地震挤压伤致下肢横纹肌溶解症的MRI表现

目的 分析地震挤压伤致下肢横纹肌溶解症的MRI表现及临床应用价值.方法 回顾性分析5.12汶川大地震中临床确诊为地震挤压伤致双下肢横纹肌溶解症的3例患者双下肢MR平扫、增强、短时间反转恢复(STIR)序列和MR血管成像(MRA)征象,评价MR检查在挤压伤所致横纹肌溶解症临床诊治中的作用.结果 3例患者受压肢体MRI表现为皮下脂肪及筋膜肿胀、肌束紊乱、肌间隙模糊或可见局限性积液;受损肌肉在T2WI呈片状混杂高信号影,在T1WI呈等信号或稍低信号影,其内间杂有不均匀稍高信号影;STIR序列成像呈高信号影.增强可见不规则强化;在MRA,3例患者下肢主要动脉均未见明显狭窄及闭塞征象.结论 MRI能及时显示地震挤压伤受累肌肉范围、程度及相应的血管受累情况,可为其临床的及时诊断及治疗评估提供有利信息.

MR manifestation of lower extremity rhabdomyolysis caused by crush injury in earthquake

Objective Rhabdomyolysis (RM) is a common disorder resulting from a large variety of causes. Acute injury is one of the main reasons. The purpose is to describe the MRI manifestations of rhabdomyolysis caused by 5.12 Wenchuan earthquake in Sichuan province and to discuss their importance in diagnosis and treatment of rhabdomyolysison in clinic practice. Methods Three patients with rhebdomyolysis caused by earthquake were studied via 1.5 T MRI. In all the patients, T, and T2 weighted sequences with and without fat suppression, and short time inversion recovery (STIR) of both lower extremities were obtained in axial, coronal and sagittal planes. All patients were given contrast material during imaging, and MRA (magnetic resonance angiography) of both lower extremity vessels were performed. The MRI characteristics of damaged extremities in 3 cases were studied. Results MRI showed swelling of the affected muscles and subcutaneous fat tissue on both T1 and T2 weighted images. The margins of involved muscles were blurred. On T1 weighted images, swollen muscles showed equal or slightly decreased intensity with small patterns of increased intensity in some local areas. On T2 weighted and STIR sequences, the affected muscles showed inhomogeneons increased signal intensity with clearer margin. Slight fluid collection in spatium intermusculare was observed. Contrast-enhanced scanning showed nonhomologous intensification of damaged muscles, the enhancement inside the muscles was decreased when compared with normal muscles. The locations of all these abnormal intensity were correlated with the injury history and clinic physical examinations. MRA showed no lower extremity vessels were affected. Conclusion MRI has very high sensitivity in detecting the injury of muscles. It's very useful in evaluating the extent and severity of muscles affected in rhabdomyolysis caused by trauma. Also it's very valuable to evaluate the condition of blood vessels in involved extremity for predicting the prognosis of the disease. Therefore MRI possesses a very important role in the diagnosis and treatment of RM.