Clinical agreement between automated and calculated ultrasound measurements of bladder volume

Abstract

Non-invasive urine volume measurement is an important tool in the management of dysfunctional and neuropathic bladders in children. Ultrasound imaging devices have been used for many years for this purpose. An automated scanner (Bladderscan) is now available and has been recommended by a number of authors, but there is conflicting evidence in the literature regarding the accuracy and appropriate clinical application of the device. We aimed to assess the level of clinical agreement between the two methods. 36 urine volume measurements were made on 11 children using both instruments. Although there was a good correlation between the methods (r=0.97), the clinical agreement was poor (limits of agreement +/-77 ml). 13 voided volumes were directly measured and compared with the difference between pre- and post-void ultrasound measurements. The systematic errors were small but the mean absolute errors were 54 ml and 23 ml, respectively, for the automated and ultrasound imaging methods. If used correctly, ultrasound imaging provides more accurate results and can compete with the cost, convenience and ease of use of the automated method. Low cost, highly portable ultrasound imaging devices are now available and should be used in preference to the Bladderscan.

Reliability of bladder volume measurement with BladderScan® in paediatric patients

“…The authors reported a good correlation between the two methods but poor limits of agreement when the data were analysed by means of the Bland ÁAltman plot. The wide variation in the limits of agreement reported in the present series of a large cohort of children of different ages and with different bladder volumes confirms the data of Dudley et al [15].…”

“…Similarly to our study, Dudley et al [15] recently compared the BladderScan BVI 2500 and conventional ultrasonography for measuring bladder volume in 11 children aged 5Á11 years. The authors reported a good correlation between the two methods but poor limits of agreement when the data were analysed by means of the Bland ÁAltman plot.…”

“…We preferred to study several children once, instead of the same few children several times [15], in order to evaluate whether different bladder shapes and sizes and different anatomical conformations would influence the results. Bland ÁAltman analysis.…”

“…Although BladderScan proved to be superior to standard ultrasonography, the technique is not entirely free from artefacts [11 Á13]. Particularly in children, there is weak and conflicting evidence regarding the accuracy of BladderScan BVI 2500 for determining bladder volume [14,15]. Moreover, no clinical experience has been reported in the literature on the reliability of BladderScan BVI 6200, which has been introduced more recently and optimized to measure bladder volume in children up to 122 cm in height and 27 kg in weight.…”

Comparison Of Urinary Bladder Volume In Children Using Suprapubic Ultrasonic Bi-Planner Technique With Voided Urine Volume

“…If used correctly, ultrasound imaging provides more accurate results and can compare with the cost, convenience and case of use of the automated method. Low cost, highly portable ultrasound imaging devices are now available and should be used in preference to the Bladder scan 3 . In a study Harrison and associates assessed residual urine volume in children using ultrasonography.…”