A Hamilton doctor is leading a review of 3,500 CT scans and mammograms conducted by a radiologist with a "performance issue."

Dr. Brian Yemen, chief of diagnostic imaging at Juravinski Hospital and Cancer Centre and McMaster University Medical Centre at Hamilton Health Sciences, is spearheading the investigation into the work done by Dr. Ivo Slezic at two Toronto area hospitals, the Queensway Health Centre and the Mississauga Hospital.

The review covers Dr. Slezic's work done between April 1, 2012 and March 31, 2013.

Dr. Yemen said that the review will be done "quickly and properly," and that as many as 17 radiologists on the review team will begin by looking at the most recent cases where there's probably the biggest potential impact on patient care.

Dr. Slezic's "privileges" to provide diagnostic testing were restricted as of April 1, 2013, and Trillium Health Partners notified the Ontario College of Physicians and Surgeons of the restrictions on June 6, according to the college's website.

"Ontarians quite rightly expect the highest standard of care from their hospitals, and from the physicians and health professionals who work in them," Health Minister Deb Matthews said in a statement.

"Our hospitals take concerns about quality of care very seriously. I have been assured that affected patients are being properly informed and that their cases are being reviewed as quickly as possible so that follow-up care can be provided."

The head of Trillium Health issued an apology and said the hospital will follow up directly with all patients as soon as their tests have been reviewed.

"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," said chief executive Michelle DiEmanuele.

Dr. Slezic worked at the hospitals for 33 years, though he is no longer employed by Trillium Health Partners, a spokesperson for the hospital said.