短时翻转恢复序列在皮肌炎、多发性肌炎中的应用价值

目的探讨短时翻转恢复(short-tau inversion recovery,STIR)序列在皮肌炎、多发性肌炎中的应用价值。材料与方法回顾分析我院12例经临床确诊和(或)穿刺活检病理证实的皮肌炎/多发性肌炎患者资料。选择双侧大腿肌肉作为感兴趣区,采用常规T1WI、T2WI及STIR序列进行扫描,观察STIR序列与T1WI、T2WI在病变检出能力上的差异。结果 (1)本组12例患者于MRI上发现双侧大腿有不同程度异常信号表现,其中提示为肌炎11例、肌筋膜炎8例、皮下结缔组织炎9例、肌肉萎缩伴脂肪浸润1例。(2)在STIR序列上,12例患者均被发现双侧大腿有异常信号;T1WI仅发现5例皮下结缔组织炎,1例肌肉萎缩,未发现肌炎、肌筋膜炎;T2WI发现6例肌炎,1例肌肉萎缩及2例皮下结缔组织炎,未发现肌筋膜炎。(3)在STIR序列上,发现有7例患者的双侧大腿后、内侧肌群信号较其他受累肌群信号高,经病理证实该处肌肉损伤程度较重。结论 STIR序列具有高软组织分辨率和高灵敏性,可明显提高软组织炎性病变的检出率,其信号强度可主观反映肌肉的损伤程度,在临床上具有重要应用价值。

Value of short-tau inversion recovery sequences in the MR imaging diagnosis of polymyositis and dermatomyositis

Objective: To assess the value of short-tau inversion recovery (STIR) sequence in dermatomyositis (DM) and polymyositis (PM) and investigate its application in clinical practice. Materials and Methods: Twelve patients with a diagnosis of DM/PM were respectively evaluated using clinical examination and muscle biopsy-proved. All the patients were preformed with MRI of their thigh, including the images of T1-weighted imaging (T1WI); T2-weighted imaging (T2WI) and STIR sequences. The abilities of detecting lesions among these sequences were observed and compared. Results: All of included patients were detected abnormal MRI appearances of their thigh muscle, which representing myositis in 11 cases, fasciitis in 8 cases, subcutaneous inflammation in 9 cases, and myoatrophy with fatty infiltration in 1 cases. The STIR sequence discovered all of abnormal lesions; T1WI sequence found 5 cases of subcutaneous inflammation and 1 cases of myoatrophy, but none of myositis or myofasciitis were found; T2WI sequence found 6 cases of myositis, one case of myoatrophy and 2 cases of subcutaneous inflammation, none of myofascitis were found. On the STIR sequence, compared with other bilateral thigh muscle groups, 7 patients showed higher signal intensity on medial and rear thigh muscle groups, had confirmed by pathology that muscle edema were seriously than other groups. Conclusions: With high resolution and high sensitivity of soft tissue, the STIR sequence can significantly improve the detection rate of soft tissue inflammation. The signal intensity can subjectively reflected the degree of muscle damage, and it has important value in clinical practice.