The Clinical Application Of MR Colonography Using Dark Lumen Technique In Diagnosis Of Ulcerative Colitis And Colon Cancer

Objective Using of dark lumen magnetic resonance colonography(MRC) technique to comprehensively analyze the ulcerative colitis and colon cancer imaging features, and optimize MRC sequences and related parameters, evaluating its clinical value in diagnosis of colorectal lesion.Materials and Methods A total of 52 patients who were suspected to have ulcerative colitis and ulcerative type of colon cancer from April 2014 to June 2016 in Tianjin Union Medical Center were included in this prospective study, all patients undertook dark lumen MRC examination. And all patients performed colonoscopy or surgery a week before or after MRC examination, then getting pathologic examination after operation. Patients were divided into two groups: ulcerative colitis group(UC group,15 cases) and ulcerative type of colon cancer group(UTCC group,37 cases). The diagnostic criteria of UC according to the diagnostic criteria of inflammatory bowel disease. Comparing the dark lumen MRC imaging results with the colonoscopy or surgical pathology, analyzing the incomplete colonoscopy examination reasons and rates in two groups. The large bowel was divided into six segments and to compare of bowel dilatation and image quality. Optimizing of dark lumen MRC sequences, and comprehensively analyzing the diagnostic advantage of T2-HASTE, 3D-T1-VIBE,and DWI sequences between the two groups. To semi-quantitatively analyze clinical values of the maximum value(ME) and the relative enhancement ratio(Er) in two groups with use of dynamic contrast enhanced sequence. Taking advantage of Er, ADC value and related serological markers' ROC curves in order to get the critical threshold, sensitivity,and specificity of the differential diagnosis in two groups.Results(1)52 cases of ulcerative colorectal lesions, incomplete colonoscopy rate was 67.31%, of which UTCC group was higher than the UC group(81.10%> 33.30%).(2)In Dark lumen MRC examination,the image quality of rectal and sigmoid segments were better, and worse in the ascending colon and descending colon. About the mean distention levels: the distention of the two groups had no significantly difference. In UTCC group,sigmoid colon distention was poorest(1.75);in UC group, the sigmoid colon and transverse colon were distention was poorer(1.73 and 1.87)in UC group.(3) The coincidence rates of UTCC group was higher than UC group(coincidence rate: 97.28%>80.00%) in the dark-lumen MRC examination. And depth of invasion in UTCC group was higher than UC group with obviously statistically significant(P=0.000).(4)T2-HASTE?3D-VIBE and DWI sequences can be use for tumor T staging, and contrast enhanced 3D-VIBE sequence and DWI sequence were better than T2-HASTE sequence, the differences were statistically significant(P values were 0.027 and 0.034 respectively).The accuracy of DWI sequence in T staging was higher than 3D-VIBE enhance sequence,but with no statistically significant.(5)Parameters of 3D-T1-VIBE sequence: ME and Er can distinguish benign from malignant colorectal lesion, with the Er parameter having high sensitivity and specificity in two groups.(6)In DWI sequence, quantitative parameters ADC value can objectively evaluate UC and UTCC, and the diagnostic sensitivity was 92.90% and specificity of 94.70%.(7) The distribution of CEA, CA19-9 and CA-724 in the two groups were significantly different(P <0.05),and the level were higher in UTCC group with lower sensitivity and specificity. The relative enhancement ratio combined with serum tumor markers as diagnostic criteria for two two groups: the specificity was higher and the sensitivity was relatively good.Conclusion(1)Dark-lumen MRC imaging can clearly show anatomy structures and subtle lesions of the colon, repeatability and without radiation, provide a forceful imaging features for clinic diagnosis of colonic lesions timely. MRC technique were better than colonoscopy examination for patients with incomplete colonoscopy, especially for patients with bowel obstruction.(2) Optimizing imaging detection parameters and serological examination can significantly improve the diagnostic performance of the two lesions and also provide a forceful imaging features for clinicians to diagnose UC?UC-related colon cancer and to intervene UC-related colon cancer timely.