title: Automated segmentation of psoas major muscle in X-ray CT images by use of a shape model: preliminary study.
abstract: Our motivation was to provide an automatic tool for radiologists and orthopedic surgeons for improving the quality of life of an aging population. We propose a method for generating a shape model and a fully automated segmenting scheme for the psoas major muscle in X-ray CT images by using the shape model. Our approach consists of two steps: (1) The generation of a shape model and its application to muscle segmentation. The shape model describes the muscle's outer shape and has two parameters, an outer shape parameter and a fitting parameter. The former was determined by approximating of the outer shape of the muscle region in training cases. The latter was determined for each test case in the recognition process. (2) Finally, the psoas major muscle was segmented by use of the shape model. To evaluate the performance of the method, we applied it to CT images for constructing the shape models by using 20 cases as training samples; 80 cases were used for testing. The accuracy of this method was measured by comparison of the extracted muscle regions with regions that were identified manually by an expert radiologist. The experimental results of the segmentation of the psoas major muscle gave a mean Jaccard similarity coefficient of 72.3%. The mean true segmentation coefficient was 76.2%. The proposed method can be used for the analysis of cross-sectional area and muscular thickness in a transverse section, offering radiologists an alternative to manual measurement for saving their time and improving the reproducibility of segmentation.
authors.affiliation: Division of Regeneration and Advanced Medical Sciences, Department of Intelligent Image Information, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan. kamiya@fjt.info.gifu-u.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Kamiya
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Zhou
authors.forename: Huayue
authors.initials: H
authors.lastname: Chen
authors.forename: Chisako
authors.initials: C
authors.lastname: Muramatsu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hara
authors.forename: Ryujiro
authors.initials: R
authors.lastname: Yokoyama
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016658:Psoas Muscles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*