About a quarter of people with high blood pressure have been estimated to have a problem with their adrenal glands producing too much of the hormone aldosterone, which regulates levels of salt in the body.

This problem is often missed, as the path to diagnosis is complex, involving multiple tests and, to guide treatment, an invasive procedure that is not always reliable.

The new 10-minute scan, developed at UCL and described in a research letter published in the New England Journal of Medicine, reveals overactivity in adrenal glands that was invisible with conventional tests, showing exactly where too much aldosterone is being made.