Table 5. Summary of contrastive self-supervised learning methods in medical imaging.

No.	Authors	Pretext task	Down-stream task
1	Jamaludin, Kadir & Zisserman (2017)	Longitudinal spinal MRI	Disc degeneration grading
2	Lu, Chen & Mahmood (2020)	CPC	Breast cancer classification
3	Zhu et al. (2020b)	TCPC	Brain hemorrhage classification Lung Nodule classification
4	Xie et al. (2020)	BYOL	Liver segmentation Spleen segmentation Kidney tumour seg. Abdominal organs seg.
5	Li et al. (2020a)	Feature-based softmax embedding	PM classification AMD classification Diabetic retinopathy detection
6	Sowrirajan et al. (2021)	MoCo	Tuberculosis detection Pleural effusion classification
7	Vu et al. (2021)	MoCo	Pleural effusion classification
8	Sriram et al. (2021)	MoCo	COVID patient prognosis
9	Chen et al. (2021b)	MoCo	COVID few-shot classification
10	Chaitanya et al. (2020)	SimCLR	Cardiac segmentation Prostate segmentation
11	Azizi et al. (2021)	SimCLR	Chest X-ray classification Skin lesions classification