The community-based acute-care facilities issued a statement Wednesday night that said patients of the scans being reviewed had been notified, and the radiologist is no longer working with Trillium Health.
A Trillium Health spokesperson told CBC News that 189 patients, who have had multiple exams, are part of the review.
The tests in questions were conducted between April 1, 2012, and March 31, 2013, at the Mississauga Hospital and the Queensway Health Centre in Toronto.
“We apologize for any concern the news of this review may cause and want our patients and community to know it is being done to ensure the highest quality of care at our hospital”, says Michelle DiEmanuele, president and CEO of Trillium Health.
Trillium Health has launched an external review team, led by Dr. Brian Yemen, chief of diagnostic imaging, Juravinski Hospital and Cancer Centre and McMaster University Medical Centre at Hamilton Health Sciences.
Trillium Health said the findings of Yemen's review would be made public once complete, and "expanded as necessary" based on those independent recommendations.
The hospital has also said it will be following up directly with all patients as soon as their tests have been reviewed.
Trillium Health is made up of the Credit Valley Hospital, Mississauga Hospital, and Queensway Health Centre, and serves a population of 1.15 million people.