Virtual colonoscopy screening with ultra low-dose CT and less-stressful bowel preparation: A computer simulation study

Jing Wang, Su Wang, Lihong Li, Yi Fan, Hongbing Lu, Zhengrong Liang

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Computed tomography colonography (CTC) or CT-based virtual colonoscopy (VC) is an emerging tool for detection of colonic polyps. Compared to the conventional fiber-optic colonoscopy, VC has demonstrated the potential to become a mass screening modality in terms of safety, cost, and patient compliance. However, current CTC delivers excessive X-ray radiation to the patient during data acquisition. The radiation is a major concern for screening application of CTC. In this work, we performed a simulation study to demonstrate a possible ultra low-dose CT technique for VC. The ultra low-dose abdominal CT images were simulated by adding noise to the sinograms of the patient CTC images acquired with normal dose scans at 100 mAs levels. The simulated noisy sinogram or projection data were first processed by a Karhunen-Love domain penalized weighted least-squares (KL-PWLS) restoration method and then reconstructed by a filtered backprojection algorithm for the ultra low-dose CT images. The patient-specific virtual colon lumen was constructed and navigated by a VC system after electronic colon cleansing of the orally-tagged residue stool and fluid. By the KL-PWLS noise reduction, the colon lumen can successfully be constructed and the colonic polyp can be detected in an ultra low-dose level below 50 mAs. Polyp detection can be found more easily by the KL-PWLS noise reduction compared to the results using the conventional noise filters, such as Hanning filter. These promising results indicate the feasibility of an ultra low-dose CTC pipeline for colon screening with less-stressful bowel preparation by fecal tagging with oral contrast.

Original languageEnglish (US)
Article number4689420
Pages (from-to)2566-2575
Number of pages10
JournalIEEE Transactions on Nuclear Science
Issue number5
StatePublished - Oct 2008


  • Karhunen-Love transform
  • Low dose computed tomography
  • Noise reduction
  • Partial volume image segmentation
  • Penalized weighted least-squares
  • Virtual colonoscopy

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


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