Abstract:ObjectiveTo explore the best concentration of mannitol in small intestinal imaging by multidetector-slice computed tomography enterography (MSCTE). Methods Eighty patients receiving contrast-enhanced computed tomography (CECT) scan of whole abdomen were randomly divided into four groups in which oral administration of mannitol solution of different concentrations was given to select the optimum concentration for best intestine dilatation and intestinal wall enhancement D-value. Results There were statistical differences in the measurements of small intestinal diameter among four groups(F=8.823，P＜0.05).The trend of small intestinal wall enhancement difference was similar in each group (P>0.05).There was no significant difference in duodenal diameter measurements among groups(P>0.05),but there were statistical differences in the diameter measurements of jejunums (F=9.583,P<0.01) and ileums (F=3.914,P<0.05) among four groups.There were statistical differences in intestinal wall enhancement D-values of duodenum,jejunum and ileum among groups(P<0.01).There were no significant differences in small intestinal dilatation and intestinal wall enhancement between 2.0% mannitol solution group and 2.5% mannitol solution group (P>0.05).Oral administration of 1 600 ml mannitol solution (5.0%) clearly showed ileocecal structure and was statistically different from other three groups (F=9.207,P<0.05).Conclusion 2.0% mannitol solution is a safe and reliable intestinal contrast agent,which has good application value in MSCTE examination.5.0% mannitol solution can clearly show the ileocecal structure and can be used as the preferred concentration for patients suspected of ileocecal lesions in MSCTE examination.