Abstract
A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps <10 mm, 13 polyps ≥10 mm, 24 carcinomas) were determined by region-of-interest (ROI) measurements in 38 patients who underwent contrast-enhanced CTC. In addition, the height (H) of the colonic lesions was measured in CT. CT values were also measured in the aorta (A), superior mesenteric vein (V) and colonic wall. The contrast phase was defined by \(xA + {\left( {1 - x} \right)}V\) using x as a weighting factor for describing the different contrast phases ranging from the pure arterial phase (x=1) over the intermediate phases (x=0.9–0.1) to the pure venous phase (x=0). The CT values of the lesions were correlated with their height (H), the different phases (\(xA + {\left( {1 - x} \right)}V\)) and the ratio \({\left[ {xA + {\left( {1 - x} \right)}V} \right]}/H\). The CT cut-off was linearly adjusted to the imaged contrast phase and height of the lesion by the line \(y = m{\left[ {xA + {\left( {1 - x} \right)}V} \right]}/H + y_{0} \). The slope m was determined by linear regression in the correlation (\( {\text{lesion}} \sim {\left[ {xA + {\left( {1 - x} \right)}V} \right]}/H \)) and the Y-intercept y0 by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A + 0.6V (r=0.8 for polyps ≥10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: \( {\text{cut-off}}{\left( {A,V,H} \right)} = 1.1{\left[ {0.4A + 0.6V} \right]}/H + 69.8 \). The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size.
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Nappi JJ, Frimmel H, Dachman AH, Yoshida H (2004) Computerized detection of colorectal lesions in CT colonography based on fuzzy merging and wall-thickening analysis. Med Phys 31:860–872
Gletsos M, Mougiakakou SG, Matsopoulos GK, Nikita KS, Nikita AS, Kelekis D (2003) A computer-aided diagnostic system to characterize CT focal liver lesions: design and optimization of a neural network classifier. IEEE Trans Inf Technol Biomed 7:153–162
Morrin MM, Farrell RJ, Kruskal JB, Reynolds K, McGee JB, Raptopoulos V (2000) Utility of intravenously administered contrast material at CT colonography. Radiology 217:765–771
Luboldt W, Mann C, Tryon CL et al (2002) Computer-aided diagnosis in contrast-enhanced CT colonography: an approach based on contrast. Eur Radiol 12:2236–2241 (available via www.screening.info)
Oto A, Gelebek V, Oguz BS et al (2003) CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography. Eur Radiol 13:1657–1663
Sosna J, Morrin MM, Kruskal JB, Farrell RJ, Nasser I, Raptopoulos V (2003) Colorectal neoplasms: role of intravenous contrast-enhanced CT colonography. Radiology 228:152–156
Ell C, Fischbach W, Keller R et al (2003) A randomized, blinded, prospective trial to compare the safety and efficacy of three bowel-cleansing solutions for colonoscopy. Endoscopy 35:300–304
Luboldt W, Fletcher JG, Vogl TJ (2002) Colonography: current status, research directions and challenges. Update 2002. Eur Radiol 12:502–524 (available via www.screening.info)
Luboldt W, Hoepffner N, Holzer K (2003) Multidetector CT of the colon. Eur Radiol 13[Suppl 5]:M50–M70 (available via www.screening.info)
de Vries A, Griebel J, Kremser C et al (2000) Monitoring of tumor microcirculation during fractionated radiation therapy in patients with rectal carcinoma: preliminary results and implications for therapy. Radiology 217:385–391
Wold PB, Fletcher JG, Johnson CD, Sandborn WJ (2003) Assessment of small bowel Crohn disease: noninvasive peroral CT enterography compared with other imaging methods and endoscopy—feasibility study. Radiology 229:275–281
Hauptmann S, Budianto D, Denkert C, Kobel M, Borsi L, Siri A (2003) Adhesion and migration of HRT-18 colorectal carcinoma cells on extracellular matrix components typical for the desmoplastic stroma of colorectal adenocarcinomas. Oncology 65:174–181
Vermeulen PB, Colpaert C, Salgado R et al (2001) Liver metastases from colorectal adenocarcinomas grow in three patterns with different angiogenesis and desmoplasia. J Pathol 195:336–342
Bossi P, Viale G, Lee AK, Alfano R, Coggi G, Bosari S (1995) Angiogenesis in colorectal tumors: microvessel quantitation in adenomas and carcinomas with clinicopathological correlations. Cancer Res 55:5049–5053
Pavlopoulos PM, Konstantinidou AE, Agapitos E, Kavantzas N, Nikolopoulou P, Davaris P (1998) A morphometric study of neovascularization in colorectal carcinoma. Cancer 83:2067–2075
Luboldt W, Straub J, Seemann M, Helmberger T, Reiser M (1999) Effective contrast use in CT angiography and dual-phase hepatic CT performed with a subsecond scanner. Invest Radiol 34:751–760
Inoue Y, Nakamura H, Akaji H (1998) The optimal dose of nicardipine for enhancement of indirect portography. Cardiovasc Intervent Radiol 21:17–21
Katayama H, Yamaguchi K, Kozuka T, Takashima T, Seez P, Matsuura K (1990) Adverse reactions to ionic and nonionic contrast media. A report from the Japanese Committee on the Safety of Contrast Media. Radiology 175:621–628
Christiansen C, Pichler WJ, Skotland T (2000) Delayed allergy-like reactions to X-ray contrast media: mechanistic considerations. Eur Radiol 10:1965–1975
Morcos SK, Thomsen HS (2001) Adverse reactions to iodinated contrast media. Eur Radiol 11:1267–1275
Laghi A, Iannaccone R, Bria E et al (2003) Contrast-enhanced computed tomographic colonography in the follow-up of colorectal cancer patients: a feasibility study. Eur Radiol 13:883–889
Ries LAG, Eisner MP, Kosary CL et al (2002) SEER (surveillance, epidemiology and end results) Cancer Statistics Review, 1973–1999, National Cancer Institute, Bethesda, MD http://seer.cancer.gov/csr/1973_1999/sections.html
Yoshida H, Masutani Y, MacEneaney P, Rubin DT, Dachman AH (2002) Computerized detection of colonic polyps at CT colonography on the basis of volumetric features: pilot study. Radiology 222:327–336
Kiss G, Van Cleynenbreugel J, Thomeer M, Suetens P, Marchal G (2002) Computer-aided diagnosis in virtual colonography via combination of surface normal and sphere fitting methods. Eur Radiol 12:77–81
Luboldt W, Tyron C, Kroll M et al (2004) Automated mass detection in contrast enhanced CT colonography: an approach based on contrast and volume. Eur Radiol DOI 10.1007/s00330-04-2497-8 (available via www.screening.info)
Luboldt W, Hoepffner N, Holzer K et al (2003) Early detection of colorectal tumors: CT or MRI? Radiologe 43:136–150 (available via www.screening.info)
Runge VM, Parker JR (1997) Worldwide clinical safety assessment of gadoteridol injection: an update. Eur Radiol 7[Suppl 5]:243–245
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Luboldt, W., Kroll, M., Wetter, A. et al. Phase- and size-adjusted CT cut-off for differentiating neoplastic lesions from normal colon in contrast-enhanced CT colonography. Eur Radiol 14, 2228–2235 (2004). https://doi.org/10.1007/s00330-004-2467-1
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DOI: https://doi.org/10.1007/s00330-004-2467-1