Comparison of the Accuracy of Measuring the Amount of Urine in the Bladder by Ultrasound Devices and Their Operability for the Bladder

We investigated the accuracy and operability of two ultrasound devices for the bladder. The study included 232 adult patients who underwent surgery at our hospital. Before surgery, a nurse measured the amount of urine in the bladder using Lilium α-200® and Bladder Scan BVI 6100®. The amount was measured accurately later using a catheter. The measurements by the devices were compared with the amount measured by the catheter. Both Lilium and Bladder Scan had high accuracy (correlation coefficient for Lilium is 0.56 [95% CI : 0.46-0.64], and the correlation coefficient for Bladder Scan was 0.70 [95% CI : 0.63-0.76]). However, values obtained by the two devices significantly differed from the catheter measurement. The accuracy was improved by excluding patients with 0- ml readings by the two devices (the correlation coefficient for Lilium was 0.69 (95% CI : 0.61-0.76), and the correlation coefficient for Bladder Scan was 0.81 (95% CI : 0.76-0.86). Next, the operability was evaluated using a questionnaire. Both devices had high operability, but Bladder Scan was easier to operate. Based on the above, Bladder Scan had significantly higher accuracy and operability, but both devices had a sufficiently high accuracy and operability for clinical practice.