Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney. It accounts for 90-92 % of adult renal tumors, and 2-3 % of all adult malignancies .
About half of all RCC are discovered as an incidental finding on cross-sectional imaging studies; computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) .
Adequate preoperative radiologic assessment provides the treating physician with information critical in determining the sequence of treatments, role of nephron-sparing surgery, surgical approach, the use of ablative techniques, and timing of systemic therapy for metastatic disease .
The goals of radiologic imaging are to detect and stage the primary tumor,​evaluating the possibility of regional nodal or abdominal visceral metastases , such as to the adrenal glands, liver, pancreas, and contralateral kidney, delineation of vascular anatomy and evaluation of venous thrombosis.
Recently In addition to morphologic imaging features, the dynamic contrast agent–enhancement features of clear cell, papillary, and chromophobe RCC may assist in imaging
diagnosis. By using dynamic contrast-enhanced computed tomography (CT) and dynamic contrast-enhanced MR imaging .
Diffusion-weighted MR Imaging could add supportive information for differentiation of malignant from benign masses particularly​in evaluating such patients who enhanced imaging techniques are contraindicted .