There is potential for CT colonographies to be used as a screening tool for bowel cancer instead of colonoscopies, some health practitioners say, but the procedure is not publicly funded.
The procedure uses a CT scanner to assemble a virtual picture of the bowel surface, as opposed to looking inside the bowel with a fiber-optic tube containing a tiny camera.
Polyps cannot be removed or biopsies taken during a CT colonography, and if there are any unusual findings patients have to be referred for a colonoscopy.
Costs for a CT colonography in Otago range from $495 to $620, compared with about $1100 for a basic colonoscopy at Mercy Hospital.
Otago Radiology radiologist Dr Neil Morrison said there was "absolutely" scope for CT colonography to be used as a screening tool.
At the very least, CT colonography should replace barium enemas, which were "not particularly good at finding polyps or small cancers", Dr Morrison said.
Otago Radiology had been doing about three colonographies a week for the past six months.
However, while the procedure was quick and easier for patients, it was time-consuming for radiologists.
Dunedin Hospital is already struggling to reduce waiting times for other scans on its CT scanner.
Oamaru Hospital is already offering a CT colonography service using its CT scanner and funding the procedures itself, although depending on circumstances, some doctors refer patients to Dunedin Hospital.
Oamaru Hospital manager Robert Gonzales was not sure how many Oamaru patients were using the Dunedin Hospital colonoscopy service, or how many had been declined.
Oamaru Hospital could handle up to eight patients a month using its new, high technology CT scanner.
Oamaru doctor Steve Dawson said it was not suitable for young patients because of radiation.
The Oamaru Hospital service cost $495 and was more suitable for older patients, those who could pay or had medical insurance.
Mr Gonzales said CT colonography was offered through the hospital's gastroenterology clinic once a month.
Patients needing the CT colonography were referred by Oamaru doctors and the service was paid for from the hospital's community fund, not through regional health funding.
Mr Gonzales was not aware of any local patient being declined the service at Oamaru Hospital.
Oamaru doctors made their own decisions about whether to refer patients to Oamaru Hospital or to Dunedin Hospital.
Dr Dawson said whether patients were referred to Oamaru Hospital for a CT colonoscopy or to Dunedin Hospital depended on circumstances.
Accessing the service in Dunedin "has been difficult", but he could not say how many Oamaru patients may have been declined.
