Unenhanced MRU relies upon heavily T2-weighted imaging of the intrinsic high signal intensity from urine for evaluation of the urinary tract. IV contrast is administered to provide additional information regarding obstruction, urothelial thickening, focal lesions, and stones. A contrast-enhanced T1-weighted series should include a corticomedullary, nephrographic, and excretory phase. Thin-slice acquisition and multiplanar imaging should be obtained. For the purposes of this document, we make a distinction between MRU and MRI abdomen and pelvis without and with IV contrast. MRI abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts, without both the precontrast and excretory phases, and without heavily T2- weighted images of the urinary tract. Discussion of Procedures by Variant Variant 1: Follow-up for clinically localized renal cell carcinoma; post radical or partial nephrectomy. Many tumor- and patient-specific characteristics have been shown to be predictive of local recurrence or distant metastasis of RCC after treatment [2,14-19]. In addition to these characteristics, the timing and location of tumor recurrence and the type of treatment (ie, RN versus PN) are considered in the development of imaging surveillance strategies that aim to identify asymptomatic solitary or oligometastatic disease that may benefit from early potentially curative or life-prolonging salvage treatment [10,16,20]. Among the tumor characteristics predictive of tumor recurrence, the tumor, node, and metastases staging system has been the most extensively researched; associations between pathologic T stage and both the risk and patterns of tumor recurrence have been demonstrated in many studies [14,15,17,21].
Post Treatment Follow up and Active Surveillance of Renal Cell Carcinoma. Unenhanced MRU relies upon heavily T2-weighted imaging of the intrinsic high signal intensity from urine for evaluation of the urinary tract. IV contrast is administered to provide additional information regarding obstruction, urothelial thickening, focal lesions, and stones. A contrast-enhanced T1-weighted series should include a corticomedullary, nephrographic, and excretory phase. Thin-slice acquisition and multiplanar imaging should be obtained. For the purposes of this document, we make a distinction between MRU and MRI abdomen and pelvis without and with IV contrast. MRI abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts, without both the precontrast and excretory phases, and without heavily T2- weighted images of the urinary tract. Discussion of Procedures by Variant Variant 1: Follow-up for clinically localized renal cell carcinoma; post radical or partial nephrectomy. Many tumor- and patient-specific characteristics have been shown to be predictive of local recurrence or distant metastasis of RCC after treatment [2,14-19]. In addition to these characteristics, the timing and location of tumor recurrence and the type of treatment (ie, RN versus PN) are considered in the development of imaging surveillance strategies that aim to identify asymptomatic solitary or oligometastatic disease that may benefit from early potentially curative or life-prolonging salvage treatment [10,16,20]. Among the tumor characteristics predictive of tumor recurrence, the tumor, node, and metastases staging system has been the most extensively researched; associations between pathologic T stage and both the risk and patterns of tumor recurrence have been demonstrated in many studies [14,15,17,21].