Computer-aided interpretation of chest radiography reveals the spectrum of tuberculosis in rural South Africa
Authors: Jana Fehr, Stefan Konigorski, Stephen Olivier, Resign Gunda, Ashmika Surujdeen, Dickman Gareta, Theresa Smit, Kathy Baisley, Sashen Moodley, Yumna Moosa, Willem Hanekom, Olivier Koole, Thumbi Ndung’u, Deenan Pillay, Alison D. Grant, Mark J. Siedner, Christoph Lippert, Emily B. Wong, Anand Ramnanan, Anele Mkhwanazi, Antony Rapulana, Anupa Singh, Ashentha Govender, Ayanda Zungu, Boitsholo Mfolo, Bongani Magwaza, Bongumenzi Ndlovu, Clive Mavimbela, Costa Criticos, Day Munatsi, Dilip Kalyan, Doctar Mlambo, Fezeka Mfeka, Freddy Mabetlela, Gregory Ording-Jespersen, Hannah Keal, Hlengiwe Dlamini, Hlengiwe Khathi, Hlobisile Chonco, Hlobisile Gumede, Hlolisile Khumalo, Hloniphile Ngubane, Hollis Shen, Hosea Kambonde, Innocentia Mpofana, Jabu Kwinda, Jaco Dreyer, Jade Cousins, Jaikrishna Kalideen, Janet Seeley, Kandaseelan Chetty, Kayleen Brien, Kennedy Nyamande, Kgaugelo Moropane, Khabonina Malomane, Khadija Khan, Khanyisani Buthelezi, Kimeshree Perumal, Kobus Herbst, Lindani Mthembu, Logan Pillay, Mandisi Dlamini, Mandlakayise Zikhali, Mbali Mbuyisa, Mbuti Mofokeng, Melusi Sibiya, Mlungisi Dube, Mosa Suleman, Mpumelelo Steto, Mzamo Buthelezi, Nagavelli Padayachi, Nceba Gqaleni, Ngcebo Mhlongo, Nokukhanya Ntshakala, Nomathamsanqa Majozi, Nombuyiselo Zondi, Nomfundo Luthuli, Nomfundo Ngema, Nompilo Buthelezi, Nonceba Mfeka, Nondumiso Khuluse, Nondumiso Mabaso, Nondumiso Zitha, Nonhlanhla Mfekayi, Nonhlanhla Mzimela, Nozipho Mbonambi, Ntombiyenhlanhla Mkhwanazi, Ntombiyenkosi Ntombela, Pamela Ramkalawon, Pfarelo Tshivase, Phakamani Mkhwanazi, Philippa Mathews, Phumelele Mthethwa, Phumla Ngcobo, Ramesh Jackpersad, Raynold Zondo, Rochelle Singh, Rose Myeni, Sanah Bucibo, Sandile Mthembu, Sashin Harilall, Senamile Makhari, Seneme Mchunu, Senzeni Mkhwanazi, Sibahle Gumbi, Siboniso Nene, Sibusiso Mhlongo, Sibusiso Mkhwanazi, Sibusiso Nsibande, Simphiwe Ntshangase, Siphephelo Dlamini, Sithembile Ngcobo, Siyabonga Nsibande, Siyabonga Nxumalo, Sizwe Ndlela, Skhumbuzo Mthombeni, Smangaliso Zulu, Sphiwe Clement Mthembu, Sphiwe Ntuli, Talente Ntimbane, Thabile Zondi, Thandeka Khoza, Thengokwakhe Nkosi, Thokozani Bhengu, Thokozani Simelane, Tshwaraganang Modise, Tumi Madolo, Velile Vellem, Welcome Petros Mthembu, Xolani Mkhize, Zamashandu Mbatha, Zinhle Buthelezi, Zinhle Mthembu, Zizile Sikhosana
Journal: npj Digital Medicine (2021)

Computer-aided digital chest radiograph interpretation (CAD) can facilitate high-throughput screening for tuberculosis (TB), but its use in population-based active case-finding programs has been limited. In an HIV-endemic area in rural South Africa, we used a CAD algorithm (CAD4TBv5) to interpret digital chest x-rays (CXR) as part of a mobile health screening effort. Participants with TB symptoms or CAD4TBv5 score above the triaging threshold were referred for microbiological sputum assessment. During an initial pilot phase, a low CAD4TBv5 triaging threshold of 25 was selected to maximize TB case finding. We report the performance of CAD4TBv5 in screening 9,914 participants, 99 (1.0%) of whom were found to have microbiologically proven TB. CAD4TBv5 was able to identify TB cases at the same sensitivity but lower specificity as a blinded radiologist, whereas the next generation of the algorithm (CAD4TBv6) achieved comparable sensitivity and specificity to the radiologist. The CXRs of people with microbiologically confirmed TB spanned a range of lung field abnormality, including 19 (19.2%) cases deemed normal by the radiologist. HIV serostatus did not impact CAD4TB's performance. Notably, 78.8% of the TB cases identified during this population-based survey were asymptomatic and therefore triaged for sputum collection on the basis of CAD4TBv5 score alone. While CAD4TBv6 has the potential to replace radiologists for triaging CXRs in TB prevalence surveys, population-specific piloting is necessary to set the appropriate triaging thresholds. Further work on image analysis strategies is needed to identify radiologically subtle active TB.