金井　貴幸    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Assistant Professor
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images.
Journal	Formal name：Journal of radiation research Abbreviation：J Radiat Res ISSN code：13499157/04493060
Domestic / Foregin	Foregin
Volume, Issue, Page	55(6),pp.1163-70
Author and coauthor	Kanai Takayuki, Kadoya Noriyuki, Ito Kengo, Onozato Yusuke, Cho Sang Yong, Kishi Kazuma, Dobashi Suguru, Umezawa Rei, Matsushita Haruo, Takeda Ken, Jingu Keiichi
Authorship	Lead author
Publication date	2014/11
Summary	Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy.
DOI	10.1093/jrr/rru062
PMID	25053349