Lung at thin-section CT: Influence of multiple-segment reconstruction on image quality

PURPOSE: To evaluate multiple-segment reconstruction to reduce cardiac-motion artifacts on thin-section computed tomographic (CT) images in the lung. MATERIALS AND METHODS: Fifty patients were enrolled in the study. All images were obtained with a scanner capable of 1-second revolution time. Routine lung thin-section CT examination was performed with images reconstructed with bone algorithm. Multiple-segment images reconstructed with lung algorithm were obtained for three levels in the left paracardiac region. Segment images were reconstructed retrospectively with data for 225degrees rotation rather than the 360degrees rotation used for a complete scan. To minimize differences resulting from reconstruction algorithms, additional nonsegmented reconstruction was performed with lung algorithm. Three radiologists reviewed each set of images and assigned a quality score. Multiway analysis of variance was performed to compare motion artifact reduction with 225degrees and 360degrees reconstructions. RESULTS: Differences were not significant (P > .05) between scores for images reconstructed with bone or lung algorithms. Differences were significant between scores for reconstructed images obtained with the combination of 360degrees bone and 225degrees segment algorithms (P < .001) and for those obtained with the combination of 360degrees lung and 225degrees segment algorithms (P < .001). CONCLUSION: Multiple-segment reconstruction of lung thin-section CT images is an effective technique for reducing cardiac-motion artifacts without increasing patient dose. (C) RSNA, 2003.