Over a quarter of a million people are waiting for health scans in hospitals.
According to the National Treatment Purchase Fund's data, 59,000 have been on the lists for over a year.
The stats relate to people waiting for CTs, MRIs and ultrasounds as outpatients.
Sinn Féin's health spokesperson, David Cullinane, says the total figure is very concerning, at over 251,000.
"We know that separate from diagnostic waiting lists we have jut over 900,000 people on some form of hospital or acute hospital waiting lists, and separate from that we have over 230,000 people on community waiting lists.
"To have just over 250,000 people waiting for a scan of some description waiting for a scan, it's incredible that we have as many people waiting for a scan as we do."
