Chest CT Scan for the Diagnosis of Pediatric Pulmonary TB: Radiological Findings and Its Diagnostic Significance

Abstract

Diagnosing active TB in children remains a clinical challenge, due to difficulties in achieving a definite microbiological confirmation, aspecific clinical manifestation, low sensitivity of chest radiography (CXR). For this reason, the use of chest computed tomography (CT) scan to evaluate suspected TB pediatric cases is increasing. We retrospectively reviewed records of patients aged <16 years diagnosed with active TB at the Pediatric Infectious Disease Unit of the Catholic University of the Sacred Heart to describe CT findings and to evaluate the need for its execution for diagnosis. In 41 cases, 7 CXR were normal (17.1%) while no CT scan was evaluated as negative. In 19 cases (46.3%), CXR was considered non-probable TB pulmonary, compared with 11 of 37 cases (29.7%) of CT. In 15 cases (36.6%) CXR was described as probable for TB pulmonary, instead 26 of the 37 cases evaluated by CT (70.3%) were classified as probable TB. We describe CT findings in patients with pediatric TB. We confirmed that CT can improve the diagnostic accuracy. In particular, the comparison between the CT and CXR ability in detecting cases of pulmonary TB in accordance with the proposed radiological probability criteria, showed a superiority of CT in detecting probable TB pictures (70.3%) compared with 36.6% of the x-Ray.

Diagnostic Value of Mediastinal Lymphadenopathy in Differentiating Pulmonary Tuberculosis from Community-Acquired Pneumonia in Children

“…Previous studies reported the prevalence of lymph node calcification ranged from 9% to 28% (5,13,15,16). In the present study, only one (2%) patient with TB had lymph nodes with calcification, which appeared as specks.…”

“…In our TB group, 22% of patients had isolated mediastinal LAPs without other associated parenchymal and/or pleural involvement. It was a significantly higher rate compared to the relevant literature (13,16). The presence of LAP without parenchymal involvement may be a good indicator for diagnosis of pulmonary TB in a relevant clinical setting.…”

“…To date, several studies have evaluated the CT features of mediastinal lymph nodes in pediatric pulmonary TB (5,(13)(14)(15)(16). The total number of patients in these studies ranged from 37 to 100.…”

“…In suspected pulmonary TB cases, contrast medium was used since children have scarce mediastinal fat causing less tissue contrast that limits accurate evaluation of mediastinal lymphadenopathies (16,18). Additionally, contrast medium would help to reliably differentiate lymph nodes from normal vessels (5).…”

“…A few studies in the literature determine the mediastinal LAP characteristics on a chest CT scan of children with pulmonary TB (5,(13)(14)(15)(16). To the best of our knowledge, one study (17) compared the lymph node involvement in pulmonary TB and CAP in children.…”