title: Development of pulmonary blood flow evaluation method with a dynamic flat-panel detector: quantitative correlation analysis with findings on perfusion scan.
abstract: Pulmonary blood flow is reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. Thus, decreased blood flow should be observed as a reduction of the variation of X-ray translucency. We performed the present study to investigate the feasibility of pulmonary blood flow evaluation with a dynamic flat-panel detector (FPD). Sequential chest radiographs of 14 subjects were obtained with a dynamic FPD system. The changes in pixel value in each local area were measured and mapped on the original image by use of a gray scale in which small and large changes were shown in white and black, respectively. The resulting images were compared to the findings in perfusion scans. The cross-correlation coefficients of the changes in pixel value and radioactivity counts in each local area were also computed. In all patients, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on the mapping image, and a correlation was observed between the distribution of changes in pixel value and those in radioactivity counts (0.7 <or= r, 3 cases; 0.4 <or= r < 0.7, 7 cases; 0.2 <or= r < 0.4, 4 cases). The results indicated that the distribution of changes in pixel value could provide a relative measure related to pulmonary blood flow. The present method is potentially useful for evaluating pulmonary blood flow as an additional examination in conventional chest radiography.
authors.affiliation: Department of Radiological Technology, School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kodatsuno, Kanazawa, Japan. rie44@mhs.mp.kanazawa-u.ac.jp
authors.forename: Rie
authors.initials: R
authors.lastname: Tanaka
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sanada
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujimura
authors.forename: Masahide
authors.initials: M
authors.lastname: Yasui
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Shiro
authors.initials: S
authors.lastname: Tsuji
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okamoto
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nanbu
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006321:Heart / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012039:Regional Blood Flow
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