Bladder volume measurements with a limited number of fixed ultrasound beams.
Over the past 30 years, various ultrasonic methods have been suggested to measure bladder volume. Ultrasound (US) represents a noninvasive and simple way to assess such volumes. Bladder volumes are usually estimated from cross-sectional planes obtained with instruments using full imaging capabilities, but their accuracy remains limited. This study presents a simple ultrasonic technique that allows the assessment of bladder volume, using only five US beams distributed in a single sagittal plane at predetermined angles. Depending on the number of beams intercepting the bladder, the depth and the height of the bladder could be estimated, and the volume of urine then computed from an empirical formula. To check the validity of the approach, 110 different bladder volume measurements were performed using a 2-D scanning instrument. A total of 33 measurements were used to deduce the empirical formula, which was then used to estimate the volume for the other 77 scans. The computed volumes were compared with calibrated volume data available through voiding or catheterization. A mean error of 9.64% was found, with a relatively constant accuracy for the different volume ranges investigated. Based on this method, a prototype composed of five single-element transducers was developed and tested in clinical situations with 30 patients. The measurements led to a mean error of 70 mL +/- 60 mL with respect to the reference volume. Overall, this study demonstrated the reliability of the proposed method for bladder volume measurements.
Palanchon
P
P
Department of Cardiology, Thoraxcentre, Erasmus MC, Rotterdam, The Netherlands. p.palanchon@erasmusmc.nl
van Loon
Denis
D
Bangma
C H
CH
Bom
N
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods; D001743:Urinary Bladder / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014556:Urine; D014563:Urodynamics