ABSTRACT
AIM: To study the clinical significance and radiologic features of perirenal fluid in patients with renal parenchymal disease. MATERIALS AND METHODS: During the previous 5 years, nine patients were found to have perirenal fluid on sonography associated with renal parenchymal medical disease. The clinical, radiological, histopathological and laboratory data were analysed. RESULTS: The perirenal fluid is a spontaneous subcapsular transudate in patients suffering from a nephropathy with a sodium retention state, with or without renal failure. Three sonographic patterns of perirenal fluid were observed: grade 1 is a thin layer of perirenal fluid; grade 2 is a moderate amount of perirenal fluid collection with indentations of the renal parenchyma and strands in the fluid, grade 3 is a large fluid collection surrounding the kidney. CONCLUSION: The perirenal fluid represents a sign of sodium retention state and oedema in patients with intrinsic renal parenchymal medical disease which may be caused by several nephropathies.