Objective: The purpose of this study, that examined healthy adult subjects and nephropatic patients, was to detect some relations between kidney's sonographic dimensions and renal function, expressed by creatinine clearance to evaluate more significant and useful sonographic parameters for the follow-up of nephropathies.
Subjects and methods: Age, sex, body weight, height, body mass index, creatinine clearance were evaluated in 15 healthy and in 32 nephropathic subjects. In those subjects length, width, and thickness of the kidney and its central echogenic area and the parenchimal thickness of the upper pole were measured by ultrasonographic technique. Measurements were made with the patients in supine/oblique position. Renal shape index, parenchimal volume of the kidney and volume of the central echogenic area were calculated. Renal dimensions were correlated with age, total body area, body mass index and creatinine clearance. The patients, according to creatinine clearance, were divided into three classes: Class 1 Creatinine Clearance > 70 ml/min Class 2 Creatinine Clearance > 30 < 70 ml/min Class 3 Creatinine Clearance < 30 > 10 ml/min
Results: The renal length, as renal failure progressed significantly decreased until creatinine clearance = 30 ml/min. In class 3 the renal volume and the transvers diameter decreased as renal failure progressed. The renal parenchymal volume as renal failure progressed significantly decreased. Our results demonstrated that renal length reduced inside the three classes of patients but the reduction was significant only between the first and the second classes of patients. The transverse diameter and the renal shape index did not reduce significantly inside three classes of patients. The renal parenchimal volume reduced significantly inside the 3 classes.
Conclusions: The more important measurement of renal size is longitudinal diameter in subjects with normal renal function. However, the renal parenchimal volume is the more exact sonographic parameter in end-stage renal failure.