T2 relaxation times are increased in Skeletal muscle of DMD but not BMD patients

Muscle Nerve. 2016 Jan;53(1):38-43. doi: 10.1002/mus.24679. Epub 2015 Nov 26.

Abstract

Introduction: Exon-skipping drugs in Duchenne muscular dystrophy (DMD) aim to restore truncated dystrophin expression, which is present in the milder Becker muscular dystrophy (BMD). MRI skeletal muscle T2 relaxation times as a representation of edema/inflammation could be quantitative outcome parameters for such trials.

Methods: We studied T2 relaxation times, adjusted for muscle fat fraction using Dixon MRI, in lower leg muscles of DMD and BMD patients and healthy controls.

Results: T2 relaxation times correlated significantly with fat fractions in patients only (P < 0.001). After adjusting for muscle fat, T2 relaxation times were significantly increased in 6 muscles of DMD patients (P < 0.01), except for the extensor digitorum longus. In BMD, T2 relaxation times were unchanged.

Conclusions: T2 relaxation times could be a useful outcome parameter in exon-skipping trials in DMD but are influenced by fat despite fat suppression. This should be accounted for when using quantitative T2 mapping to investigate edema/inflammation.

Keywords: Becker; Duchenne; MRI; T2; inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Female
  • Humans
  • Leg / pathology
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Muscle, Skeletal / pathology*
  • Muscular Dystrophy, Duchenne / pathology*
  • Relaxation*
  • Young Adult