Urinary Imaging in Children with Urinary Tract Infection

Urinary imaging is essential because UTI in children is usually the first prensenting sign of urinary tract anomaly.

Early diagnosis and treatment of major urinary tract anomaly are important to prevent renal damage. But thereis still considerable disagreement as to that investigation should be undertaken first. Until several years ago, IVP and VCUG were included as routine tests in all children after the first or second UTI. Recent studies indicate the ultrasound can effectively replace IVP as a screening procedure and Tc-DMSA scan is more sensitive than IVP for the detection of early stage of renal scar and predictability of VUR.

We performed the various imaging studies of urinary tract in 142 children, diagnosed as ter first UTI in Pediatric department of E.W.U.H. from March, 1984 to March, 1990 and evaluated the results retro spectively.

There results were as follow :

1) Abnormalities were observed in 42 of 142 children with(29.6%), 30 of 101 males(29.7%) and 12 of 41 female(29.2%).

2) Urinary tract anomalies were 22 primary vesicoureteral refluxes(15.5%), 9 obstructive uropathy(6.3%), 3 non-obstructing, non-refluxing megaureter(2.1%), 3 tones(2.1%), 3 renal anomaly(2.1%), one bladder diverticulum(0.7%). Obstructive uropathy was deceted more in male than female(p<0.05). Renal scars were observed in 10, 7 in male(6.9%) and 3 in female(7.3%).

3) The detection rates of abnormal finding were not significantly diffrent, 16.9% in VCUG, 22.2% in IVP, 23.3% in US and 28.1% in Tc-DMSA scan.

4) VUR, bladder diverticulum and PUV were 100% diagnosed by VCUG. Renal anomaly and dilated urinary tract of obstructive uropathy and non-obst. non-reflux. megaureter were 100% deteced by US, IVP and Tc-DMSA scan. One of 3 stones was missed by US but detected during VCUG. Ectopic ureter was the only one that needed IVP.

5) The predictive rate of VUR was 60% in Tc-DMSA scan significantly higher than US(36%) or IVP(23%)(p<0.05) . High grade VUR(Gr IV-V) was 100% predicted in all three exam but low grade VUR was more predicted by Tc-DMSA scan(50%) than US(10%) or IVP(5.6%).

6) Renal scar was diagnosed by Tc-DMSA scan(21.9%) significantly higher than IVP(6.0%) and US(1.0%). In comparision of Tc-DMSA and IVP in 32 completed cases. TC-DMSA scan had a higher diagnostic rate of renal scar with higher sensitivity than IVP.

In summary, we can decet major urinary tract anomalies and renal scar with more accuracy and less radiation with US and Tc-DMSA scan in acute stage and VCUG in 2 weeks. The additional value of IVP as a screening test was scant. IVP will be indicated in selected cases to delineate the morphology of urinary tract.