MR urography for suspected upper tract urothelial carcinoma

Abstract

The key components of the MR urography protocol for suspected upper tract urothelial carcinoma are coronal T2-weighted hydrographic sequences without contrast agent and coronal gadolinium-enhanced T1-weighted 3D-spoiled gradient-recalled echo in nephrographic and pyelographic phases. Upper tract urothelial carcinomas can be categorized into papillary tumor, flat tumor, and infiltrative tumor based on the growth pattern and extent. Papillary lesions appear as small filling defects of soft tissue signal on T2-weighted hydrographic and T1-weighted pyelographic phase images. On nephrographic phase images, the lesions show homogeneous enhancement. A flat tumor appears as a segmental area of diffuse thickening and enhancement of the urinary tract wall on nephrographic phase images. Infiltrative tumor often appears as a large heterogeneously enhancing mass. MR urography is a promising alternative for CT urography in the evaluation of upper tract urothelial carcinoma, especially when the patient has a contraindication to iodinated contrast material.

CT Urography for Diagnosis of Upper Urinary Tract Urothelial Carcinoma: Are Both Nephrographic and Excretory Phases Necessary?

“…The agreement was the lowest for the nephrographic phase alone, likely because some of the findings on nephrographic phase images were subtle. Likewise, on MR urography, the nephrographic and excretory phases have been shown to be complementary for detecting upper tract urothelial carcinoma [26].…”

Possibilities of Computed Tomography Urography and Magnetic Resonance Urography as Up-To-Date and Informative Techniques in the Diagnosis of Traumatic Ureteral Strictures

“…Установить уровень и причину урообструкции на сегодняшний день возможно с помощью компьютерно-томографической урографии (КТУ),это исследование позволяет целиком визуализировать мочевые пути и рекомендуется отечественными и зарубежными специалистами в качестве предпочтительной методики [1,11,12]. Также с этой целью используют магнитно-резонансную урографию (МРУ) [13][14][15], она требует большего количества времени, однако может оказаться исследованием выбора у пациентов с противопоказаниями к ионизирующему излучению. МРУ можно провести в статическом режиме без контрастного усиления (в этом случае основой являются Т2-взвешенные изображения (Т2-ВИ) в корональной плоскости, как при МР-холангиопанкреатографии).…”

The Potential of Magnetic Resonance Urography in the Diagnosis of Ureteral Strictures

“…A number [12,14,15]. However, the potential of the method in identifying the causes of urinary tract abnormalities remains understudied [16]. The aim of the study was to assess the sensitivity of magnetic resonance urography (both native and contrast-enhanced examinations) in the diagnosis of ureteral strictures and to evaluate its importance in the diagnostic algorithm in patients with different forms of urinary obstruction.…”