The Hospital Authority says it will start charging for non-emergency radiological exams next year, and patients will have to fully settle the bill two weeks in advance.

The body which manages the city's public hospitals says the move is aimed at optimising the use of resources and reducing the waiting time for patients.

As part of a sweeping reform for fees and charges at public healthcare institutions, patients will have to co-pay for certain services starting from January 1.

Under a three-tiered scheme, basic radiological exams such as X-ray scans will remain free of charge.

Ultrasound and breast imaging services will require a fee HK$250, while computed tomography (CT) and magnetic resonance imaging (MRI) scans will cost HK$500.

The authority's quality and safety director Michael Wong stressed that even after co-payment, such services are still 90 percent subsidised by taxpayers.

He added demand for radiological services had surged in the past decade, and estimated the move will halve the waiting time for urgent bookings to one week.

"We wish our patients to co-pay part of the medical fee so that our patients will judiciously use our public resources. This concept is not only for radiological investigations, but for all the medical services," he said.

Patients must also settle the payment 14 days ahead, or else the appointment will be cancelled. No refunds will be given for no-shows.

Elaine Kan, who chairs the radiology coordinating committee at the authority, says about one in 10 patients currently do not turn up.

She said the new rules can help them reduce wastage.

"That would allow radiology departments to have an adequate period of time to rebook and fully utilise the allocated appointment time for patients who need it," she explained.

"If the period is too short or there is no such period, then we are not able to utilise the appointment that's been freed up."

There will be a three-month grace period for patients to get used to the new arrangement.