Chapter 6 The evolution of imaging and portable imaging tools to aid tuberculosis diagnosis Jacob Bigio1,2, Claudia M. Denkinger3,4, Rigveda Kadam5, Mikashmi Kohli5, Giorgia Sulis 2,6,7 ,César Ugarte-Gil8,9, Seda Yerlikaya3 and Madhukar Pai 2,10 1 Research Institute of the McGill University Health Centre, Montreal, Canada. 2 McGill International TB Centre, Montreal, Canada. 3 Division of Infectious Diseases and Tropical Medicine, Heidelberg University Hospital and Faculty of Medicine, Heidelberg University, Heidelberg, Germany. 4 German Center for Infection Research (DZIF), partner site Heidelberg University Hospital, Heidelberg, Germany. 5 FIND, Geneva, Switzerland. 6 School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Canada. 7 Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada. 8 Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. 9 School of Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru. 10 McGill School of Population and Global Health, McGill University, Montreal, Canada. Corresponding author: Madhukar Pai (madhukar.pai@mcgill.ca) Cite as: Bigio J, Denkinger CM, Kadam R, et al. The evolution of imaging and portable imaging tools to aid tuberculosis diagnosis. In: García-Basteiro AL, Öner Eyüboğlu F, Rangaka MX, eds. The Challenge of Tuberculosis in the 21st Century (ERS Monograph). Sheffield, European Respiratory Society, 2023 pp. 78–89 [https://doi.org/10. 1183/2312508X.10024322]. @ERSpublications New portable chest X-ray and point-of-care ultrasound devices, as well as advances in computer-aided detection and artificial intelligence, have the potential to improve imaging of TB https://bit.ly/ERSM101 Copyright ©ERS 2023. Print ISBN: 978-1-84984-169-6. Online ISBN: 978-1-84984-170-2. Print ISSN: 2312-508X. Online ISSN: 2312-5098. Imaging has a long history as an aid to the diagnosis of TB. In recent years, the pace of technological development in the imaging of TB has been rapid, with the arrival of ultra-portable CXR and point-of-care ultrasound (POCUS) devices, as well as substantial advances made in computer-aided detection (CAD) of CXRs, leading to the WHO’s landmark 2021 recommendation of CAD as an alternative to human interpretation of digital CXRs for the screening of TB. However, the evidence is currently limited and of low quality for the use of POCUS as a diagnostic aid for TB. In this chapter, we review the current status of these imaging tools to aid TB diagnosis. Introduction The use of imaging to aid the diagnosis of TB has a long history. Almost as soon as X-rays were discovered in 1895, their potential utility for the identification of PTB was recognised [1]. In 1974, the era of mass radiography for TB screening came to an end when the WHO recommended that “indiscriminate TB case finding by mobile mass radiography should now be abandoned”, noting that it was expensive, required highly qualified staff and could not be used alone to establish a diagnosis of TB. Instead, the WHO promoted sputum smear microscopy of symptomatic individuals, and microscopy became a major part of the DOTS strategy [2]. 78 https://doi.org/10.1183/2312508X.10024322