Radiologists are turning up the radiation levels on obese patients.
The overweight face higher diabetes and heart disease rates, and now research shows obese patients having CT scans and X-rays are receiving higher radiation doses to counter extra fat layers.
Obesity rates have more than doubled over the past 20 years, according to OECD statistics, and the Royal Australian and New Zealand College of Radiologists has reported CT scans have increased substantially over the same period, as the technology becomes more sophisticated.
New Zealand chair Mike Baker said larger patients needed higher amounts of radiation for X-rays and CT scans. "The more body tissue there is, the more radiation you have to give, but overall the levels are small."
He said there was unlikely to be a health risk to the patient, and it had to be balanced against not getting a diagnosis.
An international study shows radiologists increase radiation exposure by up to 62 per cent on obese people, compared to normal-weight patients.
Lead author Dr Aiping Ding, of New York's Rensselaer Polytechnic Institute, said radiologists were gauging the level of radiation required by trial and error. The calculated dose reaching an obese patient's organs increased by 62 per cent in males and 59 per cent in females.
But Baker said most machines in New Zealand were auto-tuned to calculate the correct exposure.
The college's website says low-level radiation risks from CT scanning are uncertain and have been the subject of ongoing debate. It says the technology is too new to carry out long-term studies on potential risks.
CT scanners use low levels of radiation to help diagnose and monitor a number of conditions, such as cancer and stroke.
- © Fairfax NZ News