Three-Dimensional Volume Rendering of Pelvic Floor Anatomy with Focus on Fibroids in Relation to the Lower Urogenital Tract Based on Cross-Sectional MRI Images

Abstract

We aimed to assess the feasibility of developing three-dimensional (3D) models of pelvic organs using cross-sectional MRI images of patients with uterine fibroids and urinary symptoms and of obtaining anatomical information unavailable in 2D imaging modalities. We also aimed to compare two image processing applications. We performed a feasibility study analysing MRI scans from three women, aged 30 to 58 years old, with fibroids and urinary symptoms. Cross-sectional images were used to render 3D models of pelvic anatomy, including bladder, uterus and fibroids, using 3D Slicer and OsiriX. Dimensions, volumes and anatomical relationships of the pelvic organs were evaluated. Comparisons between anatomical landmarks and measurements obtained from the two image processing applications were undertaken. Rendered 3D pelvic models yielded detailed anatomical information and data on spatial relationships that were unobtainable from cross-sectional images. Models were rendered in sufficient resolution to aid understanding of spatial relationships between urinary bladder, uterus and fibroid(s). Measurements of fibroid volumes ranged from 5,336 to 418,012 mm³ and distances between the fibroid and urinary bladder ranged from 0.10 to 83.60 mm. Statistical analysis of measurements showed no significant differences in measurements between the two image processing applications. To date, limited data exist on the use of 3D volume reconstructions of routine MRI scans, to investigate pelvic pathologies such as fibroids in women with urinary symptoms. This study suggests that post-MRI image processing can provide additional information over standard MRI. Further studies are required to assess the role of these data in clinical practice, surgical planning and training. Three-dimensional reconstruction of routine two-dimensional magnetic resonance imaging provides additional anatomical information and may improve our understanding of anatomical relationships, their role in clinical presentations and possibly guide clinical and surgical management.

Keywords: 3D Slicer; 3D pelvic model; 3D volume rendering; Image processing; Lower urinary tract symptoms (LUTS); Magnetic resonance imaging (MRI); OsiriX; Uterine fibroids.