CT differential diagnostic value of small bowel wall thickness and density changes in small bowel obstruction

Objective To investigate the CT diagnostic value of small bowel wall thickness and density in differentiating simple small bowel obstruction (SI) from strangulative small bowel obstruction (ST).Methods Fifty-three cases with thickened small bowel wall (thickness ＞ 3 mm) confirmed on CT scan were reviewed,including 27 cases of SI and 26 cases of ST,in conjunction with their proven intraoperational,pathological and clinical findings.Of the 53 cases,35 cases also underwent postcontrast CT scan.CT manifestations of relationships between thickened small bowel wall and its density were classified as normal,higher or lower density in tunica mucosa of small bowel wall,higher or lower density in full thickness of small bowel wall for exploring the differential diagnostic features between SI and ST on CT scan.Chi-square or Fisher exact test were used to test the proportion difference of CT scan between SI and ST.Results In cases with normal density in tunica mucosa (NDTM) on precontrast CT,there were 21 cases of SI and 6 cases of ST(x2 =15.859,P ＜0.01).However,in cases with NDTM on postcontrast CT,there were 13 cases of SI and 5 cases of ST,and there was no significant difference (x2 =1.377,P ＞ 0.05).Thus,NDTM showed no convincing value in differentiating SI from ST.In cases with lower density in tunica mucosa (LDTM) on precontrast CT,there were 4 cases of SI and 5 cases of ST (P ＞ 0.05).In cases with LDTM on postcontrast CT,there were 4 cases of SI and 4 cases of ST (P ＞ 0.05).Thus,LDTM also showed no value in differentiating SI from ST.The lower density in full thickness of small bowel wall (LDFTS) was revealed in 0 of SI and 10 cases of ST on precontrast CT (P ＜ 0.01),and 0 of SI and 5 cases of ST on postcontrast CT (P ＜ 0.01),indicating that LDFTS showed significant value in differentiating SI from ST.Conclusion Combining the small bowel wall thickness and density,CT manifestations of early bowel wall pathological changes in small bowel obstruction can be acquired,adding some value in the differential diagnosis between SI and ST. Key words: Intestinal obstruction;  Diagnosis,differential;  Tomography,X-ray computed