Noriyuki Tawara¹, Osamu Nitta², Hironobu Kuruma², Mamoru Niitsu³, Naoyuki Tamura⁴, Hideyuki Takahashi⁴, Atsuto Hoshikawa¹, Kohei Nakajima¹, Toru Okuwaki¹, and Takashi Kawahara^1
1Department of Sports Medicine, Japan Institute of Sports Scinences, Tokyo, Japan, ²Department of Physical Therapy, Faculty of Health Sciences, Tokyo Metropolitan University, Tokyo, Japan, ³Department of Radiology, Saitama Medcical University, Saitama, Japan, ⁴Department of Sports Science, Japan Institute of Sports Sciences, Tokyo, Japan

Exercise-induced muscle activity is essential in sports medicine and rehabilitation medicine. MRI can evaluate muscle activity; T2 of the exercised muscle is increased compared to that of rested muscle. Additionally, strengthening of the rotator cuff muscles is one of the most integral parts of a rehabilitation program for athletes with shoulder injuries who must perform throwing motions during sports. Therefore, evaluation of muscle activity using T2–weighted MRI will facilitate identification the most effective exercises for strengthening the rotator cuff. The purpose of this study is to evaluate the visualization of rotator cuff’s activity induced by acute exercise.

Alyaa H. Elzibak^1,2, Alireza Akbari^2,3, and Michael D. Noseworthy^2,4
1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada, ²Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada, ³School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada, ⁴School of Biomedical Engineering, Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada

Blood oxygen level dependent (BOLD) contrast has been used to investigate the response of calf muscles to exercise. Since muscle biopsies are performed on the quadriceps, this work aimed at evaluating the recruitment of the four heads of the quadriceps femoris in exercise. Using an MRI compatible ergometer, BOLD images were acquired of the midthigh of healthy subjects. The protocol consisted of 1-minute of rest, followed by 2-minutes of intense supine thigh extension and ended with 3-minutes of recovery. Analysis revealed non-uniform activation of the muscles, with the rectus femoris and vastus intermedius playing the greatest role in the exercise.

Yoshikazu Okamoto¹, Shintaro Mori², and Yuka Kujiraoka^3
1University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan, ²University of Tsukuba, Japan, ³Tsukuba Memorial Hopital, Japan

FA, the three eigenvalues, and ADC in the gastrocnemius medialis (GCM), gastrocnemius lateralis (GCL), soleus (SOL), and anterior tibialis (AT) muscles between 12 athletes (Group A) and 11 non-athletes (Group B), and between the right and left sides, were compared using two-factor fractional ANOVA. All three eigenvalues and ADC were lower in Group A than in Group B with statistically significant differences in all muscles with a P-value of <0.01. Results might be due to an increase of density of myofilaments in the intracellular space, and deformation of the cell induced by enlargement of extracellular components.

Eric E. Sigmund¹, Steven Baete¹, Gene Y. Cho¹, Dabang Sui¹, Thompson Ukpebor¹, Kecheng Liu², Jane Kwon¹, Kellyanne McGorty¹, and Jenny Bencardino^1
1Radiology, NYU Langone Medical Center, New York, NY, United States, ²Siemens Medical Systems

Skeletal muscle pathologies can have both microstructural and microvascular underpinnings to which diffusion-weighted imaging can be made sensitive through the intravoxel incoherent motion (IVIM) approach. We performed IVIM in healthy calf muscles at 3 T both before and after treadmill exertion, and evaluated the biomarkers of tissue diffusivity, perfusion fraction, and pseudodiffusivity in 7 different muscle compartments and three orthogonal directions. The largest and most significant changes occurred for perfusion fraction, which isotropically increased by ~50%. Results are discussed in the context of muscle physiology and the sensitivities of diffusion contrast.

Prodromos Parasoglou¹, Ding Xia¹, Gregory Chang¹, and Ravinder R Regatte^1
1Center of Biomedical Imaging, NYU Langone Medical Center, New York, New York, United States

Dynamic measurements of phosphocreatine (PCr) recovery after exercise (plantar flexion) have been used to probe the capacity of mitochondria to carry out oxidative metabolism. Although valuable information can be obtained by unlocalized MRS methods, spatial mapping of PCr recovery can provide additional understanding of the patterns of disease propagation. Localized spectroscopy methods (such as chemical shift imaging) are prohibitively slow for such studies and result in coarse spatial resolution. In this work, spectral selective 3D-turbo spin echo methods are employed to measure the recovery rates of the entire volume of the calf muscle at 3T and 7T.

Noriyuki Tawara¹, Katsuya Maruyama², Mamoru Niitsu³, Naoyuki Tamura⁴, Hideyuki Takahashi⁴, Atsuto Hoshikawa¹, Kohei Nakajima¹, Toru Okuwaki¹, and Takashi Kawahara^1
1Department of Sports Medicine, Japan Institute of Sports Scinences, Tokyo, Japan, ²Siemens Japan, Tokyo, Japan, ³Department of Radiology, Saitama Medcical University, Saitama, Japan, ⁴Department of Sports Science, Japan Institute of Sports Sciences, Tokyo, Japan

Exercise-induced muscle activity is essential in sports medicine and rehabilitation medicine. MRI can evaluate muscle activity; transverse relaxation time (T2) of the exercised muscle is increased compared to that of rested muscle. Therefore, evaluation of muscle activity using T2–weighted MRI will facilitate identification the most effective exercises for strengthening the each muscle. In order to reduce the acquisition time of muscle T2 calculating, the aim of his study was to assess the pulse sequences for T2 measurement in 3.0T by comparing it with multiple spin echo (MSE). In particular, this study was verified about SE-EPI and DESS.

Marek Chmelik¹, Ivica Just Kukurova^1,2, Stephan Gruber¹, Martin Krššák³, Ladislav Valkovic¹, Siegfried Trattnig¹, and Wolfgang Bogner^1
1MR Centre of Excellence, Dept. Radiology, Medical University of Vienna, Vienna, Austria, ²Department of NMR and MS, Institute of Analytical Chemistry, Slovak University of Technology, Bratislava, Slovakia, ³Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria

As recently described ³¹P 2D-CSI based on GOIA-1D-ISIS/2D-CSI (goISICS) enables fully adiabatic acquisition with minimal chemical shift displacement error at 7T. The purpose of this study was to analyze intra- and inter-subject variability of goISICS in the calf muscle at 7T. Both, inter and intra-subject reproducibility measurements showed comparable high quality spectra in a distance of 2.5 cm and 5 cm from the surface coil and slightly lower quality in a distance of 7.5cm.The reproducibility was high for pH, γ-NTP/PCr , α-NTP/PCr and Pi/PCr and lower for β-NTP/PCr, PDE/PCr and PME/PCr.

Ke Li^1,2, Richard D Dortch^1,2, Daniel F Gochberg^1,2, Seth A Smith^1,2, Bruce Damon^1,2, and Jane H Park^1,3
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology, Vanderbilt University, Nashville, TN, United States, ³Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

The Quantitative magnetization transfer (qMT) yields parameters that describes the interactions between free and macromolecular protons in biophysical environments. A selective inversion recovery (SIR) technique was developed to determine the qMT parameters. However, the estimation of parameters based on the bi-exponential model may be biased due to the existence of a fat component. In this work, simulations were performed, by using synthesized phantom data. It was predicted that the two key parameters of interest - pm/pf and kmf, are biased with varied fat component sizes. This prediction was further verified in human muscle data with and without fat suppression pulse.

Daniel Nanz¹, Michael Alexander Fischer¹, Roman Guggenberger¹, Timo Schirmer², and Gustav Andreisek^1
1Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland, ²GE Global Research, General Electric

Para-spinal muscles of patients with chronic lower back pain are known to gradually degenerate by infiltration of fat, which has been demonstrated by single-voxel spectroscopic fat-signal-fraction quantification. Single-voxel spectroscopy suffers from several disadvantages such as a sampling problem similar to biopsy or comparatively long acquisition times. This study investigated, to what degree newly developed imaging-based fat-signal quantification methods could yield results comparable to those obtained with single-voxel spectroscopy, but in large three-dimensional imaging volumes that can be scanned in a minute or less acquisition time. The 3D imaging sequences offer fat-water separating image reconstruction with varying corrections for quantification.

Dimitrios C Karampinos¹, Lorenzo Nardo¹, Julio Carballido-Gamio¹, Ann Shimakawa², Benjamin C Ma³, Thomas M Link¹, and Roland Krug^1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, ²Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, ³Department of Orthopedic Surgery, University of California, San Francisco, San Francisco, CA, United States

The evaluation of shoulder muscle fat infiltration is important for the clinical management of patients with rotator cuff injuries. Goutallier’s classification of T1-weighted or proton-density weighted images has been traditionally used to evaluate fat infiltration in the shoulder muscles. However, this technique is semi-quantitative and therefore subjective and cannot track small fat infiltration changes. Chemical shift-based water/fat separation techniques have been recently implemented to measure fat content in skeletal muscle. In the present work, a chemical shift-based water fat separation is applied to the shoulder musculature of 31 subjects and the derived mean fat fraction quantitative measures are compared with Goutallier’s classification.

Peng Cao^1,2, Zhongwei Qiao^1,2, Anna M. Wang^1,2, Shujuan Fan^1,2, Victor B. Xie^1,2, Jian Yang^1,3, and Ed X. Wu^1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, ³Medical Imaging Center of the First Affiliated Hospital, School of Medicine of Xi'an Jiaotong University, Xi'an, Shanxi Province, China

In skeletal muscle, lipids are stored as intramyocellular lipid (IMCL) inside muscle cells and extramyocellular lipid (EMCL) in large adipocytes. IMCL exists in form of small spherical droplets that are often found next to mitochondria. In this study, we aimed to characterize the lipid diffusion within IMCL droplet. Our experimental results demonstrated that small IMCL microstructure leads to highly restricted lipid diffusion in IMCL droplet. Such IMCL diffusion characterization may provide a sensitive maker to probe the IMCL droplet microstructure, leading to a potentially valuable tool for investigating IMCL droplet dynamics and metabolism in vivo.

Valeria Righi^1,2, Caterina Constantinou³, Nikolaos Psychogios^1,2, Julie Wilhelmy⁴, Michael Mindrinos⁴, Laurence G. Rahme³, and Aria A. Tzika^1,2
1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, Massachusetts, United States, ²Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States, ³Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States, ⁴Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States

We hypothesized that a volatile aromatic molecule, 2-amino acetophenone (2-AA), produced by the human pathogen Pseudomonas aeruginosa endangers the host. We used a novel high-resolution magic-angle-spinning (HRMAS), proton nuclear magnetic resonance (NMR) metabolomics method, in vivo 31P NMR and a whole-genome expression approach to identify the effects of 2AA on murine skeletal muscle. We observed oxidative stress apoptosis and insulin resistance status associated with a mitochondrial dysfunction molecular signature in skeletal muscle following 2-AA treatment, which may be linked to 2-AA’s ability to promote bacterial phenotypic changes associated with chronic inflammatory disease and infection.

Hamed Mojahed¹, Pamela Freda², Christina Read³, Alex Dresner⁴, Truman R Brown⁵, and Fernando Arias-Mendoza^3
1Department of Biomedical Engineering, Columbia University, New York, NY, United States, ²Department of Medicine, Columbia University,³Department of Radiology, Columbia University, ⁴Philips Healthcare, Cleveland, OH, United States, ⁵Center for Advanced Imaging Research, Medical University of South Carolina, Charleston, SC, United States

Intra-myocellular lipid (IMCL) and diaphysis lipids of mixed sex acromegaly patients (including one outlier patient suspected of having a muscular degenerative disease) were studied with proton single voxel MR spectroscopy in a 1.5T Philips system. The IMCL normalized to total methyl and methylene lipid groups in diaphysis correlated with IMCL normalized to muscle water in all of the patients. However, excluding the outlier patient made the correlation more reliable. Hence studying muscle metabolites may be performed by normalizing to the bone marrow lipids but special caution must be exercised when studying patients with muscular degenerative diseases.

Decorte Nicolas¹, Laurie Cabrol¹, Mathilde Drouet¹, Noura Azzabou¹, and Pierre G. Carlier^1
1Institute of Myology, CEA, Paris, 75013, France

Abnormal skeletal muscle enhancement post Gd-contrast agent IV injection is observed in many conditions (inflammation, dystrophy, fibrosis). Reference values for normal muscles were not available, which made impossible classification and decision based on quantitative analysis. These benchmarks are provided here, with data from twelve healthy volunteers, six male, six female, 22-67 year old, having received an IV injection of Gd-DOTA. The time-courses of thigh muscle signal enhancement were analyzed both phenomenologically (time to peak, maximum relative enhancement, decay time constant) and analytically (extracellular volume fraction, rate constant and transfer constant).

R G Hernandez-Salazar¹, S Vargas-Cañas², S Hidalgo³, O Marrufo¹, S Solis⁴, A Rodriguez⁵, and R D Delgado-Hernandez^1
1Neuroradiology Dep, INNN-MVS, Mexico, DF, Mexico, ²Neurology Dep, INNN-MVS, Mexico, DF, Mexico, ³Phys Dep, UAM Iztapalapa, Mexico, DF, Mexico,⁴Phys Dep, FC UNAM, Mexico, DF, Mexico, ⁵Electrical Engineering Dep, UAM Iztapalapa, Mexico, DF, Mexico

Limb-girdle muscular dystrophies (LGMD) are a group of autosomal dominantly or recessive inherited muscular dystrophies that also present with primary proximal (limb-girdle) muscle weakness, involving the shoulder and pelvic girdles, distinct phenotypic or clinical characteristics are recognized. MRI has great potential for non-invasive characterization of muscle properties in LGMDs utilizing techniques such as Dixon-based imaging for fat-water quantification and diffusion MRI for probing muscle microstructure. The aim of this study was to compare quantitative MRI measurements from Dixon-based imaging and DWI in the thigh muscles of adults with LGMDs and healthy volunteers.

Martijn Froeling¹, Gustav J Strijkers², Frans Nollet³, Marianne de Visser⁴, Klaas Nicolay², and Aart J Nederveen^1
1Department of Radiology, Academical Medical Center, Amsterdam, Netherlands, ²Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ³Department of Rehabilitation Medicine, Academical Medical Center, Amsterdam, Netherlands,⁴Department of Neurology, Academical Medical Center, Amsterdam, Netherlands

In DTI of skeletal muscle in post-polio patients one would like to make a distinction between healthy and affected muscles and also investigate if the fat-infiltrated muscles show organized structures and thus differs from the subcutaneous fat. The aim of this work was therefore to develop a fully automated algorithm for segmentation of healthy and fat-infiltrated muscle based on the distribution of the diffusion tensor imaging parameters.

Francesco Santini¹, Michele Pansini², Tilman Schubert², and Oliver Bieri^1
1Division Radiological Physics - Institute of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland, ²Institute of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland

In this work, we present a method for accurate, quantitative measurement of muscle contraction with a temporal resolution of few milliseconds, therefore allowing the direct assessment of the reaction time of the muscle fibers, the contraction speed and the displacement.

Yoshikazu Okamoto¹, Toru Okamoto², and Yuka Kujiraoka^2
1University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan, ²Tsukuba memorial hospital

Fourteen volunteers were scanned using deterministic diffusion tensor imaging (DTI), and six fiber tractographs were constructed from a unilateral calf of each volunteer and the �gfiber density�h was calculated in each of the tractographs. The average pennation angle (AVPA) and angle variation (SDPA) were also measured for each muscle by ultrasonography (US) in the same region as the MRI scan. For all eighty-four tractography images, the correlation coefficient between the fiber density and AVPA or SDPA were well correlated (R= 0,715 and -0.472, respectively). Our data suggest that a larger, more variable pennation angle resulted in worse skeletal muscle tractography.

Ke Li^1,2, Joseph W Huston³, Nathan Bryant^1,2, and Jane H Park^1,4
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology, Vanderbilt University, Nashville, TN, United States, ³School of Medicine, Vanderbilt University, Nashville, TN, United States, ⁴Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

In this work, MRI studies of thigh muscles in an undiagnosed myopathic patient and two healthy controls are presented. No significant differences were observed in T1- and T2-weighted and STIR images or in T1 and T2 values. However, obvious abnormalities in fiber density and fiber directions were revealed with DTI-based fiber tracking in the patient�s muscles. This indicates that fiber tracking is a powerful method for identifying muscle fiber abnormalities that correlate with weakness and fatigue. This technique will promote accurate clinical evaluation of myopathy and proper assignment of therapuetic procedures for muscle rehabilitation.

Sanghamitra Sinha¹, and Ryuta Kinugasa^2,3
1University of California, San Diego, San Diego, CA, United States, ²Kanagawa University, Kanagawa, Japan, ³RIKEN, Saitama, Japan

Muscle force output is affected severely by the aging process through its dependency on various musculoskeletal (MSK) architectural and physiological factors. In six senior and six young subjects, MSK diffusion tensor imaging (DTI) and fiber tractography was used to non-invasively investigate age-related microarchitectural changes in muscle compartments of the lower leg. Analysis of the DTI parameters revealed that 3 decreased significantly with age in the plantarflexors. FA increased with age in all muscles. Finally, a decrease of MG fiber pennation angle by ~30% with age provided a partial explanation for the significant loss of muscle force output in the elderly.

Eric Chuan Qin^1,2, Lauriane Juge³, Simon Lambert³, Ralph Sinkus³, and Lynne Bilston^1,2
1Neuroscience Research Australia, Randwick, NSW, Australia, ²Prince of Wales clinical school of medicine, UNSW, Randwick, NSW, Australia, ³INSERM U773/Hôpital Beaujon, Centre de Recherche Biomédicale Bichat Beaujon (CRB3), Clichy, France

Duchenne Muscular Dystrophy (DMD) is a high incidence hereditary muscular disease that weakens the muscles which can result in premature death. Currently the gold standard in detecting abnormal changes in muscle tissues is muscle biopsy, which is invasive and painful. In this study we used a novel imaging technique which combines diffusion tensor imaging with magnetic resonance elastography to investigate the anisotropic shear moduli of the skeletal muscles of Mdx mice and wild type mice in vivo. This technique can provide additional parameters in detecting abnormal changes in muscular diseases, and allow early diagnosis and monitoring of such diseases.

Laëtitia Debernard¹, Ludovic Robert², Fabrice Charleux², and Sabine F Bensamoun^1
1Laboratoire de Biomécanique et Bioingénierie, UMR CNRS 6600, 60200, Compiègne, France, ²ACRIM, Polyclinique Saint-Côme, 60200, Compiègne, France

Age-related muscle changes have a huge impact on daily life activities in elderly people, such as gaiting, standing up, sitting down or stair climbing. Consequently, the development of adequate muscle rehabilitation programs will provide the elderly with more independence and better life. Thus, the objective of this study is to develop a MR elastography data base to measure age (20 to 80 years) and gender related changes on the passive and active muscles of the thigh. Additional measurements were also performed on the subcutaneous adipose tissue of the same subjects to elucidate the idea of fatty tissue infiltration with age.

Ryuta Kinugasa^1,2, Ali Moghadasi³, and Shantanu Sinha^3
1Kanagawa University, Yokohama, Kanagawa, Japan, ²RIKEN, Wako, Saitama, Japan, ³University of California San Diego, San Diego, CA, United States

Older adults have a reduced ability in the translation of work from muscle fascicle shortening to the movement of the aponeurosis. Such non-invasive, high-SNR, large Field-of-view imaging with VE-PC techniques allow determination of physiological, clinically significant parameters with good accuracy and reliability

Jin Yamamura¹, Tony Schmidt¹, Roland Fischer², Jerry Wang³, and Gerhard Adam^1
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ²Children's Hospital and Research Center Oakland, Oakland, California, United States, ³Department of Radiology, Children's Medical Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States

MRS of the muscle in forensic medicine

Bing Keong Li¹, Ewald Weber¹, Fabian Bartel¹, Dru Morris², Craig Engstrom¹, Adnan Trakic¹, Hua Wang¹, Ben Kelley², and Stuart Crozier^1
1School of ITEE, The University of Queensland, Brisbane, Queensland, Australia, ²X Radiology Australia, Brisbane, Queensland, Australia

A prototype 3-element open phased array knee coil for dynamic musculoskeletal (MSK) MR imaging of the knee was constructed and tested in a 1.5T Siemens Espree system. The acquired MR images of the knee joint, flexed to a variety of angles and also at the normal relaxed position, show that the open design concept is feasible and can facilitate diagnostic and functional assessment of knee injuries and pathology.

Bing Keong Li¹, Ewald Weber¹, Fabian Bartel¹, Dean Hunt², Craig Engstrom¹, Hua Wang¹, Adnan Trakic¹, Tim Demetriades², and Stuart Crozier^1
1School of ITEE, The University of Queensland, Brisbane, Queensland, Australia, ²X Radiology Australia, Brisbane, Queensland, Australia

A prototype 1.5 T receive-only 3-element multi-directional MSK phased array wrist coil that is capable to maintain its performance even when it is angulated from +/-55° to B0 was constructed and successfully tested. The ability to angulate the coil through a wide range of angles, allows positioning the coil in the center of the DSV with the possibility for relaxed overhead positioning of the wrist through “horizontal flexion” of the elbow. With this setup, high quality wrist images can be acquired and patient comfort can be achieved.

Abdullah Ok¹, Jan Rieger^1,2, Celal Özerdem¹, and Thoralf Niendorf^1,3
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück-Center for Molecular Medicine, Berlin, Germany, ²MRI.TOOLS GmbH, Berlin, Germany,³Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Berlin, Germany

A flexible transceiver coil was designed to be used in musculoskeletal imaging at 7.0 T. Phantom studies showed an average SNR increase of 14%. The coil's performance was then evaluated in vivo.

Hwayoung Kate Lee¹, Patrick Pierce¹, Carol Finn², Martin Raymond Prince^2,3, and Stacy Smith^1
1Department of Radiology, Brigham & Women's Hospital, Boston, MA, United States, ²Department of Radiology, Columbia University College of Physicians and Surgeons, New York, NY, United States, ³Department of Radiology, Weill Cornell Medical College, New York, NY, United States

Recognition of MR artifacts and familiarity with them are crucial for proper image interpretation and correct diagnosis. A clear understanding of MR parameters and trade-offs is essential to optimizing image quality. This educational exhibit aims to familiarize radiologists with a spectrum of MR artifacts (physiological, inherent physical and mechanical) that can occur in musculoskeletal and body imaging, discuss underlying scientific principles leading to artifacts and provide remedies to reduce artifacts without significantly increasing scan time or compromising signal-to-noise ratio, contrast-to-noise, resolution and field-of-view. Additional strategies to take advantage of artifacts and improve imaging quality will be discussed.

Kathryn Stevens¹, Bao Do¹, Luis Gutierrez¹, Pauline Worters¹, Brian Hargreaves¹, Kevin Koch², and Garry Gold^1
1Radiology, Stanford Medical Center, Stanford, CA, United States, ²GE Healthcare

While MRI of patients with orthopedic hardware is often limited by susceptibility artifacts, several methods have recently been developed to dramatically reduce these artifacts. We describe the initial clinical experience with Hybrid at 3.0T in patients with spinal hardware, hip replacements, femoral pins/rods and ACL reconstruction. Imaging around metal implants with Hybrid resulted in a dramatic decrease in image artifacts compared to conventional 2D FSE, allowing improved visualization of periprosthetic tissues, despite longer scan times and reduced spatial resolution.

Gunilla Maria Muller¹, Bjorn Lundin², Thord von Schewelov³, Markus F Muller⁴, Olle Ekberg⁵, and Sven Mansson^6
1Skane University Hospital, Radilogy, Malmo, Skane, Sweden, ²Radiology, Skane University Hospital, Lund, Sweden, ³Orthopedic Surgery, Skane University Hospital, Malmo, Sweden, ⁴Radiology, Skane University Hospital, Malmo, Sweden, ⁵Radiology, Skane University Hospital, Malmo, Skane, Sweden, ⁶Radiation Physics, Skane University Hospital, Malmo, Sweden

Sequences reducing metal artifacts in patients with hip prosthesis enable MRI visualization of periprosthetic tissue, thereby allowing early diagnosis of complications.

Prodromos Parasoglou¹, Ding Xia¹, and Ravinder R Regatte^1
1Center of Biomedical Imaging, NYU Langone Medical Center, New York, New York, United States

Localized 31P-MRS methods can provide quantitative information for the concentration of several metabolites in the human skeletal muscle. However, these methods suffer from long acquisition times and coarse resolution, limiting their potential use in the clinical setting. Imaging of a single metabolite can be achieved at a much higher spatial and temporal resolution, with the use of spectrally selective imaging methods. In this study, we report the implementation of a 3D spectrally selective turbo spin echo sequence to image phosphocreatine in the human calf muscle with high SNR on a 3T clinical system in a clinically feasible scan time.

Nicolas Decorte¹, Ericky Caldas de Almeida Araujo¹, Alexandre Vignaud², and Pierre G. Carlier^1
1Institute of Myology, AIM and CEA, Paris, 75013, France, ²Siemens Healthcare, Saint Denis, France

Functional NMR imaging, among its many variations, offers the possibility to measure non-invasively muscle perfusion by arterial spin labeling (ASL) and blood oxygenation via the T2 dependence on haemoglobin saturation. In this study, we show that muscle ASL and T2 determination of arterial and venous blood may be combined to calculate muscle oxygen consumption non-invasively and with a temporal resolution compatible with physiological studies.

Martijn Froeling^1,2, Aart J Nederveen¹, Klaas Nicolay², and Gustav J Strijkers^2
1Department of Radiology, Academical Medical Center, Amsterdam, Netherlands, ²Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

In this study we explored the effect of different tensor estimation methods on diffusion parameters in muscle DTI using simulations and acquired data.

Saori Watanabe¹, Tosiaki Miyati¹, Risa Yorimitsu¹, Hirohito Kan², Syuya Fujihara³, Harumasa Kasai², Nobuyuki Arai², Masaki Hara², and Yuta Shibamoto^2
1Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan, ²Department of Radiology, Nagoya City University Hospital, Nagoya, Japan, ³School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan

Diffusion analysis with the apparent diffusion coefficient (ADC) enabled to obtain information of bone marrow composition. However, it is appropriate that the unit of water molecular displacement in the bone marrow is �gƒÊm�h than �gmm2/sec�h of ADC. Therefore, we evaluated water molecular displacement in the vertebral bone marrow using q-space analysis to provide the detailed information on vertebral bone marrow. Correlation of displacement vs BMD was greater than that of ADC vs BMD. Water molecular displacement analysis with q-space makes it noninvasively possible to obtain more detailed information of changing bone marrow composition, and metabolism.

Juliet Compston¹, Amanda Cox², Michael Stone³, Jane Turton³, Irene Debiram¹, and Kristin James^2
1School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom, ²Acuitas Medical, Swansea, United Kingdom, ³Llandough Hospital, Cardiff, United Kingdom

A new magnetic resonance-based technique, designed to measure biologic texture too fine to be resolved by conventional MR imaging, was evaluated for its ability to assess bone health through quantification of trabecular bone structure in the L1 vertebrae of post-menopausal women. The technique provides a measure of the characteristic distance between trabecular elements by signal analysis of a finely sampled one-dimensional, spatially encoded echo from a selectively excited internal volume. In this study we were able to separate a cohort of healthy women from a group comprised of osteopenic and osteoporotic women with 85% certainty.

Daniel Ludwig Weber^1,2, Stefan Weick², Markus Lototchi², Sairamesh Raghuraman^2,3, Titus Lanz³, Daniel Haddad^1,2, and Peter Michael Jakob^1,2
1MRB Research Center for Magnetic Resonance Bavaria e.V., Würzburg, Bavaria, Germany, ²Department of Experimental Physics 5 (Biophysics), University of Würzburg, Würzburg, Bavaria, Germany, ³RAPID Biomedical GmbH, Rimpar, Bavaria, Germany

Dynamic 3D imaging may provide valuable additional information in knee injuries and increases specificity of the diagnosis. A motion device was used allowing an active and thus physiological movement of the knee. For the correlation between the motion and the MR acquisition, a retrospective self-gated 3D sequence with a quasi-random sampling scheme together with a 16 channel U-shaped phased array coil was used. The upward and downward motions were differentiated using the derivative of the DC-signal. Six 3D datasets (corresponding to motion states) were reconstructed retrospectively. For the reconstruction of the images, adaptive combining and iterative GRAPPA was applied.

Saikat Pal¹, Thor Besier², Michael Fredericson¹, Gary Beaupre³, Scott Delp¹, and Garry Gold^1
1Stanford University, Stanford, California, United States, ²University of Auckland, New Zealand, ³VA Palo Alto, Palo Alto, California, United States

Patellofemoral (PFP) pain is common. Although there are several potential causes, patella alta (greater than normal patella height relative to the tibia or femur) is considered a pre-disposing factor in patellar maltracking and pain. However, evidence supporting a relationship between patella alta and maltracking is limited. The purpose of this study was to evaluate the relationship between patella height and patellar tracking in pain-free control and PFP subjects using novel upright, weightbearing MRI. We observed significantly greater patella height in maltracking PFP subjects. This study overcomes a critical barrier in understanding the mechanisms for PFP by providing new evidence relating patellar maltracking to patella height.

Sairam Geethanath¹, Steen Moeller², and Vikram D Kodibagkar^1,3
1Joint program in biomedical engineering, UT Arlington/UT Southwestern Medical Center, Dallas, Texas, United States, ²University of Minnesota, Minneapolis, Minnesota, United States, ³School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona, United States

Concurrent Dephasing and excitation (CODE) is a novel pulse sequence which facilitates imaging of short T2 components. Currently, exquisite 3D images can be acquired within minutes but imaging dynamics of the knee and T2 exchange contrast agents, would require an even faster imaging scheme. The application of compressed sensing to accelerate CODE MRI has been demonstrated on 5 knee data sets for acceleration factors of 2, 3, 4 and 5. Compressed sensing based reconstruction of the MR volume shows high fidelity with lower noise as quantified by root-mean-square-error with respect to the original full k-space reconstruction.

Oliver Kraff^1,2, Stephan Orzada^1,2, Mark E Ladd^1,2, Stefan Landgraeber³, Thomas C Lauenstein², and Jens M Theysohn^2
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, ²Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, ³Department of Orthopedic Surgery, University Hospital Essen, Essen, Germany

In this study, various gradient (MEDIC, DESS) and spin echo (PD, T2, T1, STIR) sequences of a typical, clinical examination protocol were compared to stage patients with avascular necrosis (AVN) of the femoral head at 7T. Five healthy volunteers and five patients with AVN were imaged at 7T and 3T. While for gradient echo images, overall image quality was comparable to 3T imaging, STIR images were impaired by variations in signal homogeneity and fat suppression.

Benjamin Schmitt¹, Toshiyuki Shiomi², Siegfried Trattnig³, Monika Egerbacher⁴, and Pavol Szomolanyi^3
1Centre for High-Field MR, Medical University of Vienna, Vienna, Austria, ²Osaka University Graduate School of Medicine, ³Medical University of Vienna,⁴University of Veterinary Medicine Vienna

The study was performed to assess if the ionic X-ray contrast agent Hexabrix® can be used as a specific marker of cartilage GAG content via CEST MRI. The agent is used in x-ray arthrography to assess GAG content through the fixed charge density of GAG. Samples from porcine knees with and without enzymatic degrading of cartilage were immersed in Hexabrix® solutions at different concentrations, and examined with CEST MRI at 3 T. The results show CEST signal enhancements in cartilage with low GAG content, which can be attributed to accumulation of contrast agent, demonstrating the potential of the technique.

Junmin Liu¹, David W Holdsworth^1,2, and Maria Drangova^1,3
1Imaging Lab, Robarts Reseach Institution, The University of Western Ontario, London, Ontario, Canada, ²Department of Surgery, The University of Western Ontario, London, Ontario, Canada, ³Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

A new two-point Dixon fat water separation method is presented to address the concern that the phase-shift (Δθ) between fat and water in the out-of-phase complex images may not be exactly equal to π. The method derives Δθ from the histogram distribution of the phase differences between the unwrapped data sets by fitting a double Gaussian function first, selecting a threshold value, then separating fat and water. In vivo 3D experimental results of a knee demonstrate that the proposed technique offers robust fat-water separation for two-point Dixon acquisitions, despite the fact that Δθ/π was 0.92 ± 0.03.

Young Han Lee¹, Ho-Taek Song¹, Jin-suck Suh¹, and Vladimir Jellus^2
1Radiology, Severance hospital, Yonsei Univ. College of Medicine, Seoul, Seoul, Korea, ²Siemens AG, Healthcare Sector, Erlangen, Germany

The 3D UTE provides imaging of short T2 tissues which cannot be visualized on the conventional MR. By using the weighted subtractions with optimal weighting values, the each tissue can be optimally depicted by the overcoming the reduced T2 contrast to the fat or muscle.

Yoshihiro Tomoda¹, and Hitoshi Ikeda^1
1MR Engineering, GE Healthcare Japan, Hino, Tokyo, Japan

Novel FSE method is proposed to improve the T2map accuracy by calculating B1map simultaneously without scan time elongation. Compared with the legacy CPMG method, T2 estimation error is low enough in a wider range of T2 and refocus FA. In addition, lower refocus FA is applicable to the proposed method, which would decrease SAR and increase the number of max slices per acquisition.

Henk Smit¹, J. van Tiel¹, E.E. Bron¹, D. Poot¹, G.C. Houston², W.J. Niessen^1,3, H. Weinans¹, G.P. Krestin¹, S. Klein¹, E.H.G. Oei¹, and G. Kotek^1
1Erasmus MC, Rotterdam, Zuid Holland, Netherlands, ²GE Healthcare, Netherlands, ³Delft University of Technology, Netherlands

In conventional T1 mapping of the human knee cartilage the low resolution is a problem. We propose and evaluate an alternative T1 mapping technique of the cartilage. Multi-Slice Inversion Recovery with ARC parallel readout allows high resolution knee cartilage images in a short time. Also a method for error estimation of the derived T1 values is presented, which is used to compute a weighted mean T1 over a region of interest. Reproducibility is tested on healthy volunteers and sensitivity to cartilage damage is shown on an osteoarthritis patient.

Jiang Du¹, Michael Carl², Nikolaus M. Szeverenyi¹, and Graeme M. Bydder^1
1Radiology, University of California, San Diego, CA, United States, ²GE Healthcare, San Diego, CA, United States

MRI of the skin was performed with short and ultrashort TE pulse sequences using a clinical 3T system. Studies were performed in tissue samples, cadavers and human subjects. The stratum lucidum and fiber structure in the stratum papillare, stratum reticular and hypodermis were demonstrated. These showed obvious magic angle effects. Sebaceous, ecrine and apocrine glands were shown together with the arrector pili muscle. Signal was detectable in the nail. Planes parallel to the surface of the skin were particularly useful. Short T2 tissues of the skin can be well demonstrated with short and ultrashort TE sequences.

Marco Piccirelli^1,2, Chris Bockisch³, and Roger Luechinger^4
1SNS Lab, Dept. ECON, University Zurich, Zurich, Switzerland, ²Inst for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland,³Departments of Neurology, Ophthalmology, and Otolaryngology, University Hospital Zurich, Zurich, Switzerland, ⁴Inst for Biomedical Engineering, University & ETH Zurich, Zurich, Switzerland

Dynamic MRI of the orbit during eye movement with high spatiotemporal resolution is possible using a segmented acquisition. Nevertheless, the excessively long resulting scantime prohibits clinical use. Therefore, methods are needed to decrease the examination duration, such as, e.g., multichannel receive array that will enable simultaneous scanning of both orbits and kt SENSE image acquisition. Simultaneous eye tracking enable the control of the reproducibility of the eye motion, and may be used for re-measurement of k-space profiles with wrong gaze direction. We present here methodological improvements that enable dynamic imaging of the orbit with high spatiotemporal resolution at 3T.

Greg O. Cron^1,2, Merit El-Maadawy³, Joel Werier^1,2, Rebecca E. Thornhill^1,2, Robert Chatelain¹, Elizabeth Henderson¹, Claire Foottit¹, Ian Cameron^1,2, and Mark E. Schweitzer^1,2
1The Ottawa Hospital, Ottawa, ON, Canada, ²The University of Ottawa, Ottawa, ON, Canada, ³Mansoura University Hospitals, Mansoura, Egypt

Measurement of tracer kinetic parameters via dynamic contrast-enhanced (DCE) MRI is a promising technique for evaluating musculoskeletal tumor aggressiveness. Standardization and validation studies for DCE-MRI in musculoskeletal tumors have been lacking, however. The purpose of this study was to validate DCE-MRI in musculoskeletal tumors by comparing to DCE-computed tomography (CT) in the same patients. We observed reasonable agreement in tracer kinetic parameters measured with CT and MRI. In particular, Ktrans had very similar mean values and showed good correlation on a case-by-case basis. This represents an important step forward for quantification of DCE-MRI for these tumors.

Laura M Fayad¹, Fillipo Del Grande², Ney Tatizawa-Shiga², Xin Wang³, Peter B Barker², Michael A Jacobs², John A Carrino², and David A Bluemke^4
1Radiology, Orthopaedic Surgery and Oncology, Johns Hopkins University, Baltimore, MD, United States, ²Radiology, Johns Hopkins University, ³Johns Hopkins University, ⁴Radiology, NIH

The role of MR imaging in the evaluation of musculoskeletal tumors continues to evolve as new techniques emerge. While conventional T1 and fluid-sensitive sequences are entirely sufficient to determine the location and extent of a lesion, quantitative methodologies (chemical shift imaging, perfusion imaging, DWI, MR spectroscopy) have become available and provide metrics that may advance the role of MR imaging for characterization. Tumor extent is well-evaluated on anatomic pulse sequences, but with the advent of whole body imaging, the roles of MR imaging now include detection.

Jose G Raya¹, Gerd Melkus², Silvia Adam-Neumair³, Elisabeth Muetzel³, Maximilian F Reiser³, Peter M. Jakob⁴, Thorsten Kirsch⁵, and Christian Glaser^5
1Radiology, New York University Langone Medical Center, New York, New York, United States, ²University of California San francisco, ³University of Munich, ⁴University of Wuerzburg, ⁵New York University Langone Medical Center

The aim of this work was to investigate the value of DTI of articular cartilage as predictor for early cartilage damage as assessed by histopathology. 41 cartilage-on-bone samples were examined at 17.6T. After MRI samples underwent histology with safranin-O for histopathology assessment of OA (OARSI score). The prognostic value of DTI was analyzed with logistic regression. Performance of DTI was assessed with ROC-curve analysis and the prediction error with 10-flod cross-validation. DTI demonstrated very good prediction performance (Sensitivity=92.9%, Specificity=77.8%) and a correct classification of more than 3 of 4 samples (78%) in a collective with low OARSI score (1–2).

Nikita Garnov¹, Wilfried Gründer², Gregor Thörmer¹, Robert Trampel³, Robert Turner³, Thomas Kahn¹, and Harald Busse^1
1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany, ²institute of Medical Physics and Biophysics, Leipzig University, Leipzig, Germany, ³Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

Degenerative changes in arthritic joint cartilage start at the surface layer and are characterized by a decreased order of the anisotropic radial structures. A depletion of these structures could therefore be an indicator for early arthritic changes in the cartilage. In this study, the fiber structure of the knee cartilage was analyzed by high-resolution, angle-sensitive MRI measurements in a 7-T whole-body scanner. The comparison between 10 younger and 10 older healthy subjects revealed significant differences in the anisotropic structure of the femoral cartilage. The presented technique therefore holds promise for a non-invasive assessment of cartilage integrity.

Takako Aoki¹, Atsuya Watanabe², Naotaka Nitta³, Akira Furukawa¹, and Mamoru Niitsu^4
1Radiological Science, Tokyo Metropolitan University, Arakawa-ku, Tokyo, Japan, ²Orthopedic Surgery, Teikyo University Chiba Medical Center, Anesaki, Chiba, Japan, ³Biomedical Sensing and Imaging, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan, ⁴Radiology, Saitama Medical University Hospital, Iruma-gun, Saitama, Japan

This is an interesting study on diffusion weighted MRI to assess articular cartilage in porcine knees by correlating ADC maps with viscosity coefficient and relaxation time measured by indentation testing.The strength of this article is the study design, performing diffusion weighted MRI on fresh porcine knees and using indentation testing as a measure of cartilage viscosity. Shortcomings are the inclusion of only normal knees. It would have been interesting to know the performance of diffusion weighted MRI to detect and quantify cartilage lesions.

Nikolaus M. Szeverenyi¹, Jiang Du¹, Chantal Pauli², Sheronda Statum¹, Christine Chung¹, and Graeme M. Bydder^1
1Radiology, University of California, San Diego, CA, United States, ²Scripps Institute, San Diego, CA, United States

Magic angle effects are important in accounting for the signal of different layers of articular cartilage, but equally striking are vertical striations seen perpendicular to the layers. These correlate with leaves seen with freeze-fracture, but the mechanism responsible for contrast between them has not been defined. By systematically rotating cartilage relative to B0, imaging it, registering the images and studying the signal intensity, differences in degree of magic angle effect between leaves were defined. In addition, both linear and meshwork patterns of fibers were demonstrated in the leaves. These structures were most evident in uncovered cartilage.

Uwe Hans-Werner Schütz¹, Daniel Schoss¹, Hans-Jürgen Brambs¹, and Christian Billich^1
1Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany

Unique data on T2* mapping of ankle and hindfoot joints from a field study with a mobile 1.5T MRI truck trailer accompanying 22 endurance athletes on their 4,500 km multistage ultra marathon through whole Europe in 64 days are presented. A single ultra marathon does not bather the ability of cartilage to react with physiological hydration to the running burden. But daily ultra marathon over 9 weeks without any day rest shows a decrease of cartilage ability of ankle and hindfoot joints to hydrate, indicating that this immense amount of running burden initiates degenerative processes.

Ashley Williams¹, and Constance R Chu^1
1Cartilage Restoration Center, University of Pittsburgh, Pittsburgh, PA, United States

ALC tear (ACLT) is a known risk factor for OA development. Longitudinal T₂ mapping of knee cartilage microstructural status in 16 human ACLT subjects reveals that T₂ values are stable over the first 12 months following ACL reconstruction surgery and then fall between 12 and 24 months post-surgery. Longitudinal T₂ differences were seen in the deep halves of cMFC and cLFC cartilage. Longitudinal differences were not detected in superficial cartilage. Deep T₂ differences between ACLT and asymptomatic subjects suggests that T₂ mapping may be sensitive to subclinical alteration of the subsurface cartilage matrix that is not detected by arthroscopic evaluation.

Megan E Bowers¹, Ashley Williams¹, Lisa A Fortier², Albert C Chen³, Robert L Sah³, and Constance R Chu^1
1Cartilage Restoration Center, University of Pittsburgh, Pittsburgh, PA, United States, ²College of Veterinary Medicine, Cornell University, Ithaca, NY, United States, ³Cartilage Tissue Engineering Lab, University of California, San Diego, La Jolla, CA, United States

Clinical strategies to evaluate repaired articular cartilage are needed. This study’s aim was to assess T2 mapping as a surrogate for invasive and destructive tissue analysis in an equine model of articular cartilage defects repaired with either concentrated bone marrow aspirate (CBMA) or microfracture (MFx) after one year of healing. Mechanical deficits in repair tissue compared to control cartilage corresponded to significant differences in full-thickness T2 values. This result suggests that as cartilage repair techniques are translated into the human clinical setting, T2 mapping may be useful as a non-invasive surrogate for the assessment of repair tissue’s functional integrity.

Hillary J. Braun^1,2, Bragi Sveinsson^1,3, Marcus T. Alley¹, Jason L. Dragoo², Caroline D. Jordan^1,4, George Pappas², Brian A. Hargreaves¹, and Garry E. Gold^1,4
1Radiology, Stanford University, Palo Alto, CA, United States, ²Orthopaedic Surgery, Stanford University, Redwood City, CA, United States, ³Electrical Engineering, Stanford University, ⁴Bioengineering, Stanford University, Palo Alto, CA, United States

Osteoarthritis (OA) is a chronic, degenerative disease of the whole joint, disabling 10% of the population over 60, and costing as much as $60 billion each year. Advances in magnetic resonance imaging (MRI) have enabled improved visualization and quantification of early, OA-related changes to articular cartilage. T2 mapping provides an accurate measure of tissue relaxation time, with increased values correlating with changes in cartilage water content and collagen structure. The purpose of this study was to evaluate two-dimensional fast-spin echo (2D-FSE) and quantitative three-dimensional (3D) Dual-Echo Steady State (qDESS) T2 mapping methods for assessing articular knee cartilage in both healthy volunteers and patients with medial compartment OA.

Gerd Melkus¹, James Hawkins¹, Joseph Schooler¹, Xiaojuan Li¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States

3D T1rho dispersion measurements using different spin-lock field strengths (B₁ = 0.5, 1, 2, 4, 6 kHz) and T2 mapping were performed in vivo on the knee joint of male Dunkin Hartley guinea pigs at two different ages (3 months and 13 months) at 7T. While T1rho of the muscle and cartilage increases with increasing B₁-field in all four animals, T1rho values differ between age groups. There is the evidence that a more sensitive interpretation of the cartilage status can be achieved when higher B₁ -fields (4 kHz or above) are applied for in vivo T1rho mapping.

Kathryn E Keenan¹, Thor F Besier², R. Lane Smith^1,3, John M Pauly¹, Scott L Delp¹, Gary S Beaupre³, and Garry E Gold^1
1Stanford University, Stanford, CA, United States, ²University of Auckland, Auckland, New Zealand, ³Department of Veterans Affairs, Palo Alto, CA, United States

ΔT1, a simple measure of T1 dispersion, can predict changes in cartilage modulus and macromolecular content when there is no visible cartilage damage on conventional MR. We define ΔT1 as the difference between T1 relaxation times at two spin-lock frequencies. For this cadaveric patellae study, initial elastic modulus, T1 relaxation times at 0, 500 and 1000 Hz and macromolecular contents were measured. Initial elastic modulus decreased with increasing ΔT1 when there was no visible cartilage damage on conventional MR (p<0.05). ΔT1 has clinical potential to advance the understanding of osteoarthritis by predicting changes in cartilage modulus and macromolecular content in vivo.

Arturo Cardenas-Blanco^1,2, Kawan Rakhra¹, Andrew Speirs³, Ian Cameron^1,3, Mark Schweitzer^1,2, and Paul Beaule^2,4
1Diagnostic Imaging, The Ottawa Hospital, Ottawa, Ontario, Canada, ²University of Ottawa, Ottawa, Ontario, Canada, ³Carleton University, Ottawa, Ontario, Canada, ⁴Orthopedic surgery division, The Ottawa Hospital, Ottawa, Ontario, Canada

In degenerative articular disorders, pre-structural cartilage degeneration is important to diagnose, as these patients are most amenable to surgical as well as non-surgical interventions. In Femoroacetabular Impingement, intervention is most appropriately applied to those patients with pre-structural cartilage changes. Hence we sought to determine, via T1ρ, if there are early changes in cartilage proteoglycan content in patients with unilateral symptomatic CAM type FAI, as compared to their asymptomatic CAM type FAI contra-lateral side, normal volunteers, as well as a unique possibly transition group who have CAM deformity but who are asymptomatic.

Riccardo Lattanzi^1,2, Catherine Petchprapa¹, Daniele Ascani¹, Roy I Davidovitch³, Thomas Youm³, Robert J Meislin³, and Michael Recht^1
1Radiology, New York University Langone Medical Center, New York, NY, United States, ²The Bernard and Irene Schwartz Center for Biomedical Imaging, New York University Medical Center, New York, NY, United States, ³Orthopedic Surgery, New York University Hospital for Joint Diseases, New York, NY, United States

Early diagnosis of articular cartilage degeneration is critical to the success of corrective surgical procedures for patients with femoroacetabular impingement (FAI). Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) can detect early biochemical changes in articular cartilage. In this work we validated the technique for the hip at 3 T against intra-operative findings, using radial imaging planes and a method to standardize dGEMRIC measurements, in order to remove the effect of inter- and intra-patient variability. Sensitivity, specificity and accuracy were 86%, 55% and 73% for dGEMRIC, and 59%, 61% and 60% for morphologic evaluation, using corresponding proton-density-weighted radial images.

Benjamin Schmitt¹, Siegfried Trattnig², Claudia Sallinger², Jochen Hofstätter², Reinhard Windhager², and Stephan Domayer^2
1Centre for High-Field MR, Medical University of Vienna, Vienna, Austria, ²Medical University of Vienna

The study was performed to assess to which extent gagCEST signal intensities measured with a clinical 3 T MR scanner in ankle cartilage correlate to cartilage GAG content as determined by the gold standard, biochemical quantification of GAG. Therefore, 7 ankles from human cadavers were examined with both techniques in an in-vitro study and linear correlations were found between them, which suggests that gagCEST imaging reflects GAG content in cartilage tissue.

Guillaume Madelin¹, James Babb¹, Ding Xia¹, Gregory Chang¹, Alexej Jerschow², and Ravinder R Regatte^1
1Radiology Department, New York University Medical Center, New York, NY, United States, ²Chemistry Department, New York University, New York, NY, United States

Quantitative sodium MRI is highly specific to glycosaminoglycan content and could be used to assess the biochemical degradation of cartilage in early stages of osteoarthritis. The aim of this study is to assess the reproducibility and repeatability for sodium quantification in cartilage in vivo using intra-day and inter-day acquisitions at 3T and 7T, with a 3D radial sequence, with and without fluid suppression. The measured RMS CV are in the range 7-14%, therefore the repeatability and reproducibility CV of sodium quantification using sodium MRI compare favorably with the CV of other proton-based MRI techniques (T2 map, T1rho map, dGEMRIC).

Richard Hodgson¹, Andrew Grainger², Philip O'Connor², Robert Evans², Paul Emery¹, and Jane Freeston^1
1LMBRU, University of Leeds, Leeds, Yorkshire, United Kingdom, ²Chapel Allerton Hospital

Early diagnosis of arthritis is important to start appropriate treatment but diagnosis may be difficult. Whole body multiple joint MRI has the potential to help diagnosis. 15 patients presenting with arthritis were studied with whole body multiple joint MRI. MRI was more sensitive than clinical examination. More sites were involved in rheumatoid arthritis than undifferentiated arthritis. MRI revealed clinically unsuspected findings which were diagnosically useful. Whole body multiple joint MRI may be useful in early arthritis.

Hiroshi Yoshioka¹, Eiko Yamabe¹, Arash Anavim¹, Ryo Miyagi¹, Sarah Rooney¹, and Dave Hitt^2
1Radiological Sciences, UC Irvine, Irvine, CA, United States, ²Philips Healthcare, Cleveland, OH, United States

The purpose of the present study is to optimize parameters of high-resolution 3D isotropic FSE fat-suppressed proton density-weighted images (FS PDWI) of the wrist in clinical settings within approximately 5 minute scan time. Optimal 3D isotropic FS PDWI of the wrist can be obtained with either 0.3 mm voxel size, 117 ETL, and 140-160 TI or 0.35 mm voxel size, 88 ETL, and 160-180 TI with less blurring, and acceptable S/N. Additional thin slice axial and sagittal images can be reformatted without extra scan time or degradation of image quality for a more complete assessment of the wrist structures.

Cris Lovell-Smith¹, Kaywan Izadpanah², Sebastian Gruhlke¹, Julian Maclaren¹, Michael Herbst¹, Leonie Eisebraun¹, Matthias Honal¹, and Maxim Zaitsev^1
1Dept. of Radiology, University Medical Center, Freiburg, Germany, ²Dept. of Orthopedic and Trauma Surgery, University Medical Center, Freiburg, Germany

In this work we leverage a specially designed MR-compatible tracking system to track the unconstrained and unloaded motion of the fore-foot. Using a CINE sequence we collect 2D slices of the ankle during foot motion. Tracking data coupled with the image timestamps allows us to retrospectively sort the images to produce a number of 3D image stacks. These image stacks represent consistent 3D volumes at given points in the foot trajectory. We use the motion-sequences created using this technique to investigate tibiotalar impingement.

Noriyuki Tawara¹, Takahiro Ohnishi², Katsuya Maruyama², Mamoru Niitsu³, Hideyuki Takahashi⁴, Kohei Nakajima¹, Toru Okuwaki¹, and Takashi Kawahara^1
1Department of Sports Medicine, Japan Institute of Sports Scinences, Tokyo, Japan, ²Siemens Japan, Tokyo, Japan, ³Department of Radiology, Saitama Medcical University, Saitama, Japan, ⁴Department of Sports Science, Japan Institute of Sports Sciences, Tokyo, Japan

ACL injury is one of the most common, but serious injury among the sports injuries. In Japan more than 20,000 athletes are injured per year. MRI plays an important role in supporting the diagnosis of acute and chronic ligament injures. However there is no method to measure the maturation of the tendon and ligaments except UTE techniques. On the other hand, in knee MR imaging, the magic angle phenomenon affected largely to the depictability of the various ligaments. So, the aim of this work is to demonstrate the potential of 3D UTE imaging for knee�fs ligament visualization, especially ACL.

Xeni Deligianni¹, Peter Bär², Klaus Scheffler^3,4, Siegfried Trattnig⁵, and Oliver Bieri^1
1Division of Radiological Physics - Department of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, NA, Switzerland, ²Siemens (Customer Services- Application MR), Erlangen, Germany, ³MTC Department, MPI for Biological Cybernetics, Tübingen, Germany, ⁴Dept. Neuroimaging and MR-Physics, University of Tübingen, Tübingen, Germany, ⁵Medical University of Vienna

Short echo time sequences can produce signal from short T2 components, but require long reconstruction times and are sensitive to the gradient system imperfections. A standard spoiled gradient echo sequence was adapted with a variable echo time scheme and highly asymmetric Cartesian sampling in order to provide fast short echo time and high resolution and contrast images, while the reduced scan time offers the possibility to use binomial RF pulses in order to achieve fat suppression at clinically adequate scan times. The benefits of this approach were demonstrated in a 3T as well as a 7T MR scanner.

Fabian Springer^1,2, Ulrich Grosse^1,2, Roland Syha^1,2, Günter Steidle², Petros Martirosian², and Fritz Schick^2
1Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany, ²Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany

Structure and composition of solid-like tissues lead to a fast signal decay causing hardly any signal using conventional MR imaging sequences. We present a newly developed water-selective ultrashort echo time sequence for improved visualization of tendons and ligaments. Water-selective binomial excitation pulses were implemented; imaging parameters were optimised by means of an analytical description of steady-state magnetization and numerical simulations. Tendons and ligaments were exemplarily examined in-vivo and could be clearly delineated with positive contrast compared to surrounding fatty tissue. The presented sequence seems to be a promising approach which is worth being further evaluated in clinical musculoskeletal MRI.

Vladimir Juras^1,2, Sebastian Apprich¹, Christina Pressl¹, Stefan Zbyn¹, Pavol Szomolanyi¹, Stephan Domayer³, Ivan Frollo², and Siegfried Trattnig^1
1Department of Radiology, MR Centre of Excellence, Medical University of Vienna, Vienna, Austria, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia, ³Department of Orthopedics, Medical University of Vienna, Vienna, Austria, Austria

In this study, multi-parametric MRI was used to image cadaver ATs. Sodium MRI, T2 mapping, fast imaging with steady state precession (FISP), and reversed FISP (PSIF) have been used for tendon assessment. The correlation between immunohistologically assessed GAG and water content was high in some cases, especially with sodium SNR. I was shown that the biochemical content of the AT can be evaluated by quantitative MRI.

John Firebaugh¹, Jiang Du¹, Michael Carl², Christine Chung¹, Nikolaus M. Szeverenyi¹, and Graeme M. Bydder^1
1Radiology, University of California, San Diego, CA, United States, ²GE Healthcare, San Diego, CA, United States

Cadaveric digital and palmar flexor tendons were studied with short and ultrashort TE pulse sequences using a clinical 3T system. Annular, cruciate and oblique pulleys were demonstrated with high signal including a central layer which showed marked angle effects (high and low signal with change in orientation to B0) differentiating it from the other two layers. Connections to the volar plate (A1 A3 A5) and periosteum (A2 A4) were well seen. Use of shorter TE sequences shows anatomy that has not previously been demonstrated with conventional longer TE pulse sequences.

Dustin Nguyen, D.O.¹, Cheri Nguyen, M.D.¹, Mohammad Umair, D.O.², and John Loh, M.D.^1
1Radiology, Baystate Medical Center, Springfield, MA, United States, ²Radiology, Brookhaven Memorial Hospital Medical Center, Patchogue, New York, United States

Ankle pain is a common presenting complaint in the ambulatory or emergent setting with the usual etiologies being trauma or sports related injuries. The mechanism is typically traumatic secondary to a twisting-type injury. There is a subset of patients presenting with ankle pain that are due to less common etiologies such as osteochondral lesions of the talar dome, plantar fasciitis and sinus tarsi ganglia to name a few. The purpose of the poster is to educate the viewer about the less common causes of ankle pain and to emphasis a working differential diagnosis for ankle pain.

Kazuyuki Ohgi¹, Masatoshi Hotta¹, Satoshi Doishita¹, Akinori Harada¹, Akiyoshi Yamashita¹, Hiroyuki Yokote¹, Shunji Tsukuda¹, and Tetsuhisa Yamada^1
1Radiology, Japanese Red-Cross Medical Center, Tokyo, Tokyo, Japan

The purpose of this presentation is to indicate the usefulness of spinal nerve root demonstration with 3D T2*-weighted gradient-echo (T2*W GRE) imaging in the diagnosis of lumbar foraminal and extraforaminal stenosis. 3D T2*W GRE imaging can provide more specific information than conventional MRI in the presurgical evaluation of lumbar foraminal and extarforaminal stenosis. The use of this technique has a potential of preventing failed back surgery syndrome, defined as persistence of clinical symptoms even after surgery.

Toshinori Sakai^1,2, Ryo Miyagi¹, Yasunari Fujinaga¹, Eiko Yamabe¹, Nitin N Bhatia², and Hiroshi Yoshioka^1
1Radiology, University of California, Irvine, Orange, California, United States, ²Orthopaedic Surgery, University of California, Irvine, Orange, California, United States

We analyzed the fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) values at all consecutive points along the L4, L5 and S1 nerves using diffusion tensor imaging (DTI) and fiber tracking (FT). Our study demonstrated that FA values between ROI and FT methods were inconsistent (r=0.528), while ADC values had a relatively good consistency (r=0.822) (n=754/each method). Both FA and ADC values measured with FT demonstrated significant better reproducibility in both inter- and intra-rater analyses. For measurements of FA and ADC values, FT would be warranted in the future clinical application.

Gary Lee¹, Caroline Jordan^2,3, Jeff McCormick⁴, Pamela Tiet⁵, Brian Hargreaves², and Steven Conolly^1,5
1Berkeley/UCSF Bioengineering Joint Graduate Group, Berkeley, CA, United States, ²Radiology, Stanford University, ³Bioengineering, Stanford University,⁴Molecular Environmental Biology, University of California, Berkeley, ⁵Bioengineering, University of California, Berkeley

Many MRI applications are vulnerable to B₀ inhomogeneity, including robust fat suppression, which requires better than 1 ppm homogeneity. We have tailored a pyrolytic graphite composite foam with magnetic susceptibility matched to human tissue. Here, we have experimentally demonstrated that PG foam cushions improve the B₀ field uniformity to the critical threshold of 1 ppm in the neck of 6 normal volunteers at 3T. The tissue susceptibility matched PG foams consistently mitigated signal drop out, improved image SNR, and enabled far more robust frequency selective fat suppression in T₁-weighted GRE images in volunteers.

Yi-Xiang Wang¹, James F Griffith¹, Min Deng¹, Tena K Li², Lai-Shan Tam², Vivian WY Lee³, Kenneth K.C. Lee², and Edmund K Li^2
1Dept Imaging & Interventional Radiology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ²Dept Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ³School of Pharmacy, The Chinese University of Hong Kong, Hong Kong

Spine ankylosing spondylitis (AS) is a chronic inflammatory enthesopathy. MRI scoring methods for quantifying the level of spinal inflammatory activity rely on the detection of (a) bone marrow edema on T2W fat-suppressed sequences, (b) hyper-diffusion of gadolinium into the interstitium of inflamed tissues on fat-suppressed T1W sequences. While spine AS inflammation manifests as areas of edema or gadolinium enhancement, our study shows these changes do not necessarily always occur in parallel, and contrast enhanced MR imaging yielded a higher lesion score than STIR imaging. The edema lesions seemed to be more responsive to treatment than contrast enhanced lesion.

Haiyan Lv¹, Heather Ting Ma¹, James F. Griffith², Alvin F.W. Li², Yixiang Wang², David K.W. Yeung², Anthony Kwok², and Ping-Chung Leung^2
1Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, Guangdong, China, ²Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China

This study investigated pixel-by-pixel perfusion in bone marrow by fitting the signal intensity curve using Brix model. The fitted curves were classified as pattern 1, 2 and 3 according to the terminal slope, which indicated the perfusion ability. Compared with normal subjects by t-test, Modic type I showed higher pattern 1 percentage and ROI pattern percentage; Modic type II showed a lower ROI pattern percentage; and Modic type III showed no significant difference. Normal group has a higher pattern 3 percentage than other groups. This study indicated that the perfusion ability of bone marrow varied in different Modic changes.

L. Tugan Muftuler^1,2, Vance O. Gardner³, Hon J. Yu⁴, and Dennis J. Maiman^1
1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States, ²Center for Imaging Research, Medical College of Wisconsin, Milwaukee, WI, United States, ³Orthopaedic Education and Research Institute of Southern California, Orange, CA, United States, ⁴Radiology, University of California, Orange, CA, United States

In this study we used a multi-parametric MRI protocol to study pathophysiology and etiology of lumbar disc degeneration. We proposed a new quantitative metric that utilized a combination of ADC and T2 signals from the discs to assess the degree of disc degeneration. Using this new metric, we demonstrated close associations between disc degeneration, age and poor nutrient delivery to discs. We also showed quantitatively for the first time that inferior lumbar discs are more prone to degeneration than superior discs.

Gopal Varma¹, Fotini Kourtelidis¹, Alexander Ivanishev^1,2, Robert L Greenman¹, David B Hackney³, Robert E Lenkinski^1,2, and Elena Vinogradov^1,2
1Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, ²Radiology, UT Southwestern Medical Center, Dallas, TX, United States, ³Neuroradiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

The assessment of glycosaminoglycan (GAG) content in intervertebral discs might provide early indication of disc degeneration. Non-invasive MR techniques associated with GAG assessment include the use of spectroscopy, sodium imaging and chemical exchange saturation transfer. A preliminary analysis of these methods is provided, which includes application to the L4/L5 IVD of volunteers at different ages, as a first step towards a more complete evaluation.

Matthew Fenty¹, Catherine DeBrosse², Rachelle Crescenzi², Dawn Squillante³, Philip M. Maurer³, Dawn M. Elliott⁴, and Ari Borthakur^1
1CMROI, Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States, ²Department of Biochemistry & Molecular Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, United States, ³3B Orthopaedics, Philadelphia, PA, United States, ⁴Department of Bioengineering, University of Delaware, Wilmington, DE, United States

In this study, we use T1 as a quantitative biomarker to assess discs adjacent to surgically removed discs two years post-surgery. We further evaluate whether these changes in T1 were related to pre-surgical discography opening pressure or T2-MRI based Pfirrmann degenerative grades of the same adjacent discs. Pre-surgical opening pressure measurements of adjacent discs were significantly related to changes in T1 pre- and post-surgery.

Yi-Xiang Wang¹, Feng Zhao¹, James F Griffith¹, Greta SP Mok², Queenie Chan³, and Jing Yuan^1
1Dept Imaging & Interventional Radiology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ²Department of Electrical and Electronics Engineering, University of Macau, Macau, ³Philips Healthcare, Hong Kong

The purpose of the current in vivo 3.0 T MRI study is to determine the relative performance of T1rho and T2 relaxation times in their assessment of disc degeneration with reference to an 8-level disc degeneration grading systems. For nucleus pulposus, T1rho and T2 relaxation times followed the same trend with their correlations to semi-quantitative gradings. T1rho relaxation time offered distinct advantage over T2 relaxation time in the evaluation of annulus fibrosus degeneration. While there were almost no changes of annulus fibrosus T2 values as the disc degeneration grades increased, T1rho decreased apparently as disc degeneration grades increased.

Matthew Fenty¹, Catherine DeBrosse², Rachelle Crescenzi², Dawn Squillante³, Philip M. Maurer³, Dawn M. Elliott⁴, and Ari Borthakur^1
1CMROI, Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States, ²Department of Biochemistry & Molecular Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, United States, ³3B Orthopaedics, Philadelphia, PA, United States, ⁴Department of Bioengineering, University of Delaware, Wilmington, DE, United States

In a retrospective study, we determined the sensitivity of the T1 relaxation time (pre-surgery) and T2 MRI-based Pfirrmann grading in predicting painful discs in patients. ROC analyses determined area-under-curves of 91% and 84% for T1 and Pfirrmann grading, respectively, as predictor of which discs were painful (based on discographic measurements) and subsequently underwent fusion surgery. The long-term objective of this study is to evaluate quantitative and non-invasive biomarkers of disc degeneration in order to help identify discs candidates for surgery as well as measure outcomes following therapeutic interventions.

Mina Kim¹, Queenie Chan², Marina-Portia Anthony¹, Dino Samartzis³, Kenneth MC Cheung³, and Pek-Lan Khong^1
1Department of Diagnostic Radiology, University of Hong Kong, Hong Kong, SAR, China, ²Philips Healthcare, Hong Kong, ³Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong, SAR, China

Magnetic resonance imaging (MRI) has been shown to improve the diagnosis and management of patients with intervertebral disc (IVD) related disorders. Multiparametric MRI offers the possibility of noninvasively assessing multiple aspects of pathophysiological processes that exist simultaneously, thereby further assisting in patient treatment management. The purpose of this study is to determine the correlation between relaxation parameters (T1ρ and T2), diffusion properties including fractional anisotropy (FA) and mean diffusivity (MD) measured by diffusion tensor imaging (DTI) and various clinical findings in human IVD. Our results suggest that each parameter may attribute different sensitivity to tissue properties.

Mina Kim¹, Queenie Chan², Marina-Portia Anthony¹, Dino Samartzis³, Kenneth MC Cheung³, and Pek-Lan Khong^1
1Department of Diagnostic Radiology, University of Hong Kong, Hong Kong, SAR, China, ²Philips Healthcare, Hong Kong, ³Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong, SAR, China

Chemical exchange saturation transfer (CEST) and T2 relaxation time were calculated in subjects with degenerative intervertebral discs (IVDs). Our results showed that CEST and T2 decreases with increasing grade of disc degeneration and that CEST values significantly correlated with T2. This study demonstrated a potential for the future use of MRI biomarkers in identifying early degenerative changes in the IVDs.

Gopal Varma¹, Alexander Ivanishev^1,2, Robert L Greenman¹, Fotini Kourtelidis¹, David B Hackney³, Robert E Lenkinski^1,2, and Elena Vinogradov^1,2
1Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, ²Radiology, UT Southwestern Medical Center, Dallas, TX, United States, ³Neuroradiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

The biochemical processes associated with degeneration of intervertebral discs (IVDs) are complex and have been found to include a loss of glycosaminoglycans (GAG). The concentration of GAG is correlated with sodium concentration and can be assessed by sodium MRI. The SNR from sodium MRI can be improved by weighted signal averaging, which is used in this work to acquire data from the L4/L5 IVD of volunteers of varying age to look at degeneration. The results allow distinction of the Na signal from the nucleus of the IVDs, which decreases with age.

Conny Ström¹, Jörgen Strinnholm¹, Volker Otten², Jòn Hauksson¹, Morten Bruvold³, Ulrike Blume³, Chiel den Harder³, and Clemens Bos^3
1Department of Radiology, University of Umeå, Umeå, Sweden, ²Department of Orthopedy, University of Umeå, Umeå, Sweden, ³Philips Healthcare, Best, Netherlands

Wear and tear of orthopedic implants is seen in many patients approximately fifteen years after intervention. Clarification of the extent of resulting complications is crucial to evaluate to what extent implant replacement is necessary. CT provides information about bone density, bone dimensions and implant dimensions but not about tumor-like osteolytic tissue. MR covers soft tissue imaging but suffers from artifacts near metal. Recently, Slice-Encoding for Metal Artifact Correction (SEMAC) was introduced to counteract these artifacts. This work shows that, quite unlike conventional sequences, SEMAC can image osteolysis and enables tissue evaluation very close to metal implants, thus improving diagnosis quality.

Daniel Kammer¹, Anna-Katinka Bracher¹, Andreas Horneff², Erich Hell², Johannes Ulrici², Axel Bornstedt¹, and Volker Rasche^1
1Internal Medicine II, University Hospital of Ulm, Ulm, BW, Germany, ²Sirona Dental Systems

Imaging of the dynamics of the temporomandibular joint (TMJ) is of interest for varies pathologies. High-resolution or three-dimensional assessment under active mastication is currently limited by the required realtime imaging techniques. The objective of this contribution is to investigate the application of gated retrospective cine reconstruction technique for providing high-quality dynamic images of the TMJ during active mastication.

Ryo Miyagi^1,2, Eiko Yamabe¹, Yasuhiko Terada³, Saki Kono³, Daiki Tamada³, Tomomi Uchiumi³, Katsumi Kose³, and Hiroshi Yoshioka^1
1Department of Radiological Sciences, University of California Irvine, Orange, CA, United States, ²Department of Orthopaedic Surgery, Tokushima University, Tokushima, Japan, ³Institute of Applied Physics, University of Tsukuba, Tsukuba, Japan

The purpose of this study was to assess skeletal age using MRI and evaluate its validity. A total of 93 Japanese healthy children aged from 4.1 to 15.1 were recruited from the local community. There was a strong positive correlation between chronological age and skeletal age by MRI using the TW-Japan RUS system. The intra-reader and inter-reader reproducibility for the MRI skeletal age assessment were high. Disagreement of skeletal stage by MRI between readers was most frequently seen in the ulna and fifth metacarpal bone. MRI could be a non-invasive and non-radiation method of assessment of skeletal age.

Maria Isabel Menendez^1,2, Daniel Clark¹, Alicia Bertone², and Michael Knopp^1
1Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, Columbus, Ohio, United States, ²Veterinary Clinical Sciences, The Ohio State University, Columbus, Ohio, United States

MRI was used to detect and evaluate condylar subchondral bone edema of surgically created large osteochondral defects in the femoral condyle that underwent gene therapy. MRI detected changes in subchondral bone at 12, 24 and 52 weeks. CT was not able to detect condylar subchondral bone heterogeneity. Serial in vivo qMRI of condylar subchondral bone after surgically created osteochondral lesions provided evidence of support of subchondral bone changes that could not be visualized by CT. Furthermore, qMRI showed differences among different gene therapy treatments.Overall, MRI permitted an early detection of subchondral bone changes and follow up across time.

Yi Sun¹, Manuela Ventura², Egbert Oosterwijk¹, John A. Jansen², X. Frank Walboomers², and Arend Heerschap^3
1Urology, Radboud University Nijmegen Medical Center, Nijmegen, Gelderland, Netherlands, ²Biomaterials, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, ³Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands

This study examined the possibility of using ZTE to differentiate bone and Calcium Phosphate Cement(CPC) bone filler, with contrast agent incorporation. Only the incorporation of 1% Gd-DTPA(w/w) had no unfavorable effects on the solidification time and mechanical properties of material. This incorporation largely decreased T2* of CPC, was therefore explored in an in vivo experiment. The contrast was enhanced at an early stage then disappeared due to material decay and bone regeneration after eight weeks.This indicates that ZTE imaging with proper contrast agent, is a valid method to visualize CPC degradation in preclinical experiment.

Steven Reynolds¹, Nigel Hoggard¹, and Martyn Paley^1
1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

Generally MR images of cortical bone and tendons with high collagen content are shown as areas of signal void, irrespective of image weighting. The use of Ultra-short and Zero TE sequences can provide high resolution imaging of these bone structures in the presence of severe susceptibility artefact by minimising the time available for T2^* signal dephasing: producing positive contrast from cortical bone. By combining very strong gradients together with custom sized close fitting radiofrequency coils allow acquisition of images with spatial resolution of 10’s of microns. This feasibility study investigated the limits of imaging normal bone samples at high resolution in the presence of metal artifacts.

Jinjin Zhang¹, Djaudat Idiyatullin¹, Vladimir Leon Salazar², Curtis Corum¹, and Michael Garwood^1
1Center of Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States, ²Div. of TMD and Orofacial Pain, University of Minnesota, Minneapolis, Minnesota, United States

The detection and accurate prenatal diagnosis of skeletal dysplasia remain problematic with ultrasonography. Although MRI can be used to diagnose some fetal musculoskeletal abnormalities, studies using MRI to image fetal bones directly are limited. Here, SWIFT, which is sensitive to short T2 signals, was utilized to image craniofacial bones and to measure the T1 of a fetal mouse head. Due to the near absence of T2-weighting, SWIFT images display close to pure T1-weighted contrast. The feasibility of SWIFT to allow qualitative and quantitative evaluation of fetal skeleton makes it a powerful complement to ultrasonography for the detection and diagnosis of skeletal dysplasia.

Qing Yuan¹, Ivan Dimitrov², Paul T Weatherall¹, Ildiko Lingvay³, and Naim M Maalouf^3
1Radiology, UT Southwestern Medical Center, Dallas, Texas, United States, ²Philips Medical Systems, Cleveland, Ohio, United States, ³Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, United States

Bone marrow lipotoxicity has recently been postulated as a contributing mechanism to osteoporosis. We evaluated the relationship between hip bone mineral density (BMD) and bone marrow fat content in 23 volunteers. Femoral neck bone marrow fat was quantified using 1H MRS. A significant inverse correlation was found between bone marrow fat and BMD T-scores. Although women and men had similar age, body weight, femoral neck and total hip BMD, bone marrow fat content was significantly higher in men compared to women. Our data provides preliminary support to the concept of bone marrow lipotoxicity and its possible relationship with osteoporosis.

Heather Ting Ma^1,2, James F. Griffith², Haiyan Lv¹, Alvin F.W. Li², David K.W. Yeung², Anthony Kwok², and Ping-Chung Leung^2
1Department of Electronic & Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, Guangdong, China, ²Prince of Walse Hospital, The Chinese University of Hong Kong, Hong Kong, China

This study investigated perfusion distribution at proximal femur in subjects of varying bone mineral density (BMD). Dynamic contrast enhanced MRI data was extracted pixel-by-pixel and classified into 3 patterns. A notable reduced perfusion as a whole was observed in osteoporotic subjects. Moreover, perfusion distribution varies as BMD decreases, especially at the area crossing the femoral neck to the shaft. Consistent for all subjects, the perfusion decreases significantly from the lesser trochanter to the greater trochanter. Further research on perfusion distribution is promising for deepen our knowledge of the mechanism for osteoporotic fracture at proximal femur.

Richard Kijowski¹, Michael Tuite¹, Diane Krueger², Michael Kleerekoper³, and Neil Binkley^2
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, ²Medicine, University of Wisconsin, Madison, Wisconsin, United States, ³Medicine, St. Joseph Mercy Reichert Health Center, Ypsilanti, Michigan, United States

Microscopic magnetic resonance imaging (µMRI) of the wrist was performed on 18 post-menopausal women with normal or osteopenic bone mineral density (BMD) who had a history of low energy fracture and a control group of 18 age, race, and ultra-distal radius BMD-matched postmenopausal women with no history of fracture. The ultra-high resolution images were used to measure trabecular micro-architecture parameters using a semi-automated virtual bone biopsy system. Post-menopausal women with fracture had significantly lower (p<0.05) trabecular bone volume fraction and surface-to-curve ratio and significantly higher (p<0.05) erosion index than women without fracture.

Eito Kozawa¹, Waka Mizukoshi², Naoko Nishi², and Fumiko Kimura^2
1Saitama Medical University, International Medical Center, Hidaka-shi, Saitama, Japan, ²Diagnostic Imaging, Saitama Medical University, International Medical Center, Japan

Various quantitative magnetic resonance (MR) imaging techniques could improve assessment of compression fractures.