1．5TMRI用于脑内环形强化病变鉴别诊断中的应用研究

Clinical research of differential diagnosis of circular enhanced brain lesions by 1.5TMRI

目的探讨1．5TMRI在脑内环形强化病变鉴别诊断中的价值。方法回顾性分析泰山医学院附属莱芜医院影像中心选自2009年4月至2013年3月经临床手术病理证实的，表现为环形强化的脑转移瘤、胶质瘤以及脑脓肿各40例病例的1．5TMRI表现，比较各病种的影像征象差异。结果脑转移瘤与胶质瘤组间病灶的位置、数目、大小、形态、分房征、多发壁结节、外侧壁是否光整征象有差异；脑转移瘤与脑脓肿组间病灶的数目、大小、子母环征、环壁切迹征、环壁厚度、内侧壁是否光整、T2WI低信号环征、液液平征、病灶中心DWI高信号及ADC图低信号、灶周水肿程度征象有差异；胶质瘤与脑脓肿组间病灶的位置、形态、分房征、子母环征、多发壁结节、环壁切迹征、环壁厚度、内外侧壁是否光整、T2WI低信号环征、液液平征、病灶中心DWI高信号及ADC图低信号征象有差异。脑转移瘤的征象依次为多发病灶、灶周Ⅲ级水肿、小病灶、外侧壁光整、病灶位于皮髓质交界处，显示百分比分别为79．5％、70．3％、67．5％、48．5％、47．9％；胶质瘤的征象依次为分房征、病灶位置在髓质、多发壁结节、外侧壁不光整、病灶为不规则形，显示百分比分别为85．7％、78．0％、77．8％、65．4％、51．9％；脑脓肿的征象依次为子母环征、DWI高并ADC图低信号、环壁切迹征、T2WI低信号环征、液液平征，显示百分比分别为100％、100％、100％、92．6％、82．4％。结论1．5TMRI能够显示脑转移瘤、胶质瘤、脑脓肿3种病变特征性征象，对三者鉴别诊断具有重要价值。

Objective To evaluate the value of 1.5T MRI in differential diagnosis of circular enhanced brain lesions. Methods A total of 120 patients, admitted to our hospital from April 2009 to March 2013 and confirmed by clinical pathology, including 40 of brain metastasis, 40 of astrocytoma and 40 of brain abscess, were chosen in our study; The characteristic signs of MRI findings of these patients were retrospectively analyzed. Results There were significant differences in the location, number, size, morphology, ring structure, multiple mural nodules, and smooth outside wall of the lesions between patients with brain metastasis and astrocytoma. There were significant differences in the number, size, ring structure, ring wall thickness, and smooth outside wall of the lesions, T2-weighted imaging （T2WI） low signal ring sign, hydraulic fluid level sign, lesion center diffusion weighted imaging （DWI） hyperintensity and apparent diffusion coefficient （ADC） map low signal between patients with brain metastasis and abscess. There were significant differences in the location, shape and multi locular lesions between patients with astrocytoma and abscess. The signs indicating brain metastasis included multi lesions, grade Ⅲ peripheral edema, small lesions, lesions located at the juncture of gray and white matter, with displaying percentages of 79.5%, 70.3%, 67.5%, 48.5% and 47.9%. The signs indicating astrocytoma included multi locular lesion, lesions located at the white matter, multi mural nodule, rough outside wall and irregular in shape, with displaying percentages of 85.7%, 78.0 %, 77.8%, 65.4 % and 51.9%. The signs indicating abscess included daughter ring sign, DWI hyperintensity and ADC map low signal,circular wall notch sign, hype-intensity rim on T2WI and fluid-fluid level, with displaying percentages of 100%, 100%, 100%, 92.6% and 82.4%. Conclusion The 1.5T MRI can display the characteristic signs of brain metastases, gliomas and brain abscess, which enjoys high value in differential diagnosis.