Abstract:Objective: To investigate the MDCT imaging manifestations and pathological basis of bowel wall thickening due to nontumorous causes. Methods: MDCT findings of 284 patients with bowel wall thickening due to nontumorous causes confirmed by surgery, biopsy or clinical follow-up were studied retrospectively, paying attention to location, range, symmetric or asymmetric, involvement degree of thickening, attenuation, presence or absence of enhancement and associated perienteric abnormalities of thickened bowel wall. MDCT findings were analyzed with correlation with pathological changes. Results: All the non-tumorous disease caused bowel wall thickening included liver cirrhosis(109 cases) , acute pancreatitis(54 cases), bowel obstruction(36 cases), inflammatory bowel disease(14 cases), ischemic bowel disease(12 cases), radiation enterocolitis(13 cases), tuberculosis (12 cases), immune reaction(10 cases), infective enteritis(3 cases), acute appendicitis(3 cases), hypoproteinemia(5 cases), rare diseases(8 cases) and normal variants(5 cases). The attenuation pattern of the thickened bowel wall included high attenuation(1 case), iso-attenuation(144 cases), low attenuation(127 cases), fat deposition(5 cases) and pneumatosis(7 cases). The enhancement pattern of the thickened bowel wall included mild enhancement(249 cases), marked enhancement(32 cases) and unenhancement(3 cases). Degree of bowel wall thickening included mild thickening(279 cases) and marked thickening(5 cases). Two hundred and twelve patients with bowel wall thickening showed multisegmental distribution while 72 patients had single segmental involvement. Associated perienteric abnormalities of thickened bowel wall included swelling of fat(218 cases), ascites(189 cases), lymphadenopathy(5 cases), perienteirc abscess(2 cases), mesenteric vascular lesion(25 cases) and involvement of solid abdominal organs(169 cases). Conclusion: Bowel wall thickening due to nontumorous causes showed mild and homogeneous thickening, iso-attenuation or low attenuation, mild enhancement and multisegmental distribution on MDCT. Paying attention to the characteristics and pathological basis of thickening of bowel wall benefits the diagnosis and differential diagnosis of various intestinal diseases.