WATCH: UTV's Health Reporter Deborah McAleese speaks to Dr Seamus O'Reilly from the Northern Trust.
The Northern Trust says it has completed a review of 13,030 radiology images that were reported on by a locum consultant radiologist.
It says a total of six images with "Level 1 discrepancies" were identified - and a further 60 with "Level 2 discrepancies".
"Most of the images categorised as having Level 1 and Level 2 discrepancies are CT scans but some are MRI scans, chest x-rays and other x-rays," said Dr Seamus O’Reilly, the trust's medical director and chair of the steering group for the lookback review.
Each image was categorised on scale from one to five, with Level 5 meaning no discrepancy has been found and Level 1 meaning a major discrepancy has been identified that could have had immediate and significant clinical impact.
The Level 2 category also concerns a major discrepancy, with probable clinical impact.
Mr O'Reilly said "the clinical assessment group has determined that 17 patients should now be part of a Level 3 Serious Adverse Incident review" - the highest level of hospital investigation.
The trust said it will now contact affected patients and families "to inform them of the pending SAI review and to seek their participation throughout the process".
The locum consultant radiologist had been engaged by the trust from July 2019 to February 2020.
At the end of June 20201, the trust wrote to 9,091 patients to make them aware of the review concerning the images, which were taken in Antrim Area Hospital, Causeway Hospital, Whiteabbey Hospital, Mid Ulster Hospital and the Ballymena Health and Care Centre.
"A clinical assessment group made up off senior clinicians has met each week throughout the review to carefully consider the images of patients where Level 1 and Level 2 discrepancies were found," continued Dr O'Reilly.
"They also reviewed a number of images which were considered as Level 3 discrepancies.
"That detailed clinical assessment, which has resulted in 69 patients being called back, was to determine whether any clinical harm occurred as a result of the discrepancies found in the lookback review.
He went on: “We are currently in the process of appointing an independent SAI panel in line with regional guidance and have agreed draft terms of reference which will consider the methodology for the Lookback Review processes, provide individual case reports for each patient determined to be an SAI, explaining what happened, why it happened, and how this may have had an impact on the patient/relative and if the patient’s outcome would have been different had the discrepancy not occurred.
"This will involve the engagement of clinical experts in the specialties relevant to each individual case.
“The SAI review will also identify any learning of relevance across the HSC and the panel is expected to make recommendations on how radiology reporting processes may be strengthened to minimise the possibility of similar adverse events occurring in the future."