The Federal Government granted the region's third MRI Medicare licence to the privately owned Hunter Imaging Group in East Maitland in January.

The Mater's application for the licence was unsuccessful.

Mater patients have to be taken to John Hunter Hospital for MRI scans.

Mr Osborne said that as the designated cancer hospital for northern NSW, it was essential Calvary Mater had its own MRI licence because cancer patients were often too ill to travel.

"It is absolutely laughable in this day and age that a hospital charged with the responsibility of being the major cancer services provider to a very large regional community is expected to do so without a fundamental imaging modality such as MRI," he said.

MRI was often used to diagnose psychiatric patients and when the James Fletcher Hospital moved to the Calvary Mater campus in June those patients would need to be taken to John Hunter Hospital for scans, Mr Osborne said.

He said it was also inefficient to transfer so many patients to another hospital for procedures.

The region's other MRI Medicare licence also belongs to the Hunter Imaging Group for its machine at Cardiff.