膀胱内翻性尿路上皮乳头状瘤的 MRI 表现。

MRI Findings of Inverted Urothelial Papilloma of the Bladder.

机构信息

1 Department of Radiology, Nagoya City University Graduate School of Medical Sciences and Medical School, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.

2 Department of Radiology, Mayo Clinic, Rochester, MN.

出版信息

AJR Am J Roentgenol. 2015 Aug;205(2):311-6. doi: 10.2214/AJR.14.13879.

DOI:10.2214/AJR.14.13879

PMID:26204280

Abstract

OBJECTIVE

The objective of this study was to characterize MRI findings of inverted urothelial papilloma of the bladder.

MATERIALS AND METHODS

Data pertaining to 16 patients with 18 pathologically proven inverted urothelial papillomas of the bladder who had undergone MRI were retrospectively collected from seven institutions. The shape and surface characteristics of the tumors were evaluated using T2-weighted MR images. In addition, the signal intensity of inverted urothelial papillomas was visually assessed on T1-weighted, T2-weighted, and DW images and on early and delayed phase contrast-enhanced images.

RESULTS

The shape of the 18 inverted urothelial papillomas of the bladder was classified as polypoid with a stalk for 16 tumors (89%) and polypoid without a stalk for two tumors (11%). All stalks were surrounded by urine in the bladder. A total of 15 of the tumor surfaces (83%) were nonpapillary and three (17%) were papillary. All 12 of the inverted urothelial papillomas for which evaluable T1-weighted images were available were isointense with the bladder wall. The lesions had a slightly higher signal intensity than the bladder wall in 15 of the patients (83%) and showed isointensity with the bladder wall in three patients (17%). A total of three patients (17%) had tiny hyperintense foci noted on T2-weighted images. All 16 of the inverted urothelial papillomas examined by DWI had very high signal intensity. All 13 of the lesions for which early phase images were obtained using dynamic contrast-enhanced MRI showed strong enhancement. When compared with early phase images, delayed phase images of the same 13 lesions showed that enhancement was stronger in two lesions (15%), similar in six lesions (46%), and weaker in five lesions (38%).

CONCLUSION

On MRI, the typical appearance of inverted urothelial papillomas of the bladder is a polypoid shape with a nonpapillary surface and a thin short stalk surrounded by urine. Cystic foci are also occasionally seen within the tumor.

摘要

目的

本研究旨在描述膀胱内倒置尿路上皮乳头瘤的 MRI 表现。

材料与方法

回顾性收集了来自七家医疗机构的 16 例经病理证实的 18 例膀胱内倒置尿路上皮乳头瘤患者的资料。使用 T2 加权 MR 图像评估肿瘤的形状和表面特征。此外，在 T1 加权、T2 加权、DW 图像以及早期和延迟期增强图像上，视觉评估了倒置尿路上皮乳头瘤的信号强度。

结果

18 例膀胱内倒置尿路上皮乳头瘤的形状分为 16 例（89%）有蒂的息肉样和 2 例（11%）无蒂的息肉样。所有的蒂均被膀胱内的尿液环绕。15 例（83%）肿瘤表面呈非乳头状，3 例（17%）呈乳头状。12 例可评估 T1 加权图像的倒置尿路上皮乳头瘤均与膀胱壁等信号强度。15 例（83%）患者病变信号强度稍高于膀胱壁，3 例（17%）患者病变信号强度与膀胱壁等信号强度。3 例（17%）患者 T2 加权图像上可见微小高信号灶。16 例 DWI 检查的倒置尿路上皮乳头瘤均有很高的信号强度。13 例获得早期相动态增强 MRI 的病变均表现出强烈强化。与早期相相比，13 例病变的延迟相图像显示，2 例（15%）病变强化增强，6 例（46%）病变强化相似，5 例（38%）病变强化减弱。