New advances in assessment of the individual renal function in chronic unilateral renal obstruction using functional CT compared to 99mTc-DTPA renal scan

Abstract

BACKGROUND: The selection of optimal treatment for obstructive nephrouropathy requires information about the functional status of each kidney. Nuclear renal scanning objectively measure differential renal function. Multiple studies have demonstrated the role of CT in assessment of renal perfusion and GFR with triphasic CT. The aim of this study was to assess the role of CT based on renal parenchymal volume measurement in assessment of individual renal function compared to ^99mTc-DTPA renal scan in patient with unilateral renal obstruction.

MATERIALS AND METHODS: This prospective comparative study, performed between December 2011 and March 2013 included 42 patients with chronic unilateral obstruction. The percentage of the individual renal functions by ^99mTc-DTPA and by CT were assessed.

RESULTS: The percentage of the individual renal functions as estimated by ^99mTc-DTPA ranged from 0% to 40.43% (13.22). The percent renal volume estimated by CT ranged from 0 to 36.68% (15.52). The correlations between percent renal function by ^99mTc-DTPA and percent renal volume by CT were assessed in obstructed kidneys and there were statistically significant relationships (r = 0.877, P < 0.000).

CONCLUSION: CT scan can be used as an integrated modality for the assessment of the functional and morphological status of unilateral chronic renal obstruction, however ^99mTc-DTPA renal scan is a safe choice with less radiation exposure. Further comparative studies are needed to assess the role of CT-based parenchymal volume in the assessment of individual renal functions in patient with acute obstruction, bilateral nephropathy and renal impairment.