Hydronephrosis
Hydronephrosis is graded on a four point system and is classified by the amount of dilation within the kidney. The grade of hydronephrosis depends on the amount of dilation, number of calyces (small collecting cups within the kidney) seen and the presence and severity of kidney tissue thinning. This is seen by ultrasound imaging.
Grading of Hydronephrosis:
Grade 1: mild “stretching” or dilation of the renal pelvis (where urine collects and drains to the bladder) only
Grade 2: moderate “stretching” or dilatation of renal pelvis including a few calyces
Grade 3: “stretching” or dilatation of the renal pelvis, seeing all the calyces, which are uniformly “stretched” or dilated, and normal kidney tissue
Grade 4: “stretching” or dilatation of the renal pelvis, seeing all of the calyces, and thinning of the kidney tissue