Triage for COVID-19 Using Artificial Intelligence on Chest X-rays

Delft’s Free-of-charge CAD4COVID is developed with the intention to support triaging in resource-constrained settings and high-prevalence areas. The ingenuity behind CAD4COVID uses the same technical core as our proven software for tuberculosis detection, CAD4TB.

COVID-19 is a global health crisis that will long be remembered for its impact towards millions of lives globally. Both low- and high-resource countries have been greatly affected by this public health crisis. In response to this crisis, we want to support Ministries of Health and healthcare facilities around the world by leveraging our extensive experience in artificial intelligence and tuberculosis screening.

COVID-19 and TB are respiratory diseases that manifest themselves with similar symptoms of cough, fever and difficulty breathing. The ingenuity behind CAD4COVID uses the same technical core as our proven software for tuberculosis detection, CAD4TB.

Our experiences in artificial intelligence and tuberculosis screening have brought our CAD4TB to 40 countries and screened over 7 million people. Delft’s Free-of-charge CAD4COVID is developed with the intention to support triaging COVID-19 in resource-constrained settings and high-prevalence areas.

 120 hospitals and clinics onboarded to CAD4COVID-XRay and CAD4COVID-CT.

(Nov, 2020)

Bi-directional COVID-19/Tuberculosis Screening

The COVID-19 pandemic continues to have a devastating impact on the global health system, jeopardizing our collective fight to end TB by 2030. Thereupon, the importance to implement prioritized mitigation measures and innovations for TB programs have been indicated from across the globe. This includes prioritizing bi-directional screening/testing for TB and COVID-19, using X-ray with CAD (computer-aided detection).

As an integrator of digital X-ray and CAD, Delft’s solutions benefit clients and partners with years of experience and field implementation expertise worldwide. Our CAD4TB is a significant part of our approach to the bi-directional screening equation pertaining to CAD4COVID. Substantially because CAD4COVID was built upon the same high-quality standard as CAD4TB.

The diagnostic pathway for COVID-19

RT-PCR is the gold standard to confirm COVID-19. However, studies have shown that early stage of COVID-19 can be undetected by the lab test, where CT imaging is more likely to detect COVID-19 in early stages. CT imaging has shown to be a highly sensitive method to detect COVID-19.[1] It is a reliable, practical and rapid method to detect and assess COVID-19. X-ray, although not as sensitive as CT, is also used among patients presenting COVID-19 symptoms especially since it uses less radiation, and is often cheaper, quicker and easier to use than CT and more available in resource-constrained settings. Further benefits of X-ray are that they can be portable and thus used at the patient’s bedside. The power of radiology in this crisis is highlighted as such: a positive diagnosis from radiology is definitive, even when a lab test is negative.[2] Furthermore, radiology is an optimal method when it comes to assesing the progression of COVID-19 cases.

Click here for our FAQ about CAD4COVID

Why use artificial intelligence?

  • Reduce the workload of the health workforce
  • Enable quicker detection, therefore allowing for higher throughput
  • Enhance diagnostic infrastructure in resource constrained settings
  • Alleviate the burdens related to pathology tests.
  • Quantify disease progress and recovery

[1] Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Case, Radiological Society of North America, February 26 2020;

[2] CT Imaging and Differential Diagnosis of COVID-19, Canadian Association of Radiologists Journal, March 4 2020;

Experts in screening across 40 countries

As companies that have built their foundation on improving diagnostics with innovative technology, we are committed to supporting the diagnosis of COVID-19 around the world. Thirona and Delft Imaging are active in 40 countries across the world. Delft Imaging focuses on developing countries and is stepping into the fight against COVID-19 to leverage its market access into Africa to ensure no community is left out.

We are proud to be collaborating on this initiative with our sister-company Thirona and our partners Bernhoven, Radboud University, HT Medica and Universitas Indonesia.

Our proven track record of artificial intelligence for image analysis

Our extensive history in tackling infectious diseases

The foundation for CAD4COVID is CAD4TB, which is the most extensively validated AI solution for tuberculosis detection.

Lagos State

In February 2021, we successfully completed the last phase of the Lagos State Ministry of Health project which began in December 2020. Altogether 21 digital x-ray installations, including 3 mobile screening vans, 8 semi-mobile containerized x-ray systems and 10 room installations were made.


Delft Imaging installed 5 Delft Lights with CAD4TB and CAD4COVID which they use for screening migrants at the border and prisons. With the financial support of the Global Fund, SMRU is managing a tuberculosis screening program in the migrant population from Myanmar.

Jakarta – Prisons

In collaboration with Fullerton Health, the CAD4TB software was used in several prisons and a factory in Jakarta. Prisoners were first screened on symptoms and in the case symptoms were present that could indicate tuberculosis, a chest X-ray (CXR) was taken in a mobile van.