The Straits Times (3 September 2020)
Rapid flagging of pneumonia in suspected Covid19 cases allows for earlier intervention
An artificial intelligence powered tool has been developed to detect abnormal chest Xrays quickly during Covid19 screening at the National Centre for Infectious Diseases (NCID).
With rapid flagging of pneumonia cases, doctors can intervene earlier as more severe findings on chest Xrays may mean an urgent need for supplemental oxygen therapy and ventilation for patients. Suspected Covid19 patients who have pneumonia must be admitted to the hospital.
Everyone who visits the NCID Screening Centre who is suspected of Covid19 or who has respiratory symptoms must do a chest Xray. Previously, each Xray image was reviewed by a radiologist within an hour. The radiologists had to analyse each Xray result in sequence, which was timeconsuming.
Now, the AI tool, called RadiLogic, can analyse each Xray image within three seconds and highlight abnormal chest Xrays on a computer quickly, helping radiologists prioritise which images to review.
This allows radiologists to report such cases in about 50 minutes, after each patient completes the procedure.
The tool has an accuracy of up to 96.1 per cent, and has been used in the screening centre since May. The screening centre saw 200 to 300 Xray images a day during the peak of the pandemic in April.
Currently, there are 100 images coming in each day.
"The AI tool is performing close to human capabilities and it helps us prioritise the workflow to enhance our efficiency and diagnostic confidence," said Adjunct Associate Professor Tan Cher Heng, senior consultant at Tan Tock Seng Hospital’s (TTSH) department of diagnostic radiology. He is also part of the team that developed the tool.
RadiLogic is not the first AI system for chest Xrays, but the team believes that it is the first chest Xray AI tool developed for Covid19 in Singapore.
Programmed through deep learning, RadiLogic was fed with 1,000 anonymised abnormal chest Xrays from Covid19 patients and 4,000 anonymised normal chest Xrays to train it to detect pneumonia accurately.
White patches or haziness over parts of the lungs in the Xray image indicate lung infections and pneumonia. The bigger the patches, the more serious the infection.
The tool was developed by radiologists from TTSH and researchers from the Agency for Science, Technology and Research’s Institute of High Performance Computing, and Institute for Infocomm Research.
The team is hoping to deploy the tool to Covid19 screening sites such as community care facilities and border control checkpoints, where radiologists are not onsite, and other hospitals such as Singapore General Hospital.
The team is also working to enhance the tool’s AI capabilities in a few ways.
One is to train the system to distinguish between Covid19 pneumonia and other types of lung infection, while another one is to zero in on abnormal regions and indicate the probability of pneumonia.