A Semi-Automated Method for 3D Reconstruction from Routine Ultrasound Videos: Visualization of Transient Gallbladder Lesions

PurposeUltrasound imaging of the gastrointestinal tract faces two major limitations: (1) lesions are often visible only momentarily, and (2) the lack of three-dimensional context makes it difficult to understand the orientation and anatomical location of the observed cross-sections. We aimed to develop a simple, semi-automated three-dimensional (3D) reconstruction method from routine ultrasound videos to enhance the visualization of transient lesions, particularly in the gallbladder. MethodsUltrasound videos of the authors own gallbladder polyps and the stomach were used. We proposed a stepwise process including video capture, frame extraction, pixel thresholding using both global and slice-specific values, and 3D volume rendering. The system was implemented using custom Python applications incorporating interactive threshold adjustment tools and PyVista-based 3D visualization. The workflow was tested using ultrasound videos of the gallbladder and stomach, with optional probe motion monitoring using an IMU sensor. ResultsThe method successfully reconstructed 3D representations of gallbladder polyps. The reconstructed images provided improved spatial understanding of the anatomical relationship between lesions and surrounding structures, which were originally visible only momentarily. ConclusionsThis approach may serve as an initial step toward practical 3D reconstruction from routine gastrointestinal ultrasound. Further refinement and clinical validation are necessary to establish its utility in daily clinical settings.