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

• Published in: Radiological physics and technology 2011-07, Vol.4 (2), p.109-120
• Main Authors: Okumura, Eiichiro, Sanada, Shigeru, Suzuki, Masayuki, Takemura, Akihiro, Matsui, Osamu
• Format: Article
• Language: English
• Subjects: Aged; Carcinoma, Hepatocellular - diagnostic imaging; Carcinoma, Hepatocellular - pathology; Female; Humans; Imaging; Imaging, Three-Dimensional - methods; Liver - diagnostic imaging; Liver - pathology; Liver Neoplasms - diagnostic imaging; Liver Neoplasms - pathology; Male; Medical and Radiation Physics; Medicine; Medicine & Public Health; Middle Aged; Nuclear Medicine; Radiographic Image Interpretation, Computer-Assisted - methods; Radiography, Abdominal - methods; Radiology; Radiotherapy; Reproducibility of Results; Sensitivity and Specificity; Subtraction Technique; Tomography, X-Ray Computed - methods
• ISSN: 1865-0333; 1865-0341
• DOI: 10.1007/s12194-010-0110-1

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.