Approximate volumetric reconstruction from projected images

A significant problem in planning of volumetrically prescribed localized treatments is the mathematical impossibility to determine the exact three dimensional shape and volume of a target object from its projected images. Reconstruction accuracy also varies with viewing angle, depending on the convexity and aspect ratios of the target object. In response to this problem, we are developing a robust and efficient technique for approximate volumetric reconstruction, which (A) uses no prior information of the shape and volume of the target, (B) does not require exact silhouettes, (C) accepts arbitrary number of images, (D) produces solid object and measure of its volume, (E) provides confidence measure of the reconstruction and drawing of silhouettes, (F) is robust, fast and easy to implement. Preliminary tests suggest that fairly convex objects can be reconstructed from four views, and typically six views with table rotation allow us to reconstruct fine details as small as 1 mm. The method is applicable for any X-ray guided volumetric treatment. Pilot applications will be planning of radiosurgery of arterioveneous malformations (AVMs) and radiofrequency ablation of soft tissue lesions.