From X-rays to MRI scan: the inside story
The power to peer inside the human body was discovered by accident in November 1895 when a German physicist was experimenting with electrons in vacuum tubes
Willhelm R ntgen had covered the tubes with black cardboard to stop light escaping, but noticed a shimmering coming from a screen a metre away. He waved his hand between the covered tube and the screen and saw the silhouette of his bones projected on to the screen. He had discovered a new type of radiation that could travel through seemingly opaque material.
In December he took an X-ray picture of his wife s hand, declaring in a newspaper beside the image: My wife is visible .
In Britain there were fears that the new technology would allow photographers to take nude pictures of fully dressed women. A quick-thinking trader was soon selling X-ray proof underwear to guarantee a lady s modesty
One of the first X-ray machines was constructed by Russell Reynolds, a 15-year-old schoolboy from London, with the help of his father, John, a doctor. Reynolds became a pioneer of radiology, developing the first methods of taking X-ray images of internal organs.
By the late 1960s two men were independently attempting to use X-ray to create three-dimensional images, a process known as computer tomography (CT). Patients would pass through a rotating X-ray beam, detectors would capture a series of cross-sectional images. These slices could then be used to build a 3-D image.
Allan Cormack, of Tufts University, Boston, USA, published the first theoretical papers on such a system; Sir Godfrey Hounsfield, of EMI Research Laboratories in Middlesex, applied for a patent in 1968 and tested a machine in 1972. They would share the Nobel Prize for Medicine.
In 1973 Sir Peter Mansfield at the University of Nottingham invented another form of scanning. Magnetic resonance imaging (MRI) combined powerful magnetics and a radio wave through the body: atoms in the body released energy that was picked up by detectors. MRI is used to examine the brain, spine, abdomen and pelvis.
From there the journey was towards ever-sharper images: enough to make anyone s wife even more visible.
