Cartilage Imaging - Technical Developments

Wednesday, 3 June 2015

Jetse van Gorp¹, Paul de Bruin², and Peter Seevinck^1
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, ²Department of Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands

In this work we propose a flexible and quantitative method for sodium (23Na) imaging to determine the total sodium concentration (TSC) and characterize the signal decay, which is related to bound and unbound 23Na. A (compressed sensing accelerated) 3D FID spectroscopic imaging sequence is used to maximize the ratio between sampling time and total acquisition time to optimize the SNR, obtain a high temporal resolution and acquire 23Na images in both a calibration phantom and in the knee of a healthy volunteer.

Yasuhiko Terada¹, Keiichiro Ishi¹, Daiki Tamada¹, Katsumi Kose¹, Taiki Nozaki², Yasuhito Kaneko², Ryo Miyagi², and Hiroshi Yoshioka^2
1Institue of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan, ²Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States

Skeletal age of a young child is assessed by rating the maturity stage of left-hand bones in the MRI images. We have used a 0.3 T open scanner to provide a comfortable examination environment for children, and showed the validity of the skeletal age examination. However, the long scan times for 3D imaging are uncomfortable for children and often induce motion artifacts in the images. In the previous study, we used compressed sensing (CS) to shorten the long scan time, but the acceleration factor (AF) was limited to 2 because of the low signal-to-noise ratio. To further decrease the scan time, it is necessary to optimize the CS sampling pattern for skeletal age examination with knowledge of the nature of data to be reconstructed. In this study, we optimize the sampling pattern using the database of hand images obtained in the previous study and realize the 40-second scan (AF = 4). Both the simulation and experimental results reveal the validity of the CS-based skeletal examination using optimal sampling.

Jan Fritz¹, Gaurav Thawait¹, Shivani Ahlawat¹, Shadpour Demehri¹, Heiko Meyer², Wesley Gilson³, and Esther Raithel^2
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Healthcare Sector, Siemens AG, Erlangen, Bavaria, Germany, ³Siemens Healthcare USA, Baltimore, MD, United States

While high spatial resolution, isotropic 3D MRI of knee can achieve similar diagnostic performance than standard 2D MRI, the acquisition of 3D data can be time-consuming and may conflict with its practicability. K-space undersampling and iterative reconstruction is a method that can yield substantial acceleration of 3D data acquisition. In this study, we show how the implementation of k-space undersampling and iterative reconstruction into a SPACE pulse sequence prototype enables accelerated, comprehensive, high-spatial-resolution 3D MRI of the knee in under 10 min with image qualities that rivals standard 2D TSE images and potential to replace a more time-consuming 20 min standard 2D TSE MRI protocol.

Dingxin Wang^1,2, Chen Lin³, Abraham Padua⁴, Bruce Spottiswoode⁵, Jutta Ellermann², Edward Auerbach², Kamil Ugurbil², Kenneth Buckwalter³, and Vibhas Deshpande^6
1Siemens Healthcare, Minneapolis, Minnesota, United States, ²CMRR, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, United States, ³Department of Radiology, University of Indiana, Indianapolis, Indiana, United States, ⁴Siemens Healthcare, Houston, Texas, United States, ⁵Siemens Healthcare, Chicago, Illinois, United States, ⁶Siemens Healthcare, Austin, Texas, United States

Our study demonstrates the utility of multiband slice accelerated TSE for improving slice resolution (2.5 mm vs 3 mm) of clinical knee imaging at 3T with no time penalty. Multiband slice acceleration improves the acquisition efficiency of TSE, allowing more number of thinner slices to be covered per TR.

Fang Liu¹, Jarred Kaiser², Walter F. Block^1,3, Darryl G. Thelen^2,3, and Richard Kijowski^4
1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ⁴Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States

A novel dynamic and static MR method was proposed to investigate the in-vivo relationship between cartilage contact and quantitative cartilage MR parameters in an asymptomatic subject following anterior cruciate ligament reconstruction surgery. A cartilage contact map of the tibia plateau was created using dynamic SPGR-VIPR imaging performed during active loaded knee flexion and extension, cartilage thickness map was created using 3D fast spin-echo imaging, and cartilage single-component T2 and fast relaxing water fraction (Ff) maps were created using mcDESPOT imaging. Cartilage contact was found to positively correlate with cartilage thickness and cartilage Ff and negatively correlate with cartilage T2.

Andrea Lazik^1,2, Jens M Theysohn¹, Stephan Orzada², Harald H Quick^2,3, and Oliver Kraff^2
1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany, ²Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, NRW, Germany, ³High Field and Hybrid MR Imaging, University Hospital Essen, Essen, NRW, Germany

A comprehensive hip cartilage protocol was established at 7T MRI on 11 volunteers, combining morphological (DESS, T1 VIBE) and quantitative imaging techniques (T1-mapping in dGEMRIC-technique, T2-, T2*-mapping) with high spatial resolution, and applied in patients with acetabular cartilage transplants. Delineation of acetabular and femoral cartilage increased after intravenous contrast-agent administration in DESS and T1 VIBE, and was also good to excellent in the relaxation maps. Values of T2- and T2*-relaxation times were not affected by intravenous contrast agent administration. Unenhanced pre-scans for dGEMRIC were nonessential. According to these results, combining morphological and quantitative hip cartilage imaging is possible at 7T.

Keiko Amano¹, Valentina Pedoia², Drew A Lansdown¹, Cory Wyatt², Narihiro Okazaki², Favian Su², Dragana Savic², Kimberly Amrami³, Matthew Frick⁴, Joel Felmlee³, Matthew F Koff⁵, Aaron Krych⁶, Hollis Potter⁵, C. Benjamin Ma¹, Scott Rodeo⁷, Xiaojuan Li², and Sharmila Majumdar^2
1Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California, United States, ²Department of Radiology, University of California, San Francisco, San Francisco, California, United States, ³Department of Radiology, Mayo Clinic, Minnesota, United States, ⁴Radiology, Mayo Clinic, Minnesota, United States, ⁵Department of Radiology, Hospital for Special Surgery, New York, United States, ⁶Department of Orthopaedic Surgery, Mayo Clinic, Minnesota, United States, ⁷Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, United States

We present the feasibility of detecting cartilage degeneration using T1ρ and T2 in ACL-injured patients in a multicenter study. MRIs of 37 patients with ACL injuries were obtained at three institutions after injury and prior to surgery. Two healthy volunteers were scanned at all sites for reliability testing. T1ρ and T2 values were computed with an in-house Matlab program. Mean inter-site differences were between 0.8-1.6ms for the volunteers, and mean relaxation times were significantly higher on the injured knee. These data indicate good reproducibility across the three sites, and demonstrates the feasibility of expanding this technology to multiple institutions.

Guruprasad Krishnamoorthy¹, Puneet Bagga¹, Ravi Prakash Reddy Nanga¹, Hari Hariharan¹, John Bruce Kneeland², and Ravinder Reddy^1
1Center for Magnetic Resonance and Optical Imaging, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

Osteoarthritis (OA) is a degenerative disease affecting Articular Cartilage (AC) of synovial joints like knee, shoulder, hip, etc. Spin-lattice relaxation in the rotating frame (T1ρ) has been a promising quantitative MRI technique to detect biochemical changes in the AC. High resolution MRI is desired across the thickness of AC particularly in the OA subjects to identify the extent of the cartilage degeneration. Here we propose a new 3D-GRE based time efficient method to acquire T1ρ weighted images of the whole knee at an isotropic resolution that allows the reformatting of the isotropic images of knee to any desired orientation.

Noam Ben-Eliezer^1,2, Matthieu Guillemin¹, Akio Yoshimoto¹, Kai Tobias Block^1,2, Roy Davidovitch³, Thomas Youm³, Robert Meislin³, Michael Recht⁴, Daniel K Sodickson^1,2, and Riccardo Lattanzi^1,2
1Center for Biomedical Imaging, Department of Radiology, New York University Medical Center, New York, NY, United States, ²Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, ³Department of Orthopedic Surgery, New York University Hospital for Joint Diseases, New York, NY, United States, ⁴Department of Radiology, New York University Langone Medical Center, New York, NY, United States

Early diagnosis of articular cartilage defects is critical to the success of corrective surgical procedures in patients with femoroacetabular impingement (FAI). Quantitative T₂ mapping can detect early degeneration of cartilage, but it is challenging to perform in vivo, mostly due to the contamination of multi spin-echo protocols by stimulated and indirect echoes, non-rectangular slice profiles, and inhomogeneous (B₁⁺) fields. We use a recently-developed T₂ mapping technique – the echo-modulation curve (EMC) algorithm – which is able to overcome these limiting factors, for retrospective assessment of cartilage damage in FAI patients, to show increased specificity of the EMC technique versus conventional mono-exponential fitting.

Ding Xia^1,2, Li Feng^1,2, Tiejun Zhao³, and Ravinder R. Regatte^1,2
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, ²Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, ³Siemens Medical Solution USA. Inc, New York, NY, United States

This work investigates the feasibility of highly-accelerated 3D-T1rho mapping in human knee cartilage using a combination of compressed sensing and parallel imaging. Fully sampled dynamic k-space data were retrospectively undersampled at different acceleration rates from 2 to 6 and reconstructed using k-t SPARSE-SENSE, a reconstruction framework that exploits joint multicoil sparsity in dynamic imaging. The 3D T1rho maps estimated from the accelerated datasets was compared with the fully sampled reference. Accurate T1rho maps can be obtained up to 5-fold acceleration, which suggest that the proposed approach could be useful in assessing musculoskeletal diseases such as osteoarthritis with reduced scan times.

Larry Hernandez¹, Habib Al saleh¹, Kevin Johnson¹, Walter F. Block^1,2, and Richard Kijowski^3
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ²Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States

VIPR-ATR can produce 0.5mm isotropic resolution images of the hip joint with SSFP tissue contrast which can be reformatted in any orientation following a single 7.7 minute acquisition. This study compared VIPR-ATR with two-dimensional fast spin-echo (2D FSE) sequences for evaluating the hip joint in 24 patients. VIPR-ATR had significantly higher (p<0.05) normalized SNR efficiency for cartilage and fluid and significantly higher (p<0.05) normalized CNR efficiency between cartilage and other joint structures than 2D FSE sequences. VIPR-ATR had similar ability as 2D FSE images for detecting labral tears and improved ability for identifying cartilage lesions within the hip joint.

Valentina Pedoia¹, Favian Su¹, Deepak Kumar¹, Richard Souza¹, Benjamin Ma¹, Xiaojuan Li¹, and Sharmila Majumdar^1
1UCSF, San Francisco, California, United States

T1rho MRI quantitative assessment of cartilage degenerative change is usually addressed through ROI-based approaches considering T1rho mean as descriptor. However, previous studies showed that spatially assessing T1rho using laminar and texture analyses could lead to better and probably earlier identification of cartilage matrix abnormalities. Voxel Based Relaxometry (VBR) is a technique that could potentially be used for investigating local cartilage microstructural composition. In this study we show the use of VBR to study the knee cartilage. VBR showed the capability to detect specific local patterns of T1ρ increase that maybe potentially useful for a more accurate analysis and disease phenotyping

Aditi Guha¹, Deepak Kumar¹, Lorenzo Nardo¹, Richard Souza¹, Thomas Link¹, Xiaojuan Li¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States

The goal of this study is to evaluate the spatial changes in T1p values longitudinally in osteoarthritic and healthy knee using texture analysis

Aditi Guha¹, Cory Wyatt¹, Dimitrios Karampinos², Lorenzo Nardo¹, Thomas Link¹, and Sharmila Majumdar^1
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Radiology, Technische Universität München, Munich, Germany

in this study, longitudinal evaluation of our pervasively proposed stimulated echo MAPSS sequence is done. Correlation between the three non invasive biomarkers for knee osteoarthritis is evaluated.

Xiaona Li¹, Zhigang Peng¹, Pan-Li Zuo², Dingxin Wang³, and Jianling Cui^4
1the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, China, ²Siemens Healthcare, Beijing, China, ³Siemens Medical Solutions USA, Minnesota, Armenia, ⁴the 3rd Hospital of Hebei Medical University, Hebei, China

To compare the simultaneous acquisition of multiple slices (SMS) with turbo spin echo (TSE) sequences to routine TSE sequences in musculoskeletal (MSK) imaging. 10 healthy volunteers and 8 patients with knee joint disorders were examined in two sequences at 3T. The basic acquisition parameters for two sequences were similar. Slice accelerated factor was 2 and FOV shift factor was 2 for SMS sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio were calculated in volunteers, respectively. Two radiologists visually evaluated the images of patients double blindly. SMS TSE requires less scan time and offers higher SNR, especially for large coverage MSK examination.

Maria I Menendez¹, Daniel Clark¹, Bianca Hettlich¹, and Michael Knopp^1
1The Ohio State University, Columbus, Ohio, United States

The purpose of this study was to use T2, dGEMRIC and gagCEST to serially evaluate articular cartilage in an in vivo ACL OA canine model. T2 was higher in the ACL transected knee. At T2 was higher than baseline. Lower T1 was found in the ACL versus control at 12 weeks. For ACL knees, lower T1 at 6 and 12 weeks than baseline. MTRasym was not statistically significant between control and ACL knees, neither among timelines. T2 and dGEMRIC correlated moderately negative. This study showed that T2 and dGEMRIC serially evaluated cartilage in an ACL OA canine model.

Chanhee Lee¹ and Jang-Yeon Park^1
1Biomedical Engineering, IBS Center for Neuroscience Imaging Research, Sungkyunkwan University, Suwon, Gyeonggi, Korea

The subtraction between minimum TE1 (~50-200 ƒÝs) and longer TE2 (>~5ms) images was typically performed to provide a better contrast from the deeper layers of cartilage. Here, we show that decreasing ƒ´TE is more critical to enhance the image contrast of the deeper layers of articular cartilage rather than minimizing TE1 when the subtraction method is used with UTE imaging. This was demonstrated by simulation and UTE imaging.

Vladimir Juras^1,2, Klaus Bohndorf¹, Rahel Heule³, Claudia Kronnerwetter¹, Pavol Szomolanyi^1,2, Benedikt Hager¹, Oliver Bieri³, and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia, ³Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland

A clinical relevance of T2 mapping in cartilage measured by recently introduced triple-echo steady-state (3D-TESS) sequence was assessed by comparing to standard multi-echo spin-echo T2 at 3T MRI. Both methods demonstrated the ability to distinguish between healthy cartilage and lesions. Most importantly, 3D-TESS provides results similar to CPMG within substantially shorter scan times and are B0- and B1-insensitive. This benefit will be even more pronounced at ultra-high-field MR systems, where the TA of conventional T2 mapping is substantially compromised due to specific absorption rate issues.

Alina Messner¹, Sebastian Apprich², Lukas Zak³, Pavol Szomolanyi¹, and Siegfried Trattnig^1
1High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, ³Department of Traumatology, Medical University of Vienna, Vienna, Austria

The integrity of cartilage adjacent to repair tissue was assessed with zonal T2-mapping. Twelve months after MACT, the mean T2 values in cartilage surrounding the repair tissue were significantly higher than in the normal cartilage, and significantly lower than in the repair tissue zone (both p<0.001). Two years after the procedure, no significant differences between the regional T2 values could be observed. The results indicate that cartilage surrounding the transplant shows early degenerative changes one year after MACT. If this degeneration predates the MACT, cartilage transplantation may have a positive influence on the adjacent cartilage.

Victor Casula^1,2, Mikko J. Nissi^3,4, Joonas Autio³, Michaeli Shalom⁴, Silvia Mangia⁴, Edward Auerbach⁴, Jutta Ellermann⁴, Eveliina Lammentausta³, and Miika T. Nieminen^1,3
1Radiology, University of Oulu, Oulu, Oulu, Finland, ²Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Oulu, Finland,³Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ⁴Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, United States

Adiabatic T₁ and T₂ sequences were evaluated with a 3 T clinical system. The optimal parameters for in vivo quantitative imaging of articular cartilage were determined on the basis of the evaluation of relaxation time maps and in order to minimize scanning time and power deposition and maximize image quality. The results show that adiabatic T₁ and adiabatic T₁ are suitable for in vivo quantitative assessment of articular cartilage at 3 T. The preliminary results are encouraging when the techniques were applied to discriminate normal and early osteoarthritis cartilage.

Taiki Nozaki¹, Yasuhito Kaneko¹, Hon J. Yu¹, Kayleigh Kaneshiro¹, Ran Schwarzkopf², and Hiroshi Yoshioka^1
1Radiological Sciences, University of California, Irvine, Orange, California, United States, ²Orthopaedic Surgery, University of California, Irvine, Orange, California, United States

T1rho-weighted MR imaging has recently been proposed as an attractive biomarker to existing conventional morphological MRI methods, and enables us to detect early cartilage degeneration in early osteoarthritis patients before appearing morphological change. However the factors affecting the T1rho mapping such as MR sequences and operator-dependent manual cartilage segmentation is not well understood. The objective of this study was to investigate the difference of T1rho profiles between spoiled gradient echo (SPGR) and balanced steady state free precession (b-FFE) sequences.

Uchechukwuka Diana Monu^1,2, Brian A Hargreaves^1,2, Caroline D Jordan^2,3, Garry E Gold^2,3, and Emily J McWalter^2
1Electrical Engineering, Stanford University, Stanford, California, United States, ²Radiology, Stanford University, Stanford, California, United States,³Bioegineering, Stanford University, Stanford, California, United States

Osteoarthritis (OA) is a heterogeneous and multifactorial joint disease that is characterized by morphological, biochemical and structural changes to the cartilage. The etiology and progression of the disease remains largely uncertain making disease modifying treatments challenging. This works uses parametric MRI modeling and a 3D visualization technique to track clusters of elevated T2 and T1rho relaxation times in an ACL-injured population. Results show the potential for cluster analysis to identify and quantify focal defects in cartilage over time. This may provide a useful biomarker for tracking early cartilage degeneration.

Daniel R Thedens¹, Mai P Nguyen², Annunziato Amendola², and Douglas R Pedersen^2
1Radiology, University of Iowa, Iowa City, IA, United States, ²Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, United States

The purpose of this study was to non-invasively assess the joint condition of subjects who underwent joint-preserving distraction arthroplasty in an 8-10 year follow-up study. Six subjects were evaluated and compared with T1, T2, and quantitative T1 imaging, showing outcomes with a range of cartilage and subchondral bone inhomogeneities. The results demonstrated that T1 has value to gauge cartilage and joint condition in longitudinal studies of OA progression and treatment planning.

Luning Wang¹, Mikko J Nissi², Ferenc Toth³, Michael Garwood¹, Cathy Carlson³, and Jutta Ellermann^1
1Center for Magnetic Resonance Research, University of Minnesota, Twin Cities, Minneapolis, MN, United States, ²Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Finland, ³University of Minnesota, Twin Cities, Minneapolis, MN, United States

Juvenile Osteochondritis Dissecans (OCD) is an orthopaedic disease of children and young adults that may result in significant lifelong disabilities. The etiology is likely related to ischemic vascular events and subsequent epiphyseal cartilage necrosis occuring during skeletal maturation, but is poorly understood. In this work, we present multiparametric relaxation time mapping and histology of epiphyseal cartilage in a goat model of surgically-induced ischemia at different stages of lesion development. T1, T2, (CW) T1�, adiabatic T1� and TRAFF provided a sensitive, noninvasive way to detect ischemic necrosis. These noninvasive MR methods are promising both for staging lesion development and for outcome assessment after intervention in children with OCD.

Bone & UTE

Wednesday, 3 June 2015

Emeline Julie Ribot¹, Clément Tournier², Aurélien Julien Trotier¹, Didier Wecker³, Didier Letourneur⁴, Joelle Amédée², and Sylvain Miraux^1
1RMSB - UMR5536, CNRS - University Bordeaux, Bordeaux, France, Metropolitan, ²Biotis - U1026, INSERM - University Bordeaux, Bordeaux, France, Metropolitan, ³Bruker Biospin GmbH, Ettlingen, Germany, ⁴LRVT - UMR1148, INSERM - University Paris 7, Paris, France, Metropolitan

The conventional imaging method to follow bone repair is based on X-ray. To circumvent repetitive irradiation exposures, a MRI 3D bSSFP sequence was performed longitudinally on rats with biomaterials implanted in femoral condyle bone defects. Due to the insertion of a water-selective binomial radiofrequency pulse, the signal from adipose tissue within the bone marrow dropped, allowing the visualization of the biomaterials with hyperintense signal. Thus, their volumes were measured precisely over time. Their degradations corresponded with bone regeneration observed on ex vivo micro-CT.

Lindsay M Griffin¹, Stephen Honig², Yinxiao Liu³, Cheng Chen³, Punam K Saha³, Ravinder Regatte¹, and Gregory Chang^1
1Department of Radiology, New York University School of Medicine, New York, New York, United States, ²Department of Medicine, New York University, New York, United States, ³University of Iowa, Iowa, United States

This study utilized 7T MRI at the distal radius to describe how microarchitectural parameters vary depending upon distance from the end-of-bone and the relationship between microarchitectual parameters at the diaphysis, epiphysis, and metaphysis. Quality of trabecular microarchitecture appears to be greatest at the epiphysis and lowest at the diaphysis. While bone volume and trabecular connectivity were highly correlated with trabecular number at all sites, the association of trabecular network resorption (a measure of bone resorption by osteoclasts) with other measures of microarchitecture was significant in the metaphysis and epiphysis only. Future study includes how site and parameters relate to fracture risk or response to treatment.

kejun wang¹, Yunfei Zha¹, and Hao Lei^2
1Department Of Radiology, Renmin Hospital Of Wuhan University, Wuhan, Hubei, China, ²Wuhan Institute Of Physics and Mathematics,Chinese Academy of Sciences, Wuhan, Hubei, China

To investigate microvascular perfusion status, changes of fat content and fatty acid composition in bone marrow of rats femur after irradiation by x-ray via quantitative perfusion parameters of dynamic contrast-enhanced MRI (DCE-MRI) andex vivo high-resolution MAS1H NMR spectroscopy

Zhe Liu¹, Alexey Dimov¹, Jiang Du², and Yi Wang^3
1Biomedical Engineering, Cornell University, New York, New York, United States, ²Radiology, University of California, San Diego, San Diego, CA, United States, ³Radiology, Weill Cornell Medical College, NY, United States

The clinical application of UTE for quantitative susceptibility mapping is hampered by the long acquisition times needed to image the entire volume excited. Here we report on the use of compressed sensing to reduce scan time by a factor of 5 while largely maintaining image quality.

Naira P. Martinez Vera¹, Johannes Höller¹, Bernhard Neumayer¹, Thomas Widek¹, Sabine Grassegger^1,2, Thomas Ehammer¹, Eva Scheurer^1,2, and Martin Urschler^1
1Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Styria, Austria, ²Institute of Forensic Medicine, Medical University of Graz, Graz, Styria, Austria

Skeletal age estimation based on MRI data of the manubrium is of great interest due to an age-related shape change of the manubrium and the use of a non-invasive imaging technique. MRI data from male adolescents and young adults were used to analyze the age dependence of manubrium volume, area and shape. The shape analysis was based on a non-linear PCA which allowed to identify a principal component and to simulate age-related change of the shape of the manubrium. All parameters show a statistical correlation with age and the PCA provides a new simulation tool which may give further insight into the manubrium’s age-related behavior.

Jing Li¹, Fei Yuan¹, Quan Zhang¹, Jun Zhao¹, and Yu Zhang^2
1MRI Department, PingJin Hospital, He Dong District, TianJin, China, ²Philips Healthcare, Beijing, China

Patients who require long-term steroid use are at high risk for occurrence of osteonecrosis. Early diagnosis of this complication is essential as the prognosis is affected by the stage of the disease. However, there is no consensus on whether screening of bone necrosis should be performed for long-term glucocorticoid. Magnetic resonance imaging (MRI) is more sensitive than plain film for diagnosing early-stage bone necrosis [1]. Traditionally functional magnetic resonance imaging (fMRI) using blood oxygenation level-dependent (BOLD) contrast has appeared to measure vascular oxygenation change due to neuron activity. This study attempted to compare BOLD-MRI with conventional MRI sequence on determining the onset of osteonecrosis of the femoral head following steroid-related osteonecrosis.

Doron Cohn Yakubovich¹, Uzi Eliav², Gadi Pelled^1,3, Dan Gazit^1,3, Zulma Gazit^1,3, and Gil Navon^2
1Skeletal Biotech Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel, Israel, ²School of Chemistry, Tel Aviv University, Tel Aviv, Israel, Israel,³Department of Surgery and Cedars-Sinai Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States

Calvarial bone grafts often fail to integrate due scar tissue formation at the grafts proximity. In order to examine parathyroid hormone (PTH, a bone anabolic agent) effect on the extent of scaring, we used MTC and the magnetization exchange μMRI scanning protocol, MEX. The results show that μMRI reveals changes in the extent of scaring and bone formation as a result of the PTH administration in comparison to the control animals, enabling differentiation between new bone formation and scar tissue. Our technique will enable clinical longitudinal, non-invasive follow up of various fibrosis related conditions.

Joshua Michael Farber¹, Jose Tamez-Pena², David Hunter³, Michael Hannon⁴, Saara Totterman⁵, Zhijie Wang⁶, Robert Boudreau⁷, and Kent Kowh^8
1Radiology, Qmetrics Technologies, Cincinnati, Ohio, United States, ²Imaging Sciences, Escuela de Medicina, Tec de Monterray, Monterray, Monterray, Mexico, ³Rheumatology, Royal North Shore Hosp. and Northern Clinical Sch, Univ. of Sydney, Sydney, Sydney, Australia, ⁴Epidemiology, Dept. of Epidemiology, Univ. of Pittsburgh, Pittsburgh, Pennsylvania, United States, ⁵Radiology, Qmetrics Technologies, Rochester, New York, United States, ⁶Dept. of Epidemiology, Univ. of Pittsburgh, Pittsburgh, Pennsylvania, United States, ⁷Epidemiology, dept. of Epidemiology, Univ. of Pittsburgh, Pittsburgh, Pennsylvania, United States, ⁸Rheumatology, The University of Arizona, Arthritis Center, Tuscon, Arizona, United States

This work analyzes knee bone curvature from OAI data sets in patients with OA and predicts which subjects will advance to TKR within five years of the initial imaging. The MRI analysis is correlated with KL scores and all TKR subjects are compared with match controls who do not advance to TKR. The result is the development of a biomarker, based on MRI bone curvatre changes, for end-stage knee OA as defined by the need for TKR.

Sabine GRASSEGGER^1,2, Thomas EHAMMER¹, Thomas WIDEK¹, Andreas PETROVIC³, Pia BAUMANN⁴, and Eva SCHEURER^1,2
1Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Styria, Austria, ²Institute of Forensic Medicine, Medical University of Graz, Graz, Styria, Austria, ³Institute of Medical Engineering, Graz University of Technology, Graz, Styria, Austria, ⁴University Centre of Legal Medicine, University of Lausanne, Lausanne, Vaud, Switzerland

The application of ionizing radiation without medical indication is prohibited in many countries. Thus, for the application in age assessment (i.e., in criminal proceedings and sports regulations) the Dvorak method based on MRI of the wrist was developed as an alternative to the standard X-ray based methodology according to Greulich&Pyle, and is regularly used by the FIFA for age testing in adolescent soccer athletes. The accuracy of both methods was evaluated in volunteers comparing estimated with chronological age. While Greulich&Pyle was quite accurate, Dvorak showed a great systematic deviation and cannot be recommended for age estimation.

Bainan Wu¹, Robert Nikolov², Hongda Shao², Jun Chen², Graeme Bydder², Maurizio Pellecchia¹, and Jiang Du^2
1Sanford-Burnham Medical Research Institute, La Jolla, California, United States, ²Radiology, University of California, San Diego, San Diego, California, United States

The purpose of this study is to measure and report the field dependence of NMR relaxation times (T* and T1) of the free and bound water in cortical bone at magnetic field strenghts corresponding to frequencies of 600 MHz and 700MHz. T2* of bound/free water is measured to be 6.2(0.1)µs /80(3)µs at 600MHz and decreases to 5.4(0.1)µs /63(5)µs at 700 MHz. T1 of bound/free water is reported to be 628/632ms at 600 MHz and 661/672 ms at 700 MHz. At both field strengths, the free water contributes to about 10% of the NMR signal.

Chao-Ying Wang¹, Guo-Shu Huang², Shih-Wei Chiang^2,3, Yi-Chih Hsu², Ming-Huang Lin⁴, and Hsiao-Wen Chung^3
1Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, Taiwan, ²Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan, Taiwan, ³Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, Taiwan, ⁴Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan, Taiwan

A rat model study of Chronic Kidney Disease(CKD) investigated by quantitative MR imaging

Katharina Baron¹, Bernhard Neumayer¹, Thomas Widek¹, Sylvia Scheicher¹, Eva Maria Hassler², Fritz Schick³, and Eva Scheurer^1
1Ludwig Boltzmann Institute for Clinical-Forensic Imaging (LBI-CFI), Graz, Styria, Austria, ²Department of Radiology, Medical University of Graz, Styria, Austria, ³Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Baden-Württemberg, Germany

The determination of the time frame of fracture healing is of particular interest in the field of clinical forensic examinations of child abuse, but can also be applied to accident reconstructions and medical investigations regarding bone healing. The preliminary results of this clinical study indicate that the determination of the quantitative parameters T1, T2, and MTR is a promising method for an accurate determination of fracture healing phases. Provided that the discovered characteristics are confirmed for a larger number of volunteers this will allow for the application in an improved, objective estimation of the age of a fracture.

Allegra Conti¹, Raffaele Sinibaldi¹, Sara Spadone¹, Tonino Traini², Giuliana Tromba³, Silvia Capuani⁴, Gian Luca Romani^1,5, and Stefania Della Penna^1,5
1Department of Neuroscience, Imaging and Clinical Sciences, G. D'Annunzio Univ. of Chieti and Pescara, Chieti, CH, Italy, ²Department of Stomatology and Biotechnologies, G. D'Annunzio Univ. of Chieti and Pescara, Chieti, CH, Italy, ³Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, TS, Italy, ⁴Physics Department, 'La Sapienza' University of Rome, Roma, RM, Italy, ⁵Institute for Advanced Biomedical Technologies (ITAB), G. D'Annunzio Univ. of Chieti and Pescara, Chieti, CH, Italy

We present here a 3D analysis of extracted human jawbone cores following restoration of bone mass. First, X-ray Synchtron-Radiation-micro-CT and micro-MR images were co-registered using a new in-house software. Then, a clusterization algorithm was applied to generate a 3D meta-structure of the sample, producing six clusters. Histology made on sample slabs was used to label the clusters as mature bone, two types of newly formed bone, soft tissue, multinucleate cells and empty spaces. Notably, the presence of two different phases of newly formed bone was not revealed by MRI and SRCT when used as separate imaging tools.

Alan C. Seifert¹, Suzanne L. Wehrli², and Felix W. Wehrli^1
1University of Pennsylvania, Philadelphia, PA, United States, ²Children's Hospital of Philadelphia, Philadelphia, PA, United States

Increased cortical porosity is a major cause of the impaired strength of osteoporotic bone. MicroCT and gravimetry are accepted methods for validation of porosity and matrix density, but involve long scan times and destruction of specimens, respectively. In this work, we compare several NMR methods for quantification of bound and pore water (biomarkers for matrix density and porosity, respectively). T2 fitting of CPMG data at 9.4T outperforms T2* fitting of FIDs at 3T, while 2H IR at 9.4T performs approximately as well as T2* fitting. Incorporation of a second T1 dimension yields improved fidelity for both T2 and T2* fitting.

Shahrokh Abbasi Rad^1,2, Atena Akbari¹, Niloofar Tondro³, Mohsen Shojaee-Moghaddam³, and Hamidreza Saligheh Rad^1,2
1Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran, ²Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran, ³Imaging Center, Payambaran Hospital, Tehran, Iran

There exist three types of proton pools in the cortical bone: loosely bonded to the collagen matrix, tightly bonded to the minerals, and mobile protons residing in the pores of cortical bone like Haversian canals, lacunae and canaliculi. Mobile water can be considered as a reliable determinant of cortical bone porosity. As the porosity increases with age, we hypothesized that mobile water concentration of the cortical bone must be in good correlation with age, and investigated it using a clinically available MRI pulse sequence named Short Echo Time (STE), which employs echo-time in the range of 0.5 to 1.5 ms.

Gavin McKenzie¹, Michelle Mauermann², Robert Spinner², Doris Wenger², Joel Felmlee², Shuji Nagata³, Benjami Howe², and Kimberly Amrami^2
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Mayo Clinic, MN, United States, ³Kurume University School of Medicine, Kurume, Japan

To present the characteristic MRI findings of peripheral nerve intraneural perineurioma.

Leon C. Ho^1,2, Ian A. Sigal³, Ning-Jiun Jan³, Tao Jin¹, Ed X. Wu², Seong-Gi Kim^1,4, Joel S. Schuman³, and Kevin C. Chan^1,3
1Neuroimaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China, ³Departments of Ophthalmology and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, ⁴Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Suwon, Korea

The sclera and cornea are fibrous connective tissues in the outer coat of the eye which may undergo microscopic structural realignment and macromolecular changes in healthy aging and in diseases such as myopia, ocular hypertension and glaucoma. Recently, we demonstrated the use of the magic-angle effect to improve MRI sensitivity to reveal T2 and T2* relaxation changes in scleral and corneal tissues upon intraocular pressure loading. In this study, we further evaluated the corneoscleral shells using high-field DTI and MTI at the magic angle in order to test the hypotheses that (1) the microstructural organization and macromolecular contents of the sclera and cornea can be detected and differentiated with high-field MRI; and (2) acute ocular hypertension may alter DTI and MTI properties in these fibrous tissues.

Marius Stefan Horger¹, Nina Schwenzer¹, Sergios Gatidis¹, Christian la Fougere², Konstantin Nikolaou¹, and Alexander Walter Sauter^1,3
1Radiology, Eberhard-Karls-University Tuebingen, Tuebingen, Germany, ²Nuclear Medicine, Eberhard-Karls-University Tuebingen, Tuebingen, Germany,³Radiology and Nuclear Medicine, University Hospital Basel, Tuebingen, Germany

PET/MRI as a combined morphologic and functional technique offers valuable data with respect to disease extent and activity in SSc and results correlate positively with clinical and laboratory scores. Interestingly, FDG-PET and MRI seem to assess the inflammatory processes from different points of view and thus providing complementary information.

Li-Sha Duan¹, Meng-Jun Wang¹, Feng Sun¹, Zhen-Jiang Zhao¹, Mei Xing¹, Yu-Feng Zang², Steven Louis³, Sheng-Jie Cui⁴, Han Zhang², and Jianling Cui^1
1Department of Radiology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China, ²Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, Zhejiang, China, ³Physics Department, Oakland University, Rochester, Michigan, United States,⁴Department of Anatomy and Cell Biology, Wayne State University School of Medicine, East Canfield Avenue, Detroit, United States

Fifty-two patients with MSK tumors were examined using 1.5 T MR scanner with EPI BOLD. The BOLD time series in each ROI was transformed from temporal to frequency domain with a fast Fourier transformation. This power spectrum was then divided into four frequency bands. In the frequency band between 0.073 and 0.198 Hz, the BOLD fluctuations were stronger in the periphery than that in the center of malignant MSK tumors; however, no such a difference was observed for the benign tumors, which may provide the first evidence that BOLD fMRI could be utilized to delineate vascularization characteristics in MSK tumors.

Marco Vicari¹, Stefan Heldmann², Hans Meine¹, Frank Hug³, Juergen Hennig⁴, and Niklas Iblher^3
1Fraunhofer MEVIS, Bremen, Germany, ²Fraunhofer MEVIS, Luebeck, Germany, ³Department of Plastic and Hand Surgery, University Medical Center Freiburg, Freiburg, Germany, ⁴Department of Radiology, Medical Phyisics, University Medical Center Freiburg, Freiburg, Germany

Reconstructive and aesthetic facial plastic surgery can strongly benefit from quantitative assessments of the facial soft-tissue mobility. This clinical challenge can be risen by a modern and original comprehensive imaging method, joining advanced MRI and image analysis. In particular, 3D accelerated upright MRI provides, in reasonable acquisition times, high-resolution and high-contrast facial soft-tissue depiction in natural stance under physiological weight-bearing. Moreover, soft-tissue layer watershed segmentations and their constrained elastic registration between lying and sitting positions give access to full quantitative information about the complex 3D anatomy of the face structure, as a function of aging and gravity.

Jenny Yang^1,2, Jingjuan Qiao¹, Shenghui Xue¹, Fan Pu¹, Shanshan Tan¹, Jie Jiang¹, Anvi Patel¹, and Zhi-ren Liu^2,3
1Chemistry Department, Georgia State University, Atlanta, Georgia, United States, ²Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States, ³Biology Department, Georgia State University, Atlanta, Georgia, United States

This research focuses on developing rational protein based MRI contrast agents for cancer imaging. Various cancer models including breast cancer, prostate cancer and liver cancers have been successfully imaged with high sensitive and resolution under MRI.

Paolo F Felisaz¹, Eric Y Chang², Polesel Marco¹, Irene Carne³, Maugeri Giulia¹, Giovanni Palladini⁴, Obici Laura⁴, Giampaolo Merlini⁴, Baldi Maurizia⁵, Stefano Bastianello⁶, and Fabrizio Calliada^1
1Radiology Department, University of Pavia, Pavia, Italy, ²Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States, ³Medical Physics Department, IRCCS Salvatore Maugeri Foundation, Scientific Institute of Pavia, Italy, ⁴Amyloid Research and Treatment Center, Scientific Institute Policlinico San Matteo, Pavia, Italy, ⁵Radiology Department, IRCCS Salvatore Maugeri Foundation, Scientific Institute of Pavia, Italy, ⁶Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy

The aim of this study is to evaluate peripheral nerves in amyloid-related neuropathy using high-resolution MRI. A clinical 3T scanner with readily available sequences and coils are used. Our MRI protocol allows spatial resolution down to 100 μm, with demonstration of tissue detail comparable with light microscopy after histological staining. We evaluated 6 patients with various grades of amyloid-related neuropathy of the lower limbs. Amyloid neuropathy MR micro-neurograms demonstrate an obvious pathologic pattern with increased amounts of epineurial fat and decreased number of fascicles. Early diagnosis of this neuropathy may impact patient treatment and outcome.

Yongxian Qian¹, Ashley A. Williams², and Constance R. Chu^2
1Qian's Lab for MRI, General Labs Cloud LLC, Pittsburgh, PA, United States, ²Orthopaedic Surgery, Stanford University, Redwood City, CA, United States

Very initial testing results on human knee cartilage explants are presented to demonstrate the consistency in evaluation of collagen fiber disruption between noninvasive UTE-based short-T2* mapping and destructive imaging of polarized light microscopy (PLM). This consistency is suggestive of the potential of short component of transverse (T2) relaxation as an imaging biomarker for detecting disruption of collagen fibers in cartilage.

Audrey P. Fan¹, Feliks Kogan¹, Dawn Holley¹, Andrei Iagaru¹, Greg Zaharchuk¹, and Garry E. Gold^1
1Radiology, Stanford University, Stanford, CA, United States

[^18F]-FDG tracer uptake is a potential PET marker of musculoskeletal inflammation, but its biodistribution in osteoarthritis (OA) and colocalization with morphological changes are not well studied. We characterized [^18F]-FDG tracer uptake within different areas of OA joint damage in the hip identified on simultaneously acquired structural MRI scans. Twenty patients (mean age = 67 years) were scanned on a 3T hybrid PET-MR system with time-of-flight PET and with T2 STIR (short TI inversion recovery) MRI. An experienced radiologist identified 7 subchondral cysts and 10 areas of bone marrow lesions (BMLs) on the MR images. Mean standard uptake value (SUV_mean) was highest in joint fluid, which may reflect increased tracer diffusion or high glucose metabolism due to inflammation. SUV_mean was also elevated in subchondral cysts and BMLs relative to SUV in normal regions of the femoral head. Our observations enable improved understanding of [¹⁸F]-FDG uptake in normal and diseased joint tissue.

Translational MR Imaging of Musculoskeletal Physiology

Wednesday, 3 June 2015

Qun He¹, Zhe Liu², Hongda Shao¹, Alexey Dimov², Graeme M Bydder¹, Yi Wang², and Jiang Du^1
1Radiology, University of California, San Diego, CA, United States, ²Biomedical Engineering, Cornell University, Ithaca, New York, United States

We aim to assess the feasibility of QSM within meniscus by studying bovine specimens at 11.7 T using a pre-clinical system to provide short TE images of high spatial resolution.

Nathaniel E. Calixto¹, Lorenzo Nardo¹, Deepak Kumar², Richard B. Souza¹, Xiaojuan Li¹, Thomas M. Link¹, and Sharmila Majumdar^1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, United States, ²Division of Physical Therapy, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina, United States

While T1ρ and T2 MR relaxation times have become established metrics for cartilage assessment, the T1ρ/T2 ratio could eliminate hydration effects and better represent macromolecular integrity. A lowered T1ρ/T2 ratio in patellofemoral cartilage was associated with ACL lesions, consistent with the relationship between ACL pathology and patellofemoral osteoarthritis. In subjects with healthy patellofemoral cartilage, significant T1ρ/T2 ratio differences were observed between those with and without ACL lesions; no significant differences were observed with T1ρ or T2 individually, suggesting heightened sensitivity of the T1ρ/T2 ratio. Future work is necessary to verify the applicability of the T1ρ/T2 ratio in other anatomy.

Angela E Li¹, Darryl B Sneag^1,2, Alissa J Burge^1,2, Shari T Jawetz^1,2, Joseph D Lipman³, and Hollis G Potter^1,2
1Radiology, Hospital for Special Surgery, New York, NY, United States, ²Weill Cornell Medical College, New York, NY, United States, ³Biomechanics, Hospital for Special Surgery, New York, NY, United States

Radiographs have been traditionally used to evaluate the polyethylene tibial insert in total knee arthroplasty, although assessment is limited. With the development of MRI and metal reduction techniques, the polyethylene tibial insert can be visualized. We review the MRI scanning considerations to optimize evaluation of the prosthesis. The expected MRI appearance of polyethylene tibial inserts will be correlated with corresponding macroscopic photographs of common total knee arthroplasty designs. Complications related to the polyethylene liner including polyethylene wear, fracture of the polyethylene liner, or dissociation of the polyethylene component or tibial locking pin will also be discussed.

Jan Fritz¹, Gaurav Thawait¹, Shadpour Demehri¹, Shivani Ahlawat¹, Heiko Meyer², Wesley Gilson³, Esther Raithel², and Mathias Nittka^2
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Healthcare Sector, Siemens AG, Bavaria, Germany, ³Siemens Healthcare USA, Baltimore, United States

Because susceptibility artifacts increase with field strength, MRI of implants is commonly performed at 1.5T. However, 3T MRI offers substantially higher SNR and may be the only available option. SEMAC can achieve substantial metal artifact reduction at 3T, but the required increase of SEMAC-encoding steps prolongs scan times. Capitalizing on the inherent sparsity of SEMAC data, pseudo-randomized undersampling and iterative reconstruction can substantially accelerate data acquisition. We show the clinical feasibility of highly accelerated 3T MRI of metal-on-metal hip arthroplasty implants using a highly undersampled TSE SEMAC sequence with metal artifact reduction capabilities and acquisition times similar to 1.5T.

TAO AI¹, Panli Zuo², Yiqi Hu¹, Mathias Nittka³, and Liming Xia^1
1Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, ²Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, ³Siemens Healthcare, Germany, Erlangen, Germany

In order to investigate the efficacy of SEMAC and high bandwidth (high BW) techniques in metal artifact reduction and clinical applications at 3T MR imaging, tissue specimens with CoCr/Ti and OxZr/Ti implants and ten patients with total knee replacements were imaged, and the artifact size, distortion and image quality were quantitatively and qualitatively assessed. The results demonstrated that SEMAC allows for significant metal artifact reduction and distortion correction at 3T MR imaging of knee implants, as compared with the conventional and increased readout bandwidth sequences. With optimizations, SEMAC would be routinely chosen for the clinical application of knee prosthesis.

Martijn A Cloos¹, Mary Bruno¹, Tiejun Zhao², Leeor Alon¹, Riccardo Lattanzi¹, and Danial K Sodickson^1
1Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, ²Siemens Medical Solutions USA Inc., Malvern, PA, United States

Under some circumstances, the complex electrodynamic interactions between the subject and the incident RF field can distort RF excitation to such an extent that the diagnostic value of MRI is compromised. Metal implants, in particular, are a well-known source of MR artifacts, resulting not only from distortion of the main magnetic field, but also from distortions of the excitation RF field. In this work, we explore the potential of a generalized implementation of the recently proposed plug & play parallel transmission framework, to enable rapid multiparamatric mapping (T1, T2, PD) in the presence of orthopedic implants.

Jan Fritz¹, Gaurav Thawait¹, Shadpour Demehri¹, Shivani Ahlawat¹, Heiko Meyer², Wesley Gilson³, Esther Raithel², and Mathias Nittka^2
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Healthcare Sector, Siemens AG, Bavaria, Germany, ³Siemens Healthcare USA, Baltimore, United States

Slice-encoding metal artifact correction (SEMAC) affords powerful metal artifact reduction, but may be considered impractical due to long acquisition times. The inherent sparsity of SEMAC data, however, offers potential for substantial acceleration through the use of pseudo-randomized k-space undersampling and iterative reconstruction. We show the clinical usability of a highly accelerated TSE SEMAC sequence prototype employing incoherent k-space undersampling and iterative reconstruction resulting in shortening of the acquisition time by 50-60% when compared to standard TSE SEMAC sequences and comparable image quality.

Angela E Li¹, Darryl B Sneag^1,2, Alissa J Burge^1,2, Shari T Jawetz^1,2, Darius P Melisaratos^1,2, and Hollis G Potter^1,2
1Radiology, Hospital for Special Surgery, New York, NY, United States, ²Weill Cornell Medical College, New York, NY, United States

A proportion of patients will experience long term pain following total knee arthroplasty (TKA), and some of these patients ultimately undergo revision TKA. The purpose of this retrospective study was to determine the prevalence of complications seen on MRI in cohort of 113 patients who subsequently underwent revision TKA. The spectrum of complications seen on MRI included the following: polymeric synovitis in 32%, osteolysis in 27%, loosening in 22%, non-specific synovitis in 20%, prominent synovial scarring and arthrofibrosis in 13%, infection in 17%, and periprosthetic fracture in 1% of patients. We compare our results with the causes for revision TKA reported in the orthopedic literature.

Xinzeng Wang¹, Crystal E Harrison¹, Yogesh K Mariappan², Karthik Gopalakrishnan², Avneesh Chhabra^1,3, Robert E Lenkinski^1,3, and Ananth J Madhuranthakam^1,3
1Radiology, UT Southwestern Medical Center, Dallas, Texas, United States, ²Philips Innovation Campus, Philips Healthcare, Bangalore, Karnataka, India,³Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States

The visualization of nerves on MRI are often confounded by surrounding fat and the blood vessels in close proximity that appear bright on T2-weighted images. Fat suppression by STIR suffers from reduced SNR and standard motion sensitized driven equilibrium (MSDE) based blood suppression suffers from B0 and B1 inhomogeneities, particularly in difficult areas such as Brachial Plexus. In this work, we implemented an adiabatic pulse (BIR-4) based MSDE in combination with a dual-echo 2-point Dixon technique with robust fat and blood suppression without SNR penalty for volumetric neurography in clinically feasible scan times.

Eric Y Chang¹, Annette von Drygalski², Thomas J Cramer², Sheronda Statum³, Jiang Du³, and Christine B Chung^1
1Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States, ²Department of Hematology/Oncology, University of California, San Diego Medical Center, San Diego, CA, United States, ³Department of Radiology, University of California, San Diego Medical Center, San Diego, CA, United States

21 patients with hemophilic arthropathy were recruited for this prospective study. Chronically symptomatic joints (7 knee, 7 ankle, and 7 elbow joints) were evaluated using clinical pain and Hemophilia Joint Health scores as well as conventional and quantitative 3D-UTE-Cones images. Semi-quantitative International Prophylaxis Study Group (IPSG) MRI scales and UTE-T2* values of weight-bearing cartilage were calculated and correlated with clinical scores. We found that UTE-T2* values of cartilage significantly decrease as joint health declines in patients with hemophilic arthropathy.

Karen Chi-Lynn Chen^1,2, Reni Biswas², Sheronda Statum³, Won Bae², Eric Chang^1,2, and Christine Chung^1
1Radiology, Veterans Administration Healthcare System San Diego, San Diego, CA, United States, ²Radiology, University of California San Diego, San Diego, CA, United States, ³Radiology, University of California, San Diego, CA, United States

UTE T2* sequences can be used to assess the temporomandibular joint disc in vivo with differences in T2* values in symptomatic patients compared to asymptomatic volunteers. This study proves feasibility of in vivo quantitative MR evaluation of TMJ disc using the UTE T2* technique, which may provide sensitive and objective measure of TMJ disc degeneration in TMD patients.

Eric Y Chang¹, Jiang Du², Reni Biswas², Betty Tran², Sheronda Statum², Won C Bae², and Christine B Chung^1
1Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States, ²Department of Radiology, University of California, San Diego Medical Center, San Diego, CA, United States

In this study, 7 human cadaveric rotator cuff tendons were used to compare orientation-dependent value changes using T2, T2*, and MT techniques. We found that mean percent change was up to 38% using T2, up to 92% using T2*, and up to 15% using OSR. OSR measured with the UTE-MT technique may be more useful than T2 and T2* due to the strong dipolar-dipolar influence on the latter two biomarkers.

Gerd Melkus^1,2, Greg O Cron^1,2, Peder E Larson³, Adnan Sheikh^1,2, Ian Cameron^1,2, Hakim Louati^4,5, Peter Lapner⁵, Tim Ramsay⁶, and Guy Trudel^4,7
1Department of Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, ²Department of Radiology, University of Ottawa, Ottawa, ON, Canada, ³Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, ⁴Bone and Joint Laboratory, University of Ottawa, Ottawa, ON, Canada, ⁵Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada, ⁶Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada, ⁷Department of Medicine, University of Ottawa, ON, Canada

A 3D ultra-short echo time (UTE) sequence was applied to study the T2* decay of the rabbit supraspinatus tendon at 7T. Twelve echoes with echo times ranging from 0.09ms to 10ms were acquired and four different decay models (mono- and bi-exponential) were applied to fit the T2* decay. Two ROIs were chosen for their importance in supraspinatus tendon surgical repair to estimate T2*. The study demonstrated that T2* of the rabbit tendon can be quantified using 3D UTE imaging and that a 3-parameter mono-exponential signal decay model shows the best fit results for the tendon T2* decay.

Benedikt Hager¹, Vladimir Juras^1,2, Olgica Zaric¹, Vladimir Mlynarik¹, Stefan Zbyn¹, Pavol Szomolanyi^1,2, and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava, Slovakia

The purpose of this study was to demonstrate the feasibility of Glycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) imaging for the detection of degenerated menisci. The results show that the average of asymmetries in gagCEST z-spectra summed over all offsets from 0.6 to 1.8 ppm was significantly lower (p < 0.02) in degenerated meniscal horns (2.2 ± 5.5 %) compared to healthy meniscal horns (8.4 ± 3.9%), which indicates a decrease in GAG content in the degenerated menisci. This study demonstrates that gagCEST imaging holds great potential as a biomarker to differentiate between healthy and degenerated menisci.

Akshay S Chaudhari^1,2, Catherine J Moran², Emily J McWalter², Garry E Gold^1,2, and Brian A Hargreaves^1,2
1Bioengineering, Stanford University, Palo Alto, California, United States, ²Radiology, Stanford University, Palo Alto, California, United States

In this study, we have developed a multi-echo UTE-DESS pulse sequence. UTE-DESS offers rapid and high-resolution imaging of short T2 tissues with proton-density, T2, and diffusion contrasts, along with fat-water separation and a very high overall scan efficiency. We present our initial results of scanning the knees of healthy volunteers with multi-echo UTE-DESS. Our preliminary data shows that the contrasts generated by this sequence and its ability for fast imaging, makes the sequence potentially attractive for routine clinical study of the morphology of the connective tissues in the knee.

Volkan Emre Arpinar¹ and L Tugan Muftuler^1,2
1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States, ²Center for Imaging Research, Medical College of Wisconsin, Wisconsin, United States

Degenerating intervertebral discs sometimes lead to degenerative changes in adjacent vertebral bodies, which are classified based on the appearance of vertebral marrow in T1 and T2 weighted MRI. Although this classification is widely accepted, those images may not be sufficiently sensitive to early or transitional changes. Initial changes associated with vascularization and edema can be studied by Dynamic contrast enhanced MRI (DCEMRI). Additional information can be obtained from T1, which is reported to increase in various inflamed tissues. Our findings show significant increases in both DCEMRI and T1 with degeneration in disc endplates.

Wen Ling¹, Nam Vo², Gwendolyn A. Sowa², James Kang³, and Kyongtae Ty Bae^1
1Radiology Department, University of Pittsburgh Medical Center, Pittsburgh, PA, United States, ²Department of Orthopedic Surgery, University of Pittsburgh Medical Center, PA, United States, ³Department of Orthopedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States

The applicability of recently proposed iGagCESL on both cartilage and intervertebral disc at 3T has been evaluated by 3-pool Bloch simulation and in vivo human data (n=3), along with gagCEST. iGagCESL and gagCEST give rise to similar contrast, ~1% for cartilage and ~5% for disc, at 3T; but preserve more than10 times higher signal intensity than gagCEST. For comparison, same metrics are used for both simulation and data acquisition. Along with its additional advantages, iGagCESL is a much superior method on 3T scanner with 3~5 minutes of scan time.

Georg Riegler¹, Gregor Drlicek¹, Claudia Kronnerwetter¹, Rahel Heule², Oliver Bieri², Benedikt Hager¹, Peter Bär¹, and Siegfried Trattnig^1
1MR Centre of Excellence, Dept. of Biomedical Imaging and Image-Guided Therapy, Medical University Vienna, Vienna, Vienna, Austria, ²Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland

To determine T2 values of the median nerve with TESS and the numbers of fascicles with a PD-TSE-fat-sat in healthy volunteers and patients with carpal-tunnel-syndrome at 7-Tesla. Six volunteers and three patients were included. Axial-PD-TSE-fat-sat and axial-3D-TESS were performed. Two reader assessed T2 values and fascicles. Mean T2 values of patients were significantly higher for the median nerve in comparison to healthy subjects (P = 0.008) with an ICC of 0.97. Median of fascicle count was 19 in all subjects with an ICC of 0.81. Axial-PD-TSE-fat-sat and axial-3D-TESS provides fast and reliable morphological and biochemical assessment of the median nerve.

Paolo F Felisaz¹, Eric Y Chang², Irene Carne³, Polesel Marco¹, Stefano Montagna⁴, Maugeri Giulia¹, Baldi Maurizia⁴, Fabrizio Calliada¹, and Stefano Bastianello^5
1Radiology Department, University of Pavia, Pavia, Italy, ²Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States, ³Medical Physics Department, IRCCS Salvatore Maugeri Foundation, Scientific Institute of Pavia, Italy, ⁴Radiology Department, IRCCS Salvatore Maugeri Foundation, Scientific Institute of Pavia, Italy, ⁵Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy

The aim of this study is to present a fast and high-resolution MRI scanning technique focused on the study of peripheral nerves. We used a 3T MRI scanner with a readily available coil, optimized for clinical peripheral nerve evaluation. Sequences were based on 3D spoiled gradient echo combined with the 3-point-Dixon technique. This protocol provides a combination of high spatial resolution and adequate SNR with robust and consistent fluid-fat separation in a single acquisition, thereby microscopic nerve components can be visualized. MR micro-neurography may complement standard MR neurography protocols, for focused evaluation of a selected nerve tract.

Hongda Shao¹, Michael Carl², Eric Chang¹, Christine B Chung¹, Graeme M Bydder¹, and Jiang Du^1
1Radiology, University of California, San Diego, CA, United States, ²GE Healthcare, San Diego, CA, United States

We investigate the magic angle effect in ultrashort echo time MRI of cadaveric specimens of the human Achilles' tendon on bi-component analysis of T2* decay and magnetization transfer ratio using a clinical 3T scanner.

Jing Zhang¹, Pan-Li Zuo², Thorsten Feiweier³, and Xiaoguang Cheng^4
1Beijing Jishuitan Hospital, Beijing, Beijing, China, ²Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, ³Siemens Healthcare, Erlangen, Germany,⁴Beijing Jishuitan Hospital, Beijing, China

The purpose of this study was to assess the clinical value of IVIM and DCE in sarcoma. 7 patients with pathologically proven sarcoma were involved in this study. For IVIM, D-slow was lower in tumor masses than in healthy muscle, but D-fast and PF had no statistic difference between them. For DCE, Ktrans, Kep and Ve were higher in the tumor masses than in healthy muscles . In sarcoma, ADC and D-slow were able to provide information about cell growth, and Ktrans provided information about tumor angiogenesis.

Barbara Cervantes¹, Jan S. Bauer², Hendrik Kooijman³, Marcus Settles¹, Axel Haase⁴, Ernst J. Rummeny¹, Klaus Wörtler¹, and Dimitrios C. Karampinos^1
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Neuroradiology, Technische Universität München, Munich, Germany, ³Philips Healthcare, Hamburg, Germany, ⁴Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany

3D TSE imaging has been emerging for high-resolution MR neurography. 3D TSE refocusing-flip-angle-train design traditionally considers only the signal of a target tissue. Peripheral-nerve branches can have diameters down to a couple of millimeters and can therefore be affected not only by their own signal behavior but also by that of the surrounding tissue. The present work proposes flip-angle schemes that consider the interface between fine nerve structures and the enveloping tissue. The optimized flip-angle design is compared to cases considering only the signal behavior of nerve (standard approach) and is demonstrated in vivo in the lumbar plexus.

Vladimir Mlynarik¹, Stefan Zbyn¹, Vladimir Juras¹, Pavol Szomolanyi¹, Martin Brix¹, Benjamin Schmitt², and Siegfried Trattnig^1
1High Field MR Center, Medical University of Vienna, Vienna, Austria, ²Siemens Ltd, Macquarie Park, Australia

Application of the gagCEST mapping technique on human knee is complicated by technical limitations of scanners, safety regulations and by an inhomogeneous B₀ field over the knee cartilage. Measurements on human volunteers using either Gaussian or adiabatic full passage hs2 saturation pulses showed unexpected regional variations in MTR_asym values in femoral cartilage. By varying frequency of the saturation pulses in a range of ±60 Hz, increased intensity and improved homogeneity of the MTR_asym maps was achieved.

Mohammed Aakef¹, Tania Kumar¹, Reni Biswas¹, Betty Tran¹, Sheronda Statum¹, Eric Y Chang², Won C Bae¹, and Christine B Chung^2,3
1Radiology, Univeristy of California, San Diego, San Diego, CA, United States, ²Veterans Affairs San Diego Healthcare System, CA, United States, ³Radiology, Univeristy of California, San Diego, CA, United States

Triangular Fibrocartilage (TFC) serves important biomechanical function and its injury is a common cause of wrist pain. This study evaluated quantitative MR properties of TFC using two T1rho sequences tailored for long (MAPSS T1rho) and short (UTE T1rho) T2 components, and correlated the values with local indentation modulus of the TFC. While significant negative correlations were found, the strength of correlation was greater for UTE T1rho measurements.

Muscle MRS/MRI

Wednesday, 3 June 2015

Ivica Just Kukurova¹, Barbara Ukropcová^2,3, Marjeta Tušek Jelenc¹, Milan Sedliak⁴, Marek Chmelik¹, Jozef Ukropec², Martin Krššák^1,5, Siegfried Trattnig¹, and Ladislav Valkovič^1,6
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia, ³Faculty of Medicine, Comenius University, Bratislava, Slovakia, ⁴Faculty of Physical Education and Sport, Comenius University, Bratislava, Slovakia, ⁵Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria, ⁶Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

Reproducibility of carnosine measurement in the calf muscles was tested on 5 volunteers by STEAM sequence with very good results of CV (6.3% for SOL, 9.1% for GM). Effect of one hour running on carnosine concentration was examined on 7 volunteers, which did not prove to be significant. However, changes in the shape of the carnosine peak appeared, in form of its widening or splitting and also its shift. As carnosine is pH sensitive, we suppose it is a consequence of different use of carnosine buffering capacity in oxidative and glycolytic muscle fibres leading to different pH in these compartments.

David Bendahan¹, Benjamin Chatel¹, and Thomas Jue^2
1CNRS, CRMBM, Aix-Marseille University, Marseille, France, ²Biochem & Mol Medicine, University of California, Davis, CA, United States

To be entered

Alexander Gussew¹, Philipp Schenk^2,3, Heiko Stark⁴, Bernhard Ullrich³, Christoph Anders², Patrick Hiepe¹, Reinhard Rzanny¹, Kai Wohlfahrt⁵, Gunther Hofmann^2,3, Hans-Christoph Scholle², and Jürgen R. Reichenbach^1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Thuringia, Germany, ²Clinic for Trauma, Hand and Reconstructive Surgery, Division of Motor Research, Pathophysiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Thuringia, Germany, ³Department of Trauma Surgery, BG Clinics Bergmannstrost, Halle (Saale), Saxony-Anhalt, Germany,⁴Institute of Systematic Zoology and Evolutionary Biology, Friedrich-Schiller-University Jena, Jena, Thuringia, Germany, ⁵Clinic for Neurology, BG Clinics Bergmannstrost, Halle (Saale), Saxony-Anhalt, Germany

Functional ³¹P-MRS was performed in five patients after spinal fusion during a standardized isometric exercise to evaluate differences of load induced high energy metabolic alterations in back muscles close to the fused vertebrae segments. Compared to healthy subjects, patients showed stronger PCr depletions during exercise indicating higher energy demand and thus higher muscle stress (patients: 61 ± 17 % vs. controls: 37 ± 11 %).

Claudiu Schirda¹, Tiejun Zhao², Shailesh Raval³, SoJung Lee⁴, Silva Arslanian⁴, Hoby Hetherington¹, and Tamer Ibrahim^1,3
1Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States, ²Siemens Medical Solutions, Pittsburgh, PA, United States,³Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, ⁴Division of Weight Management and Wellness, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

Monitoring 31P metabolism during exercise and recovery has typically been done using non-localized functional 31P MRS and a surface coil. By employing a high-sensitivity dual-tuned 1H/31P volume coil, functional 2D 31P spectroscopic imaging (thus, 4D) is demonstrated.

Quinn M. Barber¹ and Atiyah Yahya^1,2
1Department of Oncology, University of Alberta, Edmonton, Alberta, Canada, ²Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada

Fat to water levels and their transverse relaxation (T2) times measured with magnetic resonance in spinal bone marrow have been relevant to the study of a number of diseases. Previous measurements characterizing fat to water ratios and T2 values have been limited to the lumbar region of the spine. In this work, fat to water ratios and fat and water T2 values are determined for the L3 and T7 vertebrae of 20 healthy volunteers; measurements were also obtained from the C4 vertebra in 19 of the volunteers. Measurements were performed with a Point RESolved Spectroscopy (PRESS) sequence at 3 T.

Gaëlle Diserens¹, Helen Anwander², Fabian Fuhrer², Chris Boesch¹, Mattias A Zumstein², and Peter Vermathen^1
1Depts. Radiology and Clinical Research, University Bern, Bern, Switzerland, ²Dept. of Orthopaedic Surgery and Traumatology, University Bern, Bern, Switzerland

The aim of this study was to compare Dixon imaging and single voxel spectroscopy (SVS) for determination of low fat contents in muscles that are not prone to motion, as shoulder muscles (infraspinatus and supraspinatus). The results clearly demonstrate that also for low contents below 10%, the lipid content can be determined reliably by both, Dixon and SVS methods. This was shown by strong correlations between results from SVS and Dixon and between independent measures of right and left shoulders and between the two different muscles investigated.

Won C Bae¹, Kyu-Sung Kwack², Gavin Hamilton¹, Reni Biswas¹, Betty Tran¹, Robert Healey³, Sheronda Statum¹, Eric Y Chang⁴, and Christine B Chung^4,5
1Radiology, Univeristy of California, San Diego, San Diego, CA, United States, ²Radiology, Ajou University Medical Center, Korea, ³Orthopedic Surgery, Univeristy of California, San Diego, CA, United States, ⁴Veterans Affairs San Diego Healthcare System, CA, United States, ⁵Radiology, Univeristy of California, San Diego, CA, United States

Current knee MR evaluation focuses on specific parts of the knee. This abstract shows feasibility and usefulness of a whole-joint quantitative MR evaluation paradigm, achieved using currently available techniques, to evaluate articular cartilage, trabecular bone, and bone marrow simultaneously.

Eugenia Rerich¹, Moritz Zaiss¹, Johannes Windschuh¹, Patrick Schünke¹, and Peter Bachert^1
1German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany

Pulsed steady-state in vitro CEST measurements of creatine followed by spillover, MT and T1 compensated evaluation - AREX - yield creatine concentration calibration. This method is applicable in vivo and allows quantification of creatine in human calf muscle.

Yuchi Liu¹, Xunbai Mei¹, Andrew Slabic¹, Nicola Lai¹, and Xin Yu^1,2
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, ²Radiology, Case Western Reserve University, Cleveland, Ohio, United States

This study investigated changes in mitochondrial response to ischemia in skeletal muscle of non-obese type 2 diabetic rats. Mitochondrial function and tissue oxygenation was evaluated in vivo using interleaved 31P Magnetic Resonance Spectroscopy (MRS) and Blood Oxygen Level-Dependent (BOLD) imaging. Results from 12- and 18-week rats showed a progression of mitochondrial dysfunction.

Sean C Forbes¹, William T Triplett¹, Rebecca Willcocks¹, Abhinandan Batra¹, Ravneet Vohra¹, James Pollaro², Dah-Jyuu Wang³, Richard Finkel⁴, Barry J Byrne⁵, Barry S Russman⁶, Erika Finanger⁶, Michael Daniels⁷, William Rooney², Glenn A Walter¹, H Lee Sweeney⁸, and Krista Vandenborne^1
1University of Florida, Gainesvillle, Florida, United States, ²Oregon Health & Science University, Oregon, United States, ³The Children's Hospital of Philadelphia, Pennsylvania, United States, ⁴Nemours Children's Hospital, Florida, United States, ⁵University of Florida, Gainesville, Florida, United States,⁶Shriners Hospital, Oregon, United States, ⁷University of Texas at Austin, Texas, United States, ⁸University of Pennsylvania, Pennsylvania, United States

This study evaluated ¹H₂O T₂ of skeletal muscle in boys with Duchenne muscular dystrophy (DMD) and unaffected controls, and in dystrophic mice before and after downhill running. Data were acquired using single voxel ¹H-MRS and analyzed for multiple components using non-negative least squares analyses (NNLS). NNLS revealed differences between dystrophic muscle and controls, including DMD having a more predominant long component. The long component was affected by corticosteroid treatment and downhill running in dystrophic muscle and was consistent with muscle damage/inflammation contributing to this component. Overall, NNLS analyses may provide valuable insight when interpreting ¹H₂O T₂ changes in dystrophic muscle.

Donnie Cameron¹, Mustapha Bouhrara¹, David A. Reiter¹, Kenneth W. Fishbein¹, Christopher M. Bergeron¹, and Richard G. Spencer^1
1National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States

In diffusion-weighted imaging (DWI) of the thigh, ‘anomalous’ diffusion models may better reflect muscle architecture than conventional Gaussian models. In this work, four models were investigated—monoexponential, intravoxel incoherent motion, diffusional kurtosis, and stretched exponential—and a triple-fat-suppressed sequence was developed to mitigate fat contributions. Eight volunteers were scanned at 3T, with sixteen b-values applied in the slice and read directions, and diffusion parameter maps were generated. In the read direction, kurtosis and the stretching parameter were non-Gaussian (>0 and <1), and the stretched exponential fit the data best—suggesting some merit for non-Gaussian models in assessment of muscle quality.

Vijay Shah¹, Therese Crilly¹, Larry Molinelli¹, William Badger², and Jon Riek^1
1VirtualScopics, Inc., Rochester, NY, United States, ²Univerisity of Rochester Medical Center, Rochester, NY, United States

This study aimed to evaluate the influence of supine rest on thigh muscle volume in a healthy volunteer. Dynamic T1-weighted MR images were acquired in the mid-thigh region for 30 minutes. On average, muscle volume in the mid-thigh region decreased by 1.21%. The average coefficient-of-variation of two consecutive acquisitions was 0.15%, indicating that the measurement technique should be sensitive to changes in volume of less than 1%. At least 15 minutes of supine rest prior to positioning on the table may help to detect smaller changes in the thigh muscle volume by eliminating variability that could be introduced by redistribution of fluid in the muscles when posture is changed.

Junghwan Kim^1,2, Serter Gumus², Piva Sara Regina³, Tae Kim², Tamer Ibrahim^1,2, and Kyongtae Ty Bae^1,2
1Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, ²Radiology, University of Pittsburgh, Pittsburgh, PA, United States, ³Physical Therapy, University of Pittsburgh, Pittsburgh, PA, United States

The BOLD MR imaging was performed at quadriceps to understand the hemodynamics at volitional exercise (VE) and neuromuscular electrical stimulation (NMES). Near-infrared spectroscopy (NIRS) was used to measure the total, deoxy- and oxy- hemoglobin concentrations to understand the mechanism of muscle hemodynamics. Measured NIRS data was then used for calculation of BOLD signal and compared to the BOLD MRI.

Jeff L Zhang¹, Christopher J Hanrahan¹, and Vivian S Lee^1
1Radiology, University of Utah, Salt Lake City, Utah, United States

DCE MRI is widely used for assessing tissue perfusion noninvasively, using indicator dilution theory, which models tissue enhancement as a convolution between the arterial input function and impulse response function. This approach requires that the system of interest is time-invariant during data acquisition, which is fulfilled in most situations. However, the convolution approach does not work when perfusion changes dramatically during the measurement period, such as skeletal muscle perfusion during exercise-recovery. In this study, we propose a new tracer kinetic model where both blood inflow and vascular volume can vary during the measurement.

Kerryanne V. Winters^1,2, Olivier Reynaud^1,2, Dmitry S. Novikov^1,2, Els Fieremans^1,2, and Sungheon G. Kim^1,2
1Department of Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging - NYU School of Medicine, New York, NY, United States, ²Center for Advanced Imaging Innovation and Research, NYU Langone Medical Center, New York, NY, United States

We quantified changes in normal skeletal muscle growth using time dependent DTI combined with the random permeable barrier model (RPBM), the conventional IDEAL-Dixon imaging and T2 mapping. Muscle development was assessed by using different age of mice and comparing the parameters of each modality. DTI-RPBM was used to monitor changes in muscle fiber size and sarcolemma permeability, and showed that younger mice had higher surface-to-volume ratio and higher membrane permeability. Dixon imaging proved that with development, fatty deposits develop and therefore increase the fat fraction of the tissue. In addition, our preliminary results also showed that T2 values decrease with age. These results demonstrate that the microstructural changes measured using DTI-RPBM during muscle development are in line with the literature and can serve as a useful tool in assessment of disease progress or treatment response in various myopathies.

Jeff L Zhang¹, Christopher J Hanrahan¹, Jason Mendes¹, Gwenael Layec², Corey Hart², Kristi Carlston¹, Michelle Mueller³, Russell S Richardson², and Vivian S Lee^1
1Radiology, University of Utah, Salt Lake City, Utah, United States, ²Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States, ³Vascular Surgery, University of Utah, Salt Lake City, Utah, United States

Without a reliable way of assessing calf muscle function, therapeutic management of PAD is highly controversial. None existing imaging is capable of quantifying exercise-induced capillary recruitment. We have applied a validated plantar-flexion exercise protocol within MRI scanner together with ASL measurements at exercise recovery to measure exercise-induced capillary recruitment, which we term Muscle Perfusion Reserve (MPR). We examined MPR in healthy subjects. MPR increased as workloads. Significant differences in MPR were found between the two healthy subjects with different body mass index. The proposed MPR has great potential of evaluating calf muscle function of PAD and improving their therapeutic management.

Melissa Hooijmans¹, Martijn Froeling², Maarten Versluis³, Andrew Webb¹, Erik Niks⁴, Jan Verschuuren⁴, and Hermien Kan^1
1Radiology, Leiden University Medical Center, Leiden, Zuid-holland, Netherlands, ²Radiology, Utrecht Medical Center, Utrecht, Netherlands, ³Philips, Netherlands, ⁴Neurology, Leiden University Medical Center, Leiden, Zuid-holland, Netherlands

Skeletal muscle DTI can potentially serve as a surrogate measure of fiber architecture. This intrinsically T2-weighted sequence is susceptible to SNR and fat percentage. In muscles of Duchenne muscular dystrophy (DMD) patients, increased %fat and higher T2 relaxation times could obscure pathophysiological effects on DTI parameter estimation. Our data show that the proposed quality criteria from simulation-based work are suited to reliably determine mean diffusivity (MD) in DMD patients and controls and that multi-parametric MRI is essential to distinguish between confounding effects and pathophysiological processes in skeletal muscle DTI.

Nathan David Bryant^1,2, Ke Li^1,2, and Bruce Damon^1,2
1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States

Dystrophic skeletal muscles, from mdx mice of advanced age and stages of myopathy, were characterized using an array of quantitative metrics derived from a multi-parametric MRI approach including: T2, DTI and qMT-MRI data that were collected in a single imaging session. These observations were compared to age matched healthy control mice. Compared to healthy control muscle, old mdx gastroc muscles were observed to have in increased T2, but were not different in terms of the diffusion indices investigated. However, the qMT parameters R1f, PSR, and kmf were all decreased in the histologically-verified fibrotic and advanced dystrophic pathology mdx muscle.

Makoto Terazono¹, Tosiaki Miyati¹, Naoki Ohno¹, Shuya Fujihara^1,2, Natsumi Makino³, Satoshi Kobayashi⁴, and Toshifumi Gabata^4
1Division of health sciences, Graduate school of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan, ²Department of Radiology, Shinshu University Hospital, Nagano, Nagano, Japan, ³School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa, Ishikawa, Japan, ⁴Department of Radiology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan

To simultaneously acquire information on R2, MBF, and restricted water diffusion in lower-leg, we devised a method using SE-diffusion-EPI imaging with different echo times, and compared these values before and after the exercise. R2, ADCr, ADCP, and Fp of the tibialis anterior (TA) of the lower-leg muscle after the exercise were significantly higher than those before the exercise. On the other hand, there was no significant correlation between R2, ADCr, ADCP, and Fp of the TA. Our method makes it possible to simultaneously obtain R2, MBF, and restricted water diffusion in lower-leg, and increase amount of the muscle functional information.

Jules Nelissen^1,2, Willeke Traa³, Kevin Moerman⁴, Cees Oomens³, Aart Nederveen⁴, Klaas Nicolay¹, and Gustav Strijkers^1,2
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ²Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands, ³Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ⁴Department of Radiology, Academic Medical Center, Amsterdam, Netherlands

To investigate the response of the vascular system on sustained mechanical loading of skeletal muscle and subsequent skeletal muscle damage after end of period of deformation a study was performed in a rat model for skeletal muscle damage. During application of sustained mechanical loading to skeletal muscle and subsequent collapse of main supplying artery the body tries to keep up blood supply. After end of indentation a hyperemic response is observed. In case of combination of skeletal muscle deformation and occlusion of main supplying vessel, more edema formation is observed, which was further confirmed by T2 ROI analysis. T2 enhancement due to skeletal muscle damage appears highly structured and matches the peri, and endomysium organization of skeletal muscle.

Heather T. Ma^1,2, James F. Griffith³, Yang Chen¹, Shoulin Huang¹, Davd K. Yeung³, Xu Xing¹, and Li Liang^1
1Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, Guangdong, China, ²Johns Hopkins University, Baltimore, MD, United States, ³The Chinese University of Hong Kong, Hong Kong, China

This study examined the BOLD effect on calf muscles in different bone mineral density (BMD) elderly females to investigate the oxygenation characteristics in osteoporotic patients. An air-cuff was used to induce ischemia and BOLD-MRI data was curve fitted to derive quantitative parameters. A significant decreased Slope during hyperemia and longer Half-life in ischemic stage were shown in the BOLD signal of subjects with lower BMD, indicating a different vascular reactivity and oxygen utilization strategy in osteoporotic patients. No significant changes of minimum ischemic value among subjects may indicate a normal oxygen utilization in total for osteoporotic patients.

Chih-Wei Yu¹, Tiffany Ting-Fang Shih¹, Hsing-Kuo Wang², Chao-Yu Hsu¹, Bang-Bin Chen¹, and Xin-Jia Chen^3
1Radiology and Medical Imaging, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan, ²School and Graduate Institute of Physical Therapy, National Taiwan University College of Medicine, Taipei, Taiwan, ³Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan

Perfusion parameters of DCE-MRI and muscle performance in rotator cuff muscles were evaluated in the 20 young badminton athletes. Perfusion parameters of MRI in the rotator cuff muscles may correlate with muscle strength and significant difference was observed in perfusion parameters between the anterior and the posterior bellies of supraspinatus muscle.

Noriyuki Tawara¹, Takahiro Ohnishi², and Toru Yamamoto^1
1Faculty of Health Sciences, Hokkaido University, Hokkaido, Japan, ²Siemens Japan, Japan

Understanding of exercised muscle activity has been the essences in sports medicine and rehabilitation medicine. Although MRI is a useful technique to obtain quantitative values of T₂ and proton density, most of the previous MRI studies discussed changes of MR signal. Changes of T₂ in the exercised muscle are speculated based on the results of the NIRS, and various physiologic mechanisms are proposed. However, physiologic understanding of exercised muscle activity is still controversial. In this study, we first tried to obtain dynamic changes of T₂ and proton density quantitatively after the muscle exercise. In conclusion, using SE-EPI, temporal resolution of dynamic study of exercise-induced muscle can be shortened to 30 s and dynamic changes of R₂ and M₀ were quantitatively obtained for the new understanding of exercised muscle activity.

Hon J. Yu^1,2, Manaswitha Khare³, Mathew Gargus³, Marie Wencel³, Abhilasha Surampalli³, Vince Caiozzo⁴, and Virginia Kimonis^3
1Radiological Sciences, University of California, Irvine, CA, United States, ²Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, United States, ³Pediatrics, University of California, Irvine, CA, United States, ⁴Orthopaedic Surgery, University of California, Irvine, CA, United States

MRI and biophysical evaluation were performed on eight subjects consisting of control and patients with varying degrees of myopathy. Despite small sample size, the potential for quantitative MRI features based on texture analysis is demonstrated as a functional means for muscle function in comparison with dynamometer-based muscle strength measurements, which could be an invaluable tool in study of the disease progression and/or treatment intervention in both clinical and research setting.