Assessment of motor function in pre-progressive and progressive stages of Duchenne muscular dystrophy in children using M-Dixon quant and T2-mapping

CHEN Taiya; LIN Jieqiong; HU Yingyi; HUANG Yang; WANG Jinggang; FANG Diangang; LU Xinguo; LI Zhiyong

doi:10.19300/j.2024.L20989

Abstract：Objective To investigate the value of M-Dixon quant and T2-mapping in evaluating motor function in children with Duchenne muscular dystrophy(DMD)in the pre-progressive and progressive stages,providing appropriate imaging tools for accurate disease assessment and monitoring the follow-up.Methods Data from 40 male children diagnosed DMD through genetic detection or histopathological biopsy were prospectively collected.There were 20 children in the pre-progressive stage(＜7 years old)and 20 children in the progressive stage(≥7 years old).All children underwent lower limb M-Dixon quant and T2-mapping examinations.MRI findings of thigh muscles in both stages were observed.The fat fraction(FF)and T2 values of 14 muscles in the right thigh were measured.Motor function was assessed using the motor function measure(MFM)scale,and the total MFM score was calculated.Pearson correlation analysis was used to evaluate the relationship between FF values,T2 values of each muscle,and the total MFM score in both groups(rFF,rT2).Results MRI showed slight fat infiltration in the thigh muscles of pre-progressive DMD children,which increased as the disease progressed.In the pre-progressive DMD children,the FF values of the gluteus maximus,semimembranosus,and semitendinosus muscles were negatively correlated with the total MFM score(all P＜0.05).Except for the adductor magnus,the T2 values of the other 13 muscles were negatively correlated with the total MFM score(all P＜0.05),with the vastus intermedius showing the strongest correlation.In the progressive DMD children,the FF values and T2 values of the 14 muscles were all negatively correlated with the total MFM score(rFF ranging from-0.877 to-0.697,rT2 ranging from-0.968 to-0.774,all P＜0.05),with the vastus lateralis showing the strongest correlation.The rT2 values for each muscle were higher than the rFF in progressive DMD children.Conclusion Thigh muscle involvement in DMD children follows a certain progression pattern.Regardless of the stage,T2-mapping technique reflects disease severity more accurately than M-Dixon Quant technique.The T2 value of the vastus intermedius in pre-progressive children and the vastus lateralis in progressive children can serve as good indicators for assessing DMD severity.