Hughes Michael S, Marsh Jon N, Wallace Kirk D, Donahue Tamara A, Connolly Anne M, Lanza Gregory M, Wickline Samuel A
Washington University, School of Medicine, St Louis, MO 63108, USA.
Ultrasound Med Biol. 2007 Aug;33(8):1236-43. doi: 10.1016/j.ultrasmedbio.2007.02.007. Epub 2007 Apr 30.
The dystrophinopathies comprise a group of X-linked genetic diseases that feature dystrophin deficiency. Duchenne and Becker muscular dystrophy are characterized by progressive weakness and wasting of skeletal, smooth, and/or cardiac muscle. Duchenne muscular dystrophy (DMD) is the most severe dystrophinopathy, with an incidence of 1:3500 male births. Despite understanding the structural and genetic basis for DMD, the pathogenesis and clinical basis for more severe involvement in specific skeletal muscle groups and the heart are poorly understood. Current techniques, such as strength testing for monitoring progress of disease and therapy in DMD patients, are imprecise and physically demanding for test subjects. Ultrasound is well-suited to detect changes in structure and organization in muscle tissue in a manner that makes low demands on the patient. Therefore, we investigated the use of ultrasound to quantitatively phenotype the remodeling process in patients with DMD. Beam-formed radio-frequency (RF) data were acquired from the skeletal muscles of nine DMD and five normal subjects imaged with a clinical imaging system (HDI5000 w/7 MHz probe applied above left biceps muscle). From these data, images were reconstructed using B-mode (log of analytic signal magnitude) and information-theoretic receivers (H(f)-receiver). H(f) images obtained from dystrophic muscle contained extensive "mottled" regions (i.e., areas with heterogeneous image contrast) that were not readily apparent from the B-Mode images. The 2-D autocorrelation of DMD H(f) images have broader peaks than those of normal subjects, which is indicative of larger scatterer sizes, consistent with pathologic changes of fibers, edema and fatty infiltration. Comparison of the relative peak widths (full width measured at 60% maximum) of the autocorrelation of the DMD and normal H(f) images shows a quantitative difference between the two groups (p < 0.005, student two-tailed paired t-test). Consequently, these imaging techniques may prove useful for longitudinal monitoring of disease progression and therapy.
肌营养不良症是一组以肌营养不良蛋白缺乏为特征的X连锁遗传病。杜氏和贝克型肌营养不良症的特点是骨骼肌、平滑肌和/或心肌进行性无力和萎缩。杜氏肌营养不良症（DMD）是最严重的肌营养不良症，男性发病率为1:3500。尽管了解了DMD的结构和遗传基础，但对于特定骨骼肌群和心脏更严重受累的发病机制和临床基础仍知之甚少。目前的技术，如用于监测DMD患者疾病进展和治疗的力量测试，不精确且对测试对象体力要求高。超声非常适合以对患者要求较低的方式检测肌肉组织的结构和组织变化。因此，我们研究了使用超声对DMD患者的重塑过程进行定量表型分析。从9名DMD患者和5名正常受试者的骨骼肌获取经波束形成的射频（RF）数据，使用临床成像系统（HDI5000，配备7MHz探头，置于左肱二头肌上方）进行成像。从这些数据中，使用B模式（解析信号幅度的对数）和信息论接收器（H(f)接收器）重建图像。从营养不良肌肉获得的H(f)图像包含广泛的“斑驳”区域（即图像对比度不均匀的区域），这些区域在B模式图像中并不明显。DMD的H(f)图像的二维自相关峰值比正常受试者的更宽，这表明散射体尺寸更大，与纤维、水肿和脂肪浸润的病理变化一致。DMD和正常H(f)图像自相关的相对峰值宽度（在最大值的60%处测量的全宽）比较显示两组之间存在定量差异（p<0.005，学生双尾配对t检验）。因此，这些成像技术可能对疾病进展和治疗的纵向监测有用。
