Combination of Increased Visceral Fat and Long Segment Involvement: Development and Validation of an updated imaging marker for differentiating Crohn’s Disease from Intestinal Tuberculosis.

Combination of Increased Visceral Fat and Long Segment Involvement: Development and Validation of an updated imaging marker for differentiating Crohn’s Disease from Intestinal Tuberculosis.

J Gastroenterol Hepatol. 2017 Dec 04;:

Authors: Kedia S, Madhusudhan KS, Sharma R, Bopanna S, Yadav DP, Goyal S, Jain S, Das P, Dattagupta S, Makharia G, Ahuja V

Abstract
BACKGROUND: Computed tomographic(CT) features(long segment, ileocaecal area involvement and lymph nodes>1cm) have demonstrated good specificity but poor sensitivity, while visceral to subcutaneous fat ratio on CT(VF/SC>0.63) has moderate sensitivity and specificity in differentiating Crohn’s disease(CD) and intestinal tuberculosis(ITB).
AIM: To develop and validate an updated model incorporating CT features and VF/SC to improve the diagnostic accuracy of imaging in differentiating CD/ITB.
METHODS: CT features and VF/SC were documented in 2 cohorts[development (n=59, follow-up: January 2012 – November 2014) and validation (n=69, follow-up: December 2014 – December 2015)] of CD/ITB patients diagnosed by standard criteria. Patients with normal CT were excluded. Features significantly different between CD/ITB were incorporated into a model.
RESULTS: In both the cohorts, necrotic lymph nodes were exclusive for ITB(23.1% vs 0 and 43.3% vs 0), while long segment involvement(57.6% vs 7.7%, p<0.001 and 52.6% vs 16.1%, p<0.001) and VF/SC ratio>0.63(72.7% vs 19.2%, p<0.001 and 81.6% vs 25.8%, p<0.001) were significantly more common in CD. A risk score of 2, based upon long segment involvement and VF/SC ratio>0.63 had an excellent specificity of 100% and 100% and sensitivity of 54% and 50% for CD in development and validation cohorts respectively. Based upon these features, in 43% patients with the diagnostic dilemma of CD/ITB, a definite diagnosis based only on imaging could be made.
CONCLUSION: Necrotic lymph nodes are exclusive for ITB, and the combination of long segment involvement and VF/SC ratio>0.63 is exclusive for CD, and these features can make a definite diagnosis in 43% patients with a CD/ITB dilemma.

PMID: 29205485 [PubMed – as supplied by publisher]

PubMed Link: https://www.ncbi.nlm.nih.gov/pubmed/29205485?dopt=Abstract