Four hospital patients in north Wales were wrongly X-rayed after administrative errors, a health board has confirmed
Three had CT (computerised tomography) scans and the fourth an ankle and wrist X-rayed before the errors were spotted.
It happened between last October and March, The hospitals involved have not been named.
A report to Betsi Cadwaladr Health Board says the patients were all told and given apologies.
It happened between last October and March, but the hospitals involved have not been named.
A report will go before a Betsi Cadwaladr University Health Board meeting next week.
The report by Adrian Thomas, the assistant director of therapies and health science, says three CT scans were carried out because the patients were incorrectly identified.
In two of the cases it was because the wrong "addressograph label" was put on the patients' referral cards in clinic.
In the third case, there were two patients with very similar names on a ward and the incorrect patient was referred for a CT scan of the chest, abdomen and pelvis.
"In these three cases full patient identity checks were performed by the CT radiographer. However the patient details matched and the scans were performed," said Mr Thomas in the report.
In the fourth case two patients attended for X-rays at the same time from accident and emergency.
"Patient B came forward when patient A was called, and due to communication difficulties and not following procedure was incorrectly identified by the radiographer," added Mr Thomas.
"All four patients who received the unintended X-rays were informed of the error and sincere apologies were given."
The patients who should have been examined were later X-rayed, and Mr Thomas said their treatment was not compromised or delayed.
The incidents were reported to Health Inspectorate Wales which said it was content with the action taken in three of the cases. A response is still awaited on the fourth.
"Establishing the correct identity of a patient is critical in all parts of the health system and the continued vigilance of staff is required to ensure patient safety," added Mr Thomas.
The board runs the three general hospitals in north Wales - Ysbyty Gwynedd in Bangor, Ysbyty Glan Clwyd at Bodelwyddan and Wrexham Maelor Hospital.