FDG-PET-CT Enterography Helps Determine Clinical Significance of Suspected Ileocecal Thickening: A Prospective Study.

BACKGROUND: Ileocecal thickening (ICT) on imaging could result from diverse etiologies but may also be clinically insignificant. AIM: Evaluation of role of combined 2-deoxy-2-fluorine-18-fluoro-D-glucose(18F-FDG)-positron emission tomography and computed tomographic enterography (PET-CTE) for determination of clinical significance of suspected ICT. METHODS: This prospective study enrolled consecutive patients with suspected ICT on ultrasound. Patients were evaluated with PET-CTE and colonoscopy. The patients were divided into: Group A (clinically significant diagnosis) or Group B (clinically insignificant diagnosis) and compared for various clinical and radiological findings. The two groups were compared for maximum standardized uptake values of terminal ileum, ileo-cecal valve, cecum and overall. RESULTS: Of 34 patients included (23 males, mean age: 40.44 ± 15.40 years), 12 (35.3%) had intestinal tuberculosis, 11 (32.4%) Crohn's disease, 3 (8.8%) other infections, 1 (2.9%) malignancy, 4 (11.8%) non-specific terminal ileitis while 3 (8.8%) had normal colonoscopy and histology. The maximum standardized uptake value of the ileocecal area overall (SUVmax-ICT-overall) was significantly higher in Group A (7.16 ± 4.38) when compared to Group B (3.62 ± 9.50, P = 0.003). A cut-off of 4.50 for SUVmax-ICT-overall had a sensitivity of 70.37% and a specificity of 100% for prediction of clinically significant diagnosis. Using decision tree model, the SUVmax-ICT with a cut-off of 4.75 was considered appropriate for initial decision followed by the presence of mural thickening in the next node. CONCLUSION: PET-CTE can help in discrimination of clinically significant and insignificant diagnosis. It may help guide the need for colonoscopy in patients suspected to have ICT on CT.

Ileocecal thickening: Clinical approach to a common problem.

Ileocecal thickening (ICT) is a common finding on radiological imaging. It can be caused by a variety of inflammatory, infectious, or neoplastic conditions, and evaluating a patient of ICT can be a challenging task. Intestinal tuberculosis (ITB), Crohn's disease (CD), and adenocarcinoma are the most common causes. Enteric bacterial infections, cytomegalovirus, histoplasmosis, amebiasis, systemic vasculitis, lymphoma, etc. should be suspected in appropriate clinical settings. However, it could often be a spurious or nonspecific finding. A thickness of more than 3 mm in a normally distended small bowel is usually considered abnormal. Detailed evaluation of imaging of the site and extent of thickening; the degree and pattern of thickening; and the associated findings, such as degree of fat stranding, fibrofatty proliferation, adjacent lymph nodes, and solid organ involvement, should be performed. Ileocolonoscopy is an important tool for diagnosing and obtaining samples for tissue diagnosis. Histopathology is usually the gold standard for diagnosis, although-not uncommonly-findings could be nonspecific, and reaching a definitive diagnosis is difficult. As such, a systematic approach with the integration of clinical, biochemical, radiological, endoscopic, histological, and other laboratory tests is the key to reaching a diagnosis. In this article, we review the causes of ICT and present a clinical approach for the management of ICT.