CT Evaluation of Large Bowel Wall Lesions

Abstract

Introduction: Clinical diagnosis and management of large bowel disease is made difficult by the non-specific nature of symptoms and a significant overlap in the presentation of different pathologic processes affecting it. Computed Tomography (CT) is being increasingly used for the diagnostic evaluation of large bowel lesions. Aim: Present study describes the role of Multidetector CT in evaluation of suspected large bowel lesions in patients referred to the Radiology Department. Materials and Methods: In this observational study, data was collected from patients of suspected large bowel lesions referred to MGM Hospital and Research Institute, Aurangabad. Total 30 patients were enrolled during November 2014 to November 2016. Patients presenting with the symptoms related to altered bowel habits/abdomen, positive large bowel wall findings on plain CT, large bowel lesions detected on ultrasound, history of trauma undergoing CT-scan with large bowel wall thickening on USG/CT were included. All patients were followed up to therapeutic/biopsy/operative diagnosis. Histopathological reports helped in the retrospective confirmation of the provisional diagnosis on Multidetector CT. Results: Overall most of the cases (benign + malignant) were reported in the age group of 41-60 years (53.3%). Bleeding per rectum and weight loss was the most common presentation (23.5%) amongst malignant lesions. Loose stool and vomiting (30.8%) was the most common presentation amongst all the benign lesions. The most common location for malignant lesions was rectum (52.9%) and for benign lesions was the long segment extending from transverse to sigmoid colon (23.1%). Malignant lesions showed heterogeneous mixed attenuation (100%), marked thickening (88.2%) and asymmetric thickening (88.2%). Benign lesions showed homogenous attenuation (92.3%), mild thickening (84.6%) and symmetrical thickening (92.3%). Focal thickening was seen in most of the malignant lesions (76.5%) and none presented with diffuse thickening. Both focal and diffuse thickening were seen in benign lesions (38.5%) followed by segmental involvement (23.1%). All of the benign lesions were associated with peripheral fat stranding. Amongst the malignant lesions, 70.6% showed presence of surrounding fat stranding. Conclusion: From the study results, it can be stated that MDCT has a high predictive value in the diagnosis and differentiation of benign and malignant lesions of the large bowel.

Keywords

• attenuation
• fat stranding
• focal and diffuse thickening