Shape-guided Conditional Latent Diffusion Models for Synthesising Brain
  Vasculature
Yash Deo Haoran Dou Nishant Ravikumar Alejandro F. Frangi Toni Lassila
The Circle of Willis (CoW) is the part of cerebral vasculature responsible
for delivering blood to the brain. Understanding the diverse anatomical
variations and configurations of the CoW is paramount to advance research on
cerebrovascular diseases and refine clinical interventions. However,
comprehensive investigation of less prevalent CoW variations remains
challenging because of the dominance of a few commonly occurring
configurations. We propose a novel generative approach utilising a conditional
latent diffusion model with shape and anatomical guidance to generate realistic
3D CoW segmentations, including different phenotypical variations. Our
conditional latent diffusion model incorporates shape guidance to better
preserve vessel continuity and demonstrates superior performance when compared
to alternative generative models, including conditional variants of 3D GAN and
3D VAE. We observed that our model generated CoW variants that are more
realistic and demonstrate higher visual fidelity than competing approaches with
an FID score 53\% better than the best-performing GAN-based model.