Technetium-99m-DMSA renal SPECT in diagnosing and monitoring pediatric acute pyelonephritis.

UNLABELLED: This study compares the sensitivity of 99mTc-dimercaptosuccinic acid (DMSA) renal SPECT with planar scintigraphy, concluding the importance of 99mTc-DMSA renal SPECT for the early diagnosis of acute pyelonephritis (APN) in patients under 3 yr of age. METHODS: Twenty-seven children under 3 yr of age, with clinical and/or laboratory suspicion of APN, were investigated. All 99mTc-DMSA renal SPECT and planar images and voiding cystoureterogram (VCUG) were obtained within 3 days of hospitalization. RESULTS: In the first examination, renal cortical defects were detected in 23 patients (42 kidneys) with SPECT and in 9 patients (11 kidneys) with planar scintigraphy. One year after treatment, constant renal cortical lesions were observed in 11 patients (14 kidneys) with SPECT and 4 patients (4 kidneys) with planar scintigraphy. The high grades of vesicoureteral reflux (VUR) (grade >or= 3) correlate better with APN diagnosed by SPECT (34 kidneys) than by planar scintigraphy (8 kidneys). Multiple renal cortical defects (number of lesions >or= 4) were only seen in patients under 1.5 yr old and none of those with a negative 99mTc-DMSA renal SPECT had a positive 99mTc-DMSA renal planar scintigraphy at any time. There is a significant difference (p < 0.05) between the diagnostic ability of these two methods of examination. CONCLUSION: Our results suggest that 99mTc-DMSA renal SPECT should be used, where possible, instead of planar DMSA in routine examination of children with clinical suspicion of APN, especially for those under 3 yr of age.