title: Implementation and evaluation of various demons deformable image registration algorithms on a GPU.
abstract: Online adaptive radiation therapy (ART) promises the ability to deliver an optimal treatment in response to daily patient anatomic variation. A major technical barrier for the clinical implementation of online ART is the requirement of rapid image segmentation. Deformable image registration (DIR) has been used as an automated segmentation method to transfer tumor/organ contours from the planning image to daily images. However, the current computational time of DIR is insufficient for online ART. In this work, this issue is addressed by using computer graphics processing units (GPUs). A gray-scale-based DIR algorithm called demons and five of its variants were implemented on GPUs using the compute unified device architecture (CUDA) programming environment. The spatial accuracy of these algorithms was evaluated over five sets of pulmonary 4D CT images with an average size of 256 x 256 x 100 and more than 1100 expert-determined landmark point pairs each. For all the testing scenarios presented in this paper, the GPU-based DIR computation required around 7 to 11 s to yield an average 3D error ranging from 1.5 to 1.8 mm. It is interesting to find out that the original passive force demons algorithms outperform subsequently proposed variants based on the combination of accuracy, efficiency and ease of implementation.
authors.affiliation: Department of Radiation Oncology, University of California San Diego, La Jolla, CA 92037, USA.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Gu
authors.forename: Hubert
authors.initials: H
authors.lastname: Pan
authors.forename: Yun
authors.initials: Y
authors.lastname: Liang
authors.forename: Richard
authors.initials: R
authors.lastname: Castillo
authors.forename: Deshan
authors.initials: D
authors.lastname: Yang
authors.forename: Dongju
authors.initials: D
authors.lastname: Choi
authors.forename: Edward
authors.initials: E
authors.lastname: Castillo
authors.forename: Amitava
authors.initials: A
authors.lastname: Majumdar
authors.forename: Thomas
authors.initials: T
authors.lastname: Guerrero
authors.forename: Steve B
authors.initials: SB
authors.lastname: Jiang
mesh_terms: D000465:Algorithms; D003196:Computer Graphics; D019992:Databases as Topic; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods