逐次近似応用再構成法が超急性期脳梗塞CT 画像におけるZ スコアマッピングに与える効果

• Published in: Nippon Hōshasen Gijutsu Gakkai zasshi Vol. 74; no. 4; pp. 375 - 381
• Main Authors: 市川, 勝弘, 石井, 一成, 村上, 卓道, 渡邊, 翔太, 細野, 眞, 坂口, 健太
• Format: Journal Article
• Language: Japanese
• Published: Kyoto 公益社団法人 日本放射線技術学会 01.01.2018; Japan Science and Technology Agency
• Subjects: Adaptive systems; Basal ganglia; Brain; Computation; Computed tomography; computed tomography (CT); Ganglia; hyperacute stroke; Image filters; Image reconstruction; Iterative methods; iterative reconstruction; Mapping; Statistics; Tomography; Z-score
• ISSN: 0369-4305; 1881-4883
• DOI: 10.6009/jjrt.2018_JSRT_74.4.375

The purpose of this study was to evaluate the effect of a hybrid-type iterative reconstruction method on Z-score mapping of hyperacute stroke in unenhanced computed tomography (CT) images. We used a hybrid-type iterative reconstruction [adaptive statistical iterative reconstruction (ASiR)] implemented in a CT system (Optima CT660 Pro advance, GE Healthcare). With 15 normal brain cases, we reconstructed CT images with a filtered back projection (FBP) and ASiR with a blending factor of 100% (ASiR100%). Two standardized normal brain data were created from normal databases of FBP images (FBP-NDB) and ASiR100% images (ASiR-NDB), and standard deviation (SD) values in basal ganglia were measured. The Z-score mapping was performed for 12 hyperacute stroke cases by using FBP-NDB and ASiR-NDB, and compared Z-score value on hyperacute stroke area and normal area between FBP-NDB and ASiR-NDB. By using ASiR-NDB, the SD value of standardized brain was decreased by 16%. The Z-score value of ASiR-NDB on hyperacute stroke area was significantly higher than FBP-NDB (p<0.05). Therefore, the use of images reconstructed with ASiR100% for Z-score mapping had potential to improve the accuracy of Z-score mapping.