title: Effectiveness of temporal and dynamic subtraction images of the liver for detection of small HCC on abdominal CT images: comparison of 3D nonlinear image-warping and 3D global-matching techniques.
abstract: Misregistration errors occur at the periphery of the hepatic region due to respiratory- and interval-related changes in hepatic shape. To reduce these misregistration errors, we developed a temporal and dynamic subtraction technique to enhance small hepatocellular carcinoma (HCC) by using a 3D nonlinear image-warping technique. The study population consisted of 21 patients with HCC. We registered the present and previous arterial-phase CT images or the present nonenhanced and arterial-phase CT images obtained in the same position by 3D global-matching plus 3D nonlinear image-warping. Temporal subtraction images were obtained by subtraction of the previous arterial-phase CT image from the warped present arterial-phase CT image. Dynamic subtraction images were obtained by subtraction of the present nonenhanced CT image from the warped present arterial-phase CT image. When we used this new technique, the number of good or excellent cases increased from 14.2% (3/21 cases) to 71.4% (15/21 cases) on temporal subtraction images. With this technique, subjective rating scores for image quality improved in 57.1% of cases (12/21 cases) on temporal subtraction images and 81.0% of cases (17/21 cases) on dynamic subtraction images. The results indicated that the new subtraction images were greatly improved by use of the 3D nonlinear image-warping technique.
authors.affiliation: Department of Medical Radiological Technology, Kagoshima Medical Technology College, 5417-1 Hirakawa, Kagoshima, Japan. rt.okumura@harada-gakuen.ac.jp
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Okumura
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sanada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takemura
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*