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.

To respond to COVID-19 crisis, we leverage our extensive experience in artificial intelligence and tuberculosis screening to support Ministries of Health and healthcare facilities around the globe.

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: CAD4COVID will generate a score between 0 and 100 indicating the extent of COVID-19 related abnormalities, display such lung abnormalities through a heatmap and quantify the percentage of the lung that is affected.

Our experiences in artificial intelligence and tuberculosis screening have brought our CAD4TB to 41 countries and screened over 8 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.

Within 8 months of the COVID-19 outbreak, 120 hospitals and clinics around the globe onboarded CAD4COVID-Xray and CAD4COVID-CT

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; https://doi.org/10.1148/radiol.2020200642

[2] CT Imaging and Differential Diagnosis of COVID-19, Canadian Association of Radiologists Journal, March 4 2020; https://doi.org/10.1177/0846537120913033

Experts in screening across 62 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 62 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.

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