TABLE 1. Description of the COVID-19 Datasets Used in the Reviewed Research.

No.	Reference	Name(s)	Description	COVID-19 Samples
1	[18]	COVID-19 Image Data Collection	Public CXR images of COVID-19 collected from various online sources with ongoing updates.
2	[20]	Figure 1 COVID-19 CXR Dataset Initiative (COVIDx)	48 CXR images of COVID-19
3	[61]	ActualMed COVID-19 CXR Dataset Initiative	N/A
4	[62]	COVID-19 Radiography Database	2,905 CXR images with 219 COVID-19 positive cases
5	[63]	Japanese Society of Radiological Technology	105 CXR images of COVID-19 cases
6	[22] sometimes referenced as [64]	ChestX-ray8 ChestX-ray14	Contains 112,120 frontal-view CXR images of 30,805 patients labeled with 14 thoracic diseases. This dataset is also called the NIH CXR dataset and RSNA Pneumonia Detection Challenge Dataset.
7	[65]	SIRM COVID-19 Database	68 COVID-19 CXR images
8	[19]	Radiopaedia.org	An open-source website that shares radiographs. As of the publication of this work, it contained 20 COVID-19 CXR images.
9	[66]	ChexPert Dataset	224,316 chest CXR images of 65,240 patients labeled for 14 thoracic diseases.
10	[67]	Twitter COVID-19 CXR Dataset/ COVID-19 Chest Imaging at thread reader	135 CXR images showing SARS-CoV-2 viral infection. This dataset is provided by a cardiothoracic radiologist from Spain through his Twitter account.
11	[68] taken from [69]	Pediatric Pneumonia Chest X-ray	5,856 pediatric CXR pneumonia images of children aged 1–5 years, labeled as “pneumonia” or “normal.”
12	[69] or [70] sometimes referenced as [23]	Labeled Optical Coherence Tomography (OCT) and Chest X-Ray Images for Classification/Kaggle Chest X-Ray Images (Pneumonia)	A dataset composed of OCT and 5,863 CXR images of normal, viral pneumonia, and bacterial pneumonia cases.
13	[71]	Open-I Repository	Open access biomedical image search engine provided by the US National Library of Medicine—CXR images of COVID-19 can be found with the relevant publication.