Computer-Aided Detection of Non-polypoid Flat Lesions in CT Colonography: Observer Performance Study

  • Yasuji Ryu
  • Janne J. Näppi
  • Minh Phan
  • Hiroyuki Yoshida
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8198)


To evaluate the effect of computer-aided detection (CADe) on the performance of human readers in the detection of non-polypoid flat lesions from a large computed tomography (CT) colonography population. A total of 153 cathartic CT colonography cases, including 45 colonoscopy-confirmed, morphologically flat lesions, were sampled from a European multi-center CT colonography trial for asymptomatic patients at increased risk of colorectal cancer. Two readers (expert and non-expert) reviewed the 153 CT colonography cases and recorded all detected lesions using primary 3D interpretation and a CADe second-read paradigm. There were 17 patients with 18 flat lesions ≥10 mm in size and 17 patients with 27 flat lesions 6 – 9 mm in size. For the flat lesions ≥10 mm, per-patient sensitivities of the expert reader for unassisted and CADe-assisted readings were 59% [95% CI: 36–78%] and 71% [47–87%], respectively, whereas those of the non-expert reader were 41% [21–65%] and 47% [37–59%], respectively. For 6-9 mm flat lesions, the corresponding per-patient sensitivities of the expert reader were 59% [36–78%] and 76% [53–89%], respectively, whereas those of the non-expert were 47% [37–59%] and 82% [59–93%]. The results indicate that the use of CADe can increase the sensitivity of human readers in the detection of flat lesions in a screening setting.


CT colonography flat lesions non-polypoid lesions computerassisted detection observer study 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Yasuji Ryu
    • 1
  • Janne J. Näppi
    • 1
  • Minh Phan
    • 1
  • Hiroyuki Yoshida
    • 1
  1. 1.3D Imaging Research, Department of RadiologyMassachusetts General Hospital and Harvard Medical SchoolBostonUSA

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