弥散加权成像在软组织脓肿中的诊断价值

Diagnostic value of diffusion-weighted magnetic resonance imaging in soft tissue abscesses

目的探究弥散加权成像(DWI)在软组织脓肿中的诊断价值。方法搜集我院48例拟诊为软组织脓肿或囊肿患者。病灶的分布部位为:眶周1例,乳房3例,腹腔内13例,肌肉内31例。在其他放射学检查后,在1.5TMR系统中行DWI。在b-1000DWI上定量测量病灶的信号强度值。行DWI后对所有病例进行穿刺,以穿刺抽吸到脓液作为诊断脓肿的金标准。结果 37例在DWI上呈高信号,其中假阳性结果2例,真阳性结果35例。10例在DWI上呈低信号,其中假阴性2例,真阴性8例。1例脓肿在DWI上未显示,而在增强MRI上显示,此例视为假阴性。DWI对软组织脓肿的敏感性和特异性分别为92.1%、80.0%。结论 DWI在软组织脓肿诊断中有较高的诊断价值,并且是一种可能用于鉴别囊肿和脓肿的重要影像学方法。

Objective To study the diagnostic value of diffusion-weighted imaging （DWI） in soft tissue abscesses. Methods The study enrolled 48 patients who were thought to have soft tissue abscess or cystic lesion as result of clinical and radiological examinations. Localizations of the lesions were： periorbital 1, breast 3,intraabdominal cavity 13, and intramuscular lesions 31. After other radiological examinations, DWI was performed with 1. 5T MR system. The signal intensity values of the lesions were evaluated qualitatively according to the hyperintensity on b-1000 DWI. All of the lesions were aspirated after DWI,and detection of pus in the aspiration material was accepted as gold standard for the diagnosis of abscess. Results In 37 of the 48 patients, hyperintensity was obtained on diffusion- weighted images. False-positive results were maintained in 2 of these patients,and true-positive results were maintained in 35 of them. In 10 of the 48 patients,hypointensity was visualized on diffusion-weighted images. False-negative results were maintained in 2 of these patients,and true-negative results were maintained in 8 of them. An abscess which was seen on post-contrast conventional MRI could not be seen on DWI, and this was regarded as false-negative. The sensitivity and specificity of diffusion-weighted images for detecting soft tissue abscesses were found to be 92.1 % and 80. 0%,respectively. Conclusion DWI has high diagnostic value in soft tissue abscesses,and it is an important imaging modality that may be used for the differentiation of cysts and abscesses.