As a standard method for the measurement of post-void residual urine volume, the urethral catheterization is commonly used. However, it is frequently associated with the discomfort of the patients, urethral trauma and urinary tract infection. A noninvasive method of determining the residual urine volume could minimize unnecessary catheterizations and be useful in the management of neurogenic bladder in the patient with spinal cord injury(SCI). This study was undertaken to evaluate the accuracy of a portable ultrasound scanner for measuring bladder volumes in SCI patients undergoing bladder training and to determine the factors affecting its accuracy. Sixty patients with SCI were included in this study. Two investigators performed the ultrasound measurement of the post-void residual urine volume alternately and the same procedures were repeated. After that, the urethral catheterization was done. In comparison of the residual volume measured by two different methods, the correlation coefficient(R²) of the two different methods was 0.996 and the mean value of difference between the residual volume measured by ulltrasound and by catheterization was 21.6 ml. The accuracy of the ultrasound measurements was not affected by gender, types of the neurogenic bladder, shape of the bladder, trabeculation of the bladder and central obesity. The results indicate that the portable ultrasound scanning method is a useful non-invasive method and can be substituted for the urethral catheterization in determination of bladder volumes in patients with SCI.

A noninvasive measurement of residual urine or bladder volume would reduce number of unnecessary catheterizations and be useful for an intermittent catheterization program in the management of neurogenic bladder. The purpose of this study is to evaluate a portable ultrasound instrument for the measurement of bladder volume and to assess the effect of several factors such as trabeculation or soft tissue thickness on the accuracy of the measurements. Nine patients with neurogenic bladder dysfunction underwent 480 bladder volume measurements using a portable ultrasonographic device(BVI-2500 BladderScan) before 60 intermittent catheterizations. Ultrasonographic measurements of urine volume were compared with catheterized urine volumes. The mean difference was 46.42⁑39.15 cc and the mean percentage error was 23.32⁑19.31%. Mean differences of each bladder capacity were not affected by bladder capacity, and mean percentage errors tend to decrease as the bladder capacity increase. Bladder trabeculation and soft tissue thickness had no effect on the accuracy of the measurements. The ultrasonographic measurements detected the presence of residual urine volumes of ≥100 cc with a sensitivity of 81% and a specificity of 93%. The repeatability(Mean/SD) was 23%. The accuracy had no correlation with the frequency of scanning.

We conclude that BVI-2500 bladder scan portable ultrasonographic device is a useful tool for the management of neurogenic bladder dysfunction in spinal cord injured people. Trabeculation and soft tissue thickness has no effect on the accuracy of the measurements.

A portable ultrasound scanner has been developed to provide a noninvasive technique of measuring the bladder urine volume. This study was undertaken to determine if bladder volumes could be accurately measured in a group of spinal cord injury patients on a clean intermittent catheterization program, using a portable ultrasound scanner(BladderManager PCI 5000). We assessed the effects of different patient positions, presence of central obesity and bladder types by the urodynamic study on the accuracy of measurements as well as the inter-tester difference. Ultrasound measurements of urine volume performed by two physicians were compared to the volumes obtained by catheterization in 17 spinal cord injury patients. Subjects were tested in the seated and supine positions. The results showed a good correlation between the catheterized volumes and ultrasound measurements (Pearson correlation coefficient=0.97, r²=0.88). The mean % error was 18% for the catheterized volumes within the ranges of 45ml-640ml. But the ultrasound measurements revealed a significantly higher % error for the bladder volumes less than 200ml. Ultrasound measurements were more accurate in a supine position and among the non-obese subjects(p＜0.05). There was no significant difference in the ultrasound measurements between areflexic type bladder and hyperreflexic type bladder neither in the inter-tester measurements..

We conclude that the Bladder Manager PCI 5000 is not an accurate tool for the assesssment of post-void residual urine volumes, however it can be a useful tool for the patients with neurogenic bladder who are performing volume-directed clean intermittent catheterization, in reducing the unnecessary catheterization or preventing the bladder overdistensions.