Auburn Research Day 2021

Joshua S. Godwin 1 ; Bradley A. Ruple 1 ; Shelby C. Osburn 1 ; Christopher G. Vann 2 ; Casey L. Sexton 1 ; Andrew D. Fruge 3 ; Joseph Edison 4,5 ; Michael Goodlett 4,6 ; Michael D. Roberts 1,7 ; Kaelin C. Young 1,7 1 School of Kinesiology, Auburn University, Auburn, AL, USA; 2 Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, Durham, NC, USA; 3 Department of Nutrition, Dietetics and Hospitality Management, Auburn University, Auburn, AL 36849; 4 Department of Athletics, Auburn University, Auburn, AL 36849; 5 Department of OMM, Edward Via College of Osteopathic Medicine, Auburn, AL 36832 ; 6 Department of Sports Medicine, Edward Via College of Osteopathic Medicine, Auburn, AL 36832; 7 Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Auburn, AL 36832 B i omed i ca l Resea rch | Gr adua te / Undergr adua te St udent Test-RE-Test Reliability of Magnetic Resonance Imaging-Derived Mid- Thigh Skeletal Muscle Cross-Sectional Area 040

Purpose: Magnetic resonance imaging (MRI) is considered the gold standard for measuring changes in skeletal muscle cross sectional area (mCSA) and/or volume over time. In order for a test to be considered the gold standard, it must have strong validity and reliability. While the validity of MRI-determined soft tissue measurements is well established, less is known regarding the precision or reliability of MRI-determined mid-thigh mCSA. The purpose of this study was to establish test- re-test reliability of MRI- determined mid-thigh mCSA from two MRI scans taken 20 minutes apart on the same group of participants. Methods: Ten male participants (age: 23.3±3 years; weight: 89.5 ± 11.6 kg; height: 182 ± 8 cm) underwent two MRI scans of both mid-thighs approximately 20 minutes apart following an overnight fast. Participants were asked to lie supine on the MRI table for 10 minutes to allow body fluid shift stabilization. Thereafter, 16 axial plane scans of each thigh were obtained using an MRI scanner (GE, 3T 750 Discovery). A T1-weighted Spin Echo protocol was used (repetition time 600 ms, echo time 15.2 ms, field of view 512 × 512 mm, slice thickness 10 mm, no gap between slices). Following the first set of scans, the participant was taken out of the gantry and off the table. The participant was then repositioned and had a second set of scans identical to the first. The 8th cross-sectional image

in each set of 16 images was used for analysis and comparison purposes. All scans were analyzed for mCSA using SliceOmatic software (version 5, Tomovision; Magog, Canada) by an experienced technician (KCY). mCSA reliability was determined by computing intra-class correlation coefficient 3,1 (ICC3,1), standard error of the measurement (SEM) and minimal difference to be considered real (MD= SEM*2.77) statistics as well as percent coefficient of variation (%CV) and Least Significant Change (LSC = %CV*2.77). Finally, a paired samples t-test was used to test for mean differences between the first and second set of scans. Results: There was no difference in mid-thigh mCSA between the first and second set of scans (206.9±29.5 vs 206.9±28.7 cm2, p=0.90). Intra-scan mCSA reliability was good with a resulting ICC of 0.996, SEM of 1.79 cm2, and minimal difference to be considered real of 4.9 cm2. Furthermore, the resultant %CV between scans was 0.84% with a LSC of 2.3%. Conclusion: Mid-thigh mCSA determined by MRI is a highly reproducible method of measurement. However, as noted here, patient positioning is extremely important when considering the importance for tracking changes in skeletal muscle size/volume.

29 2021 Via Research Recognit ion Day