الفهرس | Only 14 pages are availabe for public view |
Abstract Early detection of RCC is very important to improve the patient’s survival. The response of recent treatment options such as immunotherapy has been influenced by histologic subtype of RCC so management decisions will likely continue to be tailored to histologic subtypes. Morever patients with papillary or chromophobe RCC have a higher 5 years survival than those with clear RCC of same stage. The characterization of renal masses relies mainly on CT which remains the gold standard in the diagnosis of renal tumors and cysts. MRI is useful in the diagnosis of renal tumors when CT findings are inconclusive or when the administration of intravenous iodinated contrast material is contraindicated. The aim of the work is to study the role of MRI in diagnosis and characterization of different renal tumors. The most important questions that are raised during preoperative staging of renal cell carcinoma are the evaluation of intra- and extrarenal extent of tumor, involvement of perirenal fat, of renal veins and inferior vena cava, and of regional lymph nodes. Most of these problems can be solved using MRI which provides better results in evaluation of perirenal and vascular involvement as MRI considered to be the best noninvasive method for the assessment of tumor thrombi in the renal veins or the inferior vena cava. The presence or absence of enhancement within a renal mass is an important factor for proper characterization, MRI with intravenous contrast administration can provide excellent information for characterization and staging of different renal tumors. The degree of enhancement is one of the most valuable parameters for differentiation of RCC subtypes, as clear RCC and oncocytoma enhanced avidly during the parenchymal phase, whereas chromophobe carcinomas and angiomyolipomas enhanced moderately and papillary tumors enhanced the least. Diffusion-weighted MR imaging considered as a promising technique as it can play an important role in the characterization of the renal masses, differentiate benign and malignant solid lesions, and suggest the histotype of malignant lesions. |