Intest Res.  2022 Apr;20(2):184-191. 10.5217/ir.2020.00104.

Addition of computed tomography chest increases the diagnosis rate in patients with suspected intestinal tuberculosis

• Kedia S
• Sharma R
• Vuyyuru SK
• Madhu D
• Sahu P
• Kante B
• Das P
• Goyal A
• Madan K
• Makharia G
• Ahuja V

• KMID: 2529564
• DOI: http://doi.org/10.5217/ir.2020.00104

Abstract

Background/Aims
Intestinal tuberculosis (ITB) is difficult to diagnose due to poor sensitivity of definitive diagnostic tests. ITB may be associated with concomitant pulmonary tuberculosis (PTB) which may remain undetected on chest X-ray. We assessed the role of contrast enhanced computed tomography (CECT) chest in detecting the prevalence of active PTB, and increasing the diagnostic yield in patients with suspected ITB.
Methods
Consecutive treatment naïve patients with suspected ITB (n=200) who underwent CECT chest (n=88) and had follow-up duration>1 year were recruited in this retrospective study (February 2016 to October 2018). ITB was diagnosed in the presence of caseating granuloma, positive acid fast stain or culture for Mycobacterium tuberculosis on biopsy, presence of necrotic lymph nodes (LNs) on CT enterography or positive response to anti-tubercular therapy. Evidence of active tuberculosis on CECT-chest was defined as presence of centrilobular nodules with or without consolidation/miliary nodules/thick-walled cavity/enlarged necrotic mediastinal LNs.
Results
Sixty-five of eighty-eight patients (mean age, 33.8±12.8 years; 47.7% of females) were finally diagnosed as ITB (4-caseating granuloma on biopsy, 12-necrotic LNs on CT enterography, 1-both, and 48-response to anti-tubercular therapy) and 23 were diagnosed as Crohn’s disease. Findings of active TB on CECT chest with or without necrotic abdominal LNs were demonstrated in 5 and 20 patients, respectively. No patient with Crohn’s disease had necrotic abdominal LNs or active PTB. Addition of CECT chest in the diagnostic algorithm improved the sensitivity of ITB diagnosis from 26.2% to 56.9%.
Conclusions
Addition of CECT chest significantly improves the sensitivity for definite diagnosis in a patient with suspected ITB.

Keyword

Intestinal tuberculosis; Crohn disease; Computed tomography; Diagnosis

Figure

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  Fig. 1. (A, B) Axial computed tomography (CT) enterography images showing enlarged lymph nodes with central necrosis and peripheral enhancement in the pericolic region (white arrow) along with colonic thickening (black arrow). (C) Coronal reformatted CT enterography image showing inflammatory stricture in the ascending colon (white arrow).

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  Fig. 2. Axial contrast enhanced computed tomography (CECT) mediastinal window (A) and lung window (B) showing necrotic subcarinal lymph node (white arrow) and acinar nodules some of which show tree-in-bud morphology (black arrow). (C) Axial CECT abdomen with positive oral contrast showing thickening of ileal loops (white arrow) and few necrotic mesenteric lymph nodes (white arrowhead).

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  Fig. 3. Diagnostic algorithm in a patient with suspected ITB incorporating CT chest. aFeatures suggestive CD: (1) Clinical: diarrhea/perianal lesions/bleeding per-rectum; (2) Endoscopy: linear ulcers/cobblestoning; (3) CTE: skip lesions/comb sign/long segment involvement/increased visceral fat; or (4) Biomarker: low peripheral blood FOXP3 T regulatory cells. CD, Crohn’s disease; ITB, intestinal tuberculosis; HPE, histopathology; AFB, acid fast bacillus; MTB, Mycobacterium tuberculosis; CTE, computed tomography enterography; CECT, contrast enhanced computed tomography; TB, tuberculosis; ATT, anti-tubercular therapy.

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