Magnetic Resonance Colonography for the Detection of Colorectal Neoplasia

Abstract

In their recent study, Prof. Graser and colleges1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar concluded that there are both high-sensitivity and specificity in detecting colorectal adenomas >6 mm and advanced neoplasia by use of magnetic resonance colonography. However, there is an uncertainty in interpreting the results of this study.It is well known that nonpolypoid flat lesions are of vital importance as regards colorectal cancer development and prevention and that nonpolypoid flat lesions could be detected by colonoscopy but be usually missed-diagnoses by CT colonography even if magnetic resonance colonography.2Gluecker T.M. et al.AJR Am J Roentgenol. 2004; 182: 881-889Crossref PubMed Scopus (54) Google Scholar, 3Leung W.K. et al.Am J Gastroenterol. 2004; 99: 102-108Crossref PubMed Scopus (38) Google Scholar However, in the study by Prof. Graser et al,1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar the incidence rate of the above-mentioned nonpolypoid flat lesions detected by colonoscopy was not described. Could the true sensitivity be lower than reported in the study Prof. Graser and colleges1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar if the incidence rate of the above-mentioned nonpolypoid flat lesions detected by colonoscopy was considered? If yes, the results with the lower sensitivity could represent a very important limitation of magnetic resonance colonography. The further studied confirmed the above-mentioned questions, therefore, should be performed. In their recent study, Prof. Graser and colleges1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar concluded that there are both high-sensitivity and specificity in detecting colorectal adenomas >6 mm and advanced neoplasia by use of magnetic resonance colonography. However, there is an uncertainty in interpreting the results of this study. It is well known that nonpolypoid flat lesions are of vital importance as regards colorectal cancer development and prevention and that nonpolypoid flat lesions could be detected by colonoscopy but be usually missed-diagnoses by CT colonography even if magnetic resonance colonography.2Gluecker T.M. et al.AJR Am J Roentgenol. 2004; 182: 881-889Crossref PubMed Scopus (54) Google Scholar, 3Leung W.K. et al.Am J Gastroenterol. 2004; 99: 102-108Crossref PubMed Scopus (38) Google Scholar However, in the study by Prof. Graser et al,1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar the incidence rate of the above-mentioned nonpolypoid flat lesions detected by colonoscopy was not described. Could the true sensitivity be lower than reported in the study Prof. Graser and colleges1Graser A. et al.Gastroenterology. 2013; 144: 743-750Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar if the incidence rate of the above-mentioned nonpolypoid flat lesions detected by colonoscopy was considered? If yes, the results with the lower sensitivity could represent a very important limitation of magnetic resonance colonography. The further studied confirmed the above-mentioned questions, therefore, should be performed. Magnetic Resonance Colonography for the Detection of Colorectal Neoplasia in Asymptomatic AdultsGastroenterologyVol. 144Issue 4PreviewColonoscopy is the preferred screening test for colorectal neoplasia; the fecal occult blood test (FOBT) detects neoplasias with low levels of sensitivity. Computed tomographic colonography detects neoplasias with high levels of sensitivity but involves exposure to radiation. We investigated whether magnetic resonance colonography (MRC) can be used to screen for colorectal adenomas and cancers. Full-Text PDF ReplyGastroenterologyVol. 145Issue 2PreviewWe thank Drs Song and Huang for their thoughtful comments relating to our recently published paper on MR colonography in the detection of colonic neoplasia.1 Drs Song and Huang pointed out that we did not report on flat lesions, and that imaging may fail to detect flat lesions. In our paper, we report a total of 25 pedunculated and 108 nonpedunculated adenomatous lesions. MR colonography detected 7 of 10 nonpedunculated advanced adenoma and 20 of 98 nonpedunculated nonadvanced adenoma. Of note, in our trial studying a typical Western cohort, no flat lesions were either detected by colonoscopy nor MR colonography. Full-Text PDF