Caleb Robert Dulaney¹, Juebin Huang², Manohar Roda¹, Alexander P. Auchus², and Judy R. James^1
1Radiology, University of Mississippi, Jackson, MS, United States, ²Neurology, University of Mississippi, Jackson, MS, United States

To date there is no data on the use of DTI in analyzing physiologic changes in skeletal muscle affected by Juvenile Dermatomyositis. The aim of this study is to analyze the muscles of the thighs in patients with both active and inactive JDMS by comparing fractional anisotropy (FA) and mean apparent diffusion coefficient (ADC) values. We found that active disease caused significant decrease in FA and increase in ADC compared to inactive disease. In the future, changes in DTI parameters may be used to predict outcomes and recurrence in patients with JDMS.

Eric Barnhill¹, Paul Kennedy¹, Edwin van Beek¹, Colin Brown², and Neil Roberts^1
1Clinical Research Imaging Centre, The University of Edinburgh, Edinburgh, Midlothian, United Kingdom, ²Research and Development, The Mentholatum Company, East Kilbride, South Lanarkshire, United Kingdom

A new image processing pipeline for Magnetic Resonance Elastography, MRE-J, was used to create pixel-by-pixel maps of multiple viscoelastic properties of a transverse slice of thigh skeletal muscle in resting state. The images were consistent across multiple acquisitions and captured individual variation in resting state muscle activation. The maps allow for the quantitative mapping of neuromuscular activation patterns through all muscles of a limb. Future work will use this protocol to evaluate, target and help develop topical treatments, therapeutic techniques and training regimens.

Jeff L. Zhang¹, Christopher J. Hanrahan¹, Gwenael Layec², Jason K. Mendes¹, Corey Hart², Russell S. Richardson², and Vivian S. Lee^1
1Department of Radiology, University of Utah, Salt Lake City, UT, United States, ²Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah, United States

Compared with established tools, BOLD MRI is able to evaluate deep tissue and allows a combination of functional data with high-resolution anatomic images. Higher R2* values from BOLD typically correspond to lower muscle tissue oxygenation. However, R2* may be confounded by many factors that are not related to tissue pO2. For example, Lebon et al found that R2* values from calf muscle were strongly affected by the angle between the leg and magnetic field B0. In this study, we take into account multiple confounding factors by simulating muscle BOLD with a realistic Monte Carlo model, and quantify blood oxygen saturation (SHb) from BOLD data based on the model.

Anne Tonson¹, Jacob Deblois¹, Jessica Fay¹, Steve Foulis¹, Douglas E. Befroy², and Jane Kent-Braun^1
1Department of Kinesiology, University of Massachusetts, Amherst, MA, United States, ²Magnetic Resonance Research Center, Yale University, New Haven, CT, United States

The purpose of this study was to investigate muscle metabolic economy and [glycogen] in relation to ATP flux during brief voluntary contractions, using 13 C and 31P magnetic resonance spectroscopy (MRS) in young and older women. Although intramuscular fat was lower in young than older women, muscle size, specific strength, [glycogen], metabolic economy and the contributions of PCr, glycolysis and oxidative metabolism were not different by age. These results suggest that energetics do not differ in the unfatigued muscles of young and old.

Bart Wessels¹, Klaas Nicolaij¹, and Jeanine J. Prompers^1
1Biomedical NMR, University of Technology Eindhoven, Eindhoven, Netherlands

In vivo muscle oxidative capacity is determined both by intrinsic mitochondrial capacity and oxygen delivery. To determine if PCr recovery in rat muscle is limited by oxygen delivery we used 31P MRS under normoxic and hyperoxic conditions in fa/+ and fa/fa ZDF rats. BOLD imaging in the skeletal muscle was successfully implemented but no differences in muscle oxygenation were found between groups during and after stimulation. PCr recovery rates were similar in either group during normoxic and hyperoxic conditions, suggesting that PCr recovery was not limited by oxygen delivery and indicating an impaired intrinsic mitochondrial capacity in diabetic rats.

Jimin Ren¹, Baolian Yang², Ivan E. Dimitrov², A. Dean Sherry^1,3, and Craig R. Malloy^1,4
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Philips Medical System, Cleveland, Ohio, United States,³Department of Chemistry, University of Texas at Dallas, Richardson, Texas, United States, ⁴VA North Texas Health Care System, Dallas, Texas, United States

Phosphate exchange between PCr and gama-ATP is essential for energy homeostasis in skeletal muscle. The creatine kinase-mediated reaction is conventionally studied by MT technique, often using saturation pulses with high B1 power and long duration. It suffers from the pitfall of large spillover artifact, diminished CEST dynamic range, and increased SAR exposure. We demonstrated it is feasible to use a train of frequency-selective pulses with low saturation power, short saturation time and decreased saturation duty cycle, for generating CEST effect. This was illustrated in the Z-profiles of both PCr and gama-ATP in human skeletal muscle at 7T.

Jan Weis¹, Morten Bruvold², Francisco Ortiz-Nieto¹, and Håkan Ahlström^1
1Department of Radiology, Uppsala University Hospital, Uppsala, Sweden, ²Philips Healthcare, Best, Netherlands

This study exploits the speed benefits of echo-planar spectroscopic imaging (EPSI) to acquire proton spectra of skeletal muscle. 2D EPSI with high spatial resolution (spectral matrix 64×64) was used for the assessment of intramyocellular (IMCL) lipid content in the calf muscle and to visualise the influence of bulk magnetic susceptibility (BMS) effects on the shape and positions of extramyocellular (EMCL) lipid spectral lines. BMS shifts of EMCL intensities up to 0.5 ppm relative to correspondent IMCL lines were observed. High spatial resolution enables quantification of the muscle lipids in non-continuous and irregularly shaped volumes of interests.

Sai K. Merugumala¹, James A. Balschi², Hui Jun Liao¹, and Alexander Lin^1
1Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States, ²Physiological NMR Core Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA, United States

In vivo 31P MR spectra of skeletal muscle were obtained during an exercise protocol. A standard post processing method was compared with a method utilizing exercise time domain filtering with Spectral Improvement by Fourier Thresholding (SIFT) . S/N and time constants of Phosphocreatine (PCr) recovery are calculated after each method and then compared. Using the SIFT method showed substantial increase in S/N and the physiologically relevant time constants were calculated with narrower confidence intervals. This method could potentially be used to more reliably detect differences in in skeletal muscle mitochondrial functionality that effect the PCr recovery time constants.

Bart Wessels¹, Joep Schmitz², Klaas Nicolaij¹, and Jeanine J. Prompers^1
1Biomedical NMR, University of Technology Eindhoven, Eindhoven, Netherlands, ²Computational Biology, University of Technology Eindhoven, Eindhoven, Netherlands

Glycolytic flux and mitochondrial oxidative phosphorylation are internally regulated processes that maintain cellular energy balance. In this study we used in vivo 31P MRS to investigate the effects of mitochondrial impairments on glycolytic ATP synthesis flux during muscle stimulation in diabetic and metformin-treated diabetic rats. It was demonstrated that untreated and metformin-treated diabetic rats have a lower muscle mitochondrial oxidative capacity and a faster decrease of muscle pH during muscle stimulation when compared with healthy controls. The latter implies that in both diabetic rat models, glycolytic flux during muscle contractions was higher than in controls.

Martin Meyerspeer^1,2, Georg Bernd Fiedler^1,2, Albrecht Ingo Schmid^1,2, Elmar Laistler^1,2, and Ewald Moser^1,2
1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Wien, Austria, ²MR Centre of Excellence, Medical University of Vienna, Wien, Austria

Increasing sensitivity of MRS at high field allows to augment the spatial and temporal specificity metabolic information obtained. This work demonstrates the feasibility of localised dynamic 31P-MRS in two distinct muscles, gastrocnemius medialis (GM) and soleus (SOL), during exercise. While GM bears the main load of the plantar flexion exercise, exhibiting 83% PCr depletion and strong acidification, also SOL is active: its PCr drops by 28% and pH increases mildly during exercise. Time courses for PCr and Pi and hence pH were acquired the first time with localisation to the deeper soleus muscle with a time resolution of 6s throughout.

Jimin Ren¹, A. Dean Sherry^1,2, and Craig R. Malloy^1,3
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Department of Chemistry, University of Texas at Dallas, Richardson, Texas, United States, ³VA North Texas Health Care System, Dallas, Texas, United States

Despite its pivotal role in energy metabolism, lactate remains a challenge for in vivo quantitative detection using 1H MRS. This is mainly due to the J-modulation of lactate resonances and the interference from the overlapping lipid and water signals. We found that, while the phase and magnitude of lactate signals are sensitive to the mixing time of STEAM sequence in phantom sample, they are extremely insensitive for lactate in skeletal muscle, likely due to the quenching effect of residual dipolar coupling to the development of zero-quantum coherence. This greatly simplifies the quantitative detection of lactate by non-spectral editing approach.

Erin L. MacMillan¹, Christine Sandra Bolliger¹, Chris Boesch¹, and Roland Kreis^1
1Depts of Clinical Research & Radiology, University of Bern, Bern, Switzerland

Magnetization transfer rates from water to creatine were previously demonstrated to be different between the soleus and tibialis anterior muscles. To elucidate whether this difference arises from the muscle fibre angle to the external magnetic field, a series of spectra with increasing water inversion delay times were acquired from human tibialis anterior muscles aligned both at the magic angle and parallel to the magnetic field. Water spectra were also acquired with increasing TE times. While water T₁ and T₂ times were significantly longer at the magic angle, water-creatine MT rates did not exhibit an orientation effect.

Barbara H. Janssen¹, Sigrid Pillen², Nicoline B.M. Voet³, Arend Heerschap¹, Baziel G. van Engelen², and Nens van Alfen^2
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, ²Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, ³rehabilitation, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands

With emerging molecular therapies for neuromuscular disorders the need for non-invasive biomarkers becomes more pressing. MRI and ultrasound (US) can be performed non-invasively, without causing any harm to the patient. To investigate and compare the abilities of quantitative MRI and US in describing muscle pathology we performed both techniques in five FSHD patients. We found high and significant correlations between both techniques. Both imaging techniques are very useful in the discrimination of true muscle pathology from other health issues. When a neuromuscular disorder is non-uniformly distributed over the muscles' length we recommend multi-slice investigations.

Conrad P. Rockel¹, Alireza Akbari¹, Dinesh A. Kumbhare^2,3, and Michael D. Noseworthy^1,4
1School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada, ²Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada,³Department of Medicine, McMaster University, Hamilton, Ontario, Canada, ⁴Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada

Mean Diffusivity (DTI) was used to assess skeletal muscle dynamics following mild exercise. Diffusion differences were observed in muscles known to be involved in the exercise, while little change was observed in uninvolved muscles. Involved muscles composed mostly of fast-twitch fibers demonstrated different diffusion behaviour across time than muscles of mostly slow-twitch composition, a result thought to be due to differing levels of vascularization between the two fiber types.

Sean C. Forbes¹, Glenn Walter¹, William D. Rooney², Dah-Jyuu Wang³, Soren DeVos¹, Jim Pollaro², William Triplett¹, Donovan J. Lott¹, Rebecca J. Willcocks¹, Claudia Senesac¹, Mike Daniels⁴, Barry Byrne¹, Barry Russman², Richard Finkel³, James Meyer³, Lee Sweeney⁵, and Krista Vandenborne^1
1University of Florida, Gainesville, FL, United States, ²Oregon Health & Science Universtiy, Portland, Oregon, United States, ³The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States, ⁴The University of Texas at Austin, Austin, Texas, United States, ⁵University of Pennsylvania, Philadelphia, Pennsylvania, United States

This study evaluated the reproducibility of MR measures of skeletal muscle size, composition, and MR signal relaxation properties across multiple centers and within sites in children with Duchenne muscular dystrophy (DMD). CSAmax, lipid fraction, and MRI- and MRS-T2 were consistent across sites in a phantom (coefficient of variation, CV< 3%) and in adult subjects that travelled to each site (CV:2-7%). Also, low day-to-day variability was observed in controls and boys with DMD (CV:2-6%). The low variability across sites and from day-to-day within sites provides support for using MR to measure muscle involvement in children with DMD in multi-center studies.

Barbara H. Janssen¹, Nicoline B.M. Voet², Alexander C. Geurts², George W. Padberg³, Baziel G. van Engelen³, and Arend Heerschap^1
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, ²rehabilitation, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, ³Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands

Fascioscapulohumeral muscular dystrophy (FSHD) is one of the most common neuromuscular dystrophies. As in other muscular dystrophies inflammation is suspected to play a key role in the progression of muscle dysfunction. To study the role of inflammation in FSHD we performed a qualitative and quantitative assessment of TIRM and T1 weighted images collected at baseline and after a control period of four months. We found an increase in signal intensity of the T1 weighted images (i.e.; increased fatty infiltration) in muscles with early inflammation (i.e; hyperintensities on TIRM).

Giulia Di Pietro^1,2, Marco Palombo^2,3, Jacopo Baldi⁴, Eleonora Piccirilli⁴, Monica Celi⁴, Umberto Tarantino⁴, and Silvia Capuani^3,5
1IIT@Sapienza, Physics Department, “Sapienza” University, Roma, Rome, Italy, ²Physics Department, “Sapienza” University, Rome, Rome, Italy, ³CNR IPCF UOS Roma, Physics Department, “Sapienza” University, Rome, Rome, Italy, ⁴Department of Orthopaedics and Traumatology, University of Rome “Tor Vergata”, Roma, Roma, Italy, ⁵Sapienza University, Rome, Rome, Italy

Aim of this study was to investigate the microstructural features in muscles of osteoporotic(OP) and osteoarthritic(OA) women with DTI. Our in vitro preliminary results highlight that FA is lower in OP when compared to OA. As a consequence OP muscle has a more isotropic microstructure compared to that of OA muscle. Moreover MD, and radial diffusivity are lower in OA compare to OP, while no differences was found in axial diffusivity. These results are in agreement with previous histological results obtained in OP muscles in which type II fibers atrophy occurs, with a consequent enlargement of water spaces between fibers.

Conrad P. Rockel¹, Alireza Akbari¹, Dinesh A. Kumbhare^2,3, and Michael D. Noseworthy^1,4
1School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada, ²Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada,³Department of Medicine, McMaster University, Hamilton, Ontario, Canada, ⁴Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada

Short-term post-contraction muscle changes were investigated in the human calf following electrical nerve stimulation versus voluntary movement. Post-contraction behaviour was assessed using mean diffusivity (MD) as calculated using Diffusion Tensor Imaging (DTI). Voluntary movement elicited larger and more varied diffusion changes than electrical stimulation. However, electrical stimulation did show subtle increased diffusion in the targeted muscle (Peroneus Longus).

Alireza Akbari¹, Conrad P. Rockel¹, Dinesh A. Kumbhare^1,2, and Michael D. Noseworthy^1,3
1School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada, ²Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada,³Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada

An MR-compatible solution that delivers electrical stimulation pulses from an EMG/stimulator unit to the subject in the magnet bore is presented. This allows for quantitative and repeatable muscle activation in the study of dynamic muscle physiology using techniques like BOLD or DTI. The solution has been tested for any image artifacts or RF heating caused by the stimulation electrodes. BOLD images of the calf muscle with electrodes on at rest and while being stimulated have been presented.

Khan Hekmatyar¹, Steven J. Foltz², Marisa J. Fortunato², and Aaron M. Beedle^2
1BioImaging Research Center/Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States, ²Department of Pharmaceutical and Biomedical Sciences, University of Georgia College of Pharmacy, Athens, GA, United States

Abnormal glycosylation of α-dystroglycan impairs the structural link between the extracellular matrix and the cytoskeleton causing dystroglycanopathy-type muscular dystrophy. There are no validated therapies for dystroglycanopathies and variability in phenotypes complicates the assessment of therapeutic effect. Our aim is to assess the correlation between relaxometric measurements (T₂) in magnetic resonance (MR) imaging and histological measurements to determine the reliability and suitability of MR imaging for future therapeutic trials in animal models.

Ronald A. Meyer^1,2, Robert W. Wiseman^1,2, Jill M. Slade², Natalie M. Pizzimenti¹, and Johnathan D. Kasper^1
1Physiology, Michigan State University, East Lansing, Michigan, United States, ²Radiology, Michigan State University, East Lansing, Michigan, United States

This study demonstrates the feasibility of measuring skeletal muscle oxygen consumption during contractions by using non-invasive MRI vessel flow and venous blood oxygen saturation methods.

Andrew D. Davis¹ and Michael D. Noseworthy^2
1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada, ²Electrical and Computer Engineering, School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada

BOLD imaging is applied to skeletal muscle to examine physiological parameters related to perfusion and oxygenation. Studies involve ROI selection from time series data, and sometimes small ROIs are chosen from the muscle. This study attempted to validate the selection of small ROIs for analysis. A gamma variate curve fitting scheme for post-exercise data was also evaluated. The signal within each muscle was found to be very uniform but differed greatly between muscles. The fitting scheme produced excellent results, with R2 values ranging from 0.967 to 0.997 in exercised muscles, using between 6 and 9 coefficients.

Houchun Harry Hu¹, Skorn Ponrartana¹, Thomas G. Perkins², Jonathan M. Chia², Vicente Gilsanz¹, and Tishya A. L. Wren^3
1Radiology, Children's Hospital Los Angeles, Los Angeles, California, United States, ²Philips Healthcare, Cleveland, Ohio, United States, ³Orthopaedic Surgery, Children's Hospital Los Angeles, Los Angeles, California, United States

This pilot work utilizes chemical-shift water-fat MRI to characterize muscle fat infiltration in five pediatric patients with spina bifida. Fat-signal fraction measurements in lower extremity muscles were compared against muscle strength scores from physical assessment. High/low fat-signal fractions were associated with weak/strong muscles. Muscles with intermediate strengths exhibited a wide range of fat-signal fractions. Heterogeneity in fat-signal fraction between different muscles with similar functions was observed. Quantitative chemical-shift water-fat MRI may be able to detect sub-clinical changes in muscles that are not discernible with standard clinical assessment, and provide a more sensitive and objective assessment of muscle health and integrity.

Julia Reinhardt¹, Selina Kaspar¹, Monika Gloor², Dirk Fischer^3,4, Christoph Stippich¹, and Arne Fischmann^1
1Department of Radiology and Nuclear Medicine, Division of Diagnostic and Interventional Neuroradiolo, University of Basel Hospital, Basel, BS, Switzerland, ²Department of Radiology and Nuclear Medicine, Division of Radiological Physics, University of Basel Hospital, Basel, BS, Switzerland, ³Department of Neurology, University of Basel Hospital, Basel, BS, Switzerland, ⁴University of Basel Children’s Hospital, Basel, BS, Switzerland

We examined the influence of a single exercise session on quantitative muscle fat fraction (FF) and diffusion (fractional anisotropy (FA)) MRI measurements. Muscular exercise will result in glyocogenolysis and lipolysis as well as increased water influx into the muscle cells. We therefore expect to find a reduced relative fat fraction and lower fractional anisotropy after an exercise session. The results show no significant difference of the mean FA values but significant changes for the FF before and after the exercise. In conclusion, a single exercise session might influence the apparent muscle fat measurements.

Yasuharu Watanabe¹, Keisaku Kimura², Masahiro Umeda¹, Yuko Kawai¹, Tomokazu Murase³, Toshihiro Higuchi³, Chuzo Tanaka³, and Shoji Naruse^4
1Medical Informatics, Meiji University of Integrative Medicine, Kyoto, Japan, ²Health Promoting and Preventive Medicine, Meiji University of Integrative Medicine, Kyoto, Japan,³Neurosurgery, Meiji University of Integrative Medicine, Kyoto, Japan, ⁴Health Care and Checkup, Daini Okamoto General Hospital, Kyoto, Japan

A quasi-linear viscoelasticity model with a hysteresis in the material properties is used to study passive time-dependent responses of skeletal muscles in vivo. In this model, viscoelasticity in muscle may cause hysteresis. The purposes of this study were to analyze in detail the water movement in skeletal muscles during pushing stimulation and visualize tissue deformation of the hysteresis in vivo by using DTI. The results showed varying deformation regions between the pushing and decompressing phases. This study showed that the differences in deformation regions and the direction of water movement were the factors responsible for the hysteresis.

Skorn Ponrartana¹, Houchun Harry Hu¹, Kristine E. Andrade¹, Jonathan M. Chia², Thomas G. Perkins², Tishya A. L. Wren³, and Vicente Gilsanz^1
1Radiology, Children's Hospital Los Angeles, Los Angeles, California, United States, ²Philips Healthcare, Cleveland, Ohio, United States, ³Orthopaedic Surgery, Children's Hospital Los Angeles, Los Angeles, California, United States

This work evaluates the repeatability of chemical-shift water-fat MRI and diffusion tensor imaging measures of muscle in a wide age range of healthy children. Mean difference between measures, intra-rater agreement, and inter-rater agreement were calculated. Both water-fat MRI and diffusion tensor imaging demonstrate minimal mean difference with excellent agreement. Of these techniques, water-fat MRI had the higher level of agreement. Additionally observed was a statistically significant association of muscle fat percentage with age. Water-fat MRI and diffusion tensor imaging can be performed in a clinical setting across a broad age group with good repeatability.

Donghoon Lee¹, Zejing Wang², Joshua Park¹, Stephen Tapscott², and Martin Kushmerick^1
1University of Washington, Seattle, WA, United States, ²Fred Hutchinson Cancer Research Center, Seattle, WA, United States

Gene therapy is one of promising treatment approaches for Duchenne muscular dystrophy. One challenge is to noninvasively monitor treatment responses and thereby to evaluate treatment efficacy. Canine MR imaging was conducted to noninvasively monitor muscle changes due to disease progression and to assess the treatment response after adeno-associated virus (AAV) vector mediated gene therapy. Elevation of T2 was observed for dystrophic muscles comparing to normal muscles and reduction of T2 was monitored for the treated muscles. The results show T2 would be a potential MR marker to study muscle integrity and the treatment efficacy.

Donghoon Lee¹, Joshua Park¹, Jacqueline Wicki², Jeffrey Chamberlain², Sue Knoblaugh³, and Julie Randolph-Habecker^3
1Radiology, University of Washington, Seattle, WA, United States, ²Neurology, University of Washington, Seattle, WA, United States, ³Fred Hutchinson Cancer Research Center, Seattle, WA, United States

Muscular dystrophy is a group of inherited myogenic disorders with no cure. MRI has some key methods that can potentially provide valuable information in developing effective treatment methods for the deadly disease. Unfortunately, only a limited ability of MRI has been utilized to study muscular dystrophy. Here we performed multi-parametric MRI to evaluate treatment responses for mdx (murine model of muscular dystrophy) mice after adeno-associated virus (AAV) vector mediated gene therapy. Our results show T2, apparent diffusion coefficient and magnetization transfer ratio would be potential MR markers to evaluate the treatment efficacy.

Theodore F. Towse^1,2, Amanda K.W. Buck^2,3, Emily C. Bush³, Benjamin T. Childs³, Jared A. Godar³, Shea A. Sabin³, and Bruce M. Damon^2,4
1Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States,³Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ⁴Institute of Imaging Science, Nashville, TN, United States

Studies at 1.5 and 3 tesla suggest the skeletal muscle blood oxygenation level-dependent (BOLD) contrast is primarily due to intravascular changes in hemoglobin saturation and blood volume. As such BOLD based imaging of skeletal muscle provides a powerful tool for exploring the coupling of muscle blood flow and muscle energetics non-invasively. At ultra high field strengths, where the T2star of blood is very short, 15ms or less, the muscle BOLD contrast may be more sensitive to the vascular architecture. If this is the case BOLD based imaging may be capable of quantifying changes in the peripheral vascular anatomy as a consequence of chronic disease or in response to an intervention such as exercise training. The purpose of this study was to determine the feasibility of BOLD based imaging in skeletal muscle and to compare these results to studies at 3T.

Andrew D. Davis¹ and Michael D. Noseworthy^2
1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada, ²Electrical and Computer Engineering, School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada

BOLD imaging of skeletal muscle is difficult to interpret, since the signal depends on muscle perfusion, blood volume, and oxygen saturation. In this study, curves were fit to post-exercise BOLD data by making simple assumptions about [HHb] and [O2Hb] curve shapes and substituting values into published models. Generated curves agreed well with BOLD data, with some variability (0.831 < R-squared < 0.992). The poorer fit of soleus' fast changes compared to gastrocnemius was notable. This simple fit method generated parameters in agreement with prior literature, but further verification is needed to improve confidence before drawing absolute conclusions about physiological parameters.

Daekeon Lim¹, Young Han Lee¹, Sungjun Kim¹, Ho-Taek Song¹, and Jin-Suck Suh^1
1Department of Radiology, Research Institute of Radiological Science, Severance hospital, Seoul, Seoul, Korea

Fat suppressed 3D volume isotropic turbo spin echo acquisition(VISTA) sequence has comparable diagnostic values in grading the cartilage lesions.In grade 2 lesions, 3D VISTA image has higher diagnostic value than that of 2D sequence.

Olivier Beuf¹, Denis Grenier², Fabrice Taborik³, Anne-Laure Perrier², Kevin Tse Ve Koon², Laurent Mahieu-Williame², Luc Magnier⁴, Thomas Chuzel⁴, Stéphane Martin⁴, Xavier Pesesse⁵, Sandra Pietri⁶, Hugues Contamin³, and Emmanuel Chereul^4
1Université de Lyon; CREATIS; CNRS UMR 5220; Inserm U1044, Université de Lyon, Villeurbanne, France, ²Université de Lyon; CREATIS; CNRS UMR 5220; Inserm U1044, INSA-Lyon; Université Lyon 1, Villeurbanne, France, ³Cynbiose, Marcy l'étoile, France, ⁴VOXCAN, Marcy l’Etoile, France, ⁵Bone Therapeuthics, Grosselies, Belgium, ⁶Service de rhumatologie, Hôpital Erasme, ULB, Bruxelles, Belgium

Morphological parameters were assessed on MRI and µCT arthrography (CTA) acquisitions, to characterize an induced model of OA by transection of the anterior cruciate ligament (ACL). Three groups of young four year old female primates were constituted and followed over 180 days after surgery. In vivo MR images acquired with the array coil associated with the HR-MRI protocol nicely depicted the cartilage. The cartilage thickness µCTA measurements did not show any bias with respect to MRI-based cartilage thickness. Both imaging modalities showed superimposed 3D thickness distributions measurements. Mean cartilage thickness of medial tibia plateaus of the right joint were found constant for control group but decreased significantly for group with ACL transection from D15 to D90 and with intermediate values on D30 and D60.

Yongxian Qian^1,2, Ashley A. Williams³, Constance R. Chu³, and Fernando Emilio Boada^4
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, ²Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, ³Orthopaedic Surgery, University of PIttsburgh, Pittsburgh, PA, United States, ⁴Radiology, New York University, New York, NY, United States

This work presents the mapping of two-component T2* relaxation on cartilages in the knee in a small group of patients. The outcomes showed potential of the short-T2* relaxation to be sensitive to early degeneration in the knee cartilages.

Megan Nicole Marsh¹, Richard Souza¹, Brad Wyman², Marie-Pierre Hellio le Graverand², Thomas M. Link¹, and Sharmila Majumdar^1
1Radiology, University of California, San Francisco, San Francisco, California, United States, ²Pfizer, inc, Groton, CT, United States

This study investigated the efficacy of X-ray and MRI in determining cartilage thickness in patients with and without osteoarthritis in both loaded and unloaded conditions. The study found that MRI-measured cartilage thickness and X-ray-determined minimum joint space width are more strongly correlated when both conditions are loaded, with MRI having a higher standardized response mean from loaded to unloaded than X-ray. This contradicts past studies, which showed that X-ray has a higher standardized response mean, and indicates that loading causes cartilage deformation that is important for comparing information gathered by X-ray and MRI about joint space narrowing in OA-damaged cartilage.

Martin Brix¹, Sabine Göd², Uwe Schütz³, Christian Billich³, Klaus Friedrich², Alina Messner², and Siegfried Trattnig^2
1Department of Orthopaedics, Medical University of Vienna, Vienna, Vienna, Austria, ²Department of Radiology, MR Center of Excellence, Medical University of Vienna, Vienna, Vienna, Austria, ³Department of Radiology, University Hospital Ulm, Ulm, Baden Württemberg, Germany

In summary, 19 runners were measured on a mobile 1.5 Tesla MRI during the Transeuropean-Foot-Race, a ultramarathon with an average of 70.1 km per day for 64 consecutive days. All participants received baseline measurement before the run and afterwards severel times during the run. T2* measurement was performed in the femoropatellar joint and demonstrated a significant difference of T2* values of the patella between baseline measuremnet and the first assessment during the run.

Cory Wyatt¹, Xiaojuan Li¹, Roland Krug¹, Douglas A.C. Kelley², and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States, ²GE Healthcare Technologies, San Francisco, California, United States

T1rho and T2 relaxation times have been used as markers for matrix changes in articular cartilage and elevated T1rho/T2 values have been associated with the proteoglycan loss in osteoarthritis. While these mechanisms have been studied extensively at 3 Tesla, very few studies have been done at 7 Tesla, particularly for T1rho. In this work, T1rho and T2 values were measured in 10 healthy individuals at 3T and 7T human MRI scanners. Results show a significant decrease in T1rho and T2 values at 7T compared to 3T, which is expected according to theory. The SNR was also increased at 7T.

Fang Liu¹, Rajeev Chaudhary², Samuel A. Hurley¹, Alexey Samosonov¹, Andrew L. Alexander¹, Sean C. L. Deoni³, Walter F. Block^1,2, and Richard Kijowski^4
1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³Division of Engineering, Brown University, Providence, RI, United States, ⁴Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States

Multi-component T2 mapping using mcDESPOT was performed at 3.0T on a control and trypsin degraded ex vivo fresh bovine patella cartilage specimen. Water fraction and T2 relaxation time for the water component tightly bound to macromolecules (Wm) and bulk water loosely bound to the proteoglycan matrix (Wb) were measured for the control and trypsin degraded cartilage. Enzymatic removal of proteoglycan from cartilage resulted in a decrease in water fraction of the Wm component and an increase in the T2 relaxation time of the Wm and Wb components of cartilage.

Satoru Tamura¹, Takashi Nishii¹, Hidetoshi Hamada¹, Ken Nakata¹, Tatsuo Mae¹, Hisashi Tanaka¹, and Hideki Yoshikawa^1
1Osaka University Graduate School of Medicine, Suita, Osaka, Japan

T2 value is closely related to cartilage collagen matrix and water content, with significant correlation between higher T2 values and cartilage degenerative changes. 3D images are assumed to be more useful to evaluate the whole femoral cartilage than 2D images, regarding location and extent of cartilage disorder. The purpose of this study was to investigate whether cartilage damage on 3D T2 map of the knee joint can be detected reliably by comparing with arthroscopic findings. The sensitivity and the specificity were 70% and 88%, respectively. 3D reconstructed T2 mapping images were useful to detect the cartilage damage.

Wenbo Wei¹, Guang Jia¹, David Flanigan², Robert Siston³, Ajit Chaudhari², Becky Lathrop³, and Michael V. Knopp^1
1Department of Radiology, The Ohio State University, Columbus, OH, United States, ²Department of Orthopaedics, The Ohio State University, Columbus, OH, United States,³Department of Mechanical Engineering, The Ohio State University, Columbus, OH, United States

The prevalence of cartilage lesions is much higher in athletes like football players than the general population. This pilot study is to determine whether dGEMRIC can be used to assess potential differences in cartilage GAG concentration due to the cumulative effects of playing college level football. It demonstrates that dGEMRIC is capable of evaluating GAG content in different regions as well as the apparent differences related to cumulative years of playing football.

Michael Benson^1,2, Nicholas Lesmeister², Mikko J. Nissi^1,2, Jutta Maria Ellermann¹, and Elizabeth Arendt^2
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ²Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States

Patellofemoral joint disorders are common, and are of high socioeconomic relevance as they occur most frequently in young, active patients. They are associated with osteoarthritis in later life. Patella alta (superior patella referenced to the trochlea) is a risk factor for patellofemoral instability and may be an additive factor in the development of patellofemoral osteoarthritis. Flattened parametric maps using T2 relaxometry predicted patient specific correlations between patella alta and the location of biochemical cartilage abnormalities. This form of analysis can aid in clinical management of patients with patellofemoral disease, and serve as a reference for cartilage health over time.

Sebastian Cotofana^1,2, Wolfgang Wirth^1,2, Felix Eckstein^1,2, Martin Hudelmaier^1,2, Stefan Lohmander³, and Richard B. Frobell^3
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

The results of our tsudy show that cartilage loss in the femoral trochlea (but not in the patellar cartilage) appears to be a temporary event that occurs within a time window of 1-2 years after ACL injury, but does not seem to continue during a 5-year observational interval.

Olivier Beuf¹, Jean-Christophe Goebel², Emilie Roeder³, Anne-Laure Perrier², Denis Grenier², Pierre Gillet³, and Astrid Pinzano^3
1Université de Lyon; CREATIS; CNRS UMR 5220; Inserm U1044, Université de Lyon, Villeurbanne, France, ²Université de Lyon; CREATIS; CNRS UMR 5220; Inserm U1044, INSA-Lyon; Université Lyon 1, Villeurbanne, France, ³PPIA, UMR 7561 CNRS – Nancy Université, Vandoeuvre-Lès-Nancy, France

The biointegration of biomaterials colonized by mesenchymal stem cells or not after implantation in a calibrated full thickness focal lesion in the rat knee were followed using 7T HR-MRI. A four-channel surface coil designed for the simultaneous acquisition of both knee joints of a rat was used. The quality of the MR images obtained with the developed array coils allowed the segmentation of cartilage compartments and measurements of cartilage thickness and volumes. HR-MRI allowed the follow up of cartilage to evaluate in vivo therapeutical responses after chondrogenic biomaterial grafting.

Kenard Agbanlog¹, Agnes G. d'Entremont¹, Simon Horlick², Mojieb Manzary², Trevor Stone², Robert G. McCormack², and David R. Wilson^2
1Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada, ²Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada

Opening wedge high tibial osteotomy (OWO) is known to change the kinematics of both the tibiofemoral and patellofemoral joints; however, it is not known if this change in kinematics is associated with a change in patellar cartilage health over time. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was used as an indicator of cartilage health before surgery, 6 months post-op, and 12 months post-op (n=14). Our results show that there is a statistically significant increase in dGEMRIC T1 score between 6 and 12 months post-op. This may indicate that there is no adverse effect on patellar cartilage health following OWO.

Victor Casula¹, Jukka Hirvasniemi², Petri Lehenkari³, Risto Ojala¹, Alaaeldin Kamel⁴, Simo Saarakkala^2,4, Eveliina Lammentausta⁴, and Miika T. Nieminen^1,4
1Department of Radiology, University of Oulu, Oulu, Oulu, Finland, ²Department of Medical Technology, University of Oulu, Oulu, Oulu, Finland, ³Department of Anatomy, University of Oulu, Oulu, Oulu, Finland, ⁴Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Oulu, Finland

The aim of this study was to determine the association of T1 and T2 relaxation times and dGEMRIC to findings of arthroscopy, considered to be the gold standard for OA diagnosis. qMRI parameters were assessed at 3T in 10 patients. After imaging, arthroscopic cartilage grading was performed according to the International Cartilage Repair Society (ICRS) classification system. According to the results, qMRI parameters were not related to arthroscopic grading and may detect changes in cartilage tissue quality more sensitively as compared to arthroscopy.

Harald Widhalm¹, Martin Brix², Sebastian Apprich³, Götz Welsch⁴, Stefan Zbýn³, György Vekszler¹, Martina Hamböck¹, Michael Weber³, and Siegfried Trattnig^3
1Department of Traumatology, Medical University of Vienna, Vienna, Vienna, Austria, ²Department of Orthopaedics, Medical University of Vienna, Vienna, Vienna, Austria,³Department of Radiology, MR Center of Excellence, Medical University of Vienna, Vienna, Vienna, Austria, ⁴Department of Trauma Surgery, University Hospital Erlangen, Erlangen, Bayern, Germany

We investigated 9 patients after patella dislocation, 9 healthy volunteers and 5 knee cadaver in order to evaluate the feasibility of Sodium MRI for the assessment of osteoarthritis at the patella cartilage.

Umar Tariq¹, Peng Lai², Michael Lustig³, Marcus T. Alley⁴, Mian Zhang⁵, Garry E. Gold⁴, and Shreyas S. Vasanawala^6
1Department of Radiology, Stanford University, Stanford, CA, United States, ²GE Healthcare, Menlo Park, CA, United States, ³University of Calfornia Berkeley, Berkeley, CA, United States, ⁴Radiology, Stanford University, Stanford, CA, United States, ⁵Statistics, Stanford University, Stanford, CA, United States, ⁶Radiology, Stanford University, Stanford University, CA, United States

We compare two compressed sensing sampling strategies to obtain thinner slices with higher acceleration, assessing image quality relative to gold-standard 2D images in the delineation of anatomic structures, generally evaluated in knee MRI.

Adam Johansson¹, Anders Garpebring¹, and Tufve Nyholm^1
1Department of Radiation Sciences, Umeå University, Umeå, Sweden

Substitute CT images derived from UTE MRI images can be used for attenuation correction and radiotherapy dose planning. However, the required scan time of six minutes for a FOV of 25 cm can be too long if multiple bed positions are needed. We investigate the quality of substitute CT images derived from images reconstructed with CG-SENSE and SPIRiT. A possible reduction in scan time from 6 min to 1 min is shown when scanning a head.

Morgan Giers¹, Qingwei Liu², Ken Schmidt³, Gregory H. Turner², Alex McLaren³, Michael Caplan⁴, and Ryan Mclemore^3
1School of biological and health Systems Engineering, Arizona State University, Tempe, AZ, United States, ²Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, ³Orthopaedic Residency, Banner Good Samaritan Medical Center, Phoenix, AZ, United States, ⁴Harrington Bioengineering Department, Arizona State University, Tempe, AZ, United States

In this study, we have developed an imaging-based technique, using a gadolinium-marked small molecule, for monitoring the distribution of locally delivered antimicrobial from bone cement in extremity wounds that will enable real time analysis of drug concentration and adjustment of clinical management.

Christian B. van der Pol¹, Ania Kielar¹, Gina Di Primio¹, Marcos Sampaio¹, Mark Clemons², Arash Jaberi¹, and Mark E. Schweitzer^1
1Radiology, The Ottawa Hospital, Ottawa, Ontario, Canada, ²Medicine, The Ottawa Hospital, Ottawa, Ontario, Canada

The role of T1-weighted MRI of the axial skeleton was explored for determining prognosis in patients with metastatic breast cancer

Markus Kraiger¹, Bernhard Schnizer², and Rudolf Stollberger^1
1Institute of Medical Engineering, Graz University of Technology, Graz, Styria, Austria, ²Institute of Theoretical and Computational Physics, Graz University of Technology, Graz, Styria, Austria

Novel analytical solutions of the field of a prolate or an oblate magnetic spheroid in a static homogeneous magnetic field are computed and expressed in Cartesian coordinates. The directions of both the primary magnetic field and of the symmetry axis are completely arbitrary. These expressions have the potential to improve the modelling of susceptibility effects within biological structures such as trabecular bone or capillary network.

Krista Anne Goulding¹, Heathcliffe D'Sa¹, Youjin Chang¹, Kara McWatters², Mark E. Schweitzer³, and Joel Werier^4
1Division of Orthopaedic Surgery, University of Ottawa, Ottawa, ON, Canada, ²Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada, ³Department of Radiology, University of Ottawa, Ottawa, ON, Canada, ⁴Division of Orthopaedic Surgery, University Ottawa, Ottawa, ON, Canada

A retrospective review of five years of referrals for musculoskeletal tumours identified significant discordance in MRI interpretation between referring centres and sarcoma-designated units. More accurate reporting may be achieved by synoptic reporting or referral to a centre with expertise in musculoskeletal neoplasia.

Kevin Koch¹, Kevin King¹, Matthew F. Koff², and Hollis Potter^2
1GE Healthcare, Milwaukee, Wisconsin, United States, ²Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, United States

The MAVRIC family of metal artifact suppression techniques produces B₀ field maps as part of its unique reconstruction process. Here, we demonstrate a solution to the inverse problem of reconstructing an implant from it’s generated B₀ perturbation. MAVRIC field maps are used to determine the composition and geometry of imaged implants. A sample case is demonstrated with hip fixation hardware. There are a variety of clinical applications for this use of by-products from MAVRIC metal artifact suppression sequences.

Ronald D. Watkins¹, Caroline Jordan^1,2, Michael Muelly¹, and Garry E. Gold^1
1Radiology, Stanford University, Stanford, CA, United States, ²Bioengineering, Stanford University, Stanford, CA, United States

Two concentric birdcage volume coils are combined for operation at 1H Proton and 23Na Sodium. By using a low pass coil for 1H and a high pass coil for Sodium resonant coupling is avoided. Higher order resonant modes of each coil sections do not overlap resulting in high isolation. Some retuning of the 1H coil was needed for proximity effects. No frequency traps or special decoupling circuit were needed. The sodium coil was constructed of heavy copper tubing and produced nearly a factor of 2 SNR improvement over previous for end ring designs.

Ping-Huei Tsai^1,2, Teng-Yi Huang³, Hsiao-Wen Chung⁴, Fong Y. Tsai², and Wing P. Chan^1
1Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, ²Imaging Research Center, Taipei Medical University, Taipei, Taiwan, ³Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ⁴Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan

Previous studies have emphasized that the menisci¡¦s complex alignment of collagen fibers contributes to the execution of this function. The purpose of this study is to design a 2D multi-slice dual echo radial sequence with a minimal phase excitation pulse for facilitating visualization of the fiber orientation in human meniscus based on quantitative T2* mapping. Our findings demonstrate that the proposed method allows enhanced visualization of structural details of the human meniscus, and which contributes to derive the spatial T2* distribution and fiber orientation for diagnosing early degenerative changes.

Kevin Koch¹, Matthew F. Koff², Parina Shah², and Hollis Potter^2
1GE Healthcare, Milwaukee, Wisconsin, United States, ²Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, United States

The introduction of metal artifact suppression sequences has elicited further demands from magnetic resonance techniques in assessing tissue near failed joint replacements. Many of these failure cases require confirmation of the presence or absence of implant particulate debris. Here, we speculate that the high-susceptibility nature of some particulate matter could impact transverse relaxation-based contrast in MR images. A phantom study is used to confirm this hypothesis. The capability of exploiting these observed trends using metal-artifact suppression techniques is then explored.

Noura Azzabou^1,2 and Pierre G. Carlier^2,3
1NMR Laboratory, Institute of Myolgy, Paris, France, ²NMR Laboratory, CEA, I²BM, MIRCen, IdM, Paris, France, ³NMR Laboratory, Institute of Myology, Paris, France

To quantify skeletal muscle structural changes by NMR imaging, several sequences are necessary. These sequences can evaluate: T2 relaxation abnormalities, fat fraction and signal heterogeneity, that respectively reflect muscle tissue disorganization, in particular fibrosis. In this work, we used a standard multi spin-echo (MSE) sequence and a multi-exponential model, to derive three relevant parameters that are: muscle water T2s, muscle fat percentage and muscle water T2 heterogeneity. We showed through test on healthy subjects and patient that these parameters are not highly dependent which suggest that they are reflecting different kind of muscle disorganization.

Xiaoliang Zhang^1,2, Chunsheng Wang¹, Bing Wu¹, Yong Pang¹, Roland Krug^1,2, Peder Larson^1,2, Thomas M. Link¹, and Daniel B. Vigneron^1,2
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States, ²UC Berkeley/UCSF Joint Graduate Group in Bioengineering, San Francisco and Berkeley, California, United States

Leah C. Henze Bancroft¹, Larry Hernandez², Habib Al Saleh², Kevin M. Johnson², Richard Kijowski³, and Walter F. Block^4
1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, ²Medical Physics, University of Wisconsin - Madison, Madison, WI, United States,³Radiology, University of Wisconsin - Madison, Madison, WI, United States, ⁴Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States

Effective cartilage imaging and whole organ joint assessment requires both high isotropic resolution and fat suppression or separation. bSSFP imaging provides high intrinsic signal strength but TR constraints limit the achievable resolution. Presented here is an approach where a standard bSSFP has been implemented with using the previously developed 3D radial out and back VIPR trajectory modified to create 4 echo times for an IDEAL implementation . Here we demonstrate the high performance capabilities of this method at 3T with high resolution, 3D, T2 weighted knee imaging.

Nade Sritanyaratana¹, Pouria Mossahebi¹, Alexey A. Samsonov², Kevin M. Johnson³, Walter F. Block^1,3, and Richard Kijowski^2
1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

Quantitative Magnetization Transfer (qMT) provides information about macromolecular properties in articular cartilage. However, due to requiring a series of MT acquisitions, qMT experiments can be costly in terms of imaging time for in-vivo protocols. Previously, a stable qMT protocol was established, utilizing 8 MT acquisitions to cover the patellofemoral joint within 30 minutes. This study seeks to reduce the number of MT acquisitions from 8 to 4 while maintaining adequate image quality compared to previous qMT in-vivo studies. An optimization approach is proposed, and the approach is validated in-vivo in the patellofemoral joint and demonstrated in the tibiofemoral joint.

Iris-Melanie Noebauer-Huhmann¹, Gabriele Amann², Martin Krssák³, Pavol Szomolanyi⁴, Joannis Panotopoulos⁵, Michael Weber¹, Philipp Funovics⁵, Martin Dominkus⁵, Christian Czerny¹, Reinhard Windhager⁵, and Siegfried Trattnig^4
1Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ²Department of Pathology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ³Department of Internal Medicine III, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ⁴High field MR Center of Excellence, Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria, ⁵Department of Orthopaedic Surgery, Medical University of Vienna/Vienna General Hospital, Vienna, Austria

Accurate diagnosis of soft tissue tumors requires an optimized biopsy technique for preoperative histology. We performed staging 3T-MR of soft tissue tumors with MR-guided biopsy in 52 patients.In 49/52 patients with final surgical histology, the diagnostic yield was 97.8% (48/49). The accuracy in predicting the dignity was 100% (48/48), the accuracy in providing a definitive tissue diagnosis was 89.3%, and the accuracy in predicting the grade of the tumor was 93.6%. Our preliminary study indicates that biopsy can be performed accurately and safely by DCE-targeted MR guidance at 3T, using the DCE staging sequence in a combined staging/biopsy MRI.

Nadja Alexandra Farshad-Amacker¹, Matthew F. Koff¹, Jonathan P. Dyke², Lionel E. Lazaro³, Dean Lorich³, and Hollis G. Potter^1
1MRI Research Laboratory, Hospital for Special Surgery, New York, NY, United States, ²Department of Radiology, Weill Cornell Medical College, New York, NY, United States,³Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States

Standardized radiographs markedly underestimate the incidence of osteonecrosis (ON) after fixation of femoral neck fractures. ON was identified using MAVRIC sequence in 75% of the patients, in 60% using FSE images and <1% using conventional radiographs. There was a significant underestimation of the identified ON volume using FSE compared to MAVRIC sequence (p=0.001). It is feasible to perform postcontrast SI uptake measurements in bone around metallic implants using MAVRIC sequence. Significant increase in % SI uptake within the rim of the ON, compared to the ilium and femoral diaphysis 3 month postoperatively is shown.

Julien, Rivoire¹, Kevin F. King², and Xiaojuan Li^1
1Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California, United States, ²Applied Science Laboratory, General Electric Healthcare, Waukesha, Wisconsin, United States

In this work, a combination of compressed Sensing and parallel imaging reconstruction has been used to reconstruct MRI images for T1ρ measurement of the bone cartilage. While femoral cartilage T1ρ quantification was not affected significantly by the acceleration, the thinnest structures analyzed such as the tibia compartments suffered from higher deviation at high acceleration. Nevertheless, this preliminary data shows the feasibility of combining CS and PI and the potential acceleration benefit of using this new method to accelerate T1ρ quantification.

Deva Chan¹ and Corey P. Neu^1
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States

An intimate relationship between function and mechanical behavior is apparent in a number of orthopedic soft tissues. Until now, the measurement of Displacements Under Applied Loading with MRI (dualMRI) has been implemented on high-field MRI systems with low frequency cyclic loading. However, translation of dualMRI to clinical MRI systems would enhance the clinical potential of this technique for measuring high precision strains of tissues in their native environment. This study reports the translation of dualMRI to a 3.0T clinical system at sub-pixel displacement precision and <1% strain precision. This technique then is demonstrated in a cyclically loaded intervertebral disc segment.

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

Fat and water separated MRI enables non-invasive quantification of volume and fat infiltration in muscles. Manual segmentation of muscles is extremely time consuming why automatic alternatives are needed. . We have developed an infrastructure that enables a robust platform for non-rigid whole body registration where manual classifications of an anatomical structure in an image volume (prototype) may be automatically transferred to a new patient volume. The purpose of this work was to evaluate if using such multiple prototype voting procedure provides a robust automatic muscle classification. The result showed satisfying robustness in all 10 subjects using multiple prototype voting.

Michael Carl¹, James H. Holmes², and Graeme C. McKinnon^3
1GE Healthcare, San Diego, CA, United States, ²GE Healthcare, Madison, WI, United States, ³GE Healthcare, Waukesha, WI, United States

Imaging short T2 tissues frequently encountered in the musculoskeletal system requires specialized pulse sequences with very short echo times. There have been several k-space trajectories employed for UTE imaging, such as projection reconstruction and Cones. Here we investigate via theoretical analysis and phantom experiments the tradeoffs in terms of scan-time and image quality between undersampled PR and Cones. We found that both the very short trajectories (that require significant undersampling) and very long spiral-like trajectories are prone to different artifacts, and that intermediate Cones trajectories provide a good balance to optimize image quality.

Djaudat Idiyatullin¹, Curtis Andrew Corum², Donald Nixdorf³, and Michael Garwood^2
1Radiology, CMRR, University of Minnesota, Minneapolis, MN, United States, ²Radiology, University of Minnesota, Minneapolis, MN, United States, ³Neurology, Division of TMD & Orofacial Pain in the Department of Diagnostic & Biologic, University of Minnesota, Minneapolis, MN, United States

This work describes a simple but efficient intraoral radiofrequency coil, positioned between the upper and lower jaws in the occlusal plane, with efficient utilization of B1 field for imaging teeth and associated structures. We used a regular single loop surface coil with plane of coil oriented orthogonally to Zeeman field. We found that the sensitive volume of coil in this position includes the most important dental structures, while partially excluding the cheeks, lips and tongue that have less informative but very intense lipid signals. We present simulated data and images showing advantages of using such coil for dental applications.

Yasuhiko Terada¹, Saki Kono¹, Tomomi Uchiumi¹, Kazunori Ishizawa¹, Shinya Inamura¹, Katsumi Kose¹, Ryo Miyagi^2,3, Eiko Yamabe², Yasunari Fujinaga², and Hiroshi Yoshioka^2
1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan, ²Department of Radiological Sciences, University of California Irvine, Orange, CA, United States,³National Health Insurance Nishi-iya Clinic, Tokushima University, Miyoshi-shi, Tokushima, Japan

Skeletal age was assessed using a new, dedicated hand MRI system with a small permanent magnet, which enhanced the openness and compactness of the system and provided stress-free examinations. Measurements for 88 volunteers aged from 3.4 to 15.7 showed the high correlation between chronological and skeletal ages and the high agreement of skeletal rating between multiple raters. The quality of MR images was high in most cases. The results proved the validity of the skeletal rating using the new system.

Eva Scheurer^1,2, Thomas Widek¹, Pia Baumann^1,2, Andreas Petrovic¹, Heiko Merkens¹, and Sabine Grassegger^1
1Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Graz, Austria, ²Medical University Graz, Graz, Graz, Austria

The need for forensic age estimations currently relying on X-rays of the jaw and the wrist, and a CT of the clavicles increased with migration. However, the use of ionizing radiation without medical indication is mostly not permitted. In this study wisdom teeth, wrist and clavicles were investigated using MRI, and estimated age was compared to chronological age. Estimated age was quite accurate with reasonable variability until about 19 years, whereas older subjects were rather underestimated. Performing age estimations based on MRI of three body regions is realistic in the next years, when according reference values will be available.

Joshua Farber^1,2, Jose Tamez-Pena³, Saara Totterman⁴, Bruce Holladay⁵, Forest Heis⁵, John Larkin⁵, and Michael Greiwe^5
1Radiology, Radiology Ass of N KY, Cincinnati, Ohio, United States, ²Imaging, Qmetrics, Rochester, NY, United States, ³Mathematics and Statistics, Tec de Monterrey, Monterry, NL, Mexico, ⁴Qmetrics, Rchester, NY, United States, ⁵Orthopedic Surgery, Commonwealth Orthopeadic centers, Edgewood, KY, United States

The material presented here demonstrates a validated, automated knee articular cartilage segmentation platform that can create 3D Thickness maps of knee articular cartilage. These thickness maps delineate the location and size of articular cartilage defects, as well as the integrity of the surrounding cartilage, and provide an accurate guide for pre operative evaluation and facilitate physician - patient interactions.

Emily Alexandria Waters¹, Shawn Rose², Thomas Meade^1,3, and Harris Perlman^2
1Center for Advanced Molecular Imaging, Northwestern University, Evanston, IL, United States, ²Department of Medicine, Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ³Department of Chemistry, Northwestern University, Evanston, IL, United States

Studies of inflammatory arthritis in mice rely upon anatomically crude measures of ankle joint disease and require sacrificing large numbers of animals to obtain tissue sections. There is critical need in experimental rheumatology for noninvasive longitudinal monitoring of the progression of inflammatory arthritis in individual animals. We used high-resolution MRI to serially image soft tissue inflammation and bone destruction in ankles of acute and chronic murine models of arthritis. MRI data was validated against clinical and optical assessments. These studies lay the groundwork for using MRI to investigate joint pathology and response to therapy in animal models of rheumatic disease.

Eugene Kim¹, Yeo Ju Kim¹, Jang Gyu Cha², Youn Jeong Kim¹, Mi Young Kim¹, and Myung Kwan Lim^1
1Radiology, Inha University Hospital, Incheon, Incheon, Korea, ²Radiology, Soonchunhyang University Hospital, Bucheon, Gyeonggi-Do, Korea

Kinematic MRI of knee was performed in 5 asymptomatic volunteers in wide bore 3T MR system. All images are successfully obtained with flexion and extension position. Positional change of meniscus, tibiofemoral joint, and meniscal flounce were evaluated.

Michael Muelly¹, Ronald D. Watkins¹, Caroline Jordan^1,2, Neal K. Bangerter³, and Garry E. Gold^1
1Radiology, Stanford University, Stanford, CA, United States, ²Bioengineering, Stanford University, Stanford, CA, United States, ³Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States

Sodium MRI is useful in knee imaging to identify articular cartilage pathology. Current coil design use four ring birdcages which limit the field-of-view and signal-to-noise ratio. We report significant improvement in the signal-to-noise ratio of sodium imaging with unchanged signal-to-noise of proton imaging using an optimized two birdcage coil design.