IMAGING OF RENAL-CELL CARCINOMA WITH GADOLINIUM-ENHANCED MAGNETIC-RESONANCE - RADIOLOGICAL AND PATHOLOGICAL-STUDY

The use of gadolinium-DTPA enhanced MR imaging (Gd-MR) in detecting an d staging of large and small renal neoplasm was investigated in 61 pat ients with 66 renal cell carcinoma confirmed at surgery. The purpose o f the study was also to evaluate the signal intensity of the lesions a nd to correlate the contrast-enhanced pattern to the pathological comp onents and architecture of the surgical specimens. Forty-four tumors w ere larger than 3 cm and 22 lesions were smaller than 3 cm. Unenhanced MRI detected all large lesions (44/44) and 63% (14/22) of small lesio ns, while Gd-MRI detected all large and small neoplasms (100%). The ov erall staging accuracy was 79 and 87% for plain MRI and Gd-MRT, respec tively, but both modalities led to an overstaging of the disease. Enha nced MRI was an excellent staging modality for the evaluation of tumor vascular extension and tumor spread to adjacent structures. The most frequent Gd-MRI pattern of small RCC was hyperintensity, while large l esions were mostly hypointense. The presence of fibrohyaline component s seemed responsible for the hyperintense pattern. No specific contras t-enhanced MRT pattern was observed according to the tumor architectur e (alveolar, tubular or papillar) of noncystic lesions. On the contrar y, cystic lesion appeared as an area of low signal intensity and the u se of contrast media improved detection and characterization. The inho mogeneous signal intensity increased the detectability of the lesion.