Study on T2 mapping in thigh muscles of patients with Duchenne muscular dystrophy

Abstract

Objective  Use T₂ mapping to evaluate the fatty infiltration of thigh muscles in Duchenne muscular dystrophy (DMD) patients, so as to analyze the value of T₂ mapping and T₂ relaxation time in the diagnosis of DMD.  Methods  Sixteen DMD patients who were admitted from January 2004 to January 2013 in our hospital and were diagnosed by clinical confirmation and gene detection have participated into this study. These 16 male patients formed the DMD group. Six age- and sex-matched healthy boys were selected as control group. Clinical functional scale, thigh axial T₁WI-turbo spin echo (TSE), T₂WI-TSE, spectral attenuated inversion recovery (SPAIR)-T₂WI and T₂ mapping were performed in both 2 groups. T₁WI fatty infiltration scale and T₂ relaxation time were assessed in adductor magnus, gracilis, adductor longus, sartorius, rectus femoris, vastus intermedius, vastus medialis, vastus lateralis, biceps femoris, semitendinosus and semimembranosus. Spearman rank correlation was conducted to assess the correlation between T₂ relaxation time and T₁WI fatty infiltration scale or clinical functional scale.  Results  Compared with control group, the T₂ relaxation time of 8 muscles (adductor magnus, adductor longus, rectus femoris, vastus intermedius, vastus medialis, vastus lateralis, biceps femoris and semimembranosus) in DMD group were prolonged (P < 0.05, for all). The longest average T₂ relaxation time was found in adductor magnus. The T₂ relaxation time of adductor magnus, vastus intermedius, vastus lateralis, biceps femoris, rectus femoris, adductor longus and vastus medialis was positively correlated with T₁WI fatty infiltration scale (P < 0.05, for all), and the T₂ relaxation time of adductor magnus and semimembranosus was positively correlated with clinical funetional scale (P < 0.05, for all). A positive correlation was found in adductor magnus between T₂ relaxation time and both T1WI fatty infiltration scale (r_s = 0.867, P = 0.000) and clinical functional scale (r_s = 0.651, P = 0.005).  Conclusions  T₂ relaxation time could be used in the quantitative and objective analysis of DMD clinical severity, and adductor magnus was considered to be the most valuable muscle to reflect the clinical severity of DMD.

DOI: 10.3969/j.issn.1672-6731.2015.06.004