Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy

COMBINED EDUCATIONAL & SCIENTIFIC SESSION
Diabetes & Muscle Imaging
SKILL LEVEL: Intermediate to Advanced
ORGANIZERS: Richard Kijowski, M.D., William B. Morrison, M.D. & Ravinder Regatte, Ph.D.
Thursday, 15 May 2014
 
OVERVIEW
The course will provide an in-depth discussion of the use of MRI for evaluating musculoskeletal structures affected by diabetes. The lectures will discuss clinical applications of conventional imaging methods for assessing complications of diabetes and emerging MRI techniques for evaluating patients with the disease. The didactic lectures will be followed by presentation of scientific abstracts discussing novel MRI techniques for evaluating musculoskeletal structures affected by diabetes. The course is intended to bridge the gap between basic science research and patient care.
 
TARGET AUDIENCE
“Diabetes Hybrid Imaging” is directed at clinicians interested in learning about emerging MRI techniques used to assess diabetes and basic science researchers seeking to enhance their knowledge on potential clinical applications of novel MRI technology.
 
EDUCATIONAL OBJECTIVES

As a result of attending this course, participants should be able to:

  • Identify emerging MRI techniques for evaluating patients with diabetes; and
  • Implement new MRI techniques for assessing the complications of diabetes.
 

PROGRAM

Moderators: Eric E. Sigmund, Ph.D. & M. Albert Thomas, Ph.D.

         
13:30 MR Imaging & Spectroscopy of the Influence of Insulin Resistance Chris Boesch, M.D., Ph.D.
13:55 Use of BOLD MRI to Study Muscle Microvascular Function & Dysfunction Bruce M. Damon, Ph.D.
         
14:20 0825.   
Single Line Multiple Echo Diffusion Tensor Acquisition Technique: feasibility of dynamic diffusion tensor parameters in a flow phantom and in vivo muscle tissue on a 3T clinical scanner
Steven Baete1, Gene Cho1,2, Jenny T. Bencardino3, and Eric E Sigmund1
1Center for Biomedical Imaging, Dept. of Radiology, NYU Langone Medical Center, New York, New York, United States, 2Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, New York, United States, 3Department of Radiology, NYU Hospital for Joint Diseases, New York, New York, United States

 
The feasibility of dynamic single line acquisition of diffusion tensor parameters is demonstrated in a flow phantom and in in vivo skeletal muscle on a 3T clinical scanner. This method, Single Line Multiple Echo Diffusion Tensor Acquisition Technique SL-MEDITATE), encodes each of multiple echoes generated by five RF-pulses with different diffusion weighting. A single line is selected by orthogonal slice selective gradients. The resulting dynamic acquisition can be used to study the transient changes in diffusion tensor parameters, such as in muscle tissue following exercise, where traditional DTI methods lack temporal resolution.

 
14:30 0826.   Proton diffusion tensor spectroscopy of metabolites in human muscle in vivo
Vaclav Brandejsky1, Chris Boesch1, and Roland Kreis1
1Departments of Radiology and Clinical Research, University Bern, Bern, Switzerland

 
Purpose: To study apparent diffusivity and directionality for metabolites of skeletal muscle in humans by 1H-MRS. Methods: Diffusion tensors in tibialis anterior muscle oriented at the magic angle were determined at 3T using optimized methods including an adapted STEAM sequence and simultaneous fitting. Results: Apparent diffusivities and fractional anisotropies of taurine, creatine, trimethyl¬ammonium compounds, carnosine and water were estimated. The diffusivities of most metabolites and water were significantly different from each other. Diffusion was found to be anisotropic and the diffusion tensors to be essentially coaligned. Magnitudes of the diffusivities were largely ordered according to molecular weight.

 
14:40 0827.   
Skeletal Muscle Metabolism Measured by Hyperpolarized 13C MR Spectroscopy
Jae Mo Mo Park1, Sonal Josan1, Dirk Mayer2, Ralph Hurd3, David Bendahan4, Daniel Spielman1, and Thomas Jue5
1Radiology, Stanford University, Stanford, CA, United States, 2Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD, United States, 3GE Healthcare, Menlo Park, CA, United States, 4Centre de Resonance Magnetique Biologique et Medicale, Marseille, United States,5Biochemistry, UC Davis, Davis, CA, United States

 
In this study, we have directly followed hyperpolarized [1-13C]lactate in rat leg muscle in vivo to confirm that muscle can indeed metabolize exogenous lactate. Metabolic dynamics and 3D images were acquired at baseline and 1h after dichloroacetate. The fate of acetyl-CoA in mitochondria was further investigated using hyperpolarized [2-13C]pyruvate. The radically increased 13C-bicarbonate peak indicates pyruvate dehydrogenase (PDH) activation and a potential participation of lactate in the TCA cycle to support oxidative phosphorylation. Moreover, [2-13C]pyruvate experiment confirms that the up-regulated PDH activity results in increased pyruvate flow into the TCA cycle.

 
14:50 0828.   
Non-Invasive in vivo Measurements of Inertial Forces in Muscle using Phase Contrast Magnetic Resonance Imaging
Andrew L Wentland1, Emily J McWalter2, Saikat Pal3, Scott L Delp3, and Garry E Gold2,3
1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Bioengineering, Stanford University, Stanford, CA, United States

 
The purpose of this study was to create a novel tool for computing muscle forces non-invasively in vivo. Cross-sectional images of the forearms and lower legs of healthy volunteers were acquired with a fat/water separation technique as well as 2D phase contrast MRI during 1 Hz cycles of flexion/relaxation. Forces were derived from these images. Results indicate that this technique provides the ability to quantify inertial forces rather than applied forces. As a result, this technique provides the first known method for quantifying inertial forces. This analysis technique may be useful in evaluating muscle pathophysiology and further developing biomechanical models.

 
15:00 0829.   
Mapping the Unidirectional Pi-to-ATP Fluxes in Muscles of the Lower Leg by Using Progressive Saturation 31P-MRI with PCr Suppression at 7.0 T
Prodromos Parasoglou1, Ding Xia1, and Ravinder R Regatte1
1Radiology, NYU School of Medicine, New York, New York, United States

 
Phosphorus saturation transfer methods can assess the turnover rates of important metabolic reactions such as the adenosine triphosphate (ATP) synthesis/hydrolysis cycle. In this study, we focused on the development and implementation of an imaging method for simultaneously measuring the kinetics of ATP synthesis and the Pi-to-ATP fluxes in muscles of the lower leg. Mapping the kinetics of the ATP synthesis reaction and the Pi-to-ATP fluxes in several muscles of the leg using our imaging method could provide useful insights into the study of diseases such as insulin resistance and diabetes.

 
15:10 0830.   
Feasibility and Reproducibility of Measurement of Skeletal Muscle Blood Flow, Oxygen Extraction and VO2 with Dynamic Exercise Using MRI
Kory W. Mathewson1, Mark Haykowsky2, and Richard B. Thompson1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, 2Faculty of Rehabilitation, University of Alberta, Edmonton, Alberta, Canada

 
We propose a new imaging approach which interleaves complex-difference and susceptometry MRI acquisitions for real-time imaging of skeletal muscle blood flow (SMBF) and venous oxygen saturation (SvO2) for the calculation of skeletal muscle oxygen consumption (VO2). The goal of this study was to determine the reproducibility of this approach during sub-maximal knee-extensor exercise. The coefficient of variation from test/retest trials was 7.6%, 15.6% and 12.3% for SMBF, SvO2 and VO2, with mean values of 0.9±0.1L/min/kg, 43.2±13.5% and 95.7±18.0mL/min/kg respectively. To our knowledge, this is the first report of non-invasive skeletal muscle VO2 and its determinants (SMFB,SvO2) during dynamic exercise.

 
15:20 0831.   Dietary Nitrate Does Not Induce Hypoxia Dependent Augmented Oxygen Delivery in Skeletal Muscle in Young Healthy Subjects.
Rachel Bentley1, Stuart R Gray2, Christian Schwarzbauer1, Dana Dawson3, Michael P Frenneaux3, and Jiabao He1
1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, Aberdeenshire, United Kingdom, 2Musculoskeletal Research Programme, University of Aberdeen, Aberdeen, Aberdeenshire, United Kingdom, 3Cardiovascular Research Programme, University of Aberdeen, Aberdeen, Aberdeenshire, United Kingdom

 
Dietary nitrate improves skeletal muscle metabolic efficiency, and might induce hypoxia dependent vasodilation and consequently augment oxygen delivery. We conducted dual echo gradient echo muscle fMRI study to evaluate tissue oxygenation during plantar flexion exercise at 15% and 25% maximum voluntary contraction (MVC). Significant decreases in maximal percentage change were found in soleus (p=0.004) and gastrocnemius (p=0.017) at 15% MVC, but not at 25% MVC. This reduction is primarily found in type 1 muscle groups at lower exercise intensity, indicating that dietary nitrate affects skeletal muscle via enhancements in mitochondrial function instead of vascular effects in young healthy subjects.

 
         
15:30     Adjournment