Dr. David Schulsinger explains that perinephric fat stranding is a hazy appearance in a linear pattern in the soft tissues in the perinephric space on a computed tomography image. The perinephric space, explains Aizenstein et al. is a cone-shaped compartment that contains the kidney, adrenal glands and perinephric fat.
Dr. Schulsinger says that perinephric fat stranding is caused by any of a variety of acute processes or injuries to the kidney. Perinephric fat stranding is probably the result of increased pressure in the collecting system due to the beginning stages of ureteral obstruction. Unilateral perinephric fat stranding is often caused by calyceal rupture or perinephric inflammation.