Measurement of colonic polyp size from virtual colonoscopy studies: Comparison of manual and automated methods

Metin N. Gurcan, Randy D Ernst, Aytekin Oto, Steve Worrell, Jeff Hoffmeister, Steve Rogers

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Scopus citations


    Polyp size is an important feature descriptor for clinical classification and follow-up decision making in CT colonography. Currently, polyp size is measured from computed tomography (CT) studies manually as the single largest dimension of the polyp head, excluding the stalk if present, in either multi-planar reconstruction (MPR) or three-dimensional (3D) views. Manual measurements are subject to intra- and inter-reader variation, and can be time-consuming. Automated polyp segmentation and size measurement can reduce the variability and speed up the process. In this study, an automated polyp size measurement technique is developed. Using this technique, the polyp is segmented from the attached healthy tissue using a novel, model-based approach. The largest diameter of the segmented polyp is measured in axial, sagitttal and coronal MPR views. An expert radiologist identified 48 polyps from either supine or prone views of 52 cases of the Walter-Reed virtual colonoscopy database. Automated polyp size measurements were carried out and compared with the manual ones. For comparison, three different statistical methods were used: overall agreement using chance-corrected kappa indices; the mean absolute differences; and Bland-Altman limits of agreement. Manual and automated measurements show good agreement both in 2D and 3D views.

    Original languageEnglish (US)
    Title of host publicationMedical Imaging 2006
    Subtitle of host publicationImage Processing
    StatePublished - Jun 22 2006
    EventMedical Imaging 2006: Image Processing - San Diego, CA, United States
    Duration: Feb 13 2006Feb 16 2006

    Publication series

    NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
    Volume6144 III
    ISSN (Print)1605-7422


    OtherMedical Imaging 2006: Image Processing
    CountryUnited States
    CitySan Diego, CA



    • Polyp
    • Polyp segmentation
    • Size measurement
    • Virtual Colonoscopy

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Biomaterials
    • Atomic and Molecular Physics, and Optics
    • Radiology Nuclear Medicine and imaging

    Cite this

    Gurcan, M. N., Ernst, R. D., Oto, A., Worrell, S., Hoffmeister, J., & Rogers, S. (2006). Measurement of colonic polyp size from virtual colonoscopy studies: Comparison of manual and automated methods. In Medical Imaging 2006: Image Processing [61445B] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 6144 III).