Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy



3980-4003 Musculoskeletal System: Emerging Techniques
4004-4027 Muscle: Structure & Function

Musculoskeletal System: Emerging Techniques

Tuesday 13 May 2014
Exhibition Hall  13:30 - 14:30

  Computer #  
3980.   73 Three-Dimensional MRI-Based Statistical Shape Model of the Knee in Patients with ACL Injuries
Valentina Pedoia1, Drew Lansdown2, Paul Jung1, C. Benjamin Ma2, and Xiaojuan Li1
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.

3981.   74 Patient-reported Outcomes are associated with Cartilage T1ρ and T2 Quantification and Whole-Organ Magnetic Resonance Imaging Score (WORMS) after acute ACL injuries
Yu Zhang1,2, Michael Hoppe1, Samuel Wu3, Martin Kretzschmar3, Richard Souza3, Benjamin Ma3, and Xiaojuan Li3
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.

3982.   75 Pattern Recognition Classification of Weighted MR Images of OARSI Scored Human Articular Cartilage at 3T
Vanessa A. Lukas1, Beth G. Ashinsky1, Christopher E. Coletta2, Julianne M. Boyle1, David A. Reiter1, Corey P. Neu3, Richard G. Spencer1, and Ilya G. Goldberg2
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.

3983.   76 Clinical feasibility of a stimulated echo based diffusion sequence and correlation between T1rho and diffusion values
Aditi Guha1, Cory Wyatt1, Dimitrios Karampinos1,2, Lorenzo Nardo1, Thomas M Link1, and Sharmila Majumdar1
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.

3984.   77 Does prestructural, asymptomatic cartilage degeneration occur in early FAI? A T1rho study.
Gerd Melkus1, Kawan S Rakhra1, Arturo Cardenas-Blanco2, Andrew Speirs3, Ian Cameron1, Mark E Schweitzer4, and Paul E Beaulé5
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.

3985.   78 Evaluation of the GAG content of articular cartilage in the knee joint using gagCEST: correlation to the gold-standard with multicompartmental biochemically analyzed GAG content
Martin Brix1,2, Vladimir Mlynarik2, Benjamin Schmitt3, Pavol Szomolanyi2, Gerhard Hobusch1, Florian Sevelda1, Stephan Puchner1, Sonja Walzer1, Reinhard Windhager1, Stephan Domayer4, and Siegfried Trattnig2
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.

3986.   79 Improved visualization of cartilage canals using semi-quantitative susceptibility mapping
Mikko Johannes Nissi1,2, Ferenc Toth3, Cathy S Carlson3, and Jutta M Ellermann1
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.

3987.   80 Multi-Component T2 Analysis of Articular Cartilage in Osteoarthritis Patients using mcDESPOT at 3.0T
Fang Liu1, Richard G. Spencer2, Wally Block1,3, and Richard Kijowski4
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.

81 Quantitative VTE-T2* Imaging of the Hip Labrum
Cory Wyatt1, Martin Kretzschmar1, Deepak Kumar1, Karupppasamy Subburaj2, Thomas Link1, Richard Souza1, and Sharmila Majumdar1
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.

3989.   82 Is Bound Water a Surrogate for Collagen Matrix Density? Insights from 1H Zero Echo-Time MRI
Alan C. Seifert1, Suzanne L. Wehrli2, Henry H. Ong1, and Felix W. Wehrli1
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.

3990.   83 In Vivo MR Computation of Whole Proximal Femur Mechanical Competence Using Micro-Finite Element Analysis Applied to High-Resolution 3T MRI of Proximal Femur Microarchitecture
Alexandra Hotca1,2, Chamith S. Rajapakse, PhD3, Henry Rusinek, PhD4, Stephen Honig, MD5, Ryan Brown, PhD6, Cem M. Deniz, PhD6, Ravinder R. Regatte, PhD6, and Gregory Chang, MD1
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.

3991.   84 Adiabatic inversion recovery prepared ultrashort echo time (IR-UTE) imaging of cortical bone: effects of inversion time and undersampling
Song Gao1, Yanchun Zhu1, Huailing Zhang2, Shanglian Bao1, Xiaoguang Cheng3, Graeme Bydder4, and Jiang Du4
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.

85 Bone Mineral and Matrix Densities Measured by Solid-State 1H and 31P MRI
Alan C. Seifert1, Cheng Li1, Chamith S. Rajapakse1, Mahdieh Bashoor-Zadeh1, Yusuf A. Bhagat1, Alexander C. Wright1, Babette Zemel2, Antonios Zavaliangos3, and Felix W. Wehrli1
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.

3993.   86 3D UTE MRI derived porosity index as a practical approach to assess cortical bone porosity in human subjects
Mahdieh Bashoor-Zadeh1, Chamith S. Rajapakse1, Cheng Li1, Wenli Sun1, Alexander C. Wright1, and Felix W. Wehrli1
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.

87 Dynamic Ultrashort TE (UTE) Imaging of the Temporomandibular Joint (TMJ)
Yanchun Zhu1,2, Jiang Du3, Song Gao4, Qun He3, Dandan Zheng5, Christine B. Chung3, Graeme M. Bydder3, and Shanglian Bao1
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)

3995.   88 Cross-relaxation parameters in cortical bone from combined VFA-UTE and off-resonance saturation
Khaoula Bouazizi-Verdier1 and Geneviève Guillot1
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.

3996.   89 gagCEST MRI: A potential biomarker for post-surgery follow-up of patients with anterior cruciate ligament reconstruction
Olgica Zaric1, Pavol Szomolanyi1, Vladimir Mlynarik1, Mark Schurz2, Stefanie Syre2, Thomas Tiefenböck2, Manuela Karner1, and Siegfried Trattnig1
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.

3997.   90 Imaging of the Red and White Zones of the Meniscus Using a 3D Cones (UTE) Subtraction Pulse Sequence
Michael Carl1, Jiang Du2, Nikolaus M Szeverenyi2, Sheronda Statum2, Christine B Chung2, and Graeme M Bydder2
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.

3998.   91 In-Vivo Assessment of Multiple Water Components of Human Knee Menisci using mcDESPOT at 3.0T
Fang Liu1, Wally Block1,2, and Richard Kijowski3
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).

3999.   92 Investigation of the influence of residual 1H dipole-dipole couplings on magnetization transfer ratio maps of porcine menisci
Christina Hopfgarten1, Stefan Kirsch1, Gregor Reisig2, Michael Kreinest2, and Lothar R. Schad1
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.

4000.   93 Correlation of Morphological Score (VIMATS) with Sodium MRI in Patients with Painful Achilles tendon
Vladimir Juras1,2, Sebastian Apprich1, Pavol Szomolanyi1,2, Stefan Zbyn1, Marek Chmelik1, and Siegfried Trattnig1
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.

4001.   94 Intervertebral disc degeneration and changes in solute transport mechanisms in disc endplates studied by DCE-MRI
L.Tugan Muftuler1, Joshua J. Jarman2, Hon J. Yu3, Dennis J. Maiman4, and Vance O. Gardner5
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.

4002.   95 Assessment of an In Vitro Animal Model for Intervertebral Disc Degeneration Using MR Elastography
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.

4003.   96 Regional differences and age-related changes of apparent diffusion coefficient (ADC) in vertebral bone marrow of healthy adult.

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.


Muscle: Structure & Function

Tuesday 13 May 2014
Exhibition Hall  14:30 - 15:30

  Computer #  
4004.   73 Tracking Disease Progression in Duchenne Muscular Dystrophy: Longitudinal Changes in Quantitative MR Measures
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 Vandenborne2
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.

4005.   74 Accelerating fat fraction measurements in muscular dystrophy using compressed sensing and parallel imaging
Kieren G Hollingsworth1, David M Higgins2, Michelle McCallum3, Anna Coombs1, and Volker Straub3
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.

4006.   75 Quantitative NMRI and NMRS indices identify augmented disease progression after loss of ambulation in forearms of boys with Duchenne Muscle Dystrophy
Claire Wary1, Noura Azzabou1, Céline Giraudeau1, Julien Le Louër1, Thomas Voit2, Laurent Servais3, and Pierre G Carlier1
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.

4007.   76 T2 mapping and Single Voxel 1H-MRS Detect Skeletal Muscle Involvement in Young Boys with Duchenne Muscular Dystrophy
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 Vandenborne1
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.

4008.   77 MR supports therapeutic effects of corticosteroids in 5-7 year old boys with DMD
Ishu Arpan1, Rebecca Willcocks1, Sean Forbes1, Donovan Lott1, Claudia Senesac1, William Triplett1, Michael Daniels2, Barry Byrne3, Bill Rooney4, Erika Finanger4, Richard Finkel5, Barry Russman4,6, Gihan Tennekoon5, Dah-Jyuu Wang7, Glenn Walter8, H. Lee Sweeney9, and Krista Vandenborne1
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.

4009.   78 Multi-parametric Classification of Inflammatory Myopathies at 3.0 T
Ke Li1,2, Richard D. Dortch1,2, E. Brian Welch1,2, Susan F. Kroop3, Joseph W. Huston3, Amanda K.W. Buck1,2, Theodore F. Towse2,4, Nathan D. Bryant1,2, Bruce M. Damon1,2, and Jane H. Park5
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.

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.

4011.   80 Quantitative NMR imaging in Pompe patients to monitor the progression of skeletal muscle alterations without and with enzyme substitution therapy
Pierre G Carlier1, Noura Azzabou1, Paulo Loureiro de Sousa1, Robert-Yves Carlier2, Jean-Marc Boisserie1, Claire Wary1, David Orlikowski2, and Pascal Laforêt3
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.

4012.   81 Semi-automatic segmentation analysis of adipose tissue in thigh and lower leg to assess the fat infiltration in Type 2 Diabetes Mellitus
Sunil K. Valaparla1,2, Qi Peng3, Feng Gao1, Timothy Q. Duong1, and Geoffrey D. Clarke1,2
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.

4013.   82 Whole-body Dixon for skeletal muscle fat fraction quantification in neuromuscular disorders
Benjamin Marty1, Pierre-Yves Baudin1, Benjamin Robert2, Alexey Shukelovich1, Robert-Yves Carlier3, Noura Azzabou1, and Pierre G Carlier1
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.

4014.   83 Validation of Diffusion Tensor Imaging for Determining Muscle Pennation with Ultrasound
Emily Catherine Bush1, Theodore F Towse1, Amanda K.W. Buck1, Christopher P Elder1, Ke Li1, and Bruce M Damon1
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.

4015.   84 3D Shear strain analysis of Medial Gastrocnemius muscle based on Velocity Encoded and Diffusion Tensor Imaging data.
Vadim Malis1, Usha Sinha1, Robert Csapo2, and Shantanu Sinha2
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.

4016.   85 A Comparison of STEAM and TRSE Diffusion Tensor Imaging for Tracking Muscle Fibers
Peter A Hardy1,2, Anders Andersen2,3, Thorsten Feiweier4, Bruce Damon5, and Brian Noehren6
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.

4017.   86 Magnetic Resonance Elastography (MRE) for Measurement of Muscle Stiffness of the Shoulder: Feasibility with a 3T MR Imaging System
Sun Hwa Hong1, Suk-Joo Hong2, Joon-Shik Yoon3, Chang-Hyun Oh4, Hee Kyung Kim5, Jang-Gyu Cha6, and Kyeong Ah Kim2
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.

4018.   87 Dependence of Quantitative MRI Indices on Age, Gender, and BMI in Healthy Thigh Muscles
Ke Li1,2, Richard D. Dortch1,2, E. Brian Welch1,2, Amanda K.W. Buck1,2, Theodore F. Towse2,3, Nathan D. Bryant1,2, Bruce M. Damon1,2, and Jane H. Park4
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.

4019.   88 PCr recovery rates of gastrocnemius medialis and soleus muscles at various exercise levels
Georg B Fiedler1,2, Albrecht Ingo Schmid1,2, Sigrun Goluch1,2, Elmar Laistler1,2, Kiril Schewzow1,2, Michael Wolzt3, Ewald Moser1,2, and Martin Meyerspeer1,2
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.

4020.   89 Application of a SAGE Sequence During Isometric Contractions in Skeletal Muscle
Christopher P. Elder1,2, Jack T. Skinner1,3, Theodore F. Towse2,3, Nathan D. Bryant1,3, and Bruce M. Damon1,3
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.

4021.   90 Cross-sectional Relationships Between Muscle ATP Synthesis, Ambulatory Performance, and Age: Initial Findings from the Baltimore Longitudinal Study on Aging (BLSA)
Seongjin Choi1, David A. Reiter2, Kenneth W. Fishbein2, Eleanor M. Simonsick1, Michael Schär3, Richard G. Spencer2, and Luigi Ferrucci1
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.

4022.   91 Phase-contrast MR imaging reveals age-associated differences in plantarflexor fascicle and aponeurosis behavior in isometric contractions
Robert Csapo1, Vadim Malis2, John Hodgson1, and Shantanu Sinha1
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.

4023.   92 Age-associated Changes in Triceps Surae Muscle Composition and Plantarflexor Strength – an MR imaging based Study with Ultra-short Echo-time (UTE) and Fat-Water Quantification of Connective, Adipose and Contractile Tissues.
Robert Csapo1, Vadim Malis2, Usha Sinha3, Jiang Du4, and Shantanu Sinha1
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.

4024.   93 Mapping the Creatine Kinase Reaction Rate in Muscles of the Lower Leg Using Progressive Saturation 31P-MRI at 3.0 T.
Prodromos Parasoglou1, Ding Xia1, Greg Chang1, and Ravinder R Regatte1
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.

4025.   94 Hyperpolarized 13C lactate as a substrate for in vivo metabolic studies in skeletal muscle
Jessica A.M. Bastiaansen1, Hikari A.I. Yoshihara2,3, Yuhei Takado2,4, Rolf Gruetter1,5, and Arnaud Comment2
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.

4026.   95 Spatial and temporal pattern of sporadic signal voids in incoherent motion sensitive examinations of musculature in the lower leg
Guenter Steidle1 and Fritz Schick1
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.

4027.   96 Automatic and Quantitative Assessment of Total and Regional Muscle Tissue Volume using Multi-Atlas Segmentation
Anette Karlsson1,2, Johannes Rosander3, Thobias Romu1,2, Joakim Tallberg2, Anders Grönqvist2,4, Magnus Borga1,2, and Olof Dahlqvist Leinhard2,5
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.