Background: Renal scintigraphy with technetium 99m labeled dimercaptosuccinic acid
(99mTc-DMSA) is a traditional imaging technique commonly used to detect renal scar in
patients with probable vesicoureteral reflux (VUR) and/or urinary tract infection (UTIs).
We determined whether normal results of DMSA renal scan obviate the need for voiding
cystourethrography (VCUG) in evaluating children with UTIs.
Materials and Methods: We observed medical records from June 2006 to April 2007 retrospectively
of 208 children admitted with community acquired UTIs to Mofid children hospital
(Tehran, IR/Iran) a teaching hospital in Tehran in which their age was between 2-120
months. The association between DMSA renal scan results and VCUG findings performed 48
hours and 1 month after the diagnosis was evaluated. To examine the accuracy of abnormal
DMSA results in predicting VUR, sensitivity, specificity, positive predictive value (PPV), negative
predictive value (NPV) and negative and positive likelihood ratio (LRs) were calculated.
Results: VUR was seen in 14.0% of renal units with normal results of DMSA and 17.3% of renal
units with abnormal DMSA findings. High grade VUR (grade III–V) was seen in 18 (7.1%)
of the abnormal findings of DMSA group and in (2.8%) 1 of the normal DMSA results group
(P = 0.56). In the group with previous UTI (n = 68), the sensitivity and NPV of abnormalities
on DMSA renal scan for detecting the presence of VUR (grade III–V) were 100%, and100%, respectively.
In the group without evidence of previous UTI, the sensitivity and NPV of abnormalities
on DMSA renal scan for detecting the presence of VUR (grade III–V) were 93% and 97%,
respectively. Totally the sensitivity and NPV of abnormalities on DMSA renal scan to detect
the presence of VUR (grade III–V) were 94% and 97%, respectively.
Conclusions: As a screening test, DMSA renal scan is a high sensitive technique to assess
VUR (grade III–V) in children with UTI.