HOW do you investigate airflow inside a living lung? The problem is beyond conventional medical imaging techniques, which only show body fluids or solid tissue.
One idea, dreamed up 8 years ago, is to fill the patient’s lungs with an isotope of helium and use a modified magnetic resonance imaging (MRI) scanner to trace the gas’s movement. And at last, researchers at the Harvard-Smithsonian Centre for Astrophysics have built a cheap and simple device to do just this.
Conventional MRI machines detect water in the body. To generate the image, the spins of the hydrogen nuclei have to be lined…
