Radionuclide voiding pattern in children with unstable bladder.

Abstract

BACKGROUND: The purpose of this study was to investigate bladder function parameters by means of quantitative radionuclide cystography (QRC) in anxious, irritable children with unstable bladder. METHODS: Quantitative radionuclide cystography was performed in 18 children aged between 8 and 12 years, without evidence of neurologic and nephrologic disorders. Findings were compared with those obtained in 10 healthy children aged between 7 and 10 years. The dynamics of the bladder emptying were studied after intravenous injection of 37 MBq/10 kg b.w. 99mTc-diethylenetriaminepentaacetic acid (DTPA) in the posterior views. Images of 90 frames every 2 sec. were stored in the 64 x 64 computer matrix during voiding. The patients voided into a container and the volumes were measured. RESULTS: The parameters evaluated were: functional bladder capacity (ml)--FBC, expected bladder capacity (ml)--EBC, percentage of EBC (%), voided urine volume (ml)--VV, residual urine (ml)--RU, voiding time (sec)--VT, average flow rate (ml/sec)--AFR and peak flow rate (ml/sec)--PFR. There was a statistically significant difference between controls and children with unstable bladder in the following parameters: FBC 288 +/- 33 vs. 244 +/- 27 ml (p < 0.001), % of EBC 99 +/- 6 vs. 82 +/- 6% (p < 0.0001), VV 265 +/- 37 vs. 202 +/- 35 ml (p < 0.0001), RU 22 +/- 11 vs. 48 +/- 19 ml (p < 0.007), AFR 13 +/- 5 ml/sec vs. 9 +/- 4 ml/sec. (p < 0.01) and PFR 19 +/- 2 vs. 13 +/- 3 ml/s (p < 0.0001), respectively. The VT obtained from the control group of 23 +/- 9 s did not differ significantly from the value of children with unstable bladder of 28 +/- 14 s. CONCLUSION: The results show that quantitative radionuclide cystography is a simple, noninvasive method, which allows a good separation of patients with unstable bladder from the children with normal voiding pattern.