Figure 1. Longitudinal Clinical and FF_EF Data.

(A) Example of a region of interest drawn on the elbow flexor muscles (line) is shown on a water image (left) and corresponding fat image (right). (B) Longitudinal performance of the upper limb (PUL) 2.0 total scores (maximum 42 points) are plotted vs age. PUL total scores decrease with age, but there is a large variation in scores between patients with Duchenne muscular dystrophy of similar ages. (C) Elbow flexor fat fraction (FF_EF) results that were acquired are plotted vs age, as well as FF_EF results that were predicted with a logit transformation, linear (mixed) model, and logistic transformation. Patients with higher FF_EF results at younger ages or faster FF_EF increases had steeper predicted FF_EF slopes. (D) Predicted FF_EF results are plotted vs age, and predicted FF_EF at age at loss of hand-to-mouth movement is shown with a cross. Colors used in panels B–D are unique for each participant.