Diagnostic Value of (99m)Tc-DMSA Pinhole Imaging in Childhood Urinary Tract Infection with Renal Cortical Defect

ABSTRACT

PURPOSE: The aim of this study was to assess the diagnostic value of the (99m)Tc-DMSA pinhole imaging by comparing the detection rate of cortical defects identified from planar and pinhole imaging. METHODS: (99m)Tc-DMSA planar and pinhole imaging, voiding cystoureth-rogram(VCUG), renal ultrasonography were performed in 67 patients diagnosed with urinary tract infection at the Department of Pediatrics, Sung-Ae General Hospital, from September, 1999 to Feburary, 2001. The follow-up of (99m)Tc-DMSA pinhole imaging was performed on 25 patients. RESULTS: Overall detection rate of (99m)Tc-DMSA planar imaging was 41.8%(28 patients/67 patients), but (99m)Tc-DMSA pinhole imaging showed cortical defects in 62.7%(42 patients/67 patients) and the patients with renal cortical defects in planar imaging showed all definite or more additional cortical defects in pinhole imaging. The detection rate of cortical defect by (99m)Tc- DMSA pinhole imaging in patients with vesicoureteral reflux(VUR) was 80%(24 kidneys/30 kidneys). Those without VUR, however, also presented high detection rate as 25.9%(27 kidneys/ 104 kidneys). Out of 25 patients, improvement of cortical defect was presented in 19, no change in 4, and aggravation in 2 from the follow-up studies by (99m)Tc-DMSA pinhole imaging. CONCLUSION: This study indicates that (99m)Tc-DMSA pinhole imaging is superior to planar imaging and, hence, that pinhole imaging is a useful initial diagnostic tool for children suspected of urinary tract infection, irrespective of VUR, and to identify patients who need more extensive radiological studies and early treatment.