Jennie Maria Christin Strid¹, Erik Morre Pedersen², Olga Vendelbo², Niels Dalsgaard¹, Yousef Nejatbakhsh³, Jens Randel Nyengaard⁴, Kjeld Søballe⁵, and Thomas Fichtner Bendtsen^1
1Department of Anesthesiology, Aarhus University Hospital, Aarhus C, Denmark, ²Department of Radiology, Aarhus University Hospital, Aarhus C, Denmark, ³Hospital Pharmacy, Aarhus University Hospital, Aarhus C, Denmark, ⁴Electron Microscopy Lab and Stereology, Institute of Clinical Medicine, Aarhus University, Aarhus C, Denmark, ⁵Department of Orthopedic Surgery, Aarhus University Hospital, Aarhus C, Denmark

Ultrasound guided lumbar plexus blocks holds the potential for reducing anesthesia related complications in hip surgery in the elderly punctum. The ultrasound guidance is, however, imprecise and associated with epidural spread of local anesthetic due to limited visualization. It is the overall aim of this study to improve the quality of lumbar plexus blocks using Fusion imaging between MRI and ultrasound. Here we report preliminary results of the impact of different MR scanning positions for the accuracy of fusion imaging and report on the feasibility of using gadolinium doped anesthetics for studying the distribution of local anesthetic fluid using MRI.  

Katherine Binzel¹, Robert Magnussen², Christopher Kaeding², David C Flanigan², Wenbo Wei¹, Melanie U Knopp³, and Michael V Knopp^1
1Radiology, The Ohio State University, Columbus, OH, United States, ²Sports Medicine, The Ohio State University, Columbus, OH, United States, ³Sports Medicine, Pepperdine University, Malibu, CA, United States

Evaluation of ACL graft healing by combined PET/MR imaging is readily feasible but has limited quantitative accuracy with use of conventional PET systems. The application of next generation digital photon counting in PET improves the quantitative accuracy and precision of assessment of graft metabolic activity. This advanced imaging modality also holds potential for ultra-low dose PET imaging, enhancing the clinical utility of such a combined imaging approach for detailed assessment of ACL graft viability after reconstructive surgery.

Jos Oudeman¹, Filip Eftimov², Gustav J Strijkers³, Martijn Froeling⁴, Matthan W. A. Caan¹, Ivo N. van Schaik², Mario Maas¹, Aart J Nederveen¹, Marianne de Visser², and Camiel Verhamme^2
1Radiology, Academic Medical Center, Amsterdam, Netherlands, ²Neurology, Academic Medical Center, Amsterdam, Netherlands, ³Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands, ⁴Radiology, University Medical Center, Utrecht, Utrecht, Netherlands

Diagnosing  -treatable-  inflammatory neuropathies such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) can be challenging, especially  differentiating MMN from -untreatable- focal spinal muscular atrophy (fSMA). One of the reasons is that conduction studies cannot evaluate reliably the proximal part of the brachial plexus.  Therefore we investigated DTI of the brachial plexus in patients with CIDP, MMN, fSMA and healthy controls and found  significant differences, indicating DTI might be a valuable diagnostic tool in the clinic.

Michael Dieckmeyer¹, Stefan Ruschke¹, Hendrik Kooijman², Ernst J. Rummeny¹, Jan S. Kirschke³, Thomas Baum¹, and Dimitrios C. Karampinos^1
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Philips Research Laboratory, Hamburg, Germany, ³Neuroradiology, Technische Universität München, Munich, Germany

The apparent diffusion coefficient (ADC) of vertebral bone marrow has been proposed as a useful biomarker for differentiating between benign and malignant vertebral compression fractures and could potentially be beneficial for the understanding of physiological as well as pathological bone marrow changes. In this work we exploit the spectral resolution of diffusion weighted magnetic resonance spectroscopy (DW-MRS) to exclusively quantify the ADC of the bone marrow water component and compare it to DWI based measurements. The results of two age groups are compared.

M. Kate Curtis¹, Brianna J Stubbs¹, Vicky Ball¹, Lowri E Cochlin², Mark A Cole³, Jack J Miller^1,4, David P O'Neill¹, Kieran Clarke¹, Peter A Robbins¹, and Damian J Tyler^1,5
1Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, ²PulseTeq Ltd, Surrey, United Kingdom, ³Queen's Medical Centre, University of Nottingham Medical School, Nottingham, United Kingdom, ⁴Physics, University of Oxford, Oxford, United Kingdom, ⁵Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom

Previous techniques used to determine the hierarchy of skeletal muscle metabolic fuel selection have been unable to directly describe the changes in cellular metabolic flux during exercise. The aim of this project was to develop a technique that allows the simultaneous assessment of metabolism and function in exercising skeletal muscle in real-time, in an intact mouse, using hyperpolarized [1-¹³C] pyruvate MRS. Our results demonstrate that the technique is sensitive enough to distinguish differences in metabolic flux between the resting and exercising states shown by a significant increase in ¹³C label incorporation into bicarbonate during exercise.

Elaine Yuen Phin Lee¹, Jian He², Jose Angelo Udal Perucho¹, and Queenie Chan^3
1The Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, ²Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China, People's Republic of, ³Philips Healthcare, Hong Kong, Hong Kong

Intravoxel incoherent motion (IVIM) diffusion-weighted MRI offers the unique opportunity to simultaneously study the diffusion and perfusion changes in the bone marrow following whole-pelvis radiotherapy. We prospectively studied twenty-eight patients with cervical cancer who had paired IVIM MRI examinations before and at week-4 of treatment. We observed a distinctive positive trend of D (true diffusion coefficient) in patients who suffered hematological toxicity (HT), whilst D remained relatively stable in patients who did not suffer HT. In addition, f  (perfusion fraction) increased following treatment, but this pattern was not unique to patients who suffered HT. 

Jing Li¹, Zhuoli Zhang², Yu Zhang³, Quan Zhang¹, and Fei Yuan^4
1Pingjin Hospital, Tianjin, China, People's Republic of, ²Northwestern Univerisity, Chicago, IL, United States, ³Philips Healthcare, Beijing, China, People's Republic of, ⁴MRI, PingJin Hospital, TianJin, China, People's Republic of

This study attempted to compare BOLD with conventional MRI sequences for determining the onset of osteonecrosis of the femoral head following steroid-related osteonecrosis. 112 patients who had received steroid treatment were scanned using conventional MRI and BOLD. The manifestation in BOLD-MRI is in accordance with the pathology of ONFH, which would allow early treatment of ONFH.

 

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

Associations between quantitative MRI biomarkers in the lumbar spine and pain in chronic low back pain patients (CLBP) were studied. These biomarkers are currently being explored as quantitative metrics of disc degeneration. Since most CLBP cases are associated with pathologic disc degeneration processes, these biomarkers might provide clues about the actual source of pain. For analysis, the discs from each subject were pooled from the least to the most degenerated one using a semi-quantitative metric. Results showed that these biomarkers might aid in identifying the source of pain in CLBP patients.

Masaki Katsura^1,2, Yuichi Suzuki², Akihiro Kasahara², Harushi Mori¹, Akira Kunimatsu¹, Yoshitaka Masutani³, Masaaki Hori⁴, Shigeki Aoki⁴, and Kuni Ohtomo^1
1Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, ²Radiology, The University of Tokyo Hospital, Tokyo, Japan, ³Intelligent Systems, Graduate School of Information Sciences, Hiroshima City University, Hiroshima, Japan, ⁴Radiology, School of Medicine, Juntendo University, Tokyo, Japan

We performed q-space imaging(QSI) analyses for lumbar intervertebral discs(IVDs) in patients suffering from lower back pain with different stages of degeneration. We evaluated the correlation between the quantitative QSI measurements and the qualitative grading(Pfirrmann's scale) of disc degeneration. Our results suggest that the degenerative process of IVDs involves narrowing of the space for free water movement and a generally higher degree of microstructural complexity, in which we are unable to assess with conventional quantitative MR measurements. QSI may provide sensitive biomarkers for IVD degenerative microstructural changes and can potentially become a tool to allow characterization of various IVD pathologies.

Dominik Weidlich¹, Barbara Cervantes¹, Nico Sollmann², Hendrik Kooijman³, Jan S. Kirschke⁴, Ernst J. Rummeny¹, Axel Haase⁵, and Dimitrios C. Karampinos^1
1Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Department of Neurosurgery, Technische Universität München, Munich, Germany, ³Philips Healthcare, Hamburg, Germany, ⁴Section of Neuroradiology, Technische Universität München, Munich, Germany, ⁵Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany

T2 mapping is a great candidate for quantitatively assessing inflammatory changes in peripheral nerves. However, measuring T2 of the lumbar nerve roots is challenging because of the need for high isotropic resolution and the sensitivity of the region to transmit B1 inhomogeneities. The present work proposes a T2 preparation, based on a modified BIR-4 pulse, and combined with 3D TSE imaging for B1-insensitive high-resolution isotropic T2 mapping of the lumbar plexus. The feasibility of the method is shown in five healthy volunteers and a variation of T2 along the nerve root course is observed.

Shuji Nagata¹, Hiroshi Nishimura², Kimberly K Amrami³, Kazutaka Nashiki¹, Tatsuyuki Tonan¹, Uchiyama Yusuke¹, Kiminori Fujimoto¹, and Toshi Abe^1
1Kurume University Hospital, Kurume, Japan, ²Saiseikai Futsukaichi Hospital, Chikushino, Japan, ³Mayo Clinic, Rochester, MN, United States

A high-resolution MR neurography using 3D fat suppression T2-weighted Cube combined with double inversion recovery (3D FS DIR Cube) was evaluated the feasibility of brachial plexus assessment. 15 normal volunteers were scanned 3D FS DIR Cube, 3D FS T2-weighted Cube (3D FS T2 Cube), and 2D IDEAL water on a 3T MRI scanner using a GEM NV coil. The 3D FS DIR Cube can provide excellent contrast between brachial plexus branch and surrounding tissues and increase the conspicuity of the nerves delineation with uniformed fat suppression and vessels signal suppression compared with 3D FS T2 Cube and 2D IDEAL water.

Chao-Ying Wang¹, Yu-Juei Hsu², Yi-Jen Peng³, Yi-Chih Hsu⁴, Shih-Wei Chiang^4,5, Ming-Huang Lin⁶, Hsiao-Wen Chung⁵, and Guo-Shu Huang^4,7
1Department and Institute of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ²Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ³Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ⁴Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ⁵Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ⁶Institute of BiomedicalSciences, Academic Sinica, Taipei, Taiwan, ⁷Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan

An animal study to investigate bone marrow changes in the lumbar spine by quantitative Magenetic Resonance Imaging

Miyuki Takasu¹, Yuji Akiyama¹, Chihiro Tani¹, Yoko Kaichi¹, Takayuki Tamura¹, Koichi Oshio², and Kazuo Awai^1
1Diagnostic Radiology, Hiroshima University Hospital, Hiroshima-shi, Japan, ²Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan

The purpose of this study was to quantitatively compare various diffusion parameters obtained from monoexponential, biexponential, and gamma distribution models in differentiating vertebral lesions in human subjects. All MR parameters, except for ADCfast and frac > 3, were significantly different between normal bone marrow and lesions. Water molecular diffusion parameters may provide additional information and improve the differentiation of spinal lesions compared with conventional diffusion parameters. This also refers to differentiation of malignant lesions from acute spinal fracture, in which both PG (D) calculated from gamma distribution model and perfusion fraction f of the biexponential model proved to be useful.

Marcus Raudner¹, David Stelzeneder², Claudia Kronnerwetter¹, Vladimir Juras¹, Karin Pieber³, Reinhard Windhager², and Siegfried Trattnig^1
1High Field MR Centre, 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 Physical Medicine and Rehabilitation, Medical University of Vienna, Vienna, Austria

Anatomical determination of cause for low back pain often remains impossible in the majority of patients. This study examined the diagnostic and predictive capabilities of T2 values of the lumbar intervertebral discs (IVDs). Twenty-five symptomatic patients were examined via magnetic resonance imaging (MRI) at 3T at baseline and 5-year follow-up (FU). Combining radiological reports, morphological grading, region-of-interest (ROI) analysis and patient assessment (VAS and Roland-Morris-Disability-Questionnaire), significant predictive capabilities were identified. 

Barbara Cervantes¹, Dominik Weidlich¹, Hendrik Kooijman², Ernst Rummeny¹, Axel Haase³, Jan S Kirschke⁴, and Dimitrios C Karampinos^1
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Philips Healthcare, Hamburg, Germany, ³Zentralinstitut für Medizintechnik, Garching, Germany, ⁴Neuroradiology, Technische Universität München, Munich, Germany

Diffusion weighted imaging (DWI) can describe the microstructure of nerve fibers and is therefore a powerful tool in the study of neuropathic changes. Diffusion imaging in the body faces challenges with motion and B0 and B1 field effects. Particularly, imaging of nerves has resolution requirements that can limit the performance of the acquisition method. The lumbar plexus is a particularly difficult region to image due to the complexity of the nerve geometry there and its susceptibility to motion and field inhomogeneity. Therefore, careful considerations need to be taken in the design of a diffusion-prepared sequence for imaging the lumbar plexus. The present work proposes an adiabatic diffusion preparation module in combination with a 3D TSE readout to achieve high-resolution DWI of the lumbar plexus.

Xiaodong Zhang¹, Yingjie Mei², Jiewen Yan¹, Yanjun Chen¹, Yinxia Zhao¹, and Shaolin Li^1
1Department of medical radiology, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China, People's Republic of, ²Philips Healthcare, Guangzhou, China, People's Republic of

The aim of this study is to evaluate the value of intravoxel incoherent motion (IVIM) for the differentiation between benign and malignant vertebral bone marrow lesions. The results of our study show that IVIM is potentially a promising and valuable non-invasive method in differentiating the spinal benign and malignant diseases. 

Amy Ming-Chun Tsai Sevao¹, Alistair Young¹, Benjamin Schmitt², Hament Pandya³, Karen Billington³, Anthony Doyle³, David Grodzki⁴, and Brett Cowan^5
1Anatomy with Medical Imaging, University of Auckland, Auckland, New Zealand, ²Sydney, Australia, ³Auckland, New Zealand, ⁴Erlangen, Germany, ⁵University of Auckland, Auckland, New Zealand

Post-operative spine imaging with metal implants in situ are problematic because of the significant metal artefacts, in both CT due to beam hardening, and MRI fom signal loss. Ultrashort Echo Time (UTE) MRI has potential to significantly reduce metal artefacts because of its method of acquisition. Significant differences in metal artefacts between conventional MR and UTE are found in our study, imaging sheep spine with spinal fusion hardware in situ, with importnat clinical implications.

Takayuki Sakai¹, Atsuya Watanabe^2,3, Kiichi Nose¹, Daichi Murayama¹, Shigehiro Ochi¹, Masami Yoneyama⁴, and Noriyuki Yanagawa^1
1Eastern Chiba Medical Center, Chiba, Japan, ²Chiba university graduate school of medicine, Chiba, Japan, ³Orthopaedic surgery, Eastern Chiba Medical Center, Chiba, Japan, ⁴Philips Electronics Japan, Tokyo, Japan

 

The purpose of this study was to visualize the lumbar nerve roots and to measure their FA values in healthy volunteers and in patients with neurological symptom of leg by using TSE-DTI.   Tractography of the patients with symptomatic side of lumbar nerve roots indicated abnormalities such as narrowing, deformation, and disruption. The FA values of the symptomatic side of lumbar nerve roots were significantly lower than those of the asymptomatic side.   TSE-DTI might more accurately evaluate compressed lumbar nerve roots compared to conventional EPI-DTI. Additionally, tractography of TSE-DTI enables visualization of abnormal nerve tracts and has a lower geometric distortion for diagnosing lumbar nerve compression than EPI-DTI.

Stefan Ruschke¹, Amber Pokorney², Holger Eggers³, Jan S. Kirschke⁴, Thomas Baum⁵, Dimitrios C. Karampinos¹, and Houchun Harry Hu^2
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Radiology, Phoenix Children's Hospital, Phoenix, AZ, United States, ³Philips Research, Hamburg, Germany, ⁴Section of Diagnostic and Interventional Neuroradiology, Technische Universität München, Munich, Germany, ⁵Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany

In this work, we describe our preliminary clinical experience using a previously reported time-interleaved six-echo gradient-echo (TIMGRE) acquisition for water-fat chemical-shift encoded MRI.  The acquisition scheme involved two interleaves that acquired three echoes each with fly-back gradients.  The pulse sequence was used to quantify vertebral bone marrow fat fraction in a pilot cohort of 12 pediatric patients  (age range: 1-13 years) at 3T with 1.2-1.6 mm in-plane resolution and 1.2-3 mm slices. The knowledge on bone marrow fat fraction may provide insight into adverse effects on bone health later in life, given that there is clinical relevance of vertebral osteoporotic fractures in adults.  

Hongyue Tao¹, Yong Zhang², Yang Qiao¹, Ziying Wu³, Kui Ma³, Yinghui Hua³, and Shuang Chen^1
1Radiology, Huashan Hospital, Fudan University, Shanghai, China, People's Republic of, ²GE Healthcare, MR Research China, Shanghai, China, People's Republic of, ³Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China, People's Republic of

This preliminary study used UTE-T2*, a novel quantitative technique with potential short-T2* relaxations that are not well captured by standard T2 mapping, to investigate T2* value in Achilles tendon (AT) after tendon allograft reconstruction (AT-R) and analyze the correlation between T2* value and AOFAS score. Six patients with AT-R and 6 sex, age, and BMI matched healthy controls were recruited for comparison. The results showed T2* values of middle (MID) and muscle-tendon junction (MTJ) regions in AT-R patients were statistically lower compared with the matched regions of controls and T2* value of MID region was negatively correlated with AOFAS score, which suggest T2* may be a promising marker for the detection of matrix changes in AT after AT-R. 

Bimin Chen^1,2, Erik Dorthe³, Michael Carl⁴, Hongda Shao¹, Yajun Ma¹, Darryl D'Dlima³, Graeme M Bydder¹, and Jiang Du^1
1Radiology Department, UCSD, San Diego, CA, United States, ²Radiology Department, The first affiliated hospital of Jinan University, Guangzhou, China, People's Republic of, ³The Scripps Research Institute, San Diego, CA, United States, ⁴GE Healthcare, san diego, CA, United States

Entheses are sites where tendons, ligaments, and joint capsules attach to bone. They may be fibrous or fibrocartilaginous. Entheses are adapted at both the macroscopic and the microscopic level to distribute stress over a wide area or volume. Entheses are very commonly involved in many diseases and the primary target of disease in the seronegative spondyloarthropathies .we aim to study the MR properties of cadaveric Achilles tendon enthesis using ultrashort echo time (UTE) sequences and correlate them with biomechanics.

Noriyuki Tawara^1,2, Kanokvalee Ponkanist², Shuichi Shiratori², Anchali Krisanachinda², and Toru Yamamoto^1
1Faculty of Health Sciences, Hokkaido University, Sapporo, Japan, ²Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand

It has been reported that T₁ in skeletal muscles is proportional to the percentage of type?fibers which would be a determinant for athletic performance. However, the precision of the measured T₁ values is unclear due to various pulse sequences used for the measurement. In this study, we evaluated the reliability of T₁ measured by pulse sequences with inversion recovery technique that is believed to be most accurate in T₁ measurement. A value of goodness of fitting was employed for the quantitative evaluation of the obtained data. The influence of SNR on the T₁ measurement was also examined.

Ah Rhm Woo¹, Yeo Ju Kim¹, Mi Young Kim¹, Jang Gyu Cha², Michael Carl³, Sangwoo Lee⁴, Moonjung Hwang⁴, and Dong Eun Kim^4
1Department of radiology, Inha University Hospital, Incheon, Korea, Republic of, ²Department of radiology, Soonchunhyang University Hospital, Bucheon, Korea, Republic of, ³GE Healthcare, San Diego, CA, United States, ⁴GE Healthcare, Seoul, Korea, Republic of

We evaluated the ability of depiction of deep fascia, epimysium and periosteum in 3 dimensional Ultrashort Echo Time MR Imaging (3D UTE) with histologic correlation in porcine model. In our study, the 3D UTE might depict deep fascia and periosteum as high signal intensities whereas the ability of visualization of epimysium was uncertain and high signal intensity of artifact remains in naked cortex without periosteum.

S Sivaram Kaushik¹, Abhishiek Sharma², Rajeev Mannem¹, Cathy Marszalkowski¹, Scott Rand¹, Dennis Maiman², and Kevin M Koch^1
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, ²Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States

Failed back surgery syndrome (FBSS) is a commonly encountered clinical condition for which the root cause often remains elusive after lengthy clinical assessment. While MRI provides great potential utility for uncovering the causes of failed back surgery syndrome, it also is confounded by metal-induced artifacts. This study explores the benefits of a prospectively calibrated 3D-MSI metal artifact reduction technique in assessing instrumented FBSS. Residual artifacts and clinical diagnostic impact were assessed on a cohort of symptomatic FBSS subjects.  The results of the study indicate diagnostic advantages using calibrated 3D-MSI, even in the presence of lower-susceptibility titanium spinal hardware.

Rianne A van der Heijden^1,2, Dirk HJ Poot^1,3,4, Melek Ekinci², Esther E Bron^1,4, Jasper van Tiel^1,5, Stefan Klein^1,4, Peter LJ van Veldhoven⁶, Gabriel P Krestin¹, Jan AN Verhaar⁵, Sita MA Bierma-Zeinstra^2,5, Marienke van Middelkoop², and Edwin HG Oei^1
1Radiology, Erasmus University Medical Center, Rotterdam, Netherlands, ²General Practice, Erasmus University Medical Center, Rotterdam, Netherlands, ³Imaging Science and Technology, Delft University of Technology, Delft, Netherlands, ⁴Medical informatics, Erasmus University Medical Center, Rotterdam, Netherlands, ⁵Orthopedics, Erasmus University Medical Center, Rotterdam, Netherlands, ⁶Sports medicine, MC Haaglanden, Leidschendam, Netherlands

Diminished patellofemoral cartilage composition and vascular problems are potential pathogenic mechanisms in patellofemoral pain (PFP). These mechanisms can be studied in depth using advanced MRI techniques. We are the first to successfully apply a wide range of quantitative MRI techniques for cartilage composition and bone blood perfusion in a case-control study on PFP. The results show no significant differences in patellofemoral cartilage composition and patellar bone blood perfusion between PFP patients and healthy controls.

James MacKay¹, Samantha Low¹, Philip Murray¹, Bahman Kasmai¹, Glyn Johnson², Simon Donell^2,3, and Andoni Toms^1,2
1Radiology, Norfolk & Norwich University Hospital, Norwich, United Kingdom, ²Norwich Medical School, University of East Anglia, Norwich, United Kingdom, ³Trauma & Orthopaedics, Norfolk & Norwich University Hospital, Norwich, United Kingdom

Subchondral bone (SB) plays an important role in osteoarthritis (OA). Texture analysis (TA) is a method of quantifying changes in SB and may be a useful OA biomarker. The optimum MR method to allow TA of SB is unclear. We compared TA using two sequences which demonstrated promise in depicting SB structure in three groups of participants: normal controls (n=10), individuals with early OA (n=10) and individuals with advanced OA (n=10). TA using a 2D T1-weighted spin echo sequence demonstrated more significant differences in texture features between groups and improved classification accuracy compared to a 3D gradient echo sequence.

Hongda Shao¹, Soorena Azam ZAnganeh¹, Eric Chang¹, Graeme Bydder¹, and Jiang Du^1
1Radiology, University of California, San Diego, San Diego, CA, United States

Articular cartilage is a highly ordered tissue with an organized layered structure that can be functionally and structurally divided into the superficial, transitional, radial and the calcified cartilage. By exploiting intrinsic magnetic resonance (MR) properties of cartilage, current techniques allow for the non-invasive assessment of many of the structural components. More recently, ultrashort echo time (UTE) imaging sequences have been used to investigate the T2* relaxation times of bound and free water components in different layers of articular cartilage. However, the depth dependence of longitudinal relaxation times, or T1s are still unknown. In this study we aim to study the T1s of bound and free water in different layers of patella cartilage using UTE imaging sequences on a clinical 3T scanner.

Gerd Melkus^1,2, Helen Anwander³, Kawan S Rakhra^1,2, and Paul E Beaulé^3,4
1Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, ²Radiology, University of Ottawa, Ottawa, ON, Canada, ³Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada, ⁴Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada

In this study we systematically investigated the analysis of hip cartilage T1ρ images in healthy as well as asymptomatic and symptomatic subjects with cam deformities. Hips with cam-type deformity showed a significant T1ρ prolongation compared to the healthy subjects indicating loss of proteoglycan in the lateral third of the anterosuperior quadrant. A significant correlation between entire hip cartilage T1ρ values and WOMAC subscore pain was found. The study shows that in the presence of a cam deformity, T1ρ has the ability to detect proteoglycan depletion, the earliest stage of cartilage degeneration, even before to symptoms occur.

Patrick Omoumi¹, Tom Hilbert^1,2,3, Marion Roux¹, Jean-Baptiste Ledoux¹, Ruud B Van Heeswijk¹, Reto Meuli¹, and Tobias Kober^1,2,3
1Radiology, Lausanne University Hospital, Lausanne, Switzerland, ²Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, ³LTS5, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

A fast quantitative T2 mapping technique that additionally provides synthetic images for morphological assessment was validated by two experienced radiologists regarding (1) the T2 values through a phantom experiment and (2) the image quality through a quantitative and qualitative assessment for the knee joint in five healthy volunteers. 

Roberto Colotti¹, Patrick Omoumi¹, and Ruud B. van Heeswijk^1
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland

An isotropic three-dimensional T₂ mapping technique with adiabatic T₂ magnetization preparation for T₂ relaxation time quantification was implemented and validated at 3T in phantoms and 6 healthy volunteers.

Angéline Nemeth¹, Lucy Di Marco², Denis Grenier¹, Michaël Sdika¹, Olivier Beuf¹, and Jean-Baptiste Pialat^3
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Lyon, France, ²Radiologie et Imagerie médicale diagnostique et thérapeutique, Hôpital François Mitterrand, Dijon, France, ³Radiologie Pavillon B, Hôpital Edouard Herriot, Hospices Civils de Lyon, INSERM U1033 and Université Lyon 1, Lyon, France

To detect early changes in cartilage, quantification methods were developed with Magnetic Resonance Imaging. T1rho sequence is a valuable tool to quantitatively access the proteoglycans content, complementary to T2 mapping technique that is correlated with the collagen content. The thin cartilage thickness and deep location of the hip joint require a strong compromise between SNR, pixel size and acquisition time. The aim of this study is to test the repeatability and reproducibility of in vivo (magnetic resonance) T1rho and T2 relaxation times measures in the hip joint cartilage of thirty healthy asymptomatic volunteers. 

Razmara Nizak¹, Joris Bekkers¹, Pim de Jong², and Daniel Saris^1
1Orthopedics, UMC Utrecht, Utrecht, Netherlands, ²Radiology, UMC Utrecht, Utrecht, Netherlands

Autologous subchondral bone grafting combined with ACI (sandwich procedure) is a well-accepted procedure for the treatment of osteochondral lesions of the knee. This requires a different surgical technique and preoperative planning. Also pain from bone marrow donor site location is expected and should be part of patient consent and expectations. This study evaluates whether MRI is able to predict the need for a sandwich procedure to help in optimizing the preoperative planning and consent.

Oliver Kraff¹, Andrea Lazik-Palm^1,2, Rahel Heule^3,4, Oliver Bieri^3,4, and Harald H Quick^1,5
1Erwin L. Hahn Institute for MRI, University Duisburg-Essen, Essen, Germany, ²Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, University Hospital, Essen, Germany, ³Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland, ⁴Department of Biomedical Engineering, University of Basel, Basel, Switzerland, ⁵High Field and Hybrid MR Imaging, University Duisburg-Essen, University Hospital, Essen, Germany

Purpose was the assessment of TESS T2 relaxometry in comparison to standard CPMG as a potential candidate to improve workflow in quantitative hip MRI protocols at 7T. A total of 8 healthy volunteers were included. T2 relaxation times were measured by manually drawing regions of interest in both acetabular and femoral cartilage in multiple regions of the hip joint. Compared to CPMG, TESS provides systematically reduced T2 values in both hip cartilage layers, in line with previously reported values. Nevertheless, with a 5-fold increase in spatial coverage TESS seems to be a good candidate to improve hip protocols at 7T.

Joshua Kaggie¹, Scott Reid², Gavin Houston², Kevin F King³, Ferdia Gallagher¹, and Martin Graves^1
1Radiology, University of Cambridge, Cambridge, United Kingdom, ²GE Healthcare, Amersham, United Kingdom, ³GE Healthcare, Milwaukee, WI, United States

R1ρ, R2, and R2* imaging have been considered as biomarkers of degenerative cartilage diseases.  In order to ensure the reliability of these measurements, we acquired data in eight subjects twice and compared measurements of variability.  R1ρ-measurements had lower variability (CVRMS=21%) and a higher correlation to age (r2-value=0.566) when compared to R2 (r2-value=0.183; CVRMS=25%) and R2* (r2-value=0.092; CVRMS=38%).  These measurements suggest that R1ρ is a more sensitive biomarker than R2 or R2*.

Qun He^1,2, Jihye Baek¹, Daryl D'Lima¹, Jiang Du¹, Nikolaus M. Szeverenyi¹, and Graeme Bydder^1
1University of California, San Diego, San Diego, CA, United States, ²Ningbo Jansen NMR Technology Co., Ltd., Cixi, Zhejiang, China, People's Republic of

In vitro high resolution diffusion weighted imaging of the meniscus of the knee at 11.7T shows detailed structure of fiber groups that has not previously be seen with MRI. There were clearly differentiated from cartilaginous areas of the meniscus. The diffusion contrast adds to that which results from the magic angle effect. This acts as a T₂ filter. The diffusion contrast has more flexibility than magic angle contrast since it is not dependent on B₀ and in principle any diffusion direction can be used. The results may be translatable to high field clinical systems.

Benedikt Hager^1,2,3, Sonja Walzer³, Matthew DiFranco⁴, Vladimir Juras^1,5, Vladimir Mlynarik^1,2, Markus Schreiner³, Martin Zalaudek¹, Stefan Domayer³, Esau Poblador Rodriguez¹, Andreas Berg⁴, Reinhard Windhager³, and Siegfried Trattnig^1,2
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, ³Department of Orthopaedic Surgery, Medical University of Vienna, Vienna, Austria, ⁴Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, ⁵Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

The purpose of this study was to examine whether gagCEST imaging reflects the histopathological changes concerning glycosaminoglycan in human meniscus in vitro.  All MRI acquisitions were performed on 7T MRI with a microimaging system.  Histological staining using safranin-O was performed for correlation to imaging findings. Qualitatively, the gagCEST map and the corresponding safranin-O image show the same relative regional intensity of glycosaminoglycans. In sum, gagCEST imaging in a 7T microimaging system allows a very detailed look into the glycosaminoglycan distribution in the human meniscus.

 

 

Michael Carl¹, Yajun Ma², Graeme M Bydder², and Jiang Du^2
1Global MR Applications & Workflow, General Electric, San Diego, CA, United States, ²University of California San Diego, San Diego, CA, United States

In this work, we used a stimulated echo prepared diffusion 3DUTE sequence to image the posterior cruciate ligament. Volunteer scans in the knee were performed. We found that stimulated echo based diffusion weighted 3DUTE MR imaging can be used effectively to achieve useful b-values in short T2 MSK tissues. This initial proof-of-principle study shows good quantitative agreement with clinical EPI diffusion sequences.

Lawrence L Buchan^1,2, Honglin Zhang^1,2, Mark Harmon³, Elaine Ni Mhurchu³, Morgan Barber⁴, Shannon Jennifer Patterson⁵, Jacek Kopec⁴, Hubert Wong⁶, John Esdaile⁴, Jolanda Cibere⁴, Charles R Ratzlaff⁴, Bruce B Forster³, and David R Wilson^1
1Orthopaedics, University of British Columbia, Vancouver, BC, Canada, ²Centre for Hip Health and Mobility, Vancouver, BC, Canada, ³Radiology, University of British Columbia, Vancouver, BC, Canada,⁴Arthritis Research Canada, Richmond, BC, Canada, ⁵Vancouver Coastal Health, Vancouver, BC, Canada, ⁶University of British Columbia, Vancouver, BC, Canada

In this study, we describe a novel open MRI method for evaluating femoroacetabular impingement (FAI) in subjects with and without symptomatic FAI. First, we acquired images of subjects in postures suspected of inducing impingement using a T1-weighted gradient echo MR sequence. Second, readers measured β-angle to quantify clearance between the femur and acetabulum. Reader agreement for β-angle was equivalent or better to agreement when measuring α-angle, a similar structural measure. The open MRI method has the potential to assess functional relationships between the femur and acetabulum that otherwise cannot be assessed with closed-bore MRI scanners and conventional imaging protocols. This approach may be useful in addressing fundamental questions in FAI.

Akshay S Chaudhari^1,2, Bragi Sveinsson^1,3, Marcus T Alley¹, Emily J McWalter¹, Garry E Gold^1,2, and Brian A Hargreaves^1,2,3
1Radiology, Stanford University, Stanford, CA, United States, ²Bioengineering, Stanford University, Stanford, CA, United States, ³Electrical Engineering, Stanford University, Stanford, CA, United States

Quantitative MR imaging has the potential to provide information regarding the biochemical state of tissues and to track biochemical changes before the onset of morphological changes. However, with current MRI techniques, it is challenging to obtain signal from tissues with short-T₂ relaxation times in the knee, let alone to perform quantitative imaging on them. Ultrashort echo-time double-echo in steady state (UTEDESS) is a pulse sequence that offers echo times of 50μs, and high resolution imaging with high SNR efficiencies. In this study, UTEDESS was also used to measure T₂ relaxation times of the menisci, tendons, and ligaments in human knees. 

Benedikt Hager^1,2,3, Sonja Walzer², Vladimir Juras^1,4, Andreas Berg⁵, Matthew DiFranco⁵, Vladimir Mlynarik^1,3, Markus Schreiner², Martin Zalaudek¹, Stefan Domayer², Joachim Friske¹, Reinhard Windhager², and Siegfried Trattnig^1,3
1High Field MR Centre, Department of Biomedical Imgaing and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Orthopaedic Surgery, Medical University of Vienna, Vienna, Austria, ³Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, ⁴Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Vienna, Austria, ⁵Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria

In this study, T₂* maps of degenerated meniscal specimens were obtained using MRI on an ultra-high field scanner in combination with an MR microscopy insert and these images were compared to histological findings.  The results showed that all five investigated menisci specimens had very similar morphological appearance when comparing histological images, T₂* weighted images and T₂* maps. 

Kenneth Wengler^1,2, Mingqian Huang ², Elaine Gould², Mark Schweitzer², Seth Korbin³, James Paci³, and Xiang He^2
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, ²Radiology, Stony Brook University School of Medicine, Stony Brook, NY, United States, ³Orthopaedic Surgery, Stony Brook University School of Medicine, Stony Brook, NY, United States

3D-UTE imaging was utilized to estimate the fast T₂* component of ACL after graft repair surgery. The average fast T₂* component in the grafted ACL 3 months post-surgery for eight subjects is 1.66 +/- 0.4 ms. Two subjects currently have both 3 and 6 month post-surgery images. The ACL average fast T₂* component went from 2.55ms to 1.81ms at three and six months post-surgery respectively for the first subject, and 1.39ms to 1.24ms for the second subject. The results demonstrate promise for 3D-UTE T₂* mapping of bound water to evaluate ACL repair.

Arttu Peuna^1,2,3, Joonas Hekkala^1,3, Marianne Haapea^1,2, Jana Podlipska^1,3, Simo Saarakkala^1,2,3, Miika T Nieminen^1,2,3, and Eveliina Lammentausta^1,2
1Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, ²Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ³Research group of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland

Texture analysis methods based on gray level co-occurrence matrices can be optimized to probe the spatial information from knee MR T2 maps and of the changes caused by osteoarthritis. Curvature of the cartilage surfaces and relatively low resolution in relation to cartilage thickness set special requirements for texture analysis tools. Here we report an optimized analysis tool with customized point-wise offset angle and endpoint extrapolation for cartilage texture analysis. Method provides excellent performance compared to traditional texture analysis implementation.

Yanqiu Lv¹, Hua Cheng¹, Ningning Zhang¹, Kaining Shi², Guangheng Yin¹, Di Hu¹, Huiying Kang¹, Xiaojuan Tao¹, Feng Guan¹, Yang Wen¹, and Yun Peng^1
1Beijing Children's Hospital Affiliated To Capital Medical University, Beijing, China, People's Republic of, ²Imaging systems Clinical Science,Philips Healthcare, Beijing, China, People's Republic of

Comparing the performance of 3D T1W-WATS sequence with 2D T2*W FFE sequence in the evaluation of cartilage damage in Pediatric hemophilia joints. 16 hemophiliac joints including 8 knees and 8 ankles were scanned on a 3.0 T, signal to noise of Cartilage, relative contrast between cartilage and surrounding tissue and the impact of hemosiderin were employed to compare.Our result showed that 3D T1W-WATS sequence had better relative contrast between cartilage and surrounding tissues and the immunity to hemosiderin compared with 2D T2*W sequence.3DT1W-WATS sequence can be performed in the evaluation of cartilage damage in hemophilia patients.

Alireza Akbari^1,2 and Michael Noseworthy^1,2,3
1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, ²Imaging Research Centre, St Joseph's Healthcare, Hamilton, ON, Canada, ³Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada

We assessed articular cartilage sodium MR image SNR and blurring as a function of acquisition window length.  Increasing the acquisition window dramatically improved the SNR with minimal reduction in image quality as shown by minimal blurring.

Forrest Howell¹, Haonan Wang¹, Daniel Park², Meredith Taylor¹, Bragi Sveinsson³, and Neal Bangerter^1
1Electrical Engineering, Brigham Young University, Provo, UT, United States, ²Biomedical Imaging, Electrical Engineering, University of Oxford, Oxford, United Kingdom, ³Radioligy, Stanford University, Palo Alto, CA, United States

A modification of the dual-echo steady state (DESS) pulse sequence was recently proposed that allows the extraction of both T2 and apparent diffusion coefficient (ADC) maps from a pair of DESS acquisitions (termed quantitative DESS, or qDESS).  A careful validation of the accuracy of the qDESS T2 and ADC estimates has not yet been performed.   The qDESS sequence produces accurate, high-resolution ADC and T2 maps.  This is especially notable at 7T, where transmit B1 inhomogeneity makes it very difficult to produce reasonable T2 maps using typical multi-echo spin echo techniques.  The qDESS technique shows great promise in providing both high-resolution morphological data and maps of T2 and ADC at 3 and 7 Tesla.

Uran Ferizi¹, Ignacio Rossi², Christian Glaser³, Jenny Bencardino¹, and Jose Raya^1
1Department of Radiology, New York University School of Medicine, New York, NY, United States, ²Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, United States, ³Radiologisches Zentrum München-Pasing, Munich, Germany

The current DTI model has shown promise in capturing the early trends of change in cartilage. However, the model is very sensitive to the noise in the signal, hence blurring the contrast in the the anisotropy maps. Here we propose a simplification of the 6-parameter model to a 4-parameter one, called the "Zeppelin". The biophysical description that the Zeppelin makes remains the same and, additionally, provides fits that are more stable and provide better constrast. We also propose a new and simple 4-parameter multicompartment model (which is already known in neuroimaging). This provides an even more robust model fitting to the data, producing parameters that are analogous to those of Zeppelin, and promising more specificity to the early changes that occur in cartilage.

Ji Hyun Lee^1,2, Farid Badar^1,2, John Matyas³, and Yang Xia^1,2
1Physics, Oakland University, Rochester, MI, United States, ²Center for Biomedial Research, Oakland University, Rochester, MI, United States, ³Univeristy of Calgary, Calgary, AB, Canada

This study aims to quantify the loading-modified T1 in articular cartilage using a canine model of early osteoarthritis (OA) at different degradation stages, at a 17.6µm resolution and with the use of Gd contrast agent. Both lesion and mechanical compression were found to alter T1 in cartilage at each sub-tissue zone and topographically, which provide a better understanding of the MRI properties of cartilage during joint loading. This result could help to design effective protocols in clinical MRI to better detect and manage the osteoarthritic diseases.

Matthew F. Koff¹, Hollis G. Potter¹, Sonja Eagle¹, Scott Rodeo², Kimberly Amrami³, Aaron Krych³, Xiaojuan Li⁴, and Sharmilla Majumdar^4
1Department of Radiology and Imaging - MRI, Hospital for Special Surgery, New York, NY, United States, ²Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY, United States,³Mayo Clinic, Rochester, MN, United States, ⁴University of California San Francisco, San Francisco, CA, United States

this is a synopsis

Vadim Malis¹, Usha Sinha², Robert Csapo³, and Shantanu Sinha^3
1Physics, University of California at San Diego, San Diego, CA, United States, ²Physics, San Diego State University, San Diego, CA, United States, ³Radiology, University of California at San Diego, San Diego, CA, United States

Unilateral limb suspension is a controlled method to generate acute atrophy. The loss of muscle force with acute atrophy may be due to changes in contractile elements and extracellular matrix (ECM); a study of the strain rate (SR) patterns could provide information on these changes.  Subjects were assessed at baseline (pre-ULLS) and post-ULLS using dynamic velocity encoded phase contrast MR imaging. The indices extracted from the SR tensor show at post-ULLS (i) a decrease in the asymmetry of deformation in the fiber cross-section and (ii) larger SR-muscle fiber angles. These findings may reflect a loss of integrity in the ECM.

Usha Sinha¹, Vadim Malis², Robert Csapo³, and Shantanu Sinha^3
1Physics, San Diego State University, San Diego, CA, United States, ²Physics, University of California at San Diego, San Diego, CA, United States, ³Radiology, University of California at San Diego, San Diego, CA, United States

In-vivo studies of muscle function under different motion paradigms can elucidate the physiology of acute atrophy. This study maps the 2D strain rate tensor in subjects performing eccentric contractions before and after Unilateral Limb Suspension induced acute atrophy. As expected, strain rate values are smaller during eccentric compared to isometric contractions, since in the eccentric mode, muscle contraction occurs under lengthening conditions resulting in a net smaller local elongation. Changes of SR indices with atrophy are negligible possibly due to a balance of force loss from atrophy and greater force generation from a potentially stiffer matrix.

Alfredo Liubomir Lopez Kolkovsky^1,2, Benjamin Marty^1,2, Eric Giacomini¹, and Pierre G Carlier^1,2
1NMR Laboratory, Institut of Myology, Paris, France, ²NMR Laboratory, CEA/DSV/I2BM/MIRCen, Fontenay-aux-Roses, France

NMR allows to investigate multiple aspects of physiological parameters like regional perfusion, blood and tissue oxygenation, intracellular pH or high-energy phosphate metabolism. In the past, interleaved multiparametric multinuclear dynamic NMR imaging and spectroscopy of skeletal muscle was developed on prototype scanners. Here we evaluated an interleaved pulse sequence combining the NMR acquisition of a ¹H image and ³¹P spectrum on a clinical system without any hardware modifications from the customer. Having the possibility to run interleaved multinuclear sequences on unmodified clinical systems will greatly facilitate simultaneous measurements of tissue perfusion, oxygen content and mitochondrial ATP production in clinical research studies.

Elisabeth Klupp¹, Dominik Weidlich², Thomas Baum², Barbara Cervantes², Marcus Deschauer³, Hendrik Kooijman⁴, Ernst J. Rummeny², Claus Zimmer¹, Jan S. Kirschke¹, and Dimitrios C. Karampinos^2
1Neuroradiology, Technische Universität München, München, Germany, ²Radiology, Technische Universität München, München, Germany, ³Neurology, Technische Universität München, München, Germany, ⁴Philips Healthcare, Hamburg, Germany

There is a growing interest for applying T2 mapping for non-invasively tracking inflammatory changes in patients with neuromuscular diseases. T2 has been traditionally quantified using multi-echo spin-echo (MESE) sequences with known problems related to the refocusing pulses in presence of B1-inhomogeneity and slice profiles effects. The present work proposes the combination of an adiabatic T2-preparation with 3D TSE for B1-insenstive T2 mapping. The proposed method is compared with 2D-MESE and 3D-MESE, in terms of reproducibility on T2 quantification and sensitivity to B1 effects, in the thigh musculature of ten healthy subjects.

Prodromos Parasoglou¹, Tiejun Zhao², Oleksandr Khegai¹, Xuejiao Che¹, and Jill M Slade^3
1Department of Radiology, New York University School of Medicine, New York, NY, United States, ²Siemens Medical Solutions USA, Siemens Healthcare, New York, NY, United States, ³Department of Radiology, Michigan State University, East Lansing, MI, United States

Microvascular function in the skeletal muscle can be assessed through blood oxygenation level dependent (BOLD) MRI signal changes after performing a brief exercise or following a period of induced ischemia. Such BOLD related relaxation changes are mainly attributed to intravascular mechanisms, such as changes in the hemoglobin content and oxygen saturation levels. In this work, we developed and implemented a rapid echo-planar imaging (EPI) method to map T₂* changes, following a single maximum voluntary contraction on a 3 T whole body clinical scanner.

Alexandra Grimm^1,2, Heiko Meyer², Mathias Nittka², Esther Raithel², Andreas Friedberger¹, Marc Teschler¹, Michael Uder³, Wolfgang Kemmler¹, Klaus Engelke¹, and Harald H. Quick^1,4
1Institute of Medical Physics, Erlangen, Germany, ²Product Definition & Innovation, Siemens Healthcare GmbH, Erlangen, Germany, ³Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, ⁴Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany

Sarcopenia describes muscle degeneration. In particular with increasing age, muscle tissue is replaced by fatty infiltrations. We developed an MRI sequence protocol (T₁w TSE, PDw SPACE, PDw TSE Dixon, q-Dixon, and HISTO) for quantifying this degradation and applied it twice to 54 patients suffering from sarcopenia. Between both measurements three months of whole body electromyostimulation (EMS) training were performed. Initial results show that image data can be used for muscle segmentation and determination of muscle volumes, fat fractions, and fat distribution within the muscles. Muscle fat fractions correlate with muscle strength. In spectroscopy accurate voxel repositioning is challenging.

Jie Zheng¹, David Muccigrosso¹, Xiaodong Zhang², Hongyu An¹, Andrew R Coggan¹, Charles F Hildebolt¹, Chandu Vemuri³, Patrick Geraghty³, Mary K Hastings⁴, and Michael J Mueller^4
1Radiology, Washington University in St. Louis, St. Louis, MO, United States, ²Radiology, Peking University First Hospital, Beijing, China, People's Republic of, ³Surgery, Washington University in St. Louis, St. Louis, MO, United States, ⁴The Program in Physical Therapy, Washington University in St. Louis, St. Louis, MO, United States

     The objective of this study was to develop a non-contrast MRI based oximetry approach to assess the skeletal muscle microcirculation in diabetic and healthy feet. In both healthy and subjects with diabetes, the feasibility of the foot oximetry was examined when the subjects were at rest and during a toe-flexion isometric exercise. The percent difference in the areas of the oxygen extraction fraction within the 0.7 – 1.0 range between rest and exercise was significantly different between healthy subjects and subjects with diabetes. This is the first MRI foot oximetry developed for assessing regional skeletal muscle oxygenation.

Ping Wang^1,2, Henry Zhu^1,2, Hakmook Kang³, and John C. Gore^1,2
1Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, ²Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ³Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States

Simultaneous acquisitions of sodium concentrations and T_1ρ in muscles from different aged individuals show that sodium values increase with age and are accompanied by increases in the dispersion of spin-lock relaxation rates (i.e. the difference in R_1ρ = 1/T_1ρ at low and high locking frequencies).  A previous study has suggested that such differences in R_1ρ at different fields reflects the contribution of chemical exchange to relaxation, which is known to dominate transverse relaxation at high fields, and potentially reflects GAG concentration in cartilage.  In this study, we found ΔR_1ρ in muscle was smaller than in cartilage at 3T but was measureable and showed a strong correlation with sodium content in muscle.  The increase in sodium with age possibly corresponds to the loss of muscle mass and increase in extracellular volume within a voxel, but this appears to be accompanied by an increase in exchangeable protons as well.

Benjamin Gilles¹, Charles de Bourguignon², Pierre Croisille³, Grégoire Millet⁴, Magalie Viallon³, and Olivier Beuf^5
1LIRMM; CNRS (UMR 5506) Université de Montpellier, Montpellier, France, ²Radiology Dept, CHU de Saint Etienne, Saint Etienne, France, ³CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Saint Etienne, France, ⁴Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland, ⁵CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Villeurbanne, France

Acute loss of skeletal muscle mass is a common feature of several pathologies such as stroke, cancer, chronic obstructive pulmonary disease. Having a none invasive method to accurately quantify muscle mass is of crucial interest to follow procedure that could prevent muscle wasting and restore physical capacity, mobility and optimize motor recovery. The aim of the current study is to propose an automatic segmentation technique to quantify muscle mass. The automatic segmentation of 3D quadriceps volumes was performed using a deformable registration technique applied to  3D isotropic in-phase (IN), out-phase (OUT), and calculated fat (F) and water (W) images obtained using a double-echo gradient echo Dixon coronal acquisition in order to test the best contrast channel for segmentation. The method was tested in a longitudinal study in athletes enrolled for the most extreme mountain ultra-marathon (The Tor des Géants, Courmayeur, Italy: +24000 positive elevation, 330km). 51 athletes were scans at departure, 27 finishers at the arrival and 2 days after recovery, leading to 105 datasets that were segmented in total. The best automatic segmentation accuracy was obtained when using the calculated Water image (DSC=0,946). 

Benjamin Leporq^1,2, Arnaud Le Troter³, Yann Le fur³, Emmanuelle Salort-Campana⁴, Maxime Guye³, Olivier Beuf², and David Bendahan^3,5
1Center of Research on inflammation; Inserm U1149, Université Paris Diderot, Paris, France, ²CREATIS CNRS UMR 5220; Inserm U1044, Université de Lyon, Villeurbanne, France, ³CRMBM; CNRS UMR 7339, Aix-Marseille University, Marseille, France, ⁴Genetique Médicale et Génomique Fonctionelle; Inserm UMR S_910, Aix Marseille University, Marseille, France, ⁵CEMEREM, Hopital de la Timone, Pôle d’imagerie médicale, AP-HM, Marseille, France

We have developed a dedicated algorithm allowing to quantify, from a single MR acquisition fat and muscle fractions together with magnetic susceptibility and transverse relaxation time (T2*). This approach was linked to a dedicated segmentation algorithm allowing to quantify specific indices which could be of interest for the assessment of disease severity and progression. Our results showed the feasibility of quantitative susceptibility mapping (QSM) in thigh muscles and demonstrated that its implementation into the fat-water separation reconstruction pipeline is possible. For dystrophies assessment, magnetic susceptibility-related information might provide a useful supplementary materials in comparison to relaxometry and fat fraction measurements.

Qing Lu¹, Shiteng Suo¹, Hui Tang¹, Jianxun Qu², Yong Zhang², and Jianrong Xu^1
1Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, People's Republic of, ²GE Healthcare China, Shanghai, China, People's Republic of

Arterial spin labeling (ASL) and intravoxel incoherent motion (IVIM) are both noninvasive MRI techniques that offer quantitative perfusion measurements. The current study showed that the ASL perfusion decreased while the IVIM vascular volume fraction increased compared to baseline under cuff compression paradigm in the lower extremity muscle, indicating that the two MRI techniques based on two completely distinct mechanisms provide complementary tissue perfusion characteristics.

Linda Heskamp¹, Marlies van Nimwegen², Barbara Janssen¹, Baziel van Engelen², and Arend Heerschap^1
1Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, ²Department of Neurology, Radboud university medical center, Nijmegen, Netherlands

We used quantitative MR to evaluate the extent of fatty infiltration and edema-like processes in muscles of patients with Myotonic Dystrophy type 1 (DM1). Fat fractions were obtained using a DIXON method and the T2 of muscle water (T2_water) was calculated using a bi-component extended phase graph model. The results show that fatty infiltration in DM1 is a slow gradual process whereby the distal part of the muscle is more heavily fat infiltrated than the proximal part. In addition, muscles that are in an active process of fatty infiltration have an elevated T2_water, possibly from reactive edema. 

Meredith Taylor¹, Haonan Wang¹, Antony JR Palmer², Andrew J Carr², Sion Glyn-Jones², Daniel Park², and Neal K Bangerter^1
1Electrical Engineering, Brigham Young University, Provo, UT, United States, ²Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom

In this study, we (1) implemented a two-acquisition 3D phase-cycled bSSFP protocol at 7 Tesla that achieves 0.31mm isotropic resolution in under 9 minutes of scan time, (2) implemented a 3D DESS protocol at 7 Tesla that achieves 0.36mm isotropic resolution in just under 7 minutes, (3) performed a contrast optimization to identify flip angles that maximize both cartilage/muscle and cartilage/synovial fluid contrast, and (3) compared to a 3D SPACE acquisition at 7T that achieves 0.55mm isotropic resolution in a scan time of 11:37.

Radka Tušková^1,2,3, Ladislav Valkovic^1,3,4,5, Martin Gajdošík^1,3, Thomas Heckmann⁶, Norbert Bachl⁶, Harald Tschan⁶, Siegfried Trattnig^1,3, and Martin Krššák^1,3,7
1High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Faculty of Chemical and Food Technology, Department of NMR Spectroscopy and Mass Spectrometry, Slovak University of Technology in Bratislava, Bratislava, Slovakia, ³Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, ⁴John Radcliffe Hospital, University of Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, ⁵Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia, ⁶Center of Sport Science and University Sport, University of Vienna, Vienna, Austria, ⁷Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria

Carnitine plays an important role in fat metabolism. A long-echo time (TE of 350ms) proton magnetic resonance spectroscopy protocol was implemented for detection of skeletal muscle acetylcarnitine at rest on a clinical 7T scanner in the calf (soleus) and thigh (vastus lateralis) muscle. T2 relaxation times of the 2.13 ppm signal of acetlylcarnitine at 7T were assessed as 137.8±47.7ms. Concentrations of acetylcarnitine in vastus lateralis muscle in four healthy volunteers were found to be 1.69±0.21mmol/kg wet weight, whereas lower concentrations (i.e., 0.54±0.19mmol/kg) were found in soleus muscle.       

Xuejiao Che¹, Ryan Brown ^1,2, Leeor Alon^1,2, Ravinder R Regatte¹, and Prodromos Parasoglou^1
1Department of Radiology, New York University School of Medicine, New York, NY, United States, ²NYU WIRELESS, Polytechnic Institute of New York University, Brooklyn, NY, United States

In this work, we designed and constructed an inexpensive MR compatible ergometer that can be used for studying lower leg muscle metabolism. This ergometer allows subjects to perform a plantar flexion exercise protocol while ³¹P-MR data are acquired. The device is easy to use, and it can be positioned inside the bore of the magnet in less than 10 min. The mechanical power exerted by the subject can be estimated from force and angle displacement signals that are continuously monitored, while the exersice intensity can be varied by changing the number and/or the material of the resistive elastic cords.

Christopher J Hanrahan¹, Jeff L Zhang¹, Gwenael Layec², Corey Hart², Michelle Mueller³, Daniel Kim¹, Kristi Carlston¹, Russell S Richardson², and Vivian S Lee^1
1Radiology, Utah Center for Advanced Imaging Research (UCAIR), University of Utah School of Medicine, Salt Lake City, UT, United States, ²Internal Medicine, Division of Geriatrics, Utah Vascular Research Lab (UVRL), University of Utah School of Medicine, Salt Lake City, UT, United States, ³Surgery, University of Utah School of Medicine, Salt Lake City, UT, United States

Calf muscle perfusion by first-pass gadolinium MRI provides objective measures to help understand the relationship between vascular pathology and muscle dysfunction in peripheral arterial disease (PAD) patients. We compared perfusion in healthy and PAD subjects in exercise-recovery and, in the same PAD patients, related muscle perfusion pattern to hemodynamically significant vessel pathology found at MR arteriography.  We found no relation between specific stenosis/occlusion and the expected muscle perfusion downstream, but calf vascular pathology significantly decreased perfusion in the superficial posterior compartment muscles compared to abdominopelvic/thigh vessel abnormality.  Assessing muscle perfusion shows promise in assessing PAD disease severity and guiding treatment.

Yu Xin Yang¹, Mei Sian Chong¹, Laura Tay¹, Suzanne Yew¹, Audrey Yeo¹, and Cher Heng Tan^2
1Institute of Geriatrics and Active Ageing, Tan Tock Seng Hospital, Singapore, Singapore, ²Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore, Singapore

This study presented using MRI to quantify muscle and fat volumes in thigh for sarcopenic and sarcopenic obese (SO) populations. The correlation between different thigh components and patients’ physical performances was also assessed.  Results show that MRI is a promising tool for early detection of sarcopenia and SO. This may translate to use in clinical trials and in clinical practice. MRI measurement of inter-muscular fat volume is a valuable component in thigh to monitor patients’ physical performances.

Marko Hoehne¹, Andreas Graessl², Antje Els², Thomas Herold³, and Thoralf Niendorf^4
1HELIOS Klinikum Berlin Buch, Radiology, Max Delbrück Center for Molecular Medicine (MDC) Berlin,Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany, ²Max Delbrück Center for Molecular Medicine (MDC), Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany, ³HELIOS Klinikum Berlin Buch, Radiology, Berlin, Germany, ⁴Max Delbrück Center for Molecular Medicine (MDC), Experimental and Clinical Research Center (ECRC), Charite Campus Berlin Buch, Humboldt University Berlin, Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany

Technology advances in ultra-high field systems improve significantly diagnose of different musculoskeletal structures. A challenge of this work examines relative RF power deposition for shoulder MRI with dual echo steady state imaging at 3.0T and 7.0T. Volunteers (n=10, mean age 36.5 ± 8.51 years) were investigated at 3.0 T and 7.0 T. The flip angle was varied for each field strength. A comparison of  flip angle between 3.0T and 7.0T showed a SAR gain of approximately 2.6 for the local RF coil setup used at 7.0 T versus the body coil configuration employed at 3.0 T. It is important to considering a right choice of sequences and these parameters.

Melissa Hooijmans¹, Nathalie Doorenweerd¹, Jedrek Burakiewicz¹, Jan Verschuuren², Constantin Anastasopoulos¹, Andrew Webb¹, Erik Niks², and Hermien Kan^1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, ²Neurology, Leiden University Medical Center, Leiden, Netherlands

Progressive replacement of muscle tissue by fat is one of the main characteristics of DMD. This muscle degeneration process has been extensively studied in terms of differences between individual muscles, but not as a function of physical location within each individual muscle. This work showed non-uniform fat infiltration along the proximodistal muscle axis within individual muscles using the Dixon water/fat technique. These observations provide new insight into disease progression in DMD.

Kang Wang¹, Ken-Pin Hwang^2,3, Zac Slavens⁴, Adriana Kanwischer⁵, Kevin King⁵, Suchandrima Banerjee⁶, Pauline Worters⁶, and Ersin Bayram^2
1Global MR Applications & Workflow, GE Healthcare, Madison, WI, United States, ²Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States, ³Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States, ⁴MR Engineering, GE Healthcare, Waukesha, WI, United States, ⁵Global MR Applications & Workflow, GE Healthcare, Waukesha, WI, United States, ⁶Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States

MR imaging of bilateral brachial plexus has been challenging due to various reasons, such as fat suppression failures caused by B₀ inhomogeneity, arms wrapping in arms-down imaging for patient comfort, and long scan time, etc. In this work, these aforementioned challenges were addressed by combining and utilizing novel MR imaging techniques, and a fast and robust protocol for bilateral brachial plexus MR imaging is proposed.

Nikolaus M. Szeverenyi¹ and Graeme M. Bydder^1
1Radiology, University of California, San Diego, San Diego, CA, United States

Fasciculations are brief spontaneous contractions affecting a small number of muscle fibers.  We investigated how diffusion sensitized MR images were able to detect these contractions in the lower leg of healthy volunteers.  Large intensity decreases were observed (at random times) in random areas of muscle on images, acquired repeatedly using single shot (diffusion sensitized) EPI acquisitions over the course of several minutes.  Signal intensity reductions were attributed to intra-voxel incoherent-like motion due to displacement of tissue.  Quantification compared activated areas to total muscle area and frequency of activation on a per pixel basis.  Results were expressed as a fasciculation index parameter and in fasciculation frequency maps.

Esaú Poblador Rodriguez¹, Marek Chmelík^1,2, Vladimír Mlynárik^1,2, Siegfried Trattnig^1,2, and Wolfgang Bogner^1
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria

Once the technical limitations are cleared, Cr-CEST could replace ³¹P-MRS, becoming a powerful tool for assessment of treatment outcomes and diagnosis of muscular disorders, due to its superior spatial resolution and sensitivity. Phantom measurements show how Cr concentration and pH are linearly correlated with CEST contrast maps. The preliminary in-vivo measurements, with a time resolution of 13.1s per repetition, produce an enhancement of gastrocnemius muscle of 12% during plantar flexion exercise. However, a further increased time resolution is anticipated for dynamic studies, close to those routinely used in dynamic ³¹P-MRS.

Barbara Cervantes¹, Qinwei Zhang², Kim van de Ven³, Hendrik Kooijman⁴, Ernst Rummeny¹, Axel Haase⁵, Gustav J Strijkers², Jan S Kirschke⁶, Aart J Nederveen², and Dimitrios C Karampinos^1
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Radiology, Academic Medical Center, Amsterdam, Netherlands, ³Philips Healthcare, Best, Netherlands,⁴Philips Healthcare, Hamburg, Germany, ⁵Zentralinstitut für Medizintechnik, Garching, Germany, ⁶Neuroradiology, Technische Universität München, Munich, Germany

Quantitative MRI is becoming a promising tool in the assessment of peripheral nerve pathologies and anomalies. Peripheral neuropathy is frequently accompanied by neuropathic changes, which can be quantified with diffusion tensor imaging (DTI). Given the small sizes and oblique geometries of many peripheral nerves, peripheral-nerve DTI requires an acquisition method that can provide high-resolution, distortion-free images in acceptable clinical scanning times. The present work demonstrates isotropic- and sub-millimeter-resolution, artifact-free DTI of the nerves in the lower extremity using flow-compensated diffusion-prepared  3D turbo spin echo (TSE).

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, TX, United States, ²Philips Innovation Campus, Philips Healthcare, Bangalore, India, ³Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States

Volumetric Brachial Plexus imaging at 3T often suffers from incomplete fat suppression and reduced SNR with standard STIR and SPAIR due to increased B1 and B0 inhomogeneities. Dual-echo Dixon TSE has been shown to achieve uniform fat suppression without increasing total scan time or SNR penalty by acquiring two echoes in the same repetition. In this work, we compared 3D dual-echo Dixon TSE against current standard of care 3D STIR and 3D SPAIR for brachial plexus imaging with respect to fat suppression, blood suppression, nerve visualization and SNR at 3T. Overall, the 3D dual-echo Dixon TSE showed significantly improved performance.