磁共振动态增强扫描对肾癌诊断价值的探讨

Contrast-enhanced MRI in the diagnosis of renal carcinoma

目的:研究动态增强磁共振扫描对肾癌的诊断价值和肾癌的强化特点。方法:对35例肾癌患者行SE序列T1WI,TSE序列T2WI,T1WI,T2WI压脂像,TFE序列动态增强及SE序列延迟T1WI扫描。计算并比较不同序列肿瘤-肾实质对比-噪声比(CNR)。计算增强后肾皮质、髓质、肿瘤的信号强度,并绘出曲线,分析各自不同的强化特点。结果:共检出肾癌35例,直径2～12cm。增强后各个序列图像CNR均较增强前有统计学意义(P<0.05),动态增强序列中肿瘤-肾髓质对比在140s左右最明显。结论:磁共振动态增强扫描是诊断肾癌的有效方法。

Objective:To evaluate the usefulness of pre-and post contrast-enhanced dynamic MRI in the diagnosis of renal cell carcinomas (RCCs).Methods:Thirty-five patients with thirty-five RCCs and one angiomyolipoma were studied by both conventional spin echo and dynamic contrast-en-hanced MRI.Dynamic MRI was performed with turbo field echo sequence after bolus injection of gadolinium diethylenetriamine pentaacetic acid(Gd-DTPA).Characterization of a renal mass was done by the visual analysis of tumor vascularity as well as quantitative assessment of the contrast noise ratio(CNR)and degree of the enhancement.Results:In the dynamic study the tumor /renal medulla contrast was most conspicuous at140s after initiation of bolus injection of contrast medium.The tumor /renal medulla contrast in the dynamic study was more markedly than that of precontrast T1-weighted imaging and T2-weighted imaging(P<0.05).The tumor /renal medulla contrast in precontrast T1WI SPIR and T2WI SPIR was more striking than in conventional T1-weighted imaging and T2-weighted imaging (P<0.05).Conclusion:Dynamic contrast-enhanced MRI is a useful technique for the diagnosis of RCCs,especially for the patient who is allergic to iodinated contrast material or has renal insufficiency.