Concerns are being raised over patients waiting longer than six weeks for CT and MRI scans, with experts saying it could impact negatively on their health.
Alarming figures revealed in Waitemata District Health Board's July agenda showed the percentage of scans being done within six weeks of referral were consistently well below national targets.
The target was to achieve a 90 per cent success rate for MRI scans within the set time-frame, and 95 per cent for CT scans.
Last year those targets were met.
But the most recent monthly report showed that in May only 62 per cent of MRI scans had been complete, and only 71 per cent for CT scans - an "off track" trend that remained consistent since January.
Acting chief executive of the board and director of hospital services, Cath Cronin, said in the last two to three years, there had been significant growth in demand for these scans, which even exceeds the rapid rate of growth within our population.
"CT referral numbers are growing at around seven per cent per year while MRI referrals are up almost 14 per cent per year. This experience is common across the region," Cronin said.
She said the board was prioritising the scheduling of all urgent and acute patients.
"We have already taken steps to help reduce wait times for all of our patients, such as outsourcing services where appropriate to private Auckland-based radiology services.
"We are also running weekend clinics at North Shore Hospital as well as implementing a centralised booking system and taking steps to improve the flow of patients through our Radiology Department," Cronin said.
President of the Royal Australian and New Zealand College of Radiologists (RANZCR), Dr Lance Lawler, said the targets were there to ensure wait times were kept to a minimum.
"If there was no pressure, patients could be waiting two years and this has happened in the past."
Lawler said with the higher demand an honest discussion needed to be had about what DHBs were able to provide.
"Patients should be made aware of how long that wait could be.
"We know delays in diagnosing can lead to poorer health outcomes. Nothing can happen until a patient has a diagnosis from a scan, then a patient will have to go on a waiting list for treatment."
Lawler said the growing demand stemmed from a societal attitude of people needing to know exactly what was wrong with them and what was the best treatment available, which was understandable.
"On the flip-side of that doctors are scared not to order the test because they might get punished for that. It's a problem in management that needs discussing."