Delineation of region of interest volume in cardiac gated PET images

Positron Emission Tomography is a state of art functional imaging technique used in accurate detection of cancer. Regions of interest including tumor in the thoracic region face a unique problem of movement due to the involuntary motion of the organs. To avoid irradiation of healthy tissues during radiotherapy treatment planning, accurate tracking of the moving parts during different stages of cardiac cycle is recommended. Cardiac gating is a process of dividing a single cardiac cycle into several phases and sorting the data into each of these phases according to the location of the acquired image. The aim of this study is to accurately track the movement in cardiac gated PET images. The proposed method is a two stage approach with an initial preprocessing stage and level set deformable model is used in the second stage. The proposed method is tested on six patients´ cardiac gated data resulting in accuracies ranging between 87% and 94% in terms of percentage volume overlap.