In another study involving 579 patients, CT was reported to have a 100% negative predictive value, a 100% sensitivity, and a 95% specificity for identifying adrenal involvement [41]. Assessment of RCC nodal metastases on CT is limited [42]. This is due to the fact that CT uses size criteria for nodal metastasis (size >1 cm in short-axis), but this leads to underestimation of disease, resulting in false negatives in the presence of micrometastases in nodes <1 cm in size. Furthermore, false positives are also often seen because of presence of reactive adenopathy, with nodes >1 cm in size. CT is accurate in detecting distant metastases in the abdomen. RCC visceral metastases may occur at various organs including liver, pancreas, adrenals, and contralateral kidney. RCC metastases tend to be hypervascular, and some authors have suggested that arterial phase imaging can be useful to accurately detect the extent of distant metastases [43-46]. CT Abdomen and Pelvis Preoperative imaging of RCC provides critical information on staging and serves as a roadmap to the surgeon. Both CT and MRI are comparable in staging of the primary tumor [15,16]. Advantages of CT include rapid acquisition time that may translate to better patient compliance and high spatial resolution. Hence, it is often the most commonly used modality for this indication. CT abdomen without and with IV contrast is typically performed for charactering a renal mass as RCC and staging the tumor. Acquisition of nephrographic phase images is vital and most important in the detection and characterization of RCC. Corticomedullary phase images and excretory phase images are optional and may be helpful in differentiating RCC subtypes, distinguishing RCC from urothelial tumors and in providing complementary information on the vasculature and tumor extension into pelvicalyceal system. Perinephric tumor extension is difficult to discriminate from nonspecific perinephric stranding due to edema, vascular engorgement, or fibrosis.
Staging of Renal Cell Carcinoma. In another study involving 579 patients, CT was reported to have a 100% negative predictive value, a 100% sensitivity, and a 95% specificity for identifying adrenal involvement [41]. Assessment of RCC nodal metastases on CT is limited [42]. This is due to the fact that CT uses size criteria for nodal metastasis (size >1 cm in short-axis), but this leads to underestimation of disease, resulting in false negatives in the presence of micrometastases in nodes <1 cm in size. Furthermore, false positives are also often seen because of presence of reactive adenopathy, with nodes >1 cm in size. CT is accurate in detecting distant metastases in the abdomen. RCC visceral metastases may occur at various organs including liver, pancreas, adrenals, and contralateral kidney. RCC metastases tend to be hypervascular, and some authors have suggested that arterial phase imaging can be useful to accurately detect the extent of distant metastases [43-46]. CT Abdomen and Pelvis Preoperative imaging of RCC provides critical information on staging and serves as a roadmap to the surgeon. Both CT and MRI are comparable in staging of the primary tumor [15,16]. Advantages of CT include rapid acquisition time that may translate to better patient compliance and high spatial resolution. Hence, it is often the most commonly used modality for this indication. CT abdomen without and with IV contrast is typically performed for charactering a renal mass as RCC and staging the tumor. Acquisition of nephrographic phase images is vital and most important in the detection and characterization of RCC. Corticomedullary phase images and excretory phase images are optional and may be helpful in differentiating RCC subtypes, distinguishing RCC from urothelial tumors and in providing complementary information on the vasculature and tumor extension into pelvicalyceal system. Perinephric tumor extension is difficult to discriminate from nonspecific perinephric stranding due to edema, vascular engorgement, or fibrosis.