title: Globally optimal tumor segmentation in PET-CT images: a graph-based co-segmentation method.
abstract: Tumor segmentation in PET and CT images is notoriously challenging due to the low spatial resolution in PET and low contrast in CT images. In this paper, we have proposed a general framework to use both PET and CT images simultaneously for tumor segmentation. Our method utilizes the strength of each imaging modality: the superior contrast of PET and the superior spatial resolution of CT. We formulate this problem as a Markov Random Field (MRF) based segmentation of the image pair with a regularized term that penalizes the segmentation difference between PET and CT. Our method simulates the clinical practice of delineating tumor simultaneously using both PET and CT, and is able to concurrently segment tumor from both modalities, achieving globally optimal solutions in low-order polynomial time by a single maximum flow computation. The method was evaluated on clinically relevant tumor segmentation problems. The results showed that our method can effectively make use of both PET and CT image information, yielding segmentation accuracy of 0.85 in Dice similarity coefficient and the average median hausdorff distance (HD) of 6.4 mm, which is 10% (resp., 16%) improvement compared to the graph cuts method solely using the PET (resp., CT) images.
authors.affiliation: Department of Radiation Oncology, The University of Iowa, Iowa City, IA, USA. handongfeng@gmail.com
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Han
authors.forename: John
authors.initials: J
authors.lastname: Bayouth
authors.forename: Qi
authors.initials: Q
authors.lastname: Song
authors.forename: Aakant
authors.initials: A
authors.lastname: Taurani
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
authors.forename: John
authors.initials: J
authors.lastname: Buatti
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wu
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*