Assessment of the individual renal function in chronic unilateral renal obstruction using functional CT as compared to 99mTc-DTPA renal scan

The selection of optimal treatment of 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 assessment of renal perfusion and GFR with triphasic CT. The aim of this study is 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 patients with unilateral renal obstruction. During the indicated time interval, 42 patients with chronic unilateral obstruction; the percentage of the individual renal functions by 99mTc-DTPA and by CT were assessed. The percentage of the individual renal functions as estimated by 99mTc-DTPA in obstructed kidneys ranged from 0% to 40.43% (13.22), while by CT is in range from 0 to 36.68% (15.52). The correlation between percent renal function by 99mTc-DTPA renal scan and percent renal volume by CT were assessed in obstructed kidneys and there were statistically significant relationship (r = 0.877, P < 0.0001). CT scan can be used as an integrated modality to assess 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 evaluation of individual renal functions in patients with acute obstruction, bilateral nephropathy and renal impairment.