Reliability of ultrasound measurements of muscle thickness and echointensity in older adults with type 2 diabetes

Abstract

Ultrasound is an emerging tool for muscle-based measurements. However, the analysis of hyperechoic images (high muscle fat infiltration, as in type 2 diabetes [T2D]) can be challenging. Objective: To evaluate the reliability of ultrasound image analysis of muscle thickness and echointensity in older adults with T2D and non-diabetic controls by experienced and novice analysts. We hypothesized that reliability would be high for the experienced analysts, and lower, but acceptable, for a novice analyst. Methods: We recruited three groups: 1) adults >60 years with T2D; 2) age- and sex-matched normoglycemic controls; and 3) healthy adults 18–35 years. All participants underwent ultrasound imaging of the abdomen and anterior thigh. Ultrasound images were de-identified, randomized, and separately analyzed by two expert analysts (>3 years experience each). A subset of images was also analyzed by a novice analyst with no prior experience. Inter- and intra-rater reliability was assessed using coefficients of variation (CVs), intraclass correlation coefficients (ICCs), and Bland-Altman analysis. Results: For the expert analysts, ICCs were >0.90 and CVs were 0.90, except for rectus abdominus thickness measurements in the T2D group (ICC: 0.659 [95%CI: -0.134, 0.911]). CVs were <10 % for all measurements, except for rectus abdominus thickness in the T2D group (CV: 12.7 %). Ultrasound image analysis of muscle thickness and echointensity by experienced analysts was highly reliable. Conclusion: Novice and expert analysts produced comparable measurements, except for rectus abdominus thickness in images obtained from older adults with T2D.

Keywords

• Subcutaneous adipose tissue
• Rectus femoris
• Texture analysis
• Body composition
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