CAD COLON


CAD Performance

The CAD system

The CAD COLON scheme includes four different steps:

  1. Electronic cleansing
  2. Colon surface extraction
  3. Polyp candidates segmentation
  4. Candidates discrimination

Statistics

We here present the results of CAD validation on an independent dataset of 769 patients (174 positive) including both exams with cathartic preparation (185 patients) and fecal tagging cases (584 patients).

The fecal tagging preparations include “light” preparations, characterized by the use of stool softeners (PEG 3350, instead of the more aggressive PEG4000), as well as contrast agent adiministration on the day of the exam (sameday fecal tagging), especially suitable for screening contexts.

For a subset of 377 patients (which corresponds to the subset of all cases of the IMPACT trial acquired in Piedmont, Italy) histological data was available, hence for this subset we present results also on advanced adenomas. The total dataset included 348 polyps larger or equal to 6mm, 172 polyps larger or equal to 10mm, and 50 masses. On the subset with known histology 96 advanced adenomas were present.

Performances at the default operating point follow:




Sensitivity for polyps ≥ 6mm (C.I. 95%) 89% (85%-92%)
Sensitivity for polyps ≥ 10mm (C.I. 95%) 95% (90%-98%)
Sensitivity for advanced adenomas (C.I. 95%) 91% (83%-96%)
Sensitivity for masses (C.I. 95%) 92% (81%-98%)
By-patient sensitivity (C.I. 95%) 94% (89%-97%)
False-positives/scan: Median (IQ range) 6 (3-9)


The system also allows the choice of a second operating point which priviliges specificity, further reducing the false positive rate (the median number of false positives per scan drops to 4), while maintaining a sensitivity around 90%: 88% on advanced adenomas; 88% on polyps larger or equal to 6mm; 94% on polyps larger or equal to 10mm.


Publications on CADCOLON Performances and Related Bibliography.

  • S. Agliozzo, A. Bert, R. Baggio, L. Correale, P. Della Monica, S. Delsanto, I. Dmitriev, L. Morra, D. Regge. Validation of a CT-Colonography CAD system on the IMPACT multicenter trial data. Int J Comput Assist Radiol Surg, Vol. 4, Supp. 1 (2009).
  • D. Regge, C. Laudi, G. Galatola, P. Della Monica, L. Bonelli, G. Angelelli, R. Asnaghi, B. Barbaro, C. Bartolozzi, D. Bielen, L. Boni, C. Borghi, P. Bruzzi, M.C. Cassinis, M. Galia, T.M. Gallo, A. Grasso, C. Hassan, A. Laghi, M.C. Martina, E. Neri, C. Senore, G. Simonetti, S. Venturini, G. Gandini, Diagnostic Accuracy of Computed Tomographic Colonography for the Detection of Advanced Neoplasia in Individuals at Increased Risk of Colorectal Cancer. JAMA 301(23):2453 - 2461 (2009).
  • S. Delsanto, L. Morra, D. Campanella, V. Tartaglia, R. Baggio, S. Agliozzo, F. Cerri, E. Neri, D. Regge, Computer Aided Detection of Polyps in Virtual Colonoscopy with Sameday Fecal Tagging. Proc. SPIE Medical Imaging 2008 Vol. 6915-28.
  • L. Morra, S. Delsanto, S. Agliozzo, R. Baggio, E. Belluccio, L. Correale, D. Genova, A. Bert, D. Regge. Characteristics of false positives findings in CT Colonography CAD: a comparison of two fecal tagging regimens. Proc. SPIE Medical Imaging 2009 Vol. 7260.
  • L. Morra, S. Delsanto, D. Campanella, D. Regge, A. Bert. Adaptive remapping procedure for electronic cleansing of fecal tagging images. Proc. SPIE Medical Imaging 2009 Vol. 7260.
  • S. Agliozzo, A. Bert, R. Baggio, L. Correale, P. Della Monica, S. Delsanto, I. Dmitriev, L. Morra, D. Regge. Validation of a CT-Colonography CAD system on the IMPACT multicenter trial data. Proc. CARS 2009, Int J Comput Assist Radiol Surg, Vol. 4, Supp. 1.
  • D. Campanella, L. Morra, S. Delsanto, V. Tartaglia, R. Asnaghi, A. Bert, E. Neri, D. Regge. Comparison of three different iodine-based bowel regimens for CT Colonography. Eur Radiol. 2010 Feb; 20(2):348-58.
  • D Regge, S Agliozzo, L Correale, D Campanella, P Della Monica, A Bert, S Delsanto, L Morra, Comparing the performance of a CT Colonography Computer Aided Diagnosis (CAD) system to that of the experienced reader in a prospective multicenter setting. RSNA2008, Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago, IL, Nov. 30 - Dec. 5, 2008.
  • D Regge, L Morra, R Baggio, C Laudi, A Leto, TM Gallo, S Delsanto, L Morra, Flat lesions and masses: characterization of CT colonography CAD performances on difficult targets present in a multi-center trial dataset. RSNA2008, Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago, IL, Nov. 30 - Dec. 5, 2008.