BACKGROUND: Several dedicated computed tomography (CT) colonography phantoms have been described previously. OBJECTIVES: To compare their pros and cons and describe the construction of a dedicated phantom that can be easily manufactured. MATERIALS AND METHODS: We found 15 different phantom designs by literature search and compared their advantages and disadvantages based on their description and images. We tested various materials for density and mechanical properties and constructed a phantom from polypropylene pipes (30 mm and 50 mm in diameter, 52 cm in length). Haustral folds were created by heat shaping and 39 intermediate sessile polyps with a target size of 6-10 mm and two flat lesions were created from silicone. Nine polyps were attached to a fold. The model was placed in a 30-cm barrel filled with water to simulate attenuation of human body. Attenuation of polyps was compared to intermediate polyps found in patients. RESULTS: None of the earlier colonic phantoms found in the literature incorporated all the properties that would ensure both reproducibility and validity of the model (including a rigid wall, density of the wall and polyps similar to human colon, at least two levels of distension and durability). In the present phantom, the average size of sessile polyps was 8.6 ± 0.9 mm and their density was 53 ± 24 HU. We found no significant difference in polyp density between simulated polyps in the phantom and polyps in human subjects (P = 0.70). All polyps, with the exception of one flat lesion, were detected by computer aided detection. CONCLUSION: We constructed and validated a CT colonography phantom with correct density allowing performance of reproducible experiments.

4th department of Internal Medicine 1st Faculty of Medicine Charles University Prague Prague Czech Republic

Department of Radiology 1st Faculty of Medicine Charles University Prague Prague Czech Republic

Department of Radiology 1st Faculty of Medicine Charles University Prague Prague Czech Republic; Department of Psychiatry 1st Faculty of Medicine Charles University Prague Prague Czech Republic

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Sunshine JH, Applegate KE. Technology assessment for radiologists. Radiology. 2004;230(2):309–14. doi: 10.1148/radiol.2302031277. PubMed DOI

Oto A, Gelebek V, Oguz BS, Sivri B, Deger A, Akhan O, et al. CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography. Eur Radiol. 2003;13(7):1657–63. doi: 10.1007/s00330-002-1770-y. PubMed DOI

Karadi C, Beaulieu CF, Jeffrey RJ, Paik DS, Napel S. Display modes for CT colonography. Part I. Synthesis and insertion of polyps into patient CT data. Radiology. 1999;212(1):195–201. doi: 10.1148/radiology.212.1.r99jl25195. PubMed DOI

Branschofsky M, Vogt C, Aurich V, Beck A, Modder U, Cohnen M. Feasibility of ultra-low-dose multi-detector-row CT-colonography: detection of artificial endoluminal lesions in an in-vitro-model with optimization of image quality using a noise reduction filter algorithm. Eur J Med Res. 2006;11(1):13–9. PubMed

Dachman AH, Lieberman J, Osnis RB, Chen SY, Hoffmann KR, Chen CT, et al. Small simulated polyps in pig colon: sensitivity of CT virtual colography. Radiology. 1997;203(2):427–30. doi: 10.1148/radiology.203.2.9114099. PubMed DOI

Choi JI, Kim SH, Kim SH, Park HS, Lee JM, Lee JY, et al. Comparison of accuracy and time-efficiency of CT colonography between conventional and panoramic 3D interpretation methods: an anthropomorphic phantom study. Eur J Radiol. 2011;80(2):68–75. doi: 10.1016/j.ejrad.2010.08.022. PubMed DOI

Park SH, Choi EK, Lee SS, Byeon JS, Jo JY, Kim YH, et al. Polyp measurement reliability, accuracy, and discrepancy: optical colonoscopy versus CT colonography with pig colonic specimens. Radiology. 2007;244(1):157–64. doi: 10.1148/radiol.2441060794. PubMed DOI

Taylor S, Slater A, Honeyfield L, Burling D, Halligan S. CT colonography: effect of colonic distension on polyp measurement accuracy and agreement-in vitro study. Acad Radiol. 2006;13(7):850–9. doi: 10.1016/j.acra.2006.03.018. PubMed DOI

Na Y, Kim JS, Whiting BR, Bae KT, editors. Automatic detection of polyps from multislice ct images using 3d morphologic matching algorithm: Phantom study.; Medical Imaging 2003.; 2003; International Society for Optics and Photonics; pp. 877–81.

Wong KH, Norris JA, Holmes Iii DR, Barton MD, Davis BJ, Bieszczad J, et al. Anatomically correct deformable colon phantom. 2011;7964:79642X. doi: 10.1117/12.878173. DOI

Wessling J, Fischbach R, Meier N, Allkemper T, Klusmeier J, Ludwig K, et al. CT colonography: Protocol optimization with multi-detector row CT--study in an anthropomorphic colon phantom. Radiology. 2003;228(3):753–9. doi: 10.1148/radiol.2283020928. PubMed DOI

Wessling J, Fischbach R, Borchert A, Kugel H, Allkemper T, Osada N, et al. Detection of colorectal polyps: comparison of multi-detector row CT and MR colonography in a colon phantom. Radiology. 2006;241(1):125–31. doi: 10.1148/radiol.2411050292. PubMed DOI

Flicek KT, Hara AK, Silva AC, Wu Q, Peter MB, Johnson CD. Reducing the radiation dose for CT colonography using adaptive statistical iterative reconstruction: A pilot study. AJR Am J Roentgenol. 2010;195(1):126–31. doi: 10.2214/AJR.09.3855. PubMed DOI

Johnson KT, Carston MJ, Wentz RJ, Manduca A, Anderson SM, Johnson CD. Development of a cathartic-free colorectal cancer screening test using virtual colonoscopy: a feasibility study. AJR Am J Roentgenol. 2007;188(1):29–36. doi: 10.2214/AJR.05.1484. PubMed DOI

de Vries AH, Venema HW, Florie J, Nio CY, Stoker J. Influence of tagged fecal material on detectability of colorectal polyps at CT: phantom study. AJR Am J Roentgenol. 2008;191(4):1101. doi: 10.2214/AJR.07.3740. PubMed DOI

Laghi A, Iannaccone R, Mangiapane F, Piacentini F, Iori S, Passariello R. Experimental colonic phantom for the evaluation of the optimal scanning technique for CT colonography using a multidetector spiral CT equipment. Eur Radiol. 2003;13(3):459–66. doi: 10.1007/s00330-002-1671-0. PubMed DOI

van Wijk C, Florie J, Nio CY, Dekker E, de Vries AH, Venema HW, et al. Protrusion method for automated estimation of polyp size on CT colonography. AJR Am J Roentgenol. 2008;190(5):1279–85. doi: 10.2214/AJR.07.2865. PubMed DOI

Springer P, Stohr B, Giacomuzzi SM, Bodner G, Klingler A, Jaschke W, et al. Virtual computed tomography colonoscopy: artifacts, image quality and radiation dose load in a cadaver study. Eur Radiol. 2000;10(1):183–7. PubMed

Fletcher JG, Booya F, Melton Z, Johnson K, Guendel L, Schmidt B, et al. Automated polyp measurement with CT colonography: preliminary observations in a phantom colon model. AJR Am J Roentgenol. 2007;188(4):945–52. doi: 10.2214/AJR.06.1169. PubMed DOI

Johnson KT, Johnson CD, Anderson SM, Bruesewitz MR, McCollough CH. CT colonography: determination of optimal CT technique using a novel colon phantom. Abdom Imaging. 2004;29(2):173–6. doi: 10.1007/s00261-003-0069-z. PubMed DOI

Zalis ME, Perumpillichira JJ, Kim JY, Del Frate C, Magee C, Hahn PF. Polyp size at CT colonography after electronic subtraction cleansing in an anthropomorphic colon phantom. Radiology. 2005;236(1):118–24. doi: 10.1148/radiol.2361040231. PubMed DOI

Virmani S, Lev-Toaff A, Ciancibello L. Automatic polyp detection and measurement with computed tomographic colonography: A phantom study. Biomed Imaging Interv J. 2009;5(3):15. doi: 10.2349/biij.5.3.e15. PubMed DOI PMC

Punwani S, Halligan S, Irving P, Bloom S, Bungay A, Greenhalgh R, et al. Measurement of colonic polyps by radiologists and endoscopists: who is most accurate? Eur Radiol. 2008;18(5):874–81. doi: 10.1007/s00330-007-0830-8. PubMed DOI

Boyce CJ, Vetter JR, Pickhardt PJ. MDCT artifact related to the intra-scan gravitational flow of opacified luminal fluid (the "Dense Waterfall" sign). Abdom Imaging. 2012;37(2):292–6. doi: 10.1007/s00261-011-9731-z. PubMed DOI

Lambert L, Danes J, Jahoda J, Masek M, Lisy J, Ourednicek P. Submilisievert ultralow-dose CT colonography using iterative reconstruction technique: a feasibility study. Acta Radiol. 2015;56(5):517–25. doi: 10.1177/0284185114533683. PubMed DOI

Love A, Olsson ML, Siemund R, Stalhammar F, Bjorkman-Burtscher IM, Soderberg M. Six iterative reconstruction algorithms in brain CT: a phantom study on image quality at different radiation dose levels. Br J Radiol. 2013;86(1031):20130388. doi: 10.1259/bjr.20130388. PubMed DOI PMC

Taylor SA, Halligan S, Goh V, Morley S, Bassett P, Atkin W, et al. Optimizing colonic distention for multi-detector row CT colonography: effect of hyoscine butylbromide and rectal balloon catheter. Radiology. 2003;229(1):99–108. doi: 10.1148/radiol.2291021151. PubMed DOI

Lambert L, Ourednicek P, Jahoda J, Lambertova A, Danes J. Model-based vs hybrid iterative reconstruction technique in ultralow-dose submillisievert CT colonography. Br J Radiol. 2015;88(1048):20140667. doi: 10.1259/bjr.20140667. PubMed DOI PMC

Summers RM. Polyp size measurement at CT colonography: what do we know and what do we need to know? Radiology. 2010;255(3):707–20. doi: 10.1148/radiol.10090877. PubMed DOI PMC

Bretagne JF, Manfredi S, Piette C, Hamonic S, Durand G, Riou F. Yield of high-grade dysplasia based on polyp size detected at colonoscopy: a series of 2295 examinations following a positive fecal occult blood test in a population-based study. Dis Colon Rectum. 2010;53(3):339–45. doi: 10.1007/DCR.0b013e3181c37f9c. PubMed DOI

Sakamoto T, Matsuda T, Nakajima T, Saito Y. Clinicopathological features of colorectal polyps: evaluation of the predict, resect and discard strategies. Colorectal Disease. 2013;15(6):295–300. PubMed

Zalis ME, Barish MA, Choi JR, Dachman AH, Fenlon HM, Ferrucci JT, et al. CT colonography reporting and data system: a consensus proposal. Radiology. 2005;236(1):3–9. doi: 10.1148/radiol.2361041926. PubMed DOI

Yee J, Weinstein S, Morgan T, Alore P, Aslam R. Advances in CT Colonography for Colorectal Cancer Screening and Diagnosis. J Cancer. 2013;4(3):200–9. doi: 10.7150/jca.5858. PubMed DOI PMC

Lubner MG, Pooler BD, Kitchin DR, Tang J, Li K, Kim DH, et al. Sub-milliSievert (sub-mSv) CT colonography: a prospective comparison of image quality and polyp conspicuity at reduced-dose versus standard-dose imaging. Eur Radiol. 2015;25(7):2089–102. doi: 10.1007/s00330-015-3603-9. PubMed DOI PMC

Pickhardt PJ, Kim DH. CT colonography: pitfalls in interpretation. Radiol Clin North Am. 2013;51(1):69–88. doi: 10.1016/j.rcl.2012.09.005. PubMed DOI PMC