Evaluation of the robustness of the preprocessing technique improving reversible compressibility of CT images: Tested on various CT examinations. Issue 10 (17th September 2013)

• Record Type: Journal Article
• Authors: Jeon, Chang Ho; Kim, Kil Joong; Lee, Kyoung Ho; Kim, Bohyoung; Kim, Tae Ki; Gu, Bon Seung; Lee, Jong Min
• Is Part Of: Medical physics. Volume 40:Issue 10(2013)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2013-09-17
• Subjects: Computed tomography -- X‐ray imaging; computerised tomography -- image segmentation -- medical image processing; CT image -- image compression -- region of interest -- segmentation; Computerised tomographs -- Biological material, e.g. blood, urine; Haemocytometers -- Digital computing or data processing equipment or methods, specially adapted for specific applications -- Image data processing or generation, in general; Medical imaging -- Computed tomography -- Medical image segmentation -- Radiologists -- Lungs -- Image scanners -- Data analysis -- Computer software -- Image analysis -- Linear regression; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4820975
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: : To modify the preprocessing technique, which was previously proposed, improving compressibility of computed tomography (CT) images to cover the diversity of three dimensional configurations of different body parts and to evaluate the robustness of the technique in terms of segmentation correctness and increase in reversible compression ratio (CR) for various CT examinations. Methods: : This study had institutional review board approval with waiver of informed patient consent. A preprocessing technique was previously proposed to improve the compressibility of CT images by replacing pixel values outside the body region with a constant value resulting in maximizing data redundancy. Since the technique was developed aiming at only chest CT images, the authors modified the segmentation method to cover the diversity of three dimensional configurations of different body parts. The modified version was evaluated as follows. In randomly selected 368 CT examinations (352 787 images), each image was preprocessed by using the modified preprocessing technique. Radiologists visually confirmed whether the segmented region covers the body region or not. The images with and without the preprocessing were reversibly compressed using Joint Photographic Experts Group (JPEG), JPEG2000 two‐dimensional (2D), and JPEG2000 three‐dimensional (3D) compressions. The percentage increase in CR per examination (CRI ) was measured. Results: : The rate of correct segmentation was 100.0% (95% CI: 99.9%, 100.0%) for all the examinations. The median of CRI were 26.1% (95% CI: 24.9%, 27.1%), 40.2% (38.5%, 41.1%), and 34.5% (32.7%, 36.2%) in JPEG, JPEG2000 2D, and JPEG2000 3D, respectively. Conclusions: : In various CT examinations, the modified preprocessing technique can increase in the CR by 25% or more without concerning about degradation of diagnostic information.