A shortage of radiologists in Scotland is putting patient safety at risk, with some cancer patients waiting more than a month for diagnosis and treatment, doctors have warned.

The Royal College of Radiologists (RCR) said Scottish radiology is "on the brink of collapse" due to a combination of chronic vacancies, low trainee numbers and increasing demand.

Clinical radiologists are doctors who interpret X-rays, scans and other types of medical images to diagnose disease and injury.

Research found the five-year average of unfilled radiology posts in 2015 was 8% and nine in 10 hospitals said they cannot cope with the daily workload of producing reports for images.

The RCR said the lack of radiologists specialising in interventional radiology means only two of the 12 health boards currently offer 24-hour cover for emergency minimally invasive pinhole procedures, such as those to stop bleeding after a road traffic accident or after childbirth.

RCR spokesman Dr Grant Baxter, consultant radiologist and chairman of the college's standing Scottish committee, said: "Having been a doctor for 34 years, I have never seen it as bad as this.

"Scottish radiology is on the brink of collapse, and if that happens there will be no medical diagnoses or surgical operations at all, since none can occur without radiologists interpreting the scans and X-rays.

"A perfect storm of increased demand, no significant increase in consultant numbers or trainees, chronically unfilled posts and a tsunami of expected retirements in the next three years means that we need a sustainable solution now for the sake of our patients. Patient safety is at risk."

The RCR is calling on the Scottish Government to support recruitment from overseas to fill vacant consultant radiologist posts, increase radiology trainee numbers and improve connectivity in technology, enabling off-site image interpretation.

Scottish Conservative shadow health secretary Donald Cameron said: "This is an exceptionally grim warning from the people who know best.

"It's clear the SNP has fundamentally failed to train enough radiologists, and patients - including cancer sufferers - are the ones paying the price."

Scottish Liberal Democrat health spokesman Alex Cole-Hamilton said: "Hospitals can quickly become congested unless there are sufficient numbers of radiologists.

"This is the latest warning of a crisis in our NHS.

"Nurses say we are juggling with demographic time-bomb, charities tell us shortfalls in mental health care are leaving children in distress and A&E targets have been missed time and time again.

"The whole of the NHS is facing a perfect storm and SNP ministers are simply failing to step up to the challenge."

Health Secretary Shona Robison said: "Prompt cancer treatment is vital - and that is why we have set rigorous standards in this area.

"Under this government, the number of consultant clinical radiologists working in Scotland's NHS has increased by 46% and the number of radiography staff has risen by over 24%.

"Last year, we published our five-year £100 million cancer strategy which sets out how we will improve patients' access to cancer diagnosis and treatment.

"This included a £50 million commitment to investing in new radiotherapy equipment, as well as training and recruiting a broad range of specialists with an interest in radiotherapy including: imaging, delivering radiotherapy, delivering nuclear medicine, oncology and specialist nurses.

"We're committed to working closely with the NHS, including staff representatives like the Royal College of Radiologists, to ensure this investment sees the expected increase in the number of specialist radiotherapists working in our health service."