Comparing intramuscular blood perfusion in older adults using Angio-PL.U.S. and conventional Doppler ultrasound techniques: A cross sectional study.

Background: Angio PLanewave UltraSensitive (Angio-PL.U.S.) is an ultrafast ultrasound imaging techniques that may serve as an alternative to conventional contrast-enhanced and color Doppler ultrasound techniques in assessing tissue blood perfusion and microvascularity in diverse populations with various pathologies such as atherosclerotic plaques in the common carotid arteries, breast tissue lesions, renal cortices, and endoleaks following endovascular aneurism repair surgery. However, the use of this ultrafast imaging technique for assessing microvascular blood flow in musculoskeletal tissues is understudied.
Objective: A cross-sectional study involving healthy older adults was conducted to compare ultrafast Angio-PL.U.S. and conventional color Doppler flow imaging (CDFI) in evaluating intramuscular blood perfusion of the upper and lower extremities.
Methods: A total of 45 community dwelling older adults (males=31, females=14, age=59.1±7.6) completed the study. Bilateral biceps brachii and medial gastrocnemius intramuscular blood perfusion was estimated using the vascularity index (VI) for both imaging techniques. Intra-limb (VI difference between ultrasound techniques) and inter-limb differences [VI bilateral difference percentage (%SSD) between sides for the upper and lower limbs] were compared using Wilcoxon or Mann-Whitney U tests. Correlations between techniques were determined using Spearman’s rho (ρ).
Results: There were no significant differences between dominant and non-dominant biceps brachii (p≥0.053) and medial gastrocnemius muscles (p≥0.756) for Angio-PL.U.S and CDFI. Intra-limb differences in VI between ultrasound techniques were only apparent in non-dominant biceps brachii muscles (p=0.002). Significant %SSD between techniques was observed for biceps brachii (p=0.011), but not medial gastrocnemius muscles (p=0.089). Strong associations were observed between imaging techniques for all muscles (Spearman’s ρ=0.616-0.814, p≤0.001).