Abstract: Objective To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. Methods MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. Results The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). Conclusion Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.

Key words: magnetic resonance, computed tomography, kidney, bladder, urethra, three-dimensional reconstruction, anatomy; geometric parameters