Ultrasound in acute renal inflammatory lesions.

Ultrasound examinations were analysed in 38 patients with acute renal infections (pyelonephritis, focal pyelonephritis, renal abscess, pyonephrosis). Ultrasound examination is normal in mild inflammatory involvement of parenchyma. In severe involvement diffuse enlargement of parenchyma with low density of echoes structure is found, while in focal pyelonephritis localized low density of echoes swelling of parenchyma is seen. Fever and flank pain are common to acute ureteral obstruction and acute pyelonephritis and ultrasound can distinguish between these diseases. Among mass lesions ultrasound can distinguish between focal pyelonephritis and abscess, but cannot differentiate between tumour and focal pyelonephritis.