MR-IMAGING IN CHILDREN WITH DERMATOMYOSITIS - MUSCULOSKELETAL FINDINGS AND CORRELATION WITH CLINICAL AND LABORATORY FINDINGS
MR-IMAGING IN CHILDREN WITH DERMATOMYOSITIS - MUSCULOSKELETAL FINDINGS AND CORRELATION WITH CLINICAL AND LABORATORY FINDINGS
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DOI：
10.2214/ajr.161.2.8333378
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发表时间：
1993-08-01
影响因子：
5
通讯作者：
KEIM, DR
中科院分区：
文献类型：
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作者：
HERNANDEZ, RJ;SULLIVAN, DB;KEIM, DR
OBJECTIVE.本研究的目的是描述儿童皮肌炎的肌肉骨骼MR表现，并将MR表现与疾病活动的指标（如肌肉力量和血清肌酶水平）相关联。这项前瞻性研究包括24名儿童：19名皮肌炎儿童和5名对照组。皮肌炎的诊断建立在所有患者的临床表现和血清肌酶水平，6例患者的肌电图，4例患者的活检。在初始MR评价时，根据临床结果将患者分类为活动性（n = 15）或非活动性（n = 4）疾病。本研究共纳入了44例皮肌炎患者的MR评估：19例初次MR检查，12例活动性疾病患者在治疗4-6个月后重复检查。对5名患者进行了额外的13次检查。常规T1加权（SE 600/20）和T2加权（SE 2500/80）自旋回波和脂肪抑制的MR图像。T2加权像（TE = 80）用于比较。除了视觉评估外，还计算了同一断层扫描切片中肌肉（臀肌、内收肌、四头肌和腘绳肌）信号强度与皮下脂肪信号强度之间的比值。所有临床活动性疾病患者（n = 15）的MR检查结果均异常，而非活动性疾病患者（n = 4）的MR检查结果正常。活动性疾病患者的信号强度比大于对照受试者，而非活动性疾病患者的信号强度比与对照受试者没有差异。治疗4-6个月后，接受重复MR评估的治疗患者（n = 12）的平均信号强度比与治疗前相同患者的比值不同，但与对照受试者的比值无差异。观察到的其他MR表现为肌周水肿、化学位移伪影增强和皮下脂肪炎性改变。脂肪抑制成像增强了异常的可视化。肌肉信号强度明显异常与血清肌酶水平明显升高相关;然而，异常MR表现与血清肌酶水平正常相关。活动期儿童皮肌炎的T2加权MRI表现包括受累肌肉信号增强、肌周水肿、化学位移伪影增强和皮下脂肪信号增强。治疗后，肌肉信号强度恢复正常。这些MR表现在脂肪抑制图像上增强。肌肉的信号强度与肌力评估相关，然而，异常的MR结果和血清肌酶水平有不同的敏感性。
OBJECTIVE. The purpose of this study was to describe the musculoskeletal MR findings in childhood dermatomyositis and to correlate MR findings with indicators of disease activity such as muscle strength and serum levels of muscle enzymes.SUBJECTS AND METHODS. This prospective study included 24 children: 19 children with dermatomyositis and five control subjects. The diagnosis of dermatomyositis was established by clinical findings and serum levels of muscle enzymes in all patients, electromyography in six patients, and biopsy in four patients. At the time of the initial MR evaluation, patients were classified on the basis of clinical findings as having active (n = 15) or inactive (n = 4) disease. A total of 44 MR evaluations of patients with dermatomyositis were included in the study: 19 initial MR examinations and 12 examinations repeated after 4-6 months of therapy in patients with active disease. An additional 13 examinations were performed on five patients. Conventional T1-weighted (SE 600/20) and T2-weighted (SE 2500/80) spin-echo and fat-suppressed MR images were obtained. The T2-weighted images (TE = 80) were used for comparison. In addition to the visual assessment, ratios between the signal intensity of muscles (gluteus, adductors, quadriceps, and hamstrings) and the signal intensity of subcutaneous fat in the same tomographic section were calculated.RESULTS. All patients with clinically active disease (n = 15) had abnormal findings on MR studies, whereas those with inactive disease (n = 4) had normal MR findings. Signal-intensity ratios of patients with active disease were greater than those in control subjects, whereas the ratios in patients with inactive disease were not different from those in control subjects. After 4-6 months of therapy, the average signal-intensity ratios of treated patients with repeated MR evaluations (n = 12) differed from ratios obtained before therapy in the same patients, but were not different from the ratios in control subjects. Other MR findings observed were perimuscular edema, enhancement of the chemical-shift artifact, and inflammatory changes of subcutaneous fat. Fat-suppressed imaging enhanced visualization of abnormalities. Markedly abnormal signal intensities of muscle were associated with marked elevations of serum levels of muscle enzymes; however, abnormal MR findings were visualized with normal serum levels of muscle enzymes.CONCLUSION. Findings of active childhood dermatomyositis on T2-weighted MR images include increased signal intensity in affected muscle, perimuscular edema, enhanced chemical-shift artifact, and increased signal intensity in subcutaneous fat. After therapy, signal intensity of muscle returns to normal. These MR findings are enhanced on fat-suppressed images. Signal intensity of muscle correlates with muscle strength assessment; however, abnormal MR findings and serum levels of muscle enzymes have different sensitivities.