Colon Cleansing for Virtual Colonoscopy Using Non-linear Transfer Function and Morphological Operations

The virtual colonoscopy (VC) techniques try to simulate a real colonoscopy. A doctor who makes real colonoscopy examination does not have optimal information about anatomical structures which he looks at. He sees the inner colon structure only. 3D visualization of the colon segmented from computed tomography (CT) data allows him to see the whole organ, its inner and outer part. The VC helps doctors during diagnostic processes in identification and localization of pathological changes and offers computer support for endoscopic procedures. In this paper we present new colon cleansing method based on non-linear transfer function and morphological operations. Colon cleansing is required when we receive non-clean CT data or when a patient had administered contrast before the CT scan. It allows to see the whole colon even this one lying under fluid and to compute colon centerline correctly.