Dr Ratnayake completed a Bachelor of Medicine, Bachelor of Surgery (MBBS) at the University of Peradeniya, Sri Lanka in 1996.

Dr Ratnayake has completed a Doctor of Medicine (MD) in Radiology in 2005 from the University of Colombo, Sri Lanka and completed further specialist radiology training at the Royal Adelaide Hospital.  Dr Ratnayake was awarded a Fellowship to the Royal Australian and New Zealand College of Radiologists (RANZCR) in 2009.

In 2010, Dr Ratnayake completed a MRI fellowship at the Royal Adelaide Hospital.

Dr Ratnayake began working at Jones Radiology in 2014 and joined the Partnership group in July 2020. She has a special interest in CT and MRI, Neuroradiology and Oncology.

When not working, Dr Ratnayake enjoys keeping active and spending time with her family.