Diffusion-weighted Imaging in Ischemic Stroke

• DOI: 10.1016/j.acra.2008.09.012
• Publication Date: 2009-02-07T06:04:52Z
• Authors: Toshinori Hirai; Makoto Sasaki; Masayuki Maeda; Masahiro Ida; Shigehiko Katsura...; Masaharu Sakoh; Koichi Takano; Shoichi Arai; Teruyuki Hirano; Yutaka Kai; Shingo Kakeda; Ryuji Murakami; Ryuji Ikeda; Hirofumi Fukuoka; Akira Sasao; Yasuyuki Yamashita
• Keywords: Adult; Aged, 80 and over; Observer Variation; Reproducibility of Results; Equipment Design; Middle Aged; Sensitivity and Specificity; Brain Ischemia; Equipment Failure Analysis; Stroke; 03 medical and health sciences; Diffusion Magnetic Resonance Imaging; 0302 clinical medicine; Computer Terminals; Data Display; Humans; Aged

When evaluating ischemic stroke on diffusion-weighted magnetic resonance imaging (DWI), the display method has not been investigated. The purpose of this study was to determine whether standardization of the display method for DWI affects observers' diagnostic performance in detecting ischemic stroke on DWI.Twenty-six observers evaluated 40 DWI studies in 20 patients with acute (< 6 hours) middle cerebral arterial strokes and 20 controls for the presence of hyperintense lesions in 10 areas using the Alberta Stroke Programme Early CT Score (ASPECTS) system and one area in the corona radiata using a modified version of the ASPECTS system (ASPECTS-DWI). The images were reviewed using a standardized display method (SDM) and a conventional display method (CDM). The reading time was recorded for each session. The observers' performance was evaluated with receiver-operating characteristic analysis.In all observers with ASPECTS-DWI scores of < or = 8 points, the value of the mean average area under the receiver-operating characteristic curve was slightly higher for the SDM than the CDM, but the difference was not statistically significant. In the insular ribbon, diagnostic accuracy was significantly higher with the SDM than the CDM (P = .036). In the other locations, there were no significant differences. With the SDM, the mean reading time was reduced by 7.5 seconds (P = .024).The SDM improved diagnostic accuracy for the insular ribbon and shortened the reading time, although it did not improve observers' performance with the ASPECTS-DWI system.