Clinical Significance of Uptake Difference on DMSA Scintigraphy in Pediatric Urinary Tract Infection

PURPOSE: Disruption of normal renal development can lead to congenital anomalies of the kidney and urinary tract, including renal hypodysplasia. We aimed to clarify whether small kidney size affects clinical manifestations in children with urinary tract infection (UTI). METHODS: One hundred fifty-four patients who had their first symptomatic UTI between January 2014 and June 2015 were enrolled in this study. Differences in kidney size were estimated based on percent uptake of (99m)Tc-dimercaptosuccinic acid (DMSA) in scintigraphy. The patients who showed more than 10% difference in kidney size on DMSA scintigraphy with none or minimal cortical defects were included in group A. (group A, n=17). Laboratory, clinical, and imaging results were compared with those of the other patients (group B, n=137). RESULTS: Group A had a relatively higher incidence of vesicoureteral reflux than group B (44% vs 20%, P<0.05). The levels of plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum C-reactive protein were significantly higher in group A (193 [64-337] vs 91 [59-211] ng/mL and 4.1 [0.5-11.9] vs 2.1 [0.7-5.3] ng/mL, respectively; all P<0.05). Linear regression analysis revealed that plasma NGAL level strongly correlated with the difference in renal uptake in DMSA scintigraphy in group A (R²=0.505). CONCLUSION: The difference in kidney size could influence the clinical course and severity of pediatric UTI.

The Comparison between Pre- and Postoperative Diagnosis in Renal Masses Smaller than 3cm in Diameter / 대한비뇨기과학회지

PURPOSE: Small renal parenchymal masses smaller than 3cm in diameter have been discovered with increasing frequency. This increment also increased the detection of benign tumor as well as the renal cell carcinoma. However many of them are radiologically indeterminate. We compared the results of pathologic examinations and preoperative radiologic features to determine the characteristics in small renal masses that preoperatively differentiate benign tumors from the malignant tumors. MATERIALS AND METHODS: 27 patients who had operative management due to renal masses smaller than 3cm in diameter were retrospectively analysed. Mean age of the patients was 52.3 years and mean diameter of renal masses was 2.1+/-0.8cm. Preoperative ultrasonoraphy(USG) and computerized tomography(CT) findings were compared with postoperative results of pathologic examinations. RESULTS: Of 27 patients, 17(63%) were renal cell carcinomas, 5(7.4%) were angiomyolipomas(AMLs), 3(11.1%) were complicated cysts, 1(3.7%) was oncocytoma, 1(3.7%) was leiomyoma. Of the typical enhancement patterns of renal cell carcinoma on CT, heterogenous enhancement(29.4 vs. 14.3%), central necrosis(47.1 vs. 14.3%) were more frequent in small RCCs than small benign solid renal masses. However, early enhancement and delayed wash-out pattern(64.7 vs. 85.7%) was less frequent in small RCCs than small benign solid renal masses. All small cystic masses were shown the radiologic findings of Bosniak classification III or IV. All AMLs appeared to be sonographically homogeneous hyperechoic masses that were highly suggestive of AML. However, none of RCCs showed these sonographic findings. CONCLUSIONS: In small renal parenchymal mass smaller than 3cm in diameter, postopertive benign tumors were not uncommon regardless of the malignant features on the CT findings. Retrospectively , USG might be a better choice for AML detection than CT. Therefore, both USG and CT should be included in preoperative workup for small renal masses.