Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis and continues to be a major cause of morbidity and mortality worldwide, particularly in developing countries. Despite the availability of effective antitubercular therapy, TB remains a significant public health problem due to factors such as delayed diagnosis, incomplete treatment, and socio-economic determinants. Pulmonary tuberculosis (PTB) is the most common form of the disease and accounts for the majority of TB transmission within the community.¹,²

Radiological imaging plays a crucial role in the diagnosis and management of pulmonary tuberculosis. Chest radiography is often the initial imaging modality employed in suspected cases because it is inexpensive, widely available, and provides rapid information regarding disease presence, extent, and complications.³ Although microbiological confirmation using sputum smear microscopy, culture, or molecular tests is considered the gold standard, radiological findings frequently guide early diagnosis and initiation of treatment, especially in smear-negative cases and in children.⁴

The radiological appearance of pulmonary tuberculosis varies widely and is influenced by host immunity, age, and the stage of disease. Paediatric pulmonary tuberculosis usually represents primary infection and differs significantly from adult disease in its radiological manifestations. Children commonly exhibit lymphohematogenous spread, resulting in prominent hilar or mediastinal lymphadenopathy, segmental or lobar consolidation, and less frequently, pleural effusion or miliary nodules.⁵,⁶ Cavitation is relatively uncommon in paediatric patients due to an immature cell-mediated immune response and limited tissue necrosis.

In contrast, adult pulmonary tuberculosis is more often a manifestation of post-primary or reactivation disease. Radiological features in adults typically include upper lobe predominance, patchy or confluent consolidation, cavitary lesions, nodular opacities, fibrosis, and volume loss.⁷ Cavitary disease is of particular importance as it reflects high bacillary burden, increased infectivity, and a greater risk of disease transmission.⁸

Computed tomography (CT) of the chest has emerged as an important adjunct to chest radiography in the evaluation of pulmonary tuberculosis. CT is more sensitive in detecting early parenchymal lesions, subtle cavitation, bronchogenic spread, lymphadenopathy, and complications such as bronchiectasis and pleural involvement.⁹ In paediatric patients, CT is especially valuable for assessing mediastinal lymph nodes and airway compression, which may not be adequately demonstrated on plain radiographs.¹⁰

Despite the high prevalence of tuberculosis in endemic regions, comparative studies describing the radiological spectrum of pulmonary tuberculosis in paediatric versus adult populations within the same clinical setting are limited. A clear understanding of age-specific radiological patterns is essential for improving diagnostic accuracy, facilitating early treatment, and reducing disease-related morbidity. The present study was therefore undertaken to analyse and compare the radiological spectrum of pulmonary tuberculosis in paediatric and adult patients presenting to a tertiary care centre.

MATERIALS AND METHODS

Study Design

This was a hospital-based cross-sectional observational study conducted to evaluate the radiological spectrum of pulmonary tuberculosis in paediatric and adult patients.

Study Setting

The study was carried out in the Department of Radiodiagnosis, in collaboration with the Departments of Pulmonary Medicine and Paediatrics, at a tertiary care teaching hospital.

Study Period

The study was conducted over a period of 12 months, from January 2019 to December 2019.

Study Population and Sample Size

A total of 100 patients diagnosed with pulmonary tuberculosis were included in the study.

• Paediatric group: 40 patients (≤14 years)
• Adult group: 60 patients (>14 years)

The sample size was selected based on feasibility and availability of newly diagnosed pulmonary tuberculosis cases during the study period.

Inclusion Criteria

• Patients with clinical features suggestive of pulmonary tuberculosis
• Radiologically suspected pulmonary tuberculosis
• Microbiologically confirmed cases (sputum smear positive / CBNAAT positive) or clinically diagnosed cases started on antitubercular treatment
• Newly diagnosed, treatment-naïve patients

Exclusion Criteria

• Isolated extrapulmonary tuberculosis
• Previously treated or relapse cases of pulmonary tuberculosis
• Patients with lung malignancy or chronic interstitial lung disease
• Poor-quality or incomplete radiological images

Radiological Evaluation

Chest Radiography

All patients underwent standard chest radiography (PA view in adults; PA/AP view in paediatric patients). Radiographs were reviewed independently by two experienced radiologists, blinded to clinical details.

Computed Tomography

CT chest was performed in selected cases with:

• Inconclusive chest X-ray findings
• Suspicion of mediastinal lymphadenopathy
• Suspected complications such as cavitation or bronchiectasis

Radiological Parameters Assessed

• Hilar/mediastinal lymphadenopathy
• Pulmonary consolidation
• Cavitary lesions
• Nodular opacities
• Miliary pattern
• Pleural effusion
• Fibrosis and calcification
• Lobar distribution and laterality

Statistical Analysis

Data were analysed using SPSS version 20.0.

• Categorical variables: frequency and percentage
• Continuous variables: mean ± SD
• Comparison between paediatric and adult groups: Chi-square test
• p < 0.05 considered statistically significant

RESULTS

A total of 100 patients with pulmonary tuberculosis were evaluated, including 40 paediatric and 60 adult patients.

Male predominance was observed in both paediatric and adult groups, with a higher proportion of males in adult patients as shown in Table 1

Table 1: Demographic Characteristics

Paediatric patients predominantly showed lymphadenopathy and consolidation, whereas adult patients commonly demonstrated cavitary lesions and fibrotic changes. These differences were statistically significant as shown in Table 2

Table 2: Comparison of Radiological Findings in Paediatric and Adult Patients

Upper lobe involvement was significantly more common in adults, while paediatric patients more frequently showed middle and lower lobe disease as shown in Table 3

Table 3: Lobar Distribution of Pulmonary Tuberculosis

CT chest detected additional findings, particularly mediastinal lymphadenopathy in paediatric patients and bronchiectasis and cavitation in adults as shown in Table 4

Table 4: Additional CT Chest Findings

DISCUSSION

Pulmonary tuberculosis continues to demonstrate a wide spectrum of radiological manifestations, influenced largely by age-related immune responses and disease pathophysiology. In the present study, distinct differences were observed between paediatric and adult patients with pulmonary tuberculosis, emphasizing the importance of age-specific radiological interpretation.

In this study, a male predominance was observed in both paediatric and adult groups, with a higher proportion of males among adults. Similar gender distribution has been reported in previous studies, which attribute this pattern to increased exposure, occupational risk, smoking, and health-seeking behavior among males, particularly in adult populations.¹¹,¹²

Lymphadenopathy was the most common radiological finding in paediatric patients (65%), significantly higher than in adults. This finding is consistent with earlier studies that describe lymph node involvement as a hallmark of primary tuberculosis in children.¹³,¹⁴ The immature cell-mediated immunity in children facilitates lymphohematogenous spread of Mycobacterium tuberculosis, leading to prominent hilar and mediastinal lymphadenopathy. In contrast, adults typically mount a stronger delayed hypersensitivity response, resulting in localized parenchymal disease rather than nodal involvement.

Pulmonary consolidation was also more frequently observed in paediatric patients than adults. Segmental or lobar consolidation in children often represents primary infection and may mimic bacterial pneumonia, leading to diagnostic challenges.¹⁵ This underscores the importance of careful radiological assessment and clinical correlation in paediatric patients presenting with non-resolving pneumonia.

Cavitary lesions were significantly more common in adult patients (46.7%) compared to paediatric patients (10%). Cavitation is a characteristic feature of post-primary or reactivation tuberculosis and reflects extensive lung parenchymal destruction due to a robust immune response.¹⁶ Cavitary disease is associated with high bacillary load and increased infectivity, making early detection crucial for disease control. The low prevalence of cavitation in children observed in this study is in agreement with previous literature.¹⁷

Upper lobe predominance was significantly higher in adult patients, whereas paediatric patients more frequently showed middle and lower lobe involvement. These findings align with classical descriptions of pulmonary tuberculosis, wherein adult disease favors oxygen-rich upper lobes, while paediatric disease shows less lobar predilection.¹⁸,¹⁹ Bilateral involvement, although more common in adults, did not show a statistically significant difference, suggesting that disease dissemination may occur across age groups depending on host factors and disease duration.

Miliary tuberculosis was observed more frequently in paediatric patients than adults, though the difference was not statistically significant. This finding is clinically important, as miliary TB reflects hematogenous dissemination and is associated with severe disease and higher morbidity in children.²⁰ Early radiological recognition of miliary patterns can be lifesaving in paediatric patients.

Computed tomography of the chest provided additional diagnostic information in selected cases. CT detected mediastinal lymphadenopathy more frequently in paediatric patients and early cavitation and bronchiectasis more commonly in adults. Previous studies have demonstrated the superior sensitivity of CT in detecting occult lymph nodes, endobronchial spread, and early parenchymal changes not visible on chest radiographs.²¹,²² The findings of the present study further support the role of CT as an adjunct imaging modality, particularly in complex or equivocal cases.

Overall, the findings of this study reinforce the concept that pulmonary tuberculosis manifests differently in paediatric and adult populations. Recognizing these age-specific radiological patterns is essential for early diagnosis, appropriate treatment initiation, and prevention of complications, especially in high TB-burden settings.

CONCLUSION

Pulmonary tuberculosis shows distinct radiological patterns in paediatric and adult patients. Children commonly present with features of primary tuberculosis such as lymphadenopathy and consolidation, whereas adults predominantly exhibit cavitary and fibrotic lesions of post-primary disease. Upper lobe involvement was more frequent in adults, while middle and lower lobe involvement was common in children. Computed tomography provided additional diagnostic information in selected cases. Recognition of these age-specific radiological features facilitates early diagnosis and appropriate management of pulmonary tuberculosis.

REFERENCES

1. World Health Organization. Global tuberculosis report 2019. Geneva: WHO; 2019.
2. Dye C, Scheele S, Dolin P, Pathania V, Raviglione MC. Global burden of tuberculosis: estimated incidence, prevalence, and mortality by country. JAMA. 1999;282(7):677–686.
3. Burrill J, Williams CJ, Bain G, Conder G, Hine AL, Misra RR. Tuberculosis: a radiologic review. Radiographics. 2007;27(5):1255–1273.
4. Long R. Smear-negative pulmonary tuberculosis in industrialized countries. Chest. 2001;120(2):330–334.
5. Marais BJ, Gie RP, Schaaf HS, et al. The natural history of childhood intra-thoracic tuberculosis. Int J Tuberc Lung Dis. 2004;8(4):392–402.
6. Andronikou S, van Toorn R, Swingler G. Imaging of tuberculosis in children. Clin Chest Med. 2005;26(2):241–253.
7. Woodring JH, Vandiviere HM, Fried AM, Dillon ML, Williams TD. Update: the radiographic features of pulmonary tuberculosis. AJR Am J Roentgenol. 1986;146(3):497–506.
8. Leung AN. Pulmonary tuberculosis: the essentials. Radiology. 1999;210(2):307–322.
9. Im JG, Itoh H, Shim YS, et al. Pulmonary tuberculosis: CT findings—early active disease and sequential changes. Radiology. 1993;186(3):653–660.
10. Swingler GH, du Toit G, Andronikou S, van der Merwe L. Diagnostic accuracy of chest radiography in detecting mediastinal lymphadenopathy in suspected pulmonary tuberculosis. Arch Dis Child. 2005;90(11):1153–1156.
11. Balasubramanian R, Garg R, Santha T, et al. Gender disparities in tuberculosis: report from a rural DOTS programme in south India. Int J Tuberc Lung Dis. 2004;8(3):323–332.
12. Borgdorff MW, Nagelkerke NJD, Dye C, Nunn P. Gender and tuberculosis: a comparison of prevalence surveys with notification data. Int J Tuberc Lung Dis. 2000;4(2):123–132.
13. Marais BJ, Schaaf HS, Gie RP, Hesseling AC, Enarson DA, Beyers N. The spectrum of disease in children treated for tuberculosis in a highly endemic area. Int J Tuberc Lung Dis. 2006;10(7):732–738.
14. Andronikou S, Joseph E, Lucas S, et al. CT scanning for the detection of lymphadenopathy in children with suspected pulmonary tuberculosis. Pediatr Radiol. 2004;34(3):216–222.
15. Swingler GH. Radiologic differentiation between bacterial pneumonia and pulmonary tuberculosis in children. Pediatr Radiol. 2000;30(7):421–429.
16. Fraser RS, Müller NL, Colman N, Pare PD. Fraser and Paré’s Diagnosis of Diseases of the Chest. 4th ed. Philadelphia: Saunders; 1999.
17. Schaaf HS, Zumla A. Tuberculosis: A Comprehensive Clinical Reference. Edinburgh: Saunders Elsevier; 2009.
18. Leung AN, Müller NL, Pineda PR, FitzGerald JM. Primary tuberculosis in childhood: radiographic manifestations. Radiology. 1992;182(1):87–91.
19. Hopewell PC. Clinical features, diagnosis, and management of pulmonary tuberculosis. Thorax. 1994;49(5):465–472.
20. Sharma SK, Mohan A. Miliary tuberculosis. Microbiol Spectr. 2017;5(2).
21. Im JG, Song KS, Kang HS, et al. Mediastinal tuberculous lymphadenitis: CT manifestations. Radiology. 1987;164(1):115–119.
22. Jeong YJ, Lee KS. Pulmonary tuberculosis: up-to-date imaging and management. AJR Am J Roentgenol. 2008;191(3):834–844