Automated Bladder Volume Measurement System Using a T-shaped Cross-Array Ultrasound Probe

다국어 초록 (Multilingual Abstract)

Automated 3-D bladder ultrasound scanners have been widely used for non-invasively measuring residual urine volumes of patients suffered from urinary disorders. In automated 3-D bladder ultrasound scanners, a motorized single-element ultrasound probe is used for scanning an entire bladder so that it can accurately measure residual urine volume. However, it requires periodic motor calibration, and it is difficult to provide real-time imaging of a bladder. Alternatively, 2-D bladder ultrasound imaging, in which sagittal and transverse plane images from a bladder are acquired, can be used for measuring residual urine volumes. The accuracy from the 2-D bladder ultrasound imaging method can be lowered when the bladder has irregular shapes.
In this paper, a new automated bladder volume measurement method, in which sagittal and transverse plane images of a bladder are simultaneously acquired by using a T-shaped cross-array ultrasound probe, is presented. In the proposed method, a residual urine volume is measured by performing segmentation and image-based motion tracking on cross-sectional images, i.e., sagittal and transverse planes, obtained from the T-shaped cross-array probe after free-hand scanning. To evaluate the performance of the proposed method, a tissue mimicking bladder phantom, in which an anechoic sphere (499.1 cc) is enclosed, was manufactured. The proposed method showed the improved accuracy compared to 2-D bladder ultrasound imaging, i.e., the error rate of –6.4% (468.9 cc) vs. 10.4% (551.0 cc), respectively, while providing real-time imaging of a bladder, more than 10 frames/sec. In addition, the proposed method does not require any calibration required in conventional automated 3-D bladder scanners. The proposed method is under clinical evaluation where patients with urinary disorders are scanned with an automated bladder scanner equipped with a T-shaped cross-array probe. These results indicate that the proposed bladder volume measurement method can improve clinical usability of automated bladder scanners by improving the volume measurement accuracy while providing real-time imaging a bladder, which is important for differentiating undesired measurements of other organs, such as prostate and uterine cysts.