AGA Abstracts and assessed CTT after the swallowing 24, 48 and 72 hours in constipation patients as well as 12 and 48 hours in healthy controls. Pearson correlation coefficient was assessed the association between MRI gadolinium test and ROM to measure the accuracy of gadolinium. Result: CCT measured though gadolinium in constipation patients(55±3h) were longer (P<0.05) than healthy controls(29±2h). CCT measured by barium strips in constipation patients(57±2h) were also statistically significant longer (P<0.05) than healthy controls(32±3h). The Pearson correlation coefficients were r=0.80(P<0.05)of the constipation group and r=0.82(P<0.05)of the healthy group, respectively. Conclusion: The gadolinium with MRI test is a novel technique to assess CCT. It is an effective, safe, radiation-free, easily recognizable and convenient method compared with ROM(Pic.1 and 2). The new explored gadolinium with MRI test can be an optional replacement to the traditional method, ROM, to assess CCT. Gd-DTPA capsules in a constipation patient(48h) Barium Strips in a same constipation patient(48h) Sa1101 Advanced In Vivo Live Imaging of Vascular Network of Colon Submucosa in IBD Models Using Two-Photon Laser Microscopy Wataru Ikeda, Akiko Hamaguchi, Yoshihisa Arita, Yoshikazu Kuboi, Kenzo Muramoto, Toshio Imai Background and aims: It has been reported that crawling/rolling monocytes in blood vessels play an important role in Inflammatory Bowel Disease (IBD). To monitor and evaluate these cells in IBD models, we established an advanced imaging system for immune cells, such as monocytes, in the mouse colon. Two-photon microscopy has revolutionized functional cellular imaging in tissue, but heartbeat and peristaltic movement of intestine interfere with imaging analysis of the colon. We studied the conditions for analysis with two-photon microscopy and developed a new device for live two-photon imaging of the colon. Methods: We imaged two mouse models of IBD; 1) CD4+CD45RB high T-cell transferred and 2) oxazolone-induced colitis models using the two-photon laser microscope system (NIKON, A1RMP+ (GaAsP) with inverted microscope). To visualize blood stream, fluorochrome- conjugated dextran was injected intravenously. Fluorochrome-conjugated mAb against cell surface marker, such as CD11b and/or CD115, which is a marker for monocyte and/or neutrophil was also injected. Results: Imaging depths of 150 μm from the surface of the intestinal tract were reached allowing observation of the crypt of mucosa and the vascular network of the submucosa (thickness of muscularis externa is around 80 μm, submucosa is around 60 μm, and mucosa is over 100 μm). We developed an original device to bypass the physical interference of heartbeat and peristaltic movement with imaging. The device separates the observation area (colon) and the whole body. In brief, the inflammatory region of the colon was exteriorized by mesentery excision and separation of intestines. Attachment of the colon to the device also prevented peristaltic movement interference. This device S-224 AGA Abstracts allowed the monitoring of crawling/rolling CD11b+ or CD115+ cells in the blood vessels of the inflamed colon with the two-photon microscope. We observed an increase in crawling/ rolling CD11b+ cells in the IBD models compared with normal mice. Cells could be monitored for more than one hour and various phenotypes could be identified (e.g. crawling, rolling, firm adhesion). Conclusions: This advanced imaging system of colon allowed visualization of the blood stream and behavior of arbitrary cells without physical interference from heartbeat and peristaltic movement. Our system provides a useful method to analyze colonic inflammation, allowing visualization of the vascular network and immune cells in submucosa region. This system can be used to identify the function of inflammatory cells in colon. Sa1102 Incidental Colon Wall Thickening on Computed Tomography: What Is the Role of Follow Up Colonoscopy? Vipin Verma, Suzan Ebrahimi, Dennis Nguyen, Sanya Wadhwa, Barinder Chana, Lauren V. Halvorson, James D. Mcfadden, Won Cho Background: Even though colon wall thickening (CWT) is a common incidental finding in era of modern imaging, its clinical significance is not clear. Few studies have looked into follow up colonoscopy findings in patients with CWT and their results are contradictory. Incidence of any clinically significant abnormality and carcinoma has been reported to be 35%-98% and 0-25%, respectively. 1-3 Aim: To study the incidence of various abnormalities on follow up colonoscopy in patients with incidental solitary CWT on computer tomography (CT)- abdomen. Patients and Methods : We retrospectively reviewed charts of consecutive 91 adults aged > 18 years who underwent colonoscopy from Jan 2011-June 2014 at Medstar Washington Hospital Center for CWT noted on CT- abdomen. One experienced blinded radiologist and gastroenterologist reviewed all CT images and colonoscopies, respectively. 43 patients were excluded and final analysis was performed on 48 patients. Reason for exclusion included: colonoscopy was not performed within 3 weeks of CT (20), CT read as normal on retrospective review by radiologist (9), personal history of cancer (8) and presence of lymphadenopathy on CT scan (6). Results: Nine patients did not have colon wall biopsy as no abnormality was detected on colonoscopy. Out of 39 patients who underwent biopsy, 28 patients had biopsy at the site of CWT and 11 patients had biopsy at sites outside of an area of CWT. 12 patients had normal or nonspecific findings on pathology. 27/48 (56.2 %) patients identified to have some abnormality but management was only affected in 19 (39.5%) patients (Table 1). Only one patient was identified to have colon cancer and rest had benign etiology. Conclusion: Follow up colonoscopy in patients with CWT on CT abdomen showed benign or normal pathology in most patients and management was only affected in approx. 40% patients. Although approximately half of patients (56.2%) with CWT identified to have some abnormality on colonoscopy, incidence of cancer was very low (2%). There is an urgent need to identify the predictors of significant clinical pathology in patients with incidental CWT. Reference: 1. Cai Q, Baumgarten DA, Affronti JP, Waring JP. Incidental findings of thickening luminal gastrointestinal organs on computed tomography: An absolute indication for endoscopy. Am J Gastroenterol 2003;98:1734-7. 2. Rockey DC, Halvorsen RA Jr, Higgins JL, Cello CP. Prospective evaluation of patients with bowel wall thickening. Am J Gastroenterol 1995;90:99-103. 3. Stermer E, Lavy A et al. Incidental colorectal computed tomography abnormalities: Would you send every patient for a colonoscopy? Can J Gastroenterol. Sep 2008; 22(9): 758-760. Table 1. Colon wall biopsy findings in patients with colon wall thickening on CT-abdomen. Sa1103 Platelet Count, Non-Albumin Protein and Imaging Characteristics of Colon Wall Thickening Are Associated With Abnormal Colonoscopy Findings in Patients With Incidental Colon Wall Thickening on Computerized Tomography Vipin Verma, Suzan Ebrahimi, Dennis Nguyen, Sanya Wadhwa, Barinder Chana, Lauren V. Halvorson, Seper Dezfoli, James D. Mcfadden, Won Cho Background: Colonoscopy is an invasive procedure which has several complications. There- fore, identification of clinical markers to triage patients with incidental colon wall thickening (iCWT) for colonoscopy versus conservative management is critical. Aim: To identify radio- logical and serum predictors of abnormal findings on colonoscopy in patients with iCWT on computerized tomography (CT). Colonoscopy findings were considered significant if they led to change in management, including subspecialty referral, surgery, further imaging, procedures or medical treatment. Patients and Methods: We retrospectively reviewed charts of 280 adults (18+ years) at Medstar Washington Hospital Center who underwent colonos- copy from Jan 2011-June 2014 for abnormal CT-abdomen. 91 patients had colonoscopy to evaluate for iCWT on CT report. 20 patients were excluded as colonoscopy was not performed