Deadly cases of heart disease are being missed because of a shortage of scanners and radiologists, according to cardiac imaging experts.
They claim thousands of Scottish patients with chest pains are missing out on potentially life-saving scans.
Their research estimates that just 27% of people with symptoms of angina had the specialist CT scan last year.
The Scottish government said deaths from heart disease had fallen by 40% over the last 10 years.
Historically, people experiencing chest pain have been referred to a clinic where they undergo exercise tests to assess their heart function.
But cardiac experts claim the tests are not accurate enough to rule out underlying causes of angina.
They argue that all patients with symptoms of angina should now receive a heart scan called a computer tomography coronary angiography (CTCA), which can detect or rule out heart disease.
New analysis by The Royal College of Radiologists (RCR) and the British Society of Cardiovascular Imaging (BSCI) suggests a limited number of suspected angina patients in Scotland receive the CTCA scans.
Their figures indicate that 2,950 of these scans were carried in Scotland out last year.
But they claim that at least 10,850 patients north of the border would be expected to have suffered angina or similar chest pain.
The study says this suggests that at least 7,900 missed out the scans - about 73% of those experiencing symptoms.
Dr Giles Roditi, president of the BSCI, said: "CTCA scans are incredibly good at detecting and ruling out heart disease, almost perfect.
"It is beyond frustrating that we do not have the capacity to provide what should be a routine frontline test for everyone presenting with chest pain.
"Instead, in many hospitals it is easier for a runner with a dodgy knee to get a magnetic resonance scan than it is for a patient on the verge of a heart attack to get a CTCA.
"Deadly cases of heart disease are being missed because we can't deliver these scans properly across the UK."
Failure to invest
In 2016 the National Institute for Health and Care Excellence (NICE) said all patients with angina-type symptoms should receive a CTCA scan.
NICE guidance is only aimed at English hospitals but experts at the BSCI and the RCR believe everyone with angina should have a CTCA, regardless of where they live.
Earlier this year research published by a group of Scottish academics found that the use of CTCA scans significantly lowered the rate of heart attacks in patients with suspected angina.
Dr Nicola Strickland, president of the RCR, said: "It is remarkably sad that the CTCA technology exists to diagnose life-threatening heart disease before it kills people, but patients are being denied access because the UK government and devolved administrations are failing to invest in training the radiologist doctors needed to report these scans, as well as the state-of-the-art CT scanners needed to perform them."
Their research also found that across that UK a total of 56,289 angina patients missed out on scans last year.
A spokeswoman for the Scottish government said it was committed to ensuring the best care for people with heart disease.
"This is why we continue to implement our refreshed Heart Disease Improvement Plan 2014, which sets out the priorities and actions to deliver improved prevention, diagnosis treatment and care for people living with and affected by heart disease in Scotland," she added.
"The number of new cases of coronary heart disease (CHD) in Scotland has decreased by 27% between 2007-2017, with mortality rates also decreasing by 40% in the last 10 years."