Bland thrombus featuring a uniform signal intensity and lack of enhancement after gadolinium can be distinguished from tumor thrombus, which exhibits intermediate or high signal intensity, heterogeneous intensity, and, more reliably, the presence of small vessels. In a recent study involving 81 patients with RCC, MRI was reported to have a 92% sensitivity, an 86% specificity, an 89% positive predictive value, and a 91% negative predictive value for identifying IVC wall invasion [69]. Pitfalls of MRI include the potential for large tumors to compress the vena cava and cause flow-related artifacts. Such artifacts can be reduced with appropriate saturation pulses. MRI Head Most patients with metastases to the central nervous system are symptomatic. Thus, current guidelines do not support routine imaging of the brain to search for metastases in asymptomatic patients in the initial staging of RCC. Staging of Renal Cell Carcinoma Brain imaging should be performed only in cases with suggestive signs or symptoms [5,13]. In symptomatic patients with contraindication to IV contrast, MRI brain without contrast may be helpful. MRU There is no relevant literature suggesting that MRU offers any additional benefit over conventional MRI of the abdomen in the initial staging of RCC, and thus, this method is not included in the guidelines from the EAU and NCCN [5,13]. Radiography Chest The lung is the most common site of metastases in patients with RCC presenting with synchronous metastases. Although the incidence of metastases in RCC <4 cm is low (approximately 1%-2%), it has been reported that 20% to 30% of T1a tumors may have potentially aggressive histologic features. Hence, chest radiography is usually performed in the staging of RCC [13]. However, CT is more sensitive than radiography for the detection of pulmonary metastases from RCC during staging.
Staging of Renal Cell Carcinoma. Bland thrombus featuring a uniform signal intensity and lack of enhancement after gadolinium can be distinguished from tumor thrombus, which exhibits intermediate or high signal intensity, heterogeneous intensity, and, more reliably, the presence of small vessels. In a recent study involving 81 patients with RCC, MRI was reported to have a 92% sensitivity, an 86% specificity, an 89% positive predictive value, and a 91% negative predictive value for identifying IVC wall invasion [69]. Pitfalls of MRI include the potential for large tumors to compress the vena cava and cause flow-related artifacts. Such artifacts can be reduced with appropriate saturation pulses. MRI Head Most patients with metastases to the central nervous system are symptomatic. Thus, current guidelines do not support routine imaging of the brain to search for metastases in asymptomatic patients in the initial staging of RCC. Staging of Renal Cell Carcinoma Brain imaging should be performed only in cases with suggestive signs or symptoms [5,13]. In symptomatic patients with contraindication to IV contrast, MRI brain without contrast may be helpful. MRU There is no relevant literature suggesting that MRU offers any additional benefit over conventional MRI of the abdomen in the initial staging of RCC, and thus, this method is not included in the guidelines from the EAU and NCCN [5,13]. Radiography Chest The lung is the most common site of metastases in patients with RCC presenting with synchronous metastases. Although the incidence of metastases in RCC <4 cm is low (approximately 1%-2%), it has been reported that 20% to 30% of T1a tumors may have potentially aggressive histologic features. Hence, chest radiography is usually performed in the staging of RCC [13]. However, CT is more sensitive than radiography for the detection of pulmonary metastases from RCC during staging.