Shantanu Sinha¹, Ali Moghadasi², Vadim Malis³, and Usha Sinha^3
1Radiology, University of California at San Diego, San Diego, CA, United States, ²University of California at San Diego, San Diego, CA, United States,³Physics, San Diego State University, San Diego, CA, United States

A detailed understanding of the dynamics of quadriceps femoris and hamstring muscles will be a valuable clinical tool to evaluate association of muscle function with disease conditions such as osteoarthritis and dystrophy. We report velocity and strain rate mapping in the quadriceps and hamstring muscle under isometric and active extension-flexion contraction using a MR compatible computer -controlled, motorized hydraulic actuator. Spatial heterogeneity of velocity and strain rate is seen in the quadriceps and hamstring muscle; these patterns could potentially be altered in disease conditions or with muscle disuse.

Michael H. Buonocore^1,2, Robert D. Boutin¹, Igor Immerman³, Gerald J. Sonico², Zachary Ashwell¹, Robert M. Szabo³, and Abhijit J. Chaudhari^1
1Radiology, UC Davis, Sacramento, CA, United States, ²Imaging Research Center, UC Davis, Sacramento, CA, United States, ³Orthopedic Surgery, UC Davis, Sacramento, CA, United States

The abstract describes the use of the TrueFISP pulse sequence for observation and quantitative measurement of carpal bone angles and distances during active wrist motion, and demonstrates its performance in healthy human volunteers. High spatial and temporal resolution dynamic images provide diagnostically important measurements for assessment of carpal bone instability, tendon dislocation, and other pathologies of the wrist joint.

Ozan Sayin¹, Haris Saybasili^1,2, Liheng Guo¹, John A. Carrino³, Frances T. Sheehan⁴, Mark A. Griswold^2,5, Nicole Seiberlich⁵, and Daniel A. Herzka^6
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, ²Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, ³Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, United States, ⁴Rehabilitation Medicine, National Institutes of Health, Bethesda, MD, United States, ⁵Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ⁶Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States

Diagnosis and treatment monitoring of musculoskeletal defects require high-quality noninvasive imaging of dynamic phenomena in vivo. Real-time MRI is an emerging potential imaging strategy to achieve such a goal, thanks to recent advancements in parallel imaging. The current study demonstrate that real-time MRI with very low-latency display can be utilized to capture fast musculoskeletal motion on the knee joint. Specifically, radial GRAPPA with high degrees of undersampling (R=12) was applied and a reconstruction framework designed for low-latency display to observe free motion of the knee joint.

Riccardo Lattanzi^1,2, Alicia W. Yang^1,2, Li Feng^2,3, Michael P. Recht⁴, Daniel K. Sodickson^1,2, and Ricardo Otazo^1,2
1Radiology/Center for Biomedical Imaging, NYU Langone Medical Center, New York, NY, United States, ²The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States, ³Radiology/Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, United States, ⁴Radiology, NYU Langone Medical Center, New York, NY, United States

Magnetic resonance imaging (MRI) of the hip joint requires high-spatial resolution and signal-to-noise ratio (SNR), which results in long scan times. Compressed sensing (CS) reconstruction approaches are currently used in research to achieve very large accelerations for advanced MR studies. We explored the feasibility of using CS to achieve moderate acceleration factors in routine hip imaging, while maintaining diagnostic quality. Our results suggest that it could be possible to accelerate 2D turbo spin echo acquisitions by a factor of 4 using CS and that 6-fold acceleration is also feasible for T2 mapping based on multi spin echo time-series.

Joshua Michael Farber¹, Jose Tamez-Pena², saara Totterman³, Hubert LeJay⁴, Edward Schreyer³, and Karl Baum^3
1Radiology, Qmetrics/Rad Ass of N KY, Cincinnati, Ohio, United States, ²Mathematics and Statistics, Tec de Monterrey, Monterrey, NL, Mexico, ³Imaging, Qmetrics, Rochester, NY, United States, ⁴MRI - Global, GE, Milwaukee, Wisconsin, United States

New 3D FSE sequences acquire rich MRI data sets. In the knee, this sequence can provide morphological and quantitative data, with a single acquisition. The data can be used for to render 3D articular cartilage thickness and 3D T2 Maps.

Conny Ström¹, Jörgen Strinnholm¹, Sead Crnalic², Morten Bruvold³, Ulrike A. Blume⁴, Chiel den Harder³, and Clemens Bos^5
1Department of Radiation Sciences, Umeå University, Faculty of Medicine, Diagnostic Radiology, Umeå, Sweden, ²Department of Ortopedy, Umeå University, Faculty of Medicine, Umeå, Sweden, ³Philips Healtcare, Best, Netherlands, ⁴Philips Healtcare, Hamburg, Germany, ⁵Division Image, University Medical Center in Utrecht, Utrecht, Netherlands

Wear in metal-on-metal hip implants and released metallic debris and consequent complications caused recall of some products. Evaluation of the risk of complications is important, even before clinical symptoms arise, with T2 weighted (T2w) MRI to show inflammatory pseudotumor and synovitis locally. Slice Encoding for Metal Artifact Correction (SEMAC), resolves metal induced distortions. Here, T2w SEMAC and conventional T2w TSE are compared in their potential to show soft tissue changes close to the metal in 23 asymptomatic patients with metal-on-metal hip implants. With reduced artifact size (P<0.001), SEMAC unveiled significantly more osteolysis, fluid collection or pseudotumor, when present (P<0.001).

Greg O. Cron^1,2, Kawan Rakhra^1,2, Paul E. Beaule^1,3, Isabelle Catelas⁴, Arturo Cardenas-Blanco^1,2, Ian G. Cameron^1,2, and Mark E. Schweitzer^1,2
1Ottawa Hospital Research Institute, Ottawa, Ontario, Canada, ²Radiology, University of Ottawa, Ottawa, Ontario, Canada, ³Surgery, University of Ottawa, Ottawa, Ontario, Canada, ⁴Mechanical Engineering; Surgery; Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada

Histological differences have been observed in periprosthetic tissues from metal-on-metal (MM) compared to metal-on-polyethylene (MP) hip implants, suggesting that a perfusion difference might be expected. We developed and applied a quantitative dynamic contrast-enhanced (DCE) MRI technique to measure and compare the perfusion parameter Ktrans (index of flow and permeability) in soft tissues adjacent to MM and MP implants. We demonstrated a trimodal distribution of Ktrans values between tissues from MM and MP implants and observed higher Ktrans values in women. The trimodal distribution remains to be further investigated, however the gender difference is consistent with brain and cardiac perfusion literature.

Tao AI¹, Frank F. Goerner², Abraham Padua³, Mathias Nittka⁴, Xiaoming Li¹, and Val M. Runge^5
1Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, ²Radiology, University of Texas Medical Branch (UTMB), Galveston, Texas, United States, ³Healthcare Sector, Siemens AG, Malvern, PA, United States, ⁴Healthcare Sector, Siemens AG, Erlangen, Deutschland, Germany, ⁵Editor-in-Chief of Investigative Radiology, Galveston, TX, United States

In vitro agarose phantom and animal tissue phantom with three different types of clinically wide-used metal materials were scanned by SEMAC-VAT with a range of SEMAC-encoding steps, high bandwidth and conventional 2D TSE sequence at both 1.5T and 3T. The performance of SEMAC-VAT technique in metal artifact correction was evaluated by both quantitative and qualitative analysis. The results demonstrated SEMAC-VAT significantly reduced metal artifact due to different metal materials and optimal SEMAC-encoding steps of 15-20 for Cobalt chromium and 5-10 for both Oxidized Zirconium and Titanium were recommended for clinical use.

Weitian Chen¹, Donglai Huo², Kristin Granlund³, Garry E. Gold³, and Yuval Zur^4
1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, ²PSD Applications, GE Healthcare, Waukesha, WI, United States, ³Radiology, Stanford University, Palo Alto, CA, United States, ⁴GE Healthcare, Haifa, Israel

Fast spin echo imaging plays a central role in clinical imaging. Recently there is growing interest in using pseudo-steady-state FSE with flip angle modulation for high-resolution 3D anatomical imaging due to its high SNR efficiency. Fast spin echo sequences require the CPMG condition and the violation of it can result in image artifacts such as banding or SNR loss. A major cause to the violation of CPMG condition occurs with volume selective 3D FSE due to the eddy current effect from gradients, particularly when imaging at far off isoceter. This problem has been previously addressed in 2D FSE acquisitions, but solutions for 3D FSE can be time consuming or difficult to implement. In this work, we demonstrate that a recently developed phase correction approach can be used to improve the robustness of volume selective 3D FSE acquisition and its relevant applications.

Suraj D. Serai¹, Hee Kyung Kim¹, Paul Horn², Brenda L. Wong², and Diana Lindquist^1
1Radiology, CCHMC, Cincinnati, OH, United States, ²Neurology, CCHMC, Cincinnati, OH, United States

T1W imaging is not able to differentiate boys with DMD and minimal fatty infiltration from healthy boys. Most of the healthy boys and one-third of the boys with DMD demonstrated a minimal degree of fatty infiltration of the gluteus muscle. However using quantitative MRS, fatty infiltration measured by MRS is substantially higher in boys with DMD than in healthy boys. In fact, MRS can completely separate boys with DMD from healthy boys. Hence, we hypothesize that the advantage of using MRS over the traditional T1W imaging likely will be greater when applied to patients in the early stage disease.

Patrick Hiepe¹, Daniel Güllmar², Alexander Gussew², Reinhard Rzanny², and Jürgen R. Reichenbach^2
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital, Jena, Germany, ²Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

In this contribution the intra-voxel incoherent motion model (IVIM) imaging and local principle component analysis (LPCA) denoising was used to evaluate muscle fatigue by quantifying the load-induced perfusion changes in lower back muscles following exercise. LPCA decomposition was applied to improve image quality. Mapped diffusion coefficients (parameterized via D) and perfusion-related signal losses (parameterized via f) were used for ROI-based analyses. Mean D and f values revealed spatially varying increases post exercise which can thus be used for spatially resolved perfusion quantification as a physiological marker of muscle activity and fatigue during exercise.

Hidalgo-Tobon S. Silvia¹, Gabriela R. Hernandez Salazar², S Vargas-Cañas³, O. Marrufo-Melendez⁴, S. Solis Najera⁵, Alfredo O. Rodriguez⁶, and Rosa Delgado-Hernandez^7
1Universidad Autonoma Metropolitana, Mexico City, Mexico, Mexico, ²Insituto Nacional de Neurologia, Mexico, Mexico, Mexico, ³Insituto Nacional de Neurologia, Mexico, MExico, Mexico, ⁴Insituto Nacional de Neurologia, DF, Mexico, Mexico, ⁵UNAM, MExico, Mexico, Mexico, ⁶UAM, DF, Mexico, Mexico,⁷Imagenologia, Instituto Nacional de Neurologia y Neurocirugia, DF, Mexico, Mexico

Limb-girdle muscular dystrophies (LGMD) are a group of autosomal dominantly or recessively inherited muscular dystrophies that also present with primary proximal (limb-girdle) muscle weakness. This type of dystrophy involves the shoulder and pelvic girdles, distinct phenotypic or clinical characteristics are recognized. LGM dystor-phies affect posterior thigh muscle compartment, predomi-nantly gracilis and sartorius muscles. In the thigh, muscles at the back are affected, with a tendency to preserve the tibi-alis anterior and gastrocnemius. In this study we analyze DTI images, relation between the number of tracts, FA, and lenght in sartorius and gracilis muscle.

Prodromos Parasoglou¹, Li Feng¹, Ding Xia¹, Ricardo Otazo¹, and Ravinder R. Regatte^1
1Department of Radiology, New York University Langone Medical Center, New York, NY, United States

The rate of phosphocreatine resynthesis following physical exercise is an accepted index of mitochondrial oxidative metabolism. Several diseases can affect the efficiency of muscles� oxidative metabolism in the mitochondria, which could lead to spatial heterogeneity of the muscles� response to physical exercise. However, very little is known about these spatial gradients of metabolic properties due to the lack of imaging tools with sufficient muscle coverage and temporal resolution to measure oxidative capacity in larger areas of tissue. In this work, we developed and implemented a novel compressed sensing (CS) 3D-31P-MRI technique for imaging PCr resynthesis following exercise.

Shantanu Sinha¹, Raj Rajasekaran², Ali Moghadasi³, Youngseop Chang², and Usha Sinha^4
1Radiology, University of California at San Diego, San Diego, CA, United States, ²Medicine, University of California at San Diego, San Diego, CA, United States, ³University of California at San Diego, San Diego, CA, United States, ⁴Physics, San Diego State University, San Diego, CA, United States

The rat muscle has been shown to be ideal for modeling several MSK disease states under controlled conditions [1]. While structural imaging including diffusion tensor imaging has been performed to elucidate architectural changes in rat muscle model [2], dynamic functional imaging of the rat muscle is still a challenging unresolved problem because of electronic noise generated by stimulation circuitry. Using special noise reduction electronics as well as modulation, we successfully stimulated the rat hind leg and monitored both tissue deformation and velocity using spin tag and PC-VENC acquisitions.

Martijn Froeling¹, Gustav J. Strijkers², Aart J. Nederveen³, and Peter R. Luijten^1
1Department of Radiology, Universiy Medical Center Utrecht, Utrecht, Netherlands, ²Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ³Department of Radiology, Academic Medical Center, Amsterdam, Netherlands

The purpose of this educational poster is to define a framework for choosing the most optimal protocol for diffusion-weighted MRI of skeletal muscle.

Paul A. DiCamillo¹, Nikolaus M. Szeverenyi¹, Sheronda Statum¹, and Graeme M. Bydder^2
1Department of Radiology, University of California, San Diego, California, United States, ²Department of Radiology, University of California San Diego, San Diego, California, United States

Magic angle effects in articular cartilage have been studied extensively. The lamellar appearance of articular cartilage with signal decreasing from superficial to deep is seen at the lower end of the femur and in the tibial plateau when patients are examined with B₀ parallel to the long axis of the body. However, equally striking in articular cartilage is the appearance of vertical striations, which are orthogonal to the layers described above. In contrast to studies performed at 1.5 and 3T, striations have not been observed or commented on in the very detailed studies performed at high field (7T) over a decade or more in which magic angle effects were identified as the source of the lamellar structure seen in cartilage. In order to determine whether or not vertical striations can be seen at high field, studies of articular cartilage were performed at 3T and 11.7T.

Wei-Ching Lo¹, Karupppasamy Subburaj¹, Lorenzo Nardo¹, Sharmila Majumdar¹, Michael Ries², and Xiaojuan Li^1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, United States, ²Orthopaedic Surgery, University of California, San Francisco, San Francisco, California, United States

Along with the efforts of developing prevention strategies and new treatment methods for osteoarthritis, there are increasing demands for early diagnosis and critical treatment monitoring of cartilage degeneration in osteoarthritis. As a non-invasive imaging technique, it would be critical to link the biochemical analysis with in vivo imaging measures. This study developed a robust registration algorithm for in vivo and ex vivo cartilage imaging to explore the link between imaging measures and biochemical analysis.

Eiko Yamabe¹, Ryo Miyagi², Toshinori Sakai³, Toshiyasu Nakamura⁴, and Hiroshi Yoshioka^1
1Department of Radiological Sciences, University of California Irvine, Orange, CA, United States, ²Department of Orthopaedic Surgery, Miyoshi City National Insurance Nishi-Iya Clinic, Tokushima, Japan, ³Department of Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan, ⁴Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan

We demonstrated the clinical feasibility of diffusion tensor imaging of Guyon�fs canal in healthy volunteers and compared diffusion values of the ulnar nerve with those of the median nerve. The ulnar nerve at Guyon�fs canal, including the superficial and the deep branches, was well appreciated on fiber tracking images. FA and location of the ulnar nerve demonstrated a strong negative linear correlation from the proximal to the distal while ADC showed a moderate positive linear correlation. FA and ADC of the ulnar nerve showed lower and higher values than those of the median nerve, respectively.

Bernhard Neumayer¹, Eva Hassler^1,2, Thomas Widek¹, Kathrin Ogris¹, and Eva Scheurer^1
1Clinical Forensic Imaging, Ludwig Boltzmann Institute, Graz, Styria, Austria, ²Department of Radiology, Medical University of Graz, Graz, Styria, Austria

The estimation of the time since the origin of a hematoma is often needed to reconstruct juridically relevant events. This estimation is currently done by visual inspection which has been shown to be unreliable. This study presents an MRI model to estimate the age of soft tissue hematomas using standard clinical sequences. The application of this method results in a 95% confidence interval of approximately 1 day for hematoma ages of up to 2 weeks and, thus, shows considerable advantages compared to the current standard.

Kathryn Stevens¹, Michael Goldin², Michael Fredericson³, Christian Anderson⁴, and Marc R. Safran^4
1Department of Radiology, Stanford University, Stanford, CA, United States, ²Department of PM & R, Stanford University, Stanford, CA, United States,³Department of Orthopaedic Surgery, Stanford University, Redwood City, CA, United States, ⁴Department of Sports Medicine, Stanford University, Redwood City, CA, United States

The purpose of our study was to determine if there was an increased incidence of femoral acetabular impingement (FAI) in patients presenting with femoral neck stress fractures. We evaluated the imaging studies of patient presenting with stress injuries of the femoral neck for features to suggest either cam or pincer-type FAI. Our results suggest that patients with bony abnormalities associated with pincer impingement, such as coxa profunda and acetabular retroversion, may be at increased risk of developing stress fractures. Over-coverage of the femoral head may place additional stresses on the femoral neck, predisposing an athlete to stress fracture

Rebecca E. Thornhill¹, Greg O. Cron², Mohammad Golfam¹, Gina DiPrimio¹, Adnan Sheikh¹, Eric A. White³, Joel Werier⁴, and Mark E. Schweitzer^1
1Medical Imaging, The Ottawa Hospital, Ottawa, Ontario, Canada, ²Medical Imaging, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada,³Radiology, University of Southern California, Los Angeles, California, United States, ⁴Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada

Conventional imaging assessment of lipomatous tumors offers limited accuracy to predict malignant potential. We have identified a number of quantitative morphological and textural features that can be extracted from standard T1-weighted spin echo MR images that are capable of delineating lipomas from liposarcomas with 88% sensitivity, 90% specificity and 89% accuracy. These advanced 3 dimensional shape and textural features may identify a 'signature' pattern associated with highly malignant lipomatous tumors and offer improved diagnosis compared to conventional radiologic methods.

Hye Jin Yoo¹, Sung Hwan Hong¹, Ja-Young Choi¹, Sung Eun Kang¹, and Hye Young Sun^1
1Radiology, Seoul National University, Seoul, Seoul, Korea

Knowledge of potential pitfalls and artifacts of whole-body PET/MR is essential before interpreting hybrid imaging to avoid misdiagnosis.

Volker Rasche¹, Erich Hell², and Magrit-Ann Geibel^3
1Experimental Cardiovascular Imaging, Ulm University, Ulm, NA, Germany, ²Research and Development, Sirona Dental Systems GmbH, Bensheim, Hessen, Germany, ³Department of Operative Dentistry, Periodontology and Pedodontics, Ulm University, Ulm, Baden Wuerttemberg, Germany

The application of MRI in dental imaging is not widespread. With the introduction of ultra-short echo time imaging techniques, a major step has been taken for the application of MRI as an increasingly important imaging tool in dentistry. The aim of this educational poster is to discuss recent developments in dental MRI and its potential in the different fields of dentistry.

Helmar Waiczies^1,2, André Kühne^3,4, Lukas Winter², Tobias Frauenrath², Werner Hoffmann³, Bernd Ittermann³, Sonia Waiczies^1,2, and Thoralf Niendorf^2,5
1Magnetic Resonance Imaging in Immunology, Experimental and Clinical Research Center (ECRC), a cooperation of the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany, ²Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany, ³Department of Medical Physics and Metrological Information, Physikalisch Technische Bundesanstalt, Berlin, Germany, ⁴Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, ⁵Experimental and Clinical Research Center (ECRC), Charité University Medicine Campus Berlin-Buch, Berlin, Germany

We have developed a double-tuned ¹H/¹⁹F birdcage resonator dedicated for hand and wrist imaging at 7 T to locally image non-steroidal anti-inflammatory drugs (NSAID) such as 2-{[3-(Trifluoromethyl) phenyl]amino}benzoic acid. The preliminary in vivo images acquired by the double-tuned ¹H/¹⁹F birdcage resonator demonstrate the feasibility for 1H/19F hand- and wrist-imaging at 7 T. While the diagnostic quality of the coil needs to be assessed in patients with inflammatory rheumatoid disease, first ¹⁹F images of the NSAID are encouraging, and point towards the prospect of applying ¹⁹F-MRI to visualize and quantify the concentration of therapeutically-active compound at the sites of inflammation.

Patrick Hiepe¹, Alexander Gussew², Reinhard Rzanny², and Jürgen R. Reichenbach^2
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital, Jena, Germany, ²Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

This contribution demonstrates the feasibility of applying ³¹P-MR-CSI in lower back muscles during an isometric load to detect and quantify changes of PCr, Pi and pH. For this purpose 14 healthy volunteers were investigated, which performed a modified Sørensen test over a time period of 10 min. Load induced changes of phosphorus metabolites and increased SDs of quantified PCr and Pi intensity were observed. The latter is assumed to reflect inter-individual differences for metabolic changes and, thus, for varying degrees of muscle fatigue.

Alyaa H. Elzibak¹ and Michael D. Noseworthy^2
1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada, ²Electrical and Computer Engineering, School of Biomedical Engineering, Department of Radiology, McMaster University, Hamilton, Ontario, Canada

Changes in posture, from erect to supine, are known to affect muscle cross sectional area (CSA) measurements due to fluid shifts. Diffusion tensor imaging (DTI) and blood oxygen level dependent imaging (BOLD) have been applied to assess muscle microstructure and vasculature, respectively. In this study, we investigated changes in calf muscle DTI indices (λ1, λ2, λ3, apparent diffusion coefficient, and fractional anisotropy) and BOLD signal due to supine rest. These parameters were measured in five calf muscles at three time points: baseline, 30 and 60 minutes of bed rest. We also measured calf muscle CSA at these three times.

Su Xu^1,2, Stephen J.P. Pratt³, Roger J. Mullins^1,2, and Richard M. Lovering^3
1Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States, ²Core for Translational Research in Imaging @ Maryland, Baltimore, Maryland, United States, ³Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland, United States

In vivo high resolution T₂-weighted MRI at 7 Tesla was used to monitor dystrophic hindlimb muscles in a Duchenne muscular dystrophy murine model (mdxmouse) over time. The results clearly show areas of brightness in mdx muscles, which peaks near the critical period, when the muscles are thought to undergo maximal degeneration/regeneration. Such findings suggest that researchers need to consider the age of mdx mice when evaluating MRI findings.

Ke Li^1,2, Richard D. Dortch^1,2, Nathan D. Bryant^1,2, Amanda K.W. Buck^1,2, Theodore F. Towse^2,3, Daniel F. Gochberg^1,2, Mark D. Does^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, ³Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ⁴Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

In this work, a multi-echo sequence for T2 and a selective inversion recovery (SIR) sequence for qMT were implemented for in vivo human thigh muscle imaging at 3.0 Tesla, and their repeatability was investigated. It is shown that these methods are reliable and repeatable and have potential applications in longitudinal studies of recovery from muscle damage and treatment response.

Shuya Fujihara¹, Tosiaki Miyati¹, Saori Watanabe^1,2, Naoki Ohno¹, Takashi Hamaguchi¹, Masako Takanaga¹, and Takayuki Miyazaki^3
1Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan, ²Department of Radiology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan, ³School of Health Sciences, College of Medical Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan

To comprehend the clinical physiology of the skeletal muscle disease, direct assessment of the muscle blood flow is essential. However, muscle blood flow (MBF) is the low baseline flow, and which tends to be maintained even in disease states. Thus MBF measurement should test under stress [1]. The objective of our study is to evaluate how much change in the MBF of each lower-leg muscle at the long axis before and after exercise using three-dimensional (3D) pulsed-continuous arterial spin labeling (pCASL) MRI.3D-pCASL makes it possible to obtain volume blood flow data of the lower-leg muscle and evaluate change in regional blood flow of the lower-leg muscle after exercise.

Ke Li^1,2, Richard D. Dortch^1,2, E. Brian Welch^1,2, Susan F. Kroop³, 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, ³Rheumatology, Vanderbilt University, Nashville, TN, United States, ⁴Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

Polymyositis (PM) is a form of Idiopathic Inflammatory Myositis (IIM), with symptoms of muscle inflammation, fat infiltration/replacement, and atrophy. In this work, several quantitative methods, including Dixon fat/water imaging, T2, and diffusion tensor imaging (DTI) have been applied for the first time in a PM patient at 3.0 Tesla. It is shown that these quantitative methods may provide an improved understanding of the pathological processes associated with PM at a microscopic level, and can objectively and quantitatively characterize, on an individual basic, the severity of muscle damage.

Ke Li^1,2, Richard D. Dortch^1,2, Ha-Kyu Jeong^1,2, Amanda K.W. Buck^1,2, Theodore F. Towse^2,3, 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, ³Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ⁴Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

DT-MRI indices from the normal human thigh muscles have particular significance because of the proximal-to-distal presentation of many neuromuscular disorders, causing the thigh muscles to be an early site of pathology. In this work, DT-MRI has been performed in healthy thigh muscles at 3.0 T in order to investigate the normal values obtained by, and the repeatability of, this technique.

Patrick Hiepe¹, Alexander Gussew², Reinhard Rzanny², and Jürgen R. Reichenbach^2
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital, Jena, Germany, ²Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

This contribution evaluates the feasibility of applying SE-EPI in lower back muscles to determine T₂ relaxation changes in lower back muscles during exercise in a group of healthy volunteers. A series of T₂-weighted images with incrementally increasing echo times was acquired pre- and post-exercise. Exercise was performed over a time period of 10 min and arranged as a modified Sørensen test. In all examined lower back muscles significantly increased T₂ values were observed, whereby T₂ increases revealed spatial variations. Hence, functional T₂ quantitation can be used for spatial resolved studies of muscle fatigue.

Noriyuki Tawara¹, Takahiro Ohnishi², Katsuya Maruyama², Vladimir Jellus³, Naoyuki Tamura⁴, Hideyuki Takahashi⁴, Mamoru Niitsu⁵, Atsuto Hoshikawa¹, Kohei Nakajima¹, Toru Okuwaki¹, and Takashi Kawahara^1
1Medical Center, Japan Institute of Sports Sciences, Tokyo, Japan, ²Siemens Japan, Tokyo, Japan, ³Siemens AG, Erlangen, Germany, ⁴Department of Sports Science, Japan Institute of Sports Sciences, Tokyo, Japan, ⁵Department of Radiology, Saitama Medical University, Saitama, Japan

MRI can evaluate muscle activity; T2 of exercised muscle is greater than that of rested muscle. However, it is necessary to improve the temporal resolution of the T2 calculation. The purpose of this study was to evaluate visualization of the trunk muscle activation induced by exercise using DESS sequence. Although the DESS sequence has a temporal resolution as high as can be acquired under single breath-holding, these images have a high spatial resolution. In this study, we presented the detectability of trunk muscle activities by DESS T2 mapping.

Hata Junichi¹, Numano Tomokazu², Mizuhara Kazuyuki³, Washio Toshikatsu⁴, Takamoto Kohichi⁵, Homma Kazuhiro⁴, Yagi Kazuo², Yano Keichi¹, and Ohtomo Kuni^1
1The University of Tokyo Hospital, Bunkyou, Tokyo, Japan, ²Tokyo Metropolitan University, Arakawa, Tokyo, Japan, ³University of Tokyo Denki, Adachi, Tokyo, Japan, ⁴National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Jamaica, ⁵University of Toyama, Toyama, Toyama, Japan

When the stiffness of the skeletal muscle is evaluated, the cell structure anisotropy becomes a problem. Then, this research aimed at the analysis and the evaluation of the organization anisotropy by MRE. We had examined two mainly. At first, the change in the frequency of the wave was analyzed by an isotropic structure as an anisotropic structure. Stiffness was similarly analyzed. It ..scorching.. was suggested it was necessary to consider anisotropy when MRE was analyzed enough.

CheolPyo Hong¹, Donghoon Lee¹, Si Seung Kim², and Youngkeun Woo^3
1Radiological Science, Yonsei University, Wonju, Gangwon-do, Korea, ²Research and development, SciMedix Co.,Ltd, Incheon, Incheon, Korea, ³Physical Therapy, Jeonju University, Jeonju, Jeonbuk, Korea

Characteristics of off-center anatomy-related artifact in open MRI

Young Han Lee¹, Daekeon Lim¹, Ho-Taek Song¹, InSeong Kim², and Jin-Suck Suh^1
1Yonsei University College of Medicine Severance hospital, Seoul, Korea, ²Siemens Healthcare, Seoul, Korea

Rotator cuff tears are the common problem in the shoulder. Fatty degeneration of muscles accompanied by tendon tears is an important prognostic factor. An accurate fat assessment is essential to set up treatment plan and to predict prognosis. However, there has been no standardized quantitative grading system, and the most widely used method for fatty infiltration is still disputed. We investigated the fat quantification using fat fraction map MR from the T2*-corrected in-phase and oppose-phase Volume Interpolated Breathhold Examination (VIBE) sequence in the patients with rotator cuff pathology on a 3-T clinical MRI scanner.

Dong-Ho Ha¹ and Sunseob Choi^2
1Dong-A university, Busan, Busan, Korea, ²Dong-A University Medical Center, Busan, Busan, Korea

Previous researches 31-phosphorus magnetic resonance spectroscopy after muscle exercise were performed after isotonic stress exercise. These studies need the various custom-built exercise devices made by nonferrous materials and were limited by the space constraints. 31P-MRS study following isovolumetric muscle exercise was effective for evaluating the muscle metabolism without specialized device and space constraints.

Valeria Righi^1,2, Cibely Cristine Fontes De Oliveira³, Alexander A. Shestov⁴, Dionyssios Mintzopoulos^1,5, Nikolaos Psychogios^1,5, Caterina Constantinou^1,6, Silvia Busquets³, Francisco J. Lopez-Soriano³, Sylvain Milot⁷, Francois Lepine⁸, Michael N. Mindrinos⁹, Laurence G. Rahme⁶, Josep M. Argiles³, and Aria A. Tzika^1,5
1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States, ²Department of Science for Life Quality, University of Bologna, Rimini, Rimini, Italy, ³Cancer Research Group, Department de Bioquýmica y Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Barcelona, Spain, ⁴Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States, ⁵Department of Radiology, Athinoula A. Martinos Center of Biomedical Imaging, Boston, Massachusetts, United States, ⁶Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States, ⁷INRS-Institut Armand-Frappier, Université du Québec, Laval, Quebec, Canada, ⁸INRS-Institut Armand-Frappier, Université du Québec, Leval, Quebec, Canada, ⁹Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States

We tested the hypothesis that cancer promotes mitochondrial uncoupling in skeletal muscle. We employed in vivo 31P NMR on intact mice and GC-MS in skeletal muscle samples, in a mouse cancer cachexia model. ATP synthesis rate and TCA cycle flux were significantly reduced in cancer-bearing mice. The ratio of ATP synthesis rate/TCA cycle flux, which provides an index of mitochondrial coupling, was 32% less in cancer-bearing mice. Our results were cross-validated with genomic analysis, showing aberrant expression levels in key regulatory genes and by electron microscopy showing abnormal giant mitochondria.

Celine Baligand¹, William Triplett¹, Sean C. Forbes², Rebecca J. Willcocks², Donovan J. Lott², Soren De Vos², Jim Pollaro³, William D. Rooney³, H. Lee Sweeney⁴, Carsten G. Bonnemann⁵, Krista Vandenborne², and Glenn A. Walter^1
1Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States, ²Physical Therapy, University of Florida, Gainesville, FL, United States, ³Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon, United States, ⁴Department of Physiology, University of Pennsylvania, Philadelphia, PA, United States, ⁵Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, United States

We used chemical-shift based MRI to quantify fatty infiltration in dystrophic muscles. We evaluated the combined influence of the model used for fat spectral decomposition, T1 variations, and signal to noise on the calculated fat fraction in Duchenne muscular dystrophy (DMD), congenital muscular dystrophy (C6), and control muscles, using localized 1H-MRS as a validation measure. Our results indicated that noise bias correction and the use of a 6-peak spectral model for fat allow good agreement between MRI and MRS measurement over a large range of fat fraction values, making chemical-shift based MRI a potential complementary quantitative measure in clinical trials.

Ryusuke Nakai^1,2, Takashi Azuma³, Keiji Shigeno¹, Osamu Takizawa⁴, and Hiroo Iwata^1
1Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan, ²Kokoro Research Center, Kyoto University, Kyoto, Japan, ³National Institute of Information and Communications Technology, Suita, Osaka, Japan, ⁴Siemens Japan K.K., Tokyo, Japan

We analyzed trajectories of the mandibular condyles and articular disks during mouth opening and shutting movements using multi-section dynamic imaging. The conditions of masseter muscles were examined based on high-resolution 3D-images, the DTI technique, and T1 and T2 values; and the relationships among mandibular movement, articular disks, and the conditions of the masseter muscles were determined. In the present investigation of mandibular movement, articular disks, and masseter muscles, MRI revealed relationships among mandibular trajectories, disorder in articular disks, and the condition of the masticatory muscles. This study shows the importance of the MRI technique for identifying causes of temporomandibular-joint disease.

Prodromos Parasoglou¹, Jae-Seung Lee^1,2, Ding Xia¹, Gregory Chang¹, Alexej Jerschow^1,2, and Ravinder R. Regatte^1
1Department of Radiology, New York University Langone Medical Center, New York, NY, United States, ²Department of Chemistry, New York University, New York, NY, United States

CEST techniques allow the indirect detection of protons associated with chemically exchangeable functional groups. Alteration in the kinetics of several chemical exchange processes in skeletal muscle have been associated with several diseases such as insulin resistance and type 2 diabetes. It is often very challenging to isolate genuine CEST from MT effects that can demonstrate asymmetries with respect to the main water resonance, and can affect quantification of CEST measurements. In this work we demonstrate the in vivo application of a simultaneous two frequency CEST imaging method that allows for MT-independent CEST measurements in the human calf muscle at 7T.

Usha Sinha¹, Ali Moghadasi², and Shantanu Sinha^3
1Physics, San Diego State University, San Diego, CA, United States, ²University of California at San Diego, San Diego, CA, United States, ³Radiology, University of California at San Diego, San Diego, CA, United States

The objective quantification of regional muscle deformation is a valuable clinical tool to evaluate normal and diseased muscle. 2D Strain and strain rate are kinematic properties that have been used to characterize myocardial and lingual deformation. However, the strain rate is 3 Dal as the tissue deformations are 3 dimensional. 3D strain rate measurement is challenging and requires 4D data acquisition. We report here, 3D strain tensor mapping of the medial gastrocnemius and show that the eigenvector associated with the negative eigenvalue deviates by 8-12o from the muscle fiber direction determined from diffusion tensor imaging.

Ding Xia¹, Prodromos Parasoglou¹, Gregory Chang¹, and Ravinder R. Regatte^1
1Department of Radiology, New York University Langone Medical Center, New York, New York, United States

The creatine kinase (CK) reaction plays an important role in provision and transport of ATP. Alteration in the kinetics of the CK has been associated with many diseases, such as diabetes, inflammatory myopathies and heart diseases. Non-invasive measurement of the forward CK reaction rate and metabolic flux can be achieved through phosphorous (³¹P) magnetization transfer (MT) techniques. In our study, we developed and implemented a novel three-dimensional ³¹P-MT imaging sequence on a 3T clinical scanner that maps forward CK reaction rate and metabolic flux among different calf muscles in clinically relevant times with relatively high spatial resolution.

Xiang He¹, Serter Gumus¹, Jung-Hwan Kim¹, Ted Huppert¹, Bret Goodpaster², Dmitriy A. Yablonskiy³, and Kyongtae Ty Bae^1
1Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, ²2Department of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, PA, United States, ³Mallinckrodt Institute of Radiology, Washington University in St Louis, St Louis, MO, United States

In this study, calf muscle oxygen kinetics was investigated utilizing an MR single-voxel qBOLD (quantitative BOLD) approach during muscle exercise. Changes in muscle hemodynamics such as oxygen extraction fraction (OEF) and deoxygenated blood volume (DBV) were measured during and after isometric or dynamic knee dorsiflexion. This study demonstrated that while post-exercise hyperemia was evident, muscle functional MRI (mfMRI) response during static or dynamic exercise was dominated by changes in deoxygenated blood volume and deoxy-hemoglobin concentration.

Ke Jiang¹, Xiaotian Wang^1,2, Hulong Lei¹, Wei Yang¹, and Yin Wu^1
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China, ²Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, Liaoning, China

DTI is a powerful tool to investigate muscle structures. Most DTI studies of probing ischemic muscle were performed on adult species, results of which may not apply on other age populations. In this study, we aim to investigate age-related regeneration process of ischemic muscle. 10 young and old SD rats were longitudinally studied using DTI before and after ischemia induction. Results showed that the young group was more sensitive to ischemia and recovered more rapidly than the old group. This study demonstrates the age-related discrepancy of muscle regeneration process, and may provide supplemental information for understanding of muscle repair evolution.

Yoshikazu Okamoto¹, Tomonori Isobe¹, and Graham J. Kemp^2
1University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan, ²University of Liverpool, Liverpool, Liverpool, United Kingdom

Changes in eigenvalues of skeletal muscle due to hybrid training

Jie Zheng¹, Mary K. Hasting¹, David Muccigrosso¹, Darrah Snozek¹, Zhaoyang Fan², John Curci¹, and Michael Mueller^1
1Washington University in St. Louis, Saint Louis, Missouri, United States, ²Cedars-Sinal Medical Center, Los Angelas, California, United States

A non-contrast MRI perfusion angiosome method was developed to assess skeletal muscle perfusion in feet. The study was performed in healthy volunteers and age-matched patients with diabetes mellitus, at rest and during a foot challenge. Significant attenuations in muscle perfusion reserve were observed in diabetic feet, even without developing foot ulcers.

Delphine Perie^1,2 and Daniel Curnier^3,4
1Mechanical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada, ²Research center, CHU Sainte Justine, Montreal, Quebec, Canada,³Kinesiology, Université de Montréal, Montreal, QC, Canada, ⁴Research center, CHU Sainte Justine, Montreal, QC, Canada

The long-term objective is to quantify the early changes in the muscle elastic modulus that occur with different muscle diseases using multi-parametric MRI. We hypothesized that multi-parametric MRI is able to characterize muscles with large mechanical differences. We developed an evaluative quantitative tool of the mechanical properties of muscle tissue using multi-parametric MRI associated to principal component analysis and agglomerative hierarchical clustering. We confirmed that a non linear relationship exists between the Young’s modulus and the MRI parameters of different types of muscle. The natural division into two clusters on the dendrograms reflected the ability of our method to classify different muscle tissues.

Ziying Yin¹, Andrew S. Lee², Geoffrey S. Van Thiel², Vasili Karas², Kristen Hussey², Elizabeth F. Shewman², Dale R. Sumner², Brian J. Cole², Vincent M. Wang², and Richard L. Magin^1
1Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, ²Orthopedic Surgery, Rush University Medical Center, Chicago, IL, United States

Microfracture (MFX) and autologous matrix induced chondrogenesis (AMIC) are two surgical treatments currently used for cartilage defects. There is a growing need to compare the effectiveness of the MFX and AMIC treatments. T1ρ and T2 are highly correlated with the proteoglycan (PG) and collagenous changes that occur in cartilage regeneration, while EPIC (Equilibrium Partitioning of an Ionic Contrast-agent)-µCT provides complementary data for cartilage morphology and PG content distribution. The purpose of this study is to examine the regenerative potential of AMIC treatment in comparison to MFX in a rabbit glenohumeral joint repair model using T1ρ, T2, and EPIC-µCT.

Jose G. Raya¹, Eike Dettmann¹, Ali-mohammad Golestani¹, and Kai Tobias Block^2
1Radiology, New York University Langone Medical Center, New York, NY, United States, ²Radiology, NYU Langone Medical Center, New York, NY, United States

Diffusion tensor imaging (DTI) of articular cartilage has demonstrated high accuracy (90%) for the diagnosis of osteoarthritis (OA). In vivo DTI of articular cartilage has been performed at 7 T, which limits its clinical applicability. To perform DTI of articular cartilage at 3 T we developed a radial spin echo diffusion tensor imaging (RAISED) sequence. We optimize the RAISED sequence for articular cartilage. Phantom measurements were used to test the accuracy of the DTI parameters. In vivo validation on healthy and OA subjects demonstrated the feasibility of the RAISED sequence for in vivo DTI of articular cartilage at 3 T.

Joseph Alan Schooler¹, Deepak Kumar¹, Xiaojuan Li¹, Thomas M. Link¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States

The association of bone marrow edema-like lesions with quantitative T1rho and T2 relaxation time. Deep and superficial human knee articular cartilage layers were probed to analyze laminar degenerative patterns

Vladimir Juras¹, Maria Isabel Menedez², Jochen Hofstaetter³, Martin Brix³, Sonja M. Walzer³, Pavol Szomolanyi¹, Oliver Bieri⁴, Xeni Deligianni⁴, and Siegfried Trattnig^1
1MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, ²The Wright Center of Innovation in Biomedical Imaging, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States, ³Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, ⁴Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland

This study shows that vTE-GRE is suitable tool for measuring the thickness of osteochondral junction; however, the measured values from MR images probably combine the signal from deep and calcified layer (it is not purely calcified cartilage) which would explain the discrepancy with histologically obtained values. The optimization of the two TE combinations for the best contrast is necessary. Low TEs in VTE sequence allow accurate calculation of T2* of osteochondral junction (in the range of ~5-10ms). Histological grading of the cartilage condition corresponds to changes in T2* in osteochondral junction which may suggest the changes in collagen matrix and calcified cartilage front in different OA stages. It was shown that lead accumulates in the tidemark which may significantly contribute to T2* alteration. Relatively low number of samples does not allow generating conclusive statements; in the future, it needs to be validated in the higher number of subjects.

Jurgen Fripp¹, Rachel Surowiec², Erin Lucas², Craig Engstrom³, Chandra Shakes⁴, Raphael Schwarz⁵, Charles Ho², and Stuart Crozier^6
1The Australian eHealth Research Centre, CSIRO ICT Centre, Brisbane, Qld, Australia, ²Steadman Philippon Research Institute, Vail, Colarado, United States, ³School of Human Movement Studies, University of Queensland, Brisbane, Qld, Australia, ⁴Australian eHealth Research Centre, ICT Centre, CSIRO, Herston, Queensland, Australia, ⁵Healthcare, Siemens, Erlangen, Bavaria, Germany, ⁶The School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Qld, Australia

Quantitative MRI sequences such as T2 mapping are considered to be sensitive to the earliest biochemical changes that occur prior to gross cartilage tissue loss during Osteoarthritis (OA). We present and validate the results of an automated segmentation scheme, to segment the cartilage from clinically 3D-Fast-Spin-Echo (3D-SPACE) MR images and extract biochemical information from co-registered T2 mapping images.

Hon J. Yu¹, Dave Michael Hitt², and Hiroshi Yoshioka^3
1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, United States, ²U.S. Clinical Science, Philips Healthcare, Cleveland, OH, United States, ³Radiological Sciences, University of California, Irvine, Orange, CA, United States

T1 scans with varying TSL were performed for T1 mapping of wrist cartilage at a 3T clinical scanner. The effect of motion correction prior to the fitting for T1 mapping was tested off-line via ROI-averaged value from the T1 maps with and without motion correction and also use of R² map for overall fitting quality. A measurable deviation in ROI-averaged T1 value of cartilage (up to 22%) occurred even in presence of small mis-alignments in T1 series (< 1°/< 0.5 mm in rotation/translation) due to the thin anatomical nature of cartilage. Overall fitting quality improved with motion correction (R²=0.94-0.96 vs. 0.72-0.80). Mapping-based techniques for cartilage require a motion-correction/realignment for more accurate assessment of cartilage.

Carl Siversson^1,2, Alireza Akhondi-Asl¹, Young-Jo Kim³, and Simon K. Warfield^1
1Computational Radiology Laboratory, Children's Hospital Boston, Harvard Medical School, Boston, MA, United States, ²Dept. of Medical Radiation Physics, Lund University, Malmo, Sweden, ³Department of Orthopaedics, Children's Hospital Boston, Harvard Medical School, Boston, MA, United States

Delayed Gadolinium enhanced MRI of cartilage (dGEMRIC) is a technique for assessing cartilage quality using T1 quantification. In this work it is shown that by combining an isotropic 3D T1 map with an isotropic 3D TrueFISP image it is both feasible and robust to apply fully automated cartilage segmentation to hip-dGEMRIC data. It is also shown that it is possible to apply cartographic algorithms to the segmented cartilage, generating planar T1 maps covering the entire cartilage surface. Such planar maps are very suitable for studying patterns of cartilage degeneration.

Elisabeth Pittschieler¹, Pavol Szomolanyi^2,3, Martina Schmid-Schwap⁴, Michael Weber⁵, Hanns Plenk⁶, and Siegfried Trattnig^2
1Department of Orthodontics, Bernhard-Gottlieb University Dental Clinic, Vienna, Vienna, Austria, ²High field MR Center of Excellence, Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ³Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, ⁴Department of Prosthodontics, Bernhard Gottlieb Universitity of Dentistry, University of Vienna, Vienna, Austria, ⁵Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ⁶Department of Histology and Embryology, Medical University of Vienna, Vienna, Austria

The dGEMRIC technique is feasible for the in-vivo assessment of the fibrocartilage disc of the TMJ, by evaluating T1(Gd) within the diagnostic window 60 to 120 minutes post contrast agent application. 2D-IR sequences showed a statistically highly significant drop of T1(Gd) in the articular disc of the TMJ after i.v. contrast agents administration of the 0.2 mmol/kg of Gd-diethylenetriamine pentaacetic acid. The 3D-GRE sequence based T1(Gd) mapping confirmed results, providing higher temporal resolution by measuring in shorter time steps. The regional distribution of T1 values showed similarities to histological GAG specific staining techniques of the TMJ disc.

Kambiz A. Asher¹, Bragi Sveinsson^1,2, and Garry E. Gold^1,3
1Department of Radiology, Stanford University, Stanford, CA, United States, ²Department of Electrical Engineering, Stanford University, Stanford, CA, United States, ³Department of Bioengineering, Stanford University, Stanford, CA, United States

Multiple MRI techniques exist that assess the health of the knee cartilage. Assessment of T2 relaxation time is useful in such situations. In the assessment of knee cartilage abnormalities, 2D-FSE imaging is most often used in clinical practice, providing excellent SNR between tissues; qDESS imaging is useful in assessing morphological changes; and CubeQuant is a highly SNR efficient 3D T2 quantification method. The purpose of our study was to evaluate whether the T2 measurements as acquired through qDESS and CubeQuant techniques have similar relaxation times in healthy participants compared to T2 measurements acquired through the 2D-FSE technique.

Hon J. Yu¹, Peter Huy Pham², Dave Michael Hitt³, and Hiroshi Yoshioka^4
1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, United States, ²Loma Linda University Medical Center, Loma Linda, CA, United States, ³U.S. Clinical Science, Philips Healthcare, Cleveland, OH, United States, ⁴Radiological Sciences, University of California, Irvine, Orange, CA, United States

T2 and T1 scans were performed for T2 and T1 mapping of femoral cartilage at a 3T clinical scanner. Using a novel segmentation methodology previously demonstrated, this study shows the angular-orientation (magic-angle effect) and cartilage-depth dependent effects on T2 values of medial condyle whereas no such dependency was observed on T1. Despite of small sample size, the potential for quantitative, in vivo functional assessment of cartilage via T2 and T1 mapping is clearly demonstrated in this study.

Elisabeth Schoenbauer¹, Pavol Szomolanyi^1,2, Vladimir Juras^1,2, Toshiyuki Shiomi¹, Stefan Zbýn¹, and Siegfried Trattnig^1
1High field MR Center of Excellence, Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

T2 mapping of the articular cartilage is the technique of choice for joint MR imaging because it shows degeneration associated with changes in water content and damage to the collagen fiber network. Our current study shows that, in patients after cartilage transplantation, T2 mapping patterns, under loading, behave differently compared to the characteristic T2 mapping behavior in volunteers with healthy intact cartilage under loading conditions. This could possibly be attributable to the different ultra-structural composition of the collagen fiber network in repair tissue compared to normal healthy cartilage, and thus, could explain the different biomechanical properties.

In Chan Song¹, Hyeonjin Kim¹, Hye Jin Yoo¹, Ja-Young Choi¹, and Sung Hwan Hong^1
1Radiology, Seoul National University Hospital, Seoul, Seoul, Korea

The purpose of this study was to evaluate the effect of the selection of measured tissue and assumed constant T1 values on the measurement of T1rho using 3D-gradient echo-based T1rho-weighted imaging sequence in patients with minimal and severe osteoarthritis (OA) at 3.0T MR system. The severity of cartilage degeneration was shown to have larger effect on T1rho from the assumed constant value to the measured tissue values in T1 value at the femoral cartilage at 3.0T. Therefore the usage of measured tissue T1 when T1rho is measured should be taken into consideration for the precise diagnosis of cartilage pathphysiology or the multi-center comparative study irrespective of the selection T1 value.

Pavol Szomolanyi^1,2, Martina Schmid-Schwap³, Margit Bristela³, Elisabeth Pittschieler⁴, Astrid Skolka³, Michael Weber⁵, Eva Piehslinger³, and Siegfried Trattnig^1
1High field MR Center of Excellence, Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, ³Department of Prosthodontics, Bernhard Gottlieb University of Dentistry, Vienna, Austria, ⁴Department of Orthodontics, Bernhard Gottlieb University of Dentistry, Vienna, Austria, ⁵Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria

Our study shows that T2 relaxation time measurements of the articular disc of the temporomandibular (TMJ) joint are feasible, with a good inter-and intraobserver agreement. The proposed T2 mapping technique enabled an ultrastructural analysis of the composition of the articular disc of the TMJ. The highest T2 relaxation times were found in the anterior part of the articular disc, lower T2 values in the central part and the lowest values in the posterior part of the disc. As apparent from comparison to the histological specimens, T2 values correspond to the collagen fibers organization and structure in TMJ disc.

Mies A. Korteweg¹, Fredy Visser^2,3, Paul Cernohorsky⁴, Simon D. Strackee⁴, Peter R. Luijten², Mario Maas¹, and Dennis W.J. Klomp^2
1Radiology, Academic Medical Center, Amsterdam, Netherlands, ²7Tesla, University Medical Center Utrecht, Utrecht, Netherlands, ³Philips Healthcare, Best, Netherlands, ⁴Plastic Reconstructive Hand Surgery, Academic Medical Center, Amsterdam, Netherlands

Cartilage of the first carpometacarpal joint (CMC1) is commonly affected in osteoarthritis (OA) patients. Routine imaging cannot depict CMC1 cartilage, causing interobserver variability for disease staging and treatment planning. This study shows that routine clinical PDw-TSE and WATS sequence is feasible at 7T for the depiction of the thin layer of cartilage of the CMC1 joint. Combining the high SNR at 7T and a 32 channel high density flexible receive array has the potential to make the next step toward cartilage imaging in CMC1 OA patients, possibly providing an important staging tool for the disease extent and treatment planning.

Aditi Guha¹, Cory Wyatt¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States

Diffusion imaging has been primarily focused on brain application with limited application in knee. One limitation of DWI in knee is the long TE (40-60ms) in most sequences used. This can be a problem in knee where several tissues have short T2 relaxation times including cartilage (32ms) and meniscus (11ms). A new sequence for DWI of knee at 3T has been proposed and evaluated. The proposed stimulated echo sequence with MAPSS acquistion is more signal efficient and can image the whole volume of knee. The sequence was tested in phantoms,ex-vivo and in-vivo with encouraging results.

Rebecca Emily Feldman¹ and Christian Beaulieu^1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

Changes in sodium concentration may signify biochemical changes in cartilage that occur asymptomatically, and without loss of cartilage volume. Knee cartilage was investigated in 10 asymptomatic male volunteers, aged 19-58, using proton imaging to analyze cartilage thickness and both steady state and inversion recovery sodium sequences to assess sodium concentration. Sodium concentration was found to be unrelated to cartilage thickness, and negatively correlated to age in both patellar and lateral femoral cartilage for both sodium imaging techniques. Therefore, age should be considered in all sodium MRI measurements of cartilage.

Larry Hernandez¹, Leah C. Henze Bancroft², Walter F. Block^3,4, and Richard Kijowski^5
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, ²Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States, ³Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ⁴Medical Physics, University of Wisconsin, Madison, Wisconsin, United States, ⁵Radiology, University of Wisconsin, Madison, Wisconsin, United States

VIPR-IDEAL can produce fat-suppressed, high isotropic resolution images of the knee joint in 5 minutes at 3.0T. VIPR-IDEAL, VIPR-ATR, FSE-Cube, IDEAL-GRASS, and IDEAL-SPGR sequences were performed on both knees of four volunteers and SNR/CNR was measured using a double acquisition addition/subtraction method. VIPR-IDEAL had similar cartilage and fluid SNR as VIPR-ATR and significantly higher (p<0.01) cartilage and fluid SNR than FSE-Cube, IDEAL-GRASS, and IDEAL-SPGR. VIPR-IDEAL had significantly greater (p<0.01) suppression of bone marrow fat signal than VIPR-ATR. Our study shows that VIPR-IDEAL has the same high SNR efficiency for evaluating articular cartilage as VIPR-ATR but provides superior fat suppression.

Lasse P. Räsänen^1,2, Mika E. Mononen¹, Miika T. Nieminen^3,4, Eveliina Lammentausta³, Jukka S. Jurvelin¹, and Rami K. Korhonen^1
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, ²Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland, ³Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ⁴Department of Radiology, University of Oulu, Oulu, Finland

The collagen architecture modulates the stresses and strains in a knee joint. Here, two alternative methods for determining the depth-dependent collagen architecture from T2 profiles of clinical MRI were compared. Collagen architectures were implemented into a computational model of a knee joint and the differences in the mechanical response of cartilage were evaluated. The stresses varied up to 49% between the two models. These results emphasize the importance of the collagen architecture, and the role of the the depth-wise T2 analysis method, for evaluation of cartilage stresses and strains in a knee joint.

Hidetoshi Hamada¹, Takashi Nishii², Satoru Tamura², Tetsuya Wakayama³, Hisashi Tanaka⁴, Kenya Murase⁵, Hideki Yoshikawa¹, and Nobuhiko Sugano^2
1Department of Orthopedic surgery, Osaka university graduate school of medicine, Suita, Osaka, Japan, ²Departments of Orthopedic Medical Engineering, Osaka University Graduate School of Medicine, Suita, Osaka, Japan, ³GE Healthcare Applied Science Laboratory, Asia Pacific, Hino, Tokyo, Japan,⁴Department of Radiology, Osaka University Medical School, Suita, Osaka, Japan, ⁵Department of Medical Physics and Engineering, Osaka University Medical School, Suita, Osaka, Japan

Influence of loading on cartilage T1rho and T2 were investigated in the porcine knee joint using a custom pressure device. In general, both T1 rho and T2 values showed similar magnitudes of decrease dependent on loading force. However, they showed different load-response in the deep layers of the lateral condyles, with less sensitive changes in T2 values. This may partly reflect different mechanisms of microstructure compositional change to loading, and biochemical cartilage assessment using T1rho and T2 mapping under static loading may become potent indexes to allow non-invasive biomechanical assessment of site-specific stress distribution related with cartilage degeneration.

Stephen J. Matzat¹, Emily J. McWalter², Weitian Chen³, Marc R. Safran⁴, and Garry E. Gold^2,5
1Stanford University, Stanford, CA, United States, ²Department of Radiology, Stanford University, Stanford, CA, United States, ³MR Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, ⁴Department of Orthopaedic Surgery, Stanford University, Stanford, CA, United States,⁵Department of Bioengineering, Stanford University, Stanford, CA, United States

Patients with femoroacetabular impingement (FAI) commonly experience chondral damage in the anterior acetabulum and may be at risk for early development of osteoarthritis. Conventional MR techniques are not sensitive to detecting these early changes in the hip. This study tests if quantitative MR methods using T1ρ and T2 relaxation times can detect regional changes in patients with FAI. Results show that standard deviation of T1ρ and T2 relaxation times (as measures of cartilage heterogeneity) are elevated in cartilage of the anterior acetabulum, indicating that patients with FAI exhibit sings of early osteoarthritis.

Gunthard Lykowsky¹, Flavio Carinci¹, Kathrin Hemberger¹, Eberhard Munz², Peter M. Jakob^1,2, and Daniel Haddad^1
1MRB Research Center, Würzburg, Bavaria, Germany, ²Department of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany

Sodium is known to be a sensitive MR imaging biomarker for early diagnosis of knee articular cartilage osteoarthritis (OA). The goat animal model closely matches the human knee anatomy and can be used to mimic the progressive development of OA and monitor the loss of proteoglycans and glycosaminoglycans. In this study we used quantitative sodium MRI to track the cartilage degradation following an OA inducing surgery.

Felix Eckstein^1,2, Wolfgang Wirth^1,2, Martin Hudelmaier^1,2, Stefan Lohmander³, and Richard B. Frobell^4
1Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Salzburg, Austria, ²Chondrometrics GmbH, Ainring, Bavaria, Germany, ³Dept Orthopaedics, Clinical Sciences Lund, Lund University, Lund, SE, Sweden, ⁴Orthopedics, Clinical Sciences Lund, Lund University, Lund, SE, Sweden

An increase (rather than a decrease) in medial femorotibial cartilage thickness is seen not only in the early phase after ACL injury, but continues during a later period (2 and 5 years) after ACL injury.

Elli-Noora Salo¹, Jari Rautiainen^2,3, Virpi Tiitu⁴, Mikko A.J. Finnilä⁵, Olli-Matti Aho⁶, Petri Lehenkari⁶, Jutta Maria Ellermann⁷, Simo Saarakkala⁵, Mikko J. Nissi^7,8, and Miika T. Nieminen^1,3
1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ²Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, ³Department of Radiology, University of Oulu, Oulu, Finland, ⁴Institute of Biomedicine, Anatomy, University of Eastern Finland, Kuopio, Finland,⁵Department of Medical Technology, University of Oulu, Oulu, Finland, ⁶Department of Anatomy and Cell Biology, University of Oulu, Oulu, Finland, ⁷Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, ⁸Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States

Various quantitative MRI markers have been proposed for the quantitative assessment of articular cartilage degeneration. In this study, the sensitivity of T₁, T_1Gd, T₂, magnetization transfer ratio MTR, continuous-wave (CW) T₁, adiabatic T₁ and T₂, T_RAFF and T₁ in the presence of saturation (T_1sat) to cartilage degeneration was investigated by correlating the MRI parameters with histopathological OARSI grade. ROC analysis revealed high AUCs (0.86-1.00) for all parameters except for MTR. Similarly, good correlation with OARSI grade and MRI parameters were established apart form MTR. Cartilage degeneration was most sensitively detected with T_RAFF and T_1Gd.

Mikko J. Nissi^1,2, Silvia Mangia¹, Shalom Michaeli¹, and Miika T. Nieminen^3,4
1CMRR and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, ²Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, ³Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ⁴Department of Radiology, University of Oulu, Oulu, Finland

Several rotating frame relaxation (RFR) parameters have been recently introduced and applied for quantitative evaluation of articular cartilage. Orientation dependence of adiabatic T₁ and T₂, RAFF as well as CW-T₁ and T₂ relaxation times was investigated by imaging at 9.4T at seven different orientations of articular cartilage relative to B₀ field. Adiabatic T₂ and RAFF showed significant orientation dependence, whereas adiabatic T₁ was relatively insensitive to orientation. Continuous-wave T₁ at low spin-lock power and T₂ were orientation dependent as previously reported. The present findings promote the use of adiabatic T₁ as an orientation-independent biomarker to assess articular cartilage.