MULTILOCULAR CYSTIC NEPHROMA - MR-IMAGING APPEARANCE WITH CURRENT TECHNIQUES, INCLUDING GADOLINIUM ENHANCEMENT

The purpose of the study was to define the MRI appearance of multilocu lar cystic nephroma (MLCN), using current MR techniques, including gad olinium (Gd)-enhanced sequences. Seven patients with MLCN underwent MR imaging with the following sequences: T1-weighted spin echo with fat suppression (T1FS, five patients), T1-weighted spoiled gradient echo ( SGE, seven patients), Ta-weighted fast spin echo (two patients), and G d-enhanced T1FS (seven patients) and SGE (seven patients), MLCN was hi stologically proven by resection of the mass in six patients and by ob servation of typical imaging features with stability in appearance ove r a 6-month period in one patient. Lesion morphology and signal intens ity (SI) features were retrospectively evaluated. MRI: features of MLC N included a solitary cystic lesion with thin internal septations in s ix patients and a cluster of closely grouped cysts similar in size in one patient. Individual cystic spaces demonstrated SI, varying from lo w to high on T1-weighted images in three patients and demonstrated low -to-intermediate SI in four patients, Herniation of the lesions into t he renal collecting system and thin enhancing septa were demonstrated in all patients. A complex cystic renal lesion with enhancing septa an d herniation into the renal collecting system are the characteristic M R findings of MLCN. The direct multiplanar capability of MR may optima lly show the relationship of MLCN to the renal pelvis and, thus, facil itate correct diagnosis.