The Diagnostic Value of 99mTc DMSA Renal Scan SPECT Images in Addition to Planar Image in Children with Urinary Tract Infection

ABSTRACT

PURPOSE: 99mTc DMSA renal scan have been widely used not only for the evaluation of renal scars but also for the diagnosis of acute pyelonephritis. Recent studies have shown SPECT images have higher accuracy than the planar images with some controversy. We evaluated the availability of the SPECT images adding to planar images for the diagnosis of acute pyelonephritis(APN) and renal scar in children with urinary tract infection (UTI). METHODS: 130 children with UTI (260 kidney units) and 22 follow-up children (44 kidney units) were included between January 1, 1997 and July 31, 1999 at Ewha University Mokdong Hospital. Planar Anterior and posterior images and SPECT axial and coronal images of 99mTc DMSA renal scan were obtained with Starcam 4000-i U.S.A. GE at 3 hours after 99mTc DMSA I.V. injection. The data were analyzed by Chi square test after Yates's correction. RESULTS: The detection rate of the acute pyelonephritis by SPECT images was 12.3% higher than that of planar images (47.7% vs 35.4%) by the patient and 6.9% higher also (31.9% vs 25.4%) by the kidney unit. 18 kidney units with negative planar images had focal defect in 10 kidney units (3.8%) and multifocal defect in 8 kidney units (3.1%) on SPECT images, but 1 kidney unit with positive planar image had negative SPECT image. SPECT images were superior to the planar images in 17.3%, identical in 82.3% and inferior in 0.4% to planar image. The detection rate of the renal scars by SPECT images was 13.7% higher than planar images by the patient (68.2% vs 54.5%) and 6.8% higher also (43.2% vs 36.4%) by the kidney unit. SPECT images were superior to the planar images in 17.3% and identical in 82.3% to planar image. CONCLUSION: SPECT images had shown higher detection rate and better image than planar images for the diagnosis of the acute pyelonephritis and the evaluation of the renal scars.