Utility of routine chest radiographs in Kenya
Background: Many otherwise healthy Kenyans are required to obtain chest radiographs as part of routine medical examination to exclude pulmonary TB, a condition of significant public health concern. Many of these people are required to have these radiographs taken yearly as part of routine check-up. No local data is available to support this practice. Though a quick procedure to perform and readily available throughout the country, chest radiograph exposes the individual to a dose of ionising radiation. Ionising radiation is associated with increased risk of malignancy. The cost is also substantial.
Objective: To determine the prevalence of radiological findings consistent with PTB among routine medical examination chest radiographs.
Design: A cross-sectional descriptive study.
Settings: Department of Radiology Kenyatta National Hospital,Department of Imaging and Radiation Medicine, University of Nairobi, Plaza Imaging Solutions, a private radiology practice in Nairobi and Department of Radiology, the Nairobi Hospital.
Subjects: Four hundred and two chest radiographs of patients presenting for routine medical examinations were analysed.
Results: Sixty three radiographs had abnormal but clinically insignificant findings (16%). Only one radiograph (0.25%) had radiological features of PTB. The rest were reported as normal (84%).
Conclusion: In this study, the diagnostic yield for the intended purpose (to include/ exclude PTB) was extremely low (0.25%). It is recommended that routine chest radiographs as screening tools for active pulmonary tuberculosis be reconsidered due to poor diagnostic yield. The authors propose a bigger nation wide study before a policy decision can be proposed.