Moving forward with the echo intensity mean analyses: Exploring echo intensity bands in different age groups

Abstract This study compared ultrasound characteristics in youth, younger adults, and older adults using two different methods of analysis: based on clusters of pixel concentration of the grayscale (i.e. EI bands) and the traditionally calculated echo intensity mean. Forty-four healthy youth (13.3 ± 1.4 y), 22 younger adults (31.8 ± 10.1 y) and 53 older adults (66.7 ± 4.6 y) volunteered for the assessment of rectus femoris EI via ultrasonography. Pixel concentration (i.e. EI bands) was calculated in intervals of 0–50, 51–100, 101–150, 151–200, and 201–255 of the gray scale, while EI mean was determined as the average pixels from 0 to 255. EI0–50 significantly decreased with group age, while EI51–100, 101–150, 151–200, 201–255 and EI mean increased (P   older adults; whereas EI mean: youth = ~46% and younger adults = 29%