Hee Kyung Kim MD, Presenter: Nothing to Disclose

Tal Laor MD, Abstract Co-Author: Nothing to Disclose

Bernard J Dardzinski PhD, Abstract Co-Author: Nothing to Disclose

Madeline Chadehumbe MD, Abstract Co-Author: Nothing to Disclose

Brenda Wong, Abstract Co-Author: Nothing to Disclose

DMD is a fatal disease characterized by progressive muscle weakness and death during the 3rd decade. Steroid therapy can slow the progression of muscle weakness by decreasing inflammation. Conventional MRI detects subjective signal changes that suggest muscle inflammation and fatty infiltration, but is not an objective or quantitative method. The purpose of our study is to quantitatively measure the therapeutic effect of steroid administration on the gluteal muscles in children with DMD using T2 relaxation time mapping.

6 boys with DMD (range: 5-9 years of age) were treated with oral steroids (Deflazacort) for 11-12 months. Lower extremity MRI and T2 mapping were performed before and after treatment. Gluteus muscle inflammation and fatty infiltration were graded on conventional MRI. Coronal and axial T2 maps were generated. Mean T2 values of the gluteal muscles were obtained and histograms were created. Clinical functional assessment for each boy was also performed. The MRI data were compared between pretreatment and post treatment clinical assessments.

No change in functional score between pre- and post-therapy was observed in any of the 6 boys. The mean T2 relaxation time decreased (from 92.6 msec to 54.2 msec, and 55.4 msec to 51.4 msec) in 2 boys following treatment, but no interval change was identified with conventional MRI. An increase (mean value: 52.7 msec to 57.7 msec) in the T2 relaxation times was seen in 4 boys. Of these 4 boys, 2 showed increased fatty infiltration and inflammation on conventional MRI, and 2 showed no change.

T2 mapping can detect alterations in disease activity in boys treated with steroids for DMD when conventional MRI or clinical functional scores are unchanged.

T2 mapping can detect alterations in disease activity in boys treated with steroids for DMD when conventional MRI or clinical functional scores are unchanged.

Kim, H, Laor, T, Dardzinski, B, Chadehumbe, M, Wong, B, Effect of Steroids on T2 Relaxation Time Mapping of the Pelvis in Children with Duchenne Muscular Dystrophy (DMD): Quantitative Assessment.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6012568.html