Ultrasound image analysis method. B: ultrasound image showing ROI (white box) and whisker lines corresponding to thickness of combined (red), subcutaneous (blue) and perimuscular (green) zones. Units on y axis represent cm. Arrow shows direction of ultrasound beam. A, C: ultrasound intensity profile corresponding to image in B. Colored areas highlight the area under the curve (used as measure of echogenicity) for combined (A, red area), perimuscular (C, green area) and subcutaneous (C, blue area) zones.