEPARTMENT OF DIAGNOSTIC & INTERVENTIONAL RADIOLOGY, HONG KONG SANATORIUM & HOSPITAL, HONG KONG, Hong Kong

Diffusion-weighted MRI imaging is an emerging technique to assess bone marrow abnormality. Normal values may need to adapt for age and anatomic location to avoid misinterpretation. Previous studies showed contradictory results whether bone marrow diffusivity changes with age and focus on lumbar region only. The purpose of this study was to evaluate the regional differences and age-related changes of ADC values in vertebral bone marrow by measuring ADC values in cervical, thoracic, lumbar, sacral and both iliac bone marrow in healthy adults. Current study may give an insight to establish the normal ADC values on vertebral column for future references.

William D. Rooney¹, Sean C. Forbes², William T. Triplett³, James R. Pollaro¹, Dah-Jyuu Wang⁴, Soren deVos², James Meyer⁴, Rebecca Willcocks³, Barry Byrne⁵, Richard Finkel⁶, Barry Russman⁷, Erika Finanger⁷, Michael Daniels⁸, Lee Sweeney⁹, Glenn Walter³, and Krista Vandenborne^2
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon, United States, ²Department of Physical Therapy, University of Florida, Gainesville, Florida, United States, ³University of Florida, Physiology and Functional Genomics, Gainesville, Florida, United States, ⁴Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States, ⁵Department of Pediatrics, University of Florida, Gainesville, Florida, United States, ⁶Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States, ⁷Shriners Hospital, Portland, Oregon, United States,⁸University of Texas, Austin, Texas, United States, ⁹Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States

This study investigates the utility of quantitative MR measures to track disease progression in DMD. 3T Data were acquired from 125 DMD and 28 control boys. ¹H MRS data were acquired to estimate fat fraction (FF) in vastus lateralis (VL) and soleus (Sol) muscles. MRI quantitative T₂ (qT₂) values were determined for muscles in the upper and lower leg. DMD boys were studied at baseline, and 12 month and 24 month follow-ups. Both FF and qT₂ are increased at follow-up with greatest absolute differences found in upper leg muscles. MRI qT₂ values were strongly associated with muscle FF.

Kieren G Hollingsworth¹, David M Higgins², Michelle McCallum³, Anna Coombs¹, and Volker Straub^3
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ²Philips Healthcare, Guildford, Surrey, United Kingdom, ³Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Fat fraction measurement in muscular dystrophy has an important role to play in future therapy trials. Undersampled data reconstructed by combined compressed sensing and parallel imaging (CS-PI) can potentially reduce trial cost. 8 patients with Becker muscular dystrophy were recruited and 3 different prospective undersampling ratios were acquired. When plotted against the fat fractions derived from fully sampled data, non-significant bias and 95% limits of agreement of 1.58%, 2.17% and 2.41% were found for the three CS-PI reconstructions: equivalent PI reconstructions were of lower quality. Prospective undersampling can substantially accelerate muscle fat fraction measurement in muscular dystrophy.

Claire Wary¹, Noura Azzabou¹, Céline Giraudeau¹, Julien Le Louër¹, Thomas Voit², Laurent Servais³, and Pierre G Carlier^1
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²Institut de Myologie, Université Pierre et Marie Curie Paris 6, UM 76, INSERM U974, CNRS UMR 7215, Paris, France, ³AIM, Service Essais Cliniques et Bases de Données, Paris, France

Twelve quantitative NMRI and NMRS indices were measured to evaluate disease progression in forearms of 24 Duchenne Muscular Dystrophy patients. Fat infiltration and muscle T2 showed greater involvement in flexor compared to extensor muscle groups, however, while fat fraction increased, muscle T2 became lower in non ambulant patients. Fat infiltration and metabolic indices measured in arms of patients correlated strongly together, but not with T2, and worsened overall with patient age. However these indices evolved remarkably differently before and after loss of ambulation, evocative of concomittant progression in lower and upper limbs.

Sean C Forbes¹, Glenn A. Walter¹, William Rooney², Dah-Jyuu Wang³, William Triplett¹, Rebecca Willcocks¹, James Pollaro², Barry Byrne¹, Richard Finkel⁴, Barry Russman⁵, Erika Finanger⁵, Gihan Tennekoon³, Lee Sweeney⁶, and Krista Vandenborne^1
1University of Florida, Gainesville, Florida, United States, ²Oregon Health & Science University, Portland, Oregon, United States, ³Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States, ⁴Nemours Children’s Hospital, Florida, United States, ⁵Shriners Hospital for Children, Portland, Oregon, United States, ⁶University of Pennsylvania, Philadelphia, Pennsylvania, United States

Duchenne muscular dystrophy (DMD) is characterized by progressive muscle deterioration, loss of functional abilities, and reduced life expectancy. Functional deficits in muscle performance are often not observed in DMD until after age 7, and therefore these functional measures may not be sensitive for detecting disease progression at a young age. In this study we observed that MRI-T₂ and ¹H₂O T₂derived using ¹H-MRS were sensitive to muscle involvement at a young age (5-7 years) consistent with increased inflammation and muscle damage in DMD.

Ishu Arpan¹, Rebecca Willcocks¹, Sean Forbes¹, Donovan Lott¹, Claudia Senesac¹, William Triplett¹, Michael Daniels², Barry Byrne³, Bill Rooney⁴, Erika Finanger⁴, Richard Finkel⁵, Barry Russman^4,6, Gihan Tennekoon⁵, Dah-Jyuu Wang⁷, Glenn Walter⁸, H. Lee Sweeney⁹, and Krista Vandenborne^1
1Physical Therapy, University of Florida, Gainesville, Florida, United States, ²University of Texas, Texas, United States, ³Pediatrics and Molecular Genetics & Microbiology, University of Florida, Gainesville, Florida, United States, ⁴Oregon Health & Science University, Oregon, United States,⁵Neurology, The Children’s Hospital of Philadelphia, Pennsylvania, United States, ⁶Shriners Hospital for Children, Oregon, United States,⁷Radiology, The Children’s Hospital of Philadelphia, Pennsylvania, United States, ⁸Physiology and Functional Genomics, University of Florida, Gainesville, Florida, United States, ⁹Physiology, University of Pennsylvania, Pennsylvania, United States

The aim of this study was to evaluate impact of corticosteroids on lower extremity muscles of 5-7 year old boys with DMD using MRI and MRS. 15 boys with DMD on corticosteroids and 15 age-matched corticosteroid-naive boys were recruited. Inherent MR relaxation properties of muscle (T₂ by imaging and spectroscopy) and lipid fraction were measured. MRI/MRS results showed that T₂ values and fat fraction were lower in muscles of boys in treatment group; suggesting reduced inflammation/ damage and fat infiltration with corticosteroid treatment. Further, there was less change in fat fraction over one year in muscles of boys taking corticosteroids.

Ke Li^1,2, Richard D. Dortch^1,2, E. Brian Welch^1,2, Susan F. Kroop³, Joseph W. Huston³, Amanda K.W. Buck^1,2, Theodore F. Towse^2,4, Nathan D. Bryant^1,2, Bruce M. Damon^1,2, and Jane H. Park^5
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology, Vanderbilt University, Nashville, TN, United States, ³Rheumatology Division, School of Medicine, Vanderbilt University, Nashville, TN, United States, ⁴Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ⁵Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

The idiopathic inflammatory myopathies (IIM), including polymyositis, dermatomyositis, and inclusion body myositis, are a set of chronic disorders with pathological features of muscle inflammation, fibrosis, fat infiltration/replacement, and atrophy. IIM patients experience weakness, pain, fatigue, and difficulties in daily activities. However, clear no correlations have been established between the variations in clinical presentation of these diseases, degree of muscle enzyme elevation, and degree of weakness are not always present. In this work, a multi-parametric MRI protocol was developed to investigate the pathological processes at a microscopic level and to characterize the severity of muscle pathologies more objectively and quantitatively.

JULIEN GONDIN ¹, GUILLAUME DUHAMEL¹, MARINE THERET², KATARINA PEGAN³, CAROLE PEYSSONNAUX², SYLVAIN CUVELLIER², BENEDICTE CHAZAUD², DAVID BENDAHAN¹, and REMI MOUNIER^2
1Aix-Marseille University, CNRS, CRMBM UMR 7339, MARSEILLE, France, ²INSERM, U1016; CNRS, UMR8104; Université Paris Descartes, Institut Cochin, PARIS, France, ³Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, LJUBLJANA, Slovenia

We aimed at carefully addressing the role of myeloid HIFs in the resolution of inflammation during skeletal muscle regeneration on the basis of in vitro and ex vivo experiments combined to in vivo multimodal magnetic resonance imaging (MRI), including T2 mapping and diffusion tensor imaging. Our multiscale methodological approach clearly demonstrated that neither HIF-1α nor HIF-2α are involved in the muscle regeneration process resulting from an acute injury, thereby indicating that myeloid HIFs are dispensable for skeletal muscle regeneration. We also reported that multimodal MRI appears as a method of choice for monitoring skeletal muscle injury and repair.

Pierre G Carlier¹, Noura Azzabou¹, Paulo Loureiro de Sousa¹, Robert-Yves Carlier², Jean-Marc Boisserie¹, Claire Wary¹, David Orlikowski², and Pascal Laforêt^3
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²AP-HP Hôpital Universitaire Raymond-Poincaré, Garches, France, ³Centre de référence pour les maladies neuromusculaires de l'Est de Paris, AP-HP Hôpital Universitaire Pitié-Salpêtrière, Paris, France

In this study, we quantified muscle water T2, a marker of dystrophic disease activity, in thigh and leg muscles of glycogen storage disorder type II (GSDII) patients. One third of GSDII muscles had abnormal T2. We also investigated the relationship between T2 and the extension and progression of fatty degenerative changes in GSDII skeletal muscle. The intramuscular fat content increased faster in muscles displaying an abnormal T2. Enzyme substitution therapy was able to slow down the fatty degenerative changes of adult GSDII patients.

Sunil K. Valaparla^1,2, Qi Peng³, Feng Gao¹, Timothy Q. Duong¹, and Geoffrey D. Clarke^1,2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, ²Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, ³Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, United States

ype 2 Diabetes Mellitus (T2DM) has been associated with increased amount and distribution of intermuscular adipose tissue (IMAT). This study evaluated a fuzzy clustering (FCT) segmentation algorithm in investigating differences in distribution of IMAT and SAT in T1-weighted thigh and lower leg images between T2DM and controls. T-test showed no statistical significance between T2DM and Controls for thigh SAT and IMAT and for lower leg SAT but was significant for IMAT. FCT algorithm with low computational complexity and processing time enables effective characterization of muscular fat in MR images and can be used to assess IMAT for large-scale clinical studies.

Benjamin Marty¹, Pierre-Yves Baudin¹, Benjamin Robert², Alexey Shukelovich¹, Robert-Yves Carlier³, Noura Azzabou¹, and Pierre G Carlier^1
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²Siemens Healthcare, Saint-Denis, France, ³AP-HP Hôpital Universitaire Raymond-Poincaré, Garches, France

Fatty infiltration of muscles is a marker of disease progression in muscular dystrophies. Although routine T1-weighted imaging gives an indication of the presence or absence of muscular fat infiltration, it is difficult to extract quantitative data from these images. On the contrary, Dixon methods can give quantitative measures of water and fat fractions. Generally, whole-body exams consist in the acquisition of a T1w sequence, followed by Dixon acquisitions on targeted regions to quantitatively assess fat infiltration. In our study we demonstrate that the use of a well calibrated sequence allows replacing whole-body T1w imaging by a whole-body Dixon imaging.

Emily Catherine Bush¹, Theodore F Towse¹, Amanda K.W. Buck¹, Christopher P Elder¹, Ke Li¹, and Bruce M Damon^1
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States

Recent developed methods for non-invasively studying muscle architecture in humans in vivo include Ultrasonography (US) and Diffusion Tensor Imaging (DTI). Many studies have used either US or DTI, but there has been little or no research comparing the two techniques. The goal of this study was to compare the results of US and DTI for measuring human muscle fiber orientation in vivo. The data presented in this abstract indicate good agreement between manual US and DTI, supporting the use of DTI for in vivo muscle architecture measurements.

Vadim Malis¹, Usha Sinha¹, Robert Csapo², and Shantanu Sinha^2
1Physics, SDSU, San Diego, CA, United States, ²Radiology, UCSD, San Diego, CA, United States

The objective quantification of regional muscle deformation is a valuable clinical tool to evaluate normal and diseased muscle. Several studies have shown that the strain and strain rate (SR) tensor are not aligned with the DTI tensor indicating the presence of shear strain. We report here, 3D SR tensor mapping of the medial gastrocnemius and identify shear strain components from a series of velocity encoded images acquired during isometric contraction by aligning the 3D SR tensor along the principal axes of the diffusion tensor (Fiber Aligned Strain Rate). The in-plane shear strain component arising from asymmetric in-pane deformation was identified.

Peter A Hardy^1,2, Anders Andersen^2,3, Thorsten Feiweier⁴, Bruce Damon⁵, and Brian Noehren^6
1Radiology, University of Kentucky, Lexington, Kentucky, United States, ²MRISC, University of Kentucky, Lexington, Kentucky, United States, ³Anatomy & Neurobiology, University of Kentucky, Lexington, Kentucky, United States, ⁴Healthcare Sector, Siemens AG, Erlangen, Germany, ⁵Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, United States, ⁶Rehabilitation Sciences, University of Kentucky, Lexington, Kentucky, United States

In ten normal volunteers we compared standard Twice-Refocused Spin echo against STEAM diffusion tensor imaging for imaging the thigh. From the diffusion tensor images produced by each technique we tracked muscle fiber bundles in the Vastus Lateralus and from these estimated the pennation angle. STEAM produced superior images from which we generated improved tracking of fiber bundles and estimated the muscle pennation angle with lower variance. STEAM-DTI will give more sensitive measures for evaluation of muscle injury and the effects of therapy.

Sun Hwa Hong¹, Suk-Joo Hong², Joon-Shik Yoon³, Chang-Hyun Oh⁴, Hee Kyung Kim⁵, Jang-Gyu Cha⁶, and Kyeong Ah Kim^2
1Department of Radiology, Korea University Guro Hospital, Seoul, Seoul, Korea, ²Department of Radiology, Korea University Guro Hospital, Seoul, Korea,³2Department of Physical medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea, ⁴Department of Electronics & Information Engineering, Korea University College of Medicine, Seoul, Korea, ⁵Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States,⁶Department of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon, Gyeonggi-do, Korea

MR elastographic technique for quantitatively assessing the mechanical properties of shoulder muscles was developed. The authors extended the application of MRE of the shoulder muscles to 3.0T MR imaging system.

Ke Li^1,2, Richard D. Dortch^1,2, E. Brian Welch^1,2, Amanda K.W. Buck^1,2, Theodore F. Towse^2,3, Nathan D. Bryant^1,2, Bruce M. Damon^1,2, and Jane H. Park^4
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³4Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ⁴5Molecular Physiology and Biophysics, Nashville, TN, United States

It is known that skeletal muscle deteriorates with aging. Therefore, age may introduce bias in longitudinal studies. In addition, gender, body-mass-index (BMI), and muscle fat content may introduce bias as well. In this work, the dependence of a number of quantitative MRI indices (T1, T2, pool size ratio, FA, ADC, and λ3) on these demographic factors was investigated in healthy muscles. For healthy subjects between the ages of 19 and 65, the only significant relationships observed were with muscle fat content.

Georg B Fiedler^1,2, Albrecht Ingo Schmid^1,2, Sigrun Goluch^1,2, Elmar Laistler^1,2, Kiril Schewzow^1,2, Michael Wolzt³, Ewald Moser^1,2, and Martin Meyerspeer^1,2
1MR Centre of Excellence, Medical University of Vienna, Vienna, Vienna, Austria, ²Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Vienna, Austria, ³Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Vienna, Austria

Kinetics of phosphorus metabolites in human soleus (SOL) and gastrocnemius medialis (GM) muscles were measured during and after plantar flexion exercise bouts with varying workloads, using single-shot localized MRS (semi-LASER) at high time resolution with a custom multichannel 1H/31P coil at 7T. PCr recovery time τ was successfully quantified in GM and in SOL. In GM, τ showed positive correlation with exercise intensity and GM PCr depletion. In SOL, these correlations were not found, e.g. some datapoints with strong depletion in SOL even showed a τ of only 20s. pH in GM was also correlated to PCr depletion.

Christopher P. Elder^1,2, Jack T. Skinner^1,3, Theodore F. Towse^2,3, Nathan D. Bryant^1,3, and Bruce M. Damon^1,3
1Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, United States, ²Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ³Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States

Subtracting the time-courses of R2* and R2 from separate image acquisitions yields an estimate of R2’ that can be used for image-based calculation of muscle oxyhemoglobin saturation. An EPI based multiple spin- and gradient-echo (SAGE) method developed for brain perfusion imaging permits simultaneous measurement of R2* and R2. We applied the SAGE sequence to measurements of relaxation rates in skeletal muscle during maximal and submaximal isometric dorsiflexion contractions. Baseline SAGE R2* and R2 measurements agree with conventional multi-echo measurements. SAGE allows more direct measurement of R2* and R2 related to the BOLD effect in skeletal muscle induced by isometric contractions.

Seongjin Choi¹, David A. Reiter², Kenneth W. Fishbein², Eleanor M. Simonsick¹, Michael Schär³, Richard G. Spencer², and Luigi Ferrucci^1
1Translational Gerontology Branch, NIH/National Institute on Aging, Baltimore, MD, United States, ²Laboratory of Clinical Investigation, NIH/National Institute on Aging, Baltimore, MD, United States, ³Philips Healthcare, Cleveland, Ohio, United States

Gait speed has been established as the single most important predictor of morbidity in the elderly. In addition, muscle mitochondrial function plays a central role in mobility. 31P MRS of skeletal muscle permits the measurement of maximum ATP synthesis rate through the recovery time constant of phosphocreatine (τPCr) after exercise. In this cross-sectional study using the Baltimore Longitudinal Study on Aging cohort, we assessed the associations between 31P MRS-determined mitochondrial function, age and ambulatory speed. We found that τPCr correlated well with maximum, but not with usual, walking speed, indicating its potential usefulness as a marker for maximum energy output.

Robert Csapo¹, Vadim Malis², John Hodgson¹, and Shantanu Sinha^1
1Radiology, University of California at San Diego, San Diego, CA, United States, ²Physics, San Diego State University, San Diego, CA, United States

Plantarflexor musculo-tendinous tissue dynamics was compared by velocity-encoded phase contrast MRI in young (YW) and senior (SW) women cohorts. Submaximal, isometric contraction was associated with gastrocnemius medialis fascicle shortening and increases in pennation angles, with the effects being significantly larger in SW, in spite of greater Achilles tendon elasticity measured. Strains along superficial and deep aponeurosis were not significantly different between groups but displayed substantial, regional heterogeneity. These findings argue against a serial alignment of contractile and connective tissues and suggest that factors other than tendon compliance influence the age-dependent MSK dynamics resulting in large decrease of force in seniors.

Robert Csapo¹, Vadim Malis², Usha Sinha³, Jiang Du⁴, and Shantanu Sinha^1
1Radiology, University of California at San Diego, San Diego, CA, United States, ²Physics, San Diego State University, San Diego, CA, United States, ³Physics, San Diego State University, CA, United States, ⁴Radiology, University of California at San Diego, CA, United States

Aging skeletal muscles are characterized by a progressing accumulation of intramuscular, non-contractile tissues. To quantitate the amount of intramuscular adipose (IMAT) and connective (IMCT) tissues, MR-based fater-water quantitation (IMAT) and ultrashort echo time (IMCT) imaging techniques were applied to the study of the Triceps Surae complex in young (YW) and senior (SW) women. Both IMAT and IMCT contents were significantly larger in SW. Additional measurements of plantarflexor strength and Triceps Surae volumes suggest that the inclusion of non-contractile tissues is likely to negatively affect a muscle’s intrinsic capacity to generate force at older age.

Prodromos Parasoglou¹, Ding Xia¹, Greg Chang¹, and Ravinder R Regatte^1
1Radiology, NYU School of Medicine, New York, New York, United States

The creatine kinase reaction plays an important role is skeletal muscle. In this work we developed and implemented a progressive saturation three-dimensional 31P-MRI method for mapping the kinetics of the creatine kinase reaction, and the unidirectional phosphocreatine to adenosine triphosphate metabolic fluxes in muscles of the lower leg at 3.0 T. Mapping the kinetics of the creatine kinase reaction with large tissue coverage and relatively high spatial resolution is a promising method for the diagnosis and monitoring of several diseases that affect function of skeletal muscle.

Jessica A.M. Bastiaansen¹, Hikari A.I. Yoshihara^2,3, Yuhei Takado^2,4, Rolf Gruetter^1,5, and Arnaud Comment^2
1Laboratory of Functional and Metabolic Imaging, EPFL, Lausanne, Switzerland, ²Institute of Physics of Biological Systems, EPFL, Lausanne, Switzerland,³Department of Cardiology, CHUV, Lausanne, Switzerland, ⁴Laboratory of Biological Geochemistry, EPFL, Lausanne, Switzerland, ⁵Department of Radiology, University of Geneva and University of Lausanne, Lausanne, Switzerland

Lactate is not merely an end product in skeletal muscle metabolism but also an important metabolic intermediate. Using hyperpolarized 13C MRS, lactate metabolism can be investigated in real time, injected at physiological concentrations leaving other oxidative processes undisturbed. Here we investigated the use of hyperpolarized 13C lactate as a substrate for metabolic studies in skeletal muscle in vivo, in different nutritional states. The herein proposed method allows probing simultaneously both PDH activity and variations in alanine tissue concentration, which are associated with metabolic dysfunctions.

Guenter Steidle¹ and Fritz Schick^1
1University Department of Radiology, Section on Experimental Radiology, Tuebingen, Germany

IVIM sensitive MR images from single acquisitions recorded in resting calf musculature often display irregularly shaped areas with clear signal voids caused by unconscious focal mechanical contraction at rest. This work reports on systematic MR studies on the spatial and temporal pattern of such signal voids in calf musculature of 10 healthy. DWI or DTI measurements in the skeletal musculature of the lower leg are hampered by those sporadic activity-related signal voids, when mean signals of series of measurements are used for the calculations, and have to be considered for quantitative DWI or DTI of skeletal musculature.

Anette Karlsson^1,2, Johannes Rosander³, Thobias Romu^1,2, Joakim Tallberg², Anders Grönqvist^2,4, Magnus Borga^1,2, and Olof Dahlqvist Leinhard^2,5
1Department of Biomedical Engineering (IMT), Linköping University, Linköping, Sweden, ²Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, ³Advanced MR Analytics (AMRA) AB, Linköping, Sweden, ⁴Radiation Physics, University Hospital of Linköping, Linköping, Sweden, ⁵Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden

Accurate and precise assessment of human muscle tissue is important for further understanding of different muscle diseases and syndromes. We present a rapid whole body MR method for automatic quantification of total and regional muscle volume. The method is based on multi-atlas segmentation of intensity corrected water-fat separated images. The method was validated with a leave-one-out approach, using manually segmented atlases from 10 subjects as ground truth. The result gave a coefficient of variation on total muscle volume equal to 1.25±1.35 % (mean ± standard deviation). The method enables cost-efficient large-scale studies, investigating conditions such as sarcopenia and muscular dystrophies.