Clinical follow-up of children with low differential function on diuretic renogram.

OBJECTIVE: One of the most challenging dilemmas in pediatric urology today is to determine the optimal management of children with hydronephrotic kidney secondary to suspected ureteropelvic junction obstruction. Some believe in early surgical management while others believe in conservative management. To better define these issues, the authors retrospectively reviewed 101 patients with hydronephrosis. MATERIAL AND METHOD: The present study was approved by The Children 's Hospital of Philadelphia 's institutional review board and waiver of informed consent for retrospective study. One hundred and one children (72 males and 29 females) of ages of 6 days to 19 years with hydronephrosis with suspected UPJ obstruction underwent diuretic renograms with 99mTc DTPA. The authors classified the differential renal function into three groups: Group I: 0-15%, Group II: 16-30%, and Group III: 31-46%. RESULTS: Forty-one patients with conservative management, 32% (5 in group I: 1 in group II and 7 in group III) showed improved differential renal function. Non-operative management patients from group I and II showed no deteriorating renal function and only one case from group III had deteriorating renal function. In operative management, 78% of group I, 41% of group II, and 25% of group III showed improvement in differential renal function. In the remaining operative cases, six showed deteriorated differential renal function [1 (4%) group I: 3 (18%) group II: 2 (10%) group III] whereas 24 remained stable or unchanged [Group 1: 4 (17%), Group II: 7 (41%), Group 111: 13 (65%)]. CONCLUSION: The authors recommended conservative management for children with differential renal function between 16-46%.

Correlation of the ERPF with the extraction fraction values of technetium-99m mercaptoacetyltriglycine.

OBJECTIVE: The objective of this study was to determine if a correlation exists between the effective renal plasma flow (ERPF) and the extraction fraction (EF) using 99mTc MAG3 in children. This EF has been previously described with 9mTc DTPA. However, the renal imaging agent of choice has become 9mTc MAG3. MATERIAL AND METHOD: The study was approved by The Children's Hospital of Philadelphia's institutional review board. Informed consent was also obtained A retrospective study of 29 children (16 males, 13 females) of ages 1 month to 19.5 years who underwent 99mTc MAG3 renal scintigraphy from September 2001 to December 2001 was analysed. EF values were calculated with and without attenuation correction in each kidney by determining the counts in a region of interest, correcting for background and comparing the counts with the injected dose. The EF was compared to the ERPF calculated using the Schlegel's method. The correlation between the EF and the ERPF corrected and non-corrected for soft tissue attenuation, were determined and were identified by using linear regression analysis. RESULTS: There was significant correlation between the ERPF and the EF with (r = 0.62, p < 0.05 on the left, r = 0.51, p = 0.005 on the right) than without attenuation correction (r = 0.54, p = 0.003 on the left, r = 0.42, p = 0.022 on the right). CONCLUSION: These results indicate a correlation of the ERPF calculated using the Schlegel's method with EF obtained from a 99mTc MAG3 renal scintigraphy. The EF may be the good alternative parameter for calculation of renal function, potentially more practical in pediatric patient and the ERPF for 99mTc MAG3 using the established software program based on Schlegel's formula.

Relationship between vesicoureteral reflux and renal cortical scar development in Thai children: the significance of renal cortical scintigraphy and direct radionuclide cystography.

Relationship of vesicoureteral reflux (VUR), urinary tract infection (UTI) and subsequent renal scarring nowadays is still in question. This study aimed to determine 1) the incidence of cortical scarring in Thai children presenting with upper urinary tract infection, 2) the association between VUR with acute pyelonephritis and subsequent renal scarring, 3) the use of DMSA and direct radionuclide cystography (DRNC) scintigraphy in children with UTI. Sixty newly diagnosed UTI children underwent DRNC and Tc-99m DMSA renal cortical scintigraphy at the time of first UTI diagnosis and 6 months later. There were no significant differences of age, sex, type of antiobiotics and pathogens (E. coli vs non-E. coli) between those who did and did not develop scars (p>0.05). 58/98 of 1st DMSA abnormal kidneys (59.18%) developed scars. 60.20 per cent of 98 positive 1st DMSA had VUR while 80.33 per cent of 61 with VUR had positive 1st DMSA. 59.02 per cent of these 61 kidneys developed scars. Scar occurrence were 18.7 times in high grade VUR compared to low grades. In conclusion, there was a high incidence of acute pyelonephritis in the presence of VUR but acute pyelonephritis does not necessarily need VUR for its development. High grade reflux with upper UTI, is a strong indicator for renal scarring. Children presenting with UTI, irrespective of age, sex, or pathogen, should have both DMSA and DRNC scintigraphy performed to identify upper UTI and high risk patients who will develop subsequent renal scarring.