乏脂肪肾血管平滑肌脂肪瘤的MSCT和MR化学位移成像表现及病理基础
MSCT and MR on Chemical Shift Imaging Features of Minimal Fat Renal Angiomyolipoma Correlated with Pathology
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摘要: 目的:探讨乏脂肪肾血管平滑肌脂肪瘤(AML)的多排螺旋CT(MSCT)和MR化学位移成像(CSI)表现及病理基础,旨在提高对该病诊断的准确率。方法:回顾性分析经病理证实的16例乏脂肪肾AML患者的MSCT和MRI资料,分析病灶的大小、形态、密度、增强血供情况及CSI表现,并与手术病理结果对照。结果:16例病灶均表现为实质性肿块,10例病灶呈类圆形,6例病灶呈不规则形,9例病灶见劈裂征,6例见杯口征,5例见皮质掀起征,11例病灶CT平扫呈稍高密度,其中4例密度不均匀,内见小灶性低密度。增强扫描病灶呈快进快退、持续强化和延迟强化三种模式,但峰值强化程度均低于肾皮质。MR成像T2WI病灶均呈低信号,CSI中3例出现反相位信号下降,其中1例呈现反相位病灶中心高信号,周围绕以线状低信号环的特殊表现。结论:乏脂肪肾AML的MSCT和MRI表现有一定特征性,薄层MR反相位CSI对该病诊断有较高的价值。Abstract: Objective: To explore the Multi-slice CT(MSCT) and chemical shift imaging(CSI) manifestations of minimal fat renal angiomyolipoma(RAML) with pathology results and to improve its accuracy of diagnosis. Methods: The data of 16 cases of RAML patients were retrospectively analyzed in comparison with pathological results, including tumor size, shape, density, enhancement degree and patterns, CSI imaging features. Results: 16 lesions were all solid tumor masses. 10 lesions showed round, 6 lesions irregular in shape. moreover, split sign appearance was found in 9 lesions, cup sign in 6 lesions and cortical up sign in 5 lesions. On precontrast CT, 11 cases showed hyperattenuation, including 4 heterogeneous lesions with focal low density. Three pattern were demonstrated by enhanced scanning including wash-in and wash-out, continuous enhancement and delayed enhancement. but peak enhancement degree was lower than the renal cortex. Furthermore, 5 lesions showed hyperintensity on T2-weighted MRI. Hypointensity on out-phase CSI were seen in 3 lesions. Among them, one case showed high signal center surrounded by linear low signal ring. Conclusion: MSCT and MRI examination of minimal fat RAML demonstrates certain characteristic signs, thin layer out-phase CSI may be helpful for diagnosis of the disease.