Whole-body magnetic resonance imaging evaluation of facioscapulohumeral muscular dystrophy

Abstract

Introduction: Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary disorder that causes progressive muscle wasting. Increasing knowledge of the pathophysiology of FSHD has stimulated interest in developing biomarkers of disease severity.

Methods: Two groups of MRI scans were analyzed: whole-body scans from 13 subjects with FSHD; and upper and lower extremity scans from 34 subjects with FSHD who participated in the MYO-029 clinical trial. Muscles were scored for fat infiltration and edema-like changes. Fat infiltration scores were compared with muscle strength and function.

Results: The analysis revealed a distinctive pattern of both frequent muscle involvement and frequent sparing in FSHD. Averaged fat infiltration scores for muscle groups in the legs correlated with quantitative muscle strength and 10-meter walk times.

Conclusions: Advances in MRI technology allow for acquisition of rapid, high-quality, whole-body imaging in diffuse muscle disease. This technique offers a promising disease biomarker in FSHD and other muscle diseases.

Keywords: FSHD; MRI; facioscapulohumeral muscular dystrophy; radiographic biomarkers; whole-body imaging.

© 2015 Wiley Periodicals, Inc.

Figures

Figure 1

Heat map (A) of all 1330 muscles scored in 13 individuals with FSHD. Subjects are arranged (left to right) from lowest to highest mean MRI score. Muscles on the left and right sides of the body are placed to the left and right sides (respectively) of the labeled tick marks for each subject. Fat infiltration scores on T1-weighted MRI (from 0 to 5) and their corresponding colors are shown in the numbered bar on the right. The mean MRI score for all muscles scored within a single individual are represented in the bottom row. Muscles are listed in a superior to inferior arrangement, corresponding to the anatomic regions defined by the composite coronal MR image on the right (B).

Figure 2

Fitted regression lines for muscle strength in 5 muscle groups and 10-meter walk time against mean fat infiltration MRI score in specific muscle groups in subjects scanned using whole-body MRI.

Figure 3

Fitted regression lines for muscle strength against mean fat infiltration scores on MRI score in specific muscles groups in participants from the MYO-029 trial.