IN 1895, GERMAN physicist Wilhelm Roentgen produced the first x-ray film. Heralded as the medical miracle of the modern age, within a year x-rays were being used in diagnosis and therapy as an established branch of medicine. Roentgen, although collecting a Nobel prize for his breakthrough, did not cash in on his astonishing discovery, declining to seek patents or other claims on x-rays.
If he were to step into a hospital today, the pace of development that has swept through the field of radiobiology would surely astound him. From a single technique in the late 1890s, the radiological boom has placed imaging at the centre of all western healthcare systems. Roentgen would not even recognise the different types of imaging now on offer or the array of professionals using radiology in today’s healthcare environment.
The pace of change is no more pronounced than with Roentgen’s original creation: x-rays. By the time patients attending clinic at Hammersmith Hospital in London have returned from having their x-rays taken, their doctor is already viewing the results at a computer in the consultation room. The time taken to manually develop, print, label and transfer the film has been eliminated thanks to the hospital’s picture archiving and communications system (PACS). Today all diagnostic images used at the hospital trust are electronic.
Ten years ago, Hammersmith Hospital was the first in Europe to go filmless. This has been coupled with voice recognition software, which turns the spoken word into computer text and attaches the appropriate report to the image. The result of these developments has been to make X-rays more convenient to use: large filing systems filling basements are no longer needed and images and their reports are never lost or misfiled in some corner of the hospital.
Last year, the government announced a roll-out of PACS to all UK hospitals as part of its £6 billion NHS IT programme. The system, with its anytime-anywhere access, centralised storage and the ability to link images to previous x-rays and other patient data, demonstrates the extent to which imaging has become an essential tool in the diagnosis and treatment of illness. Researchers are continuing to study the benefits of PACS at Hammersmith, in terms of reducing the radiation dose and reducing delays by ensuring that the reported images are immediately available. This is a step towards a complete electronic patient record, making full use of the benefits that seamless access brings.
The humble x-ray now comes in many guises. Contrast media are liquids that show up under x-ray. They are swallowed to image gut function or injected to analyse blood flow and vascular anatomy. They play a crucial role in areas such as cardiology and gastroenterology. Angiography, angioplasty and stent insertion using x-ray and scanners has revolutionised the way in which we deal with heart disease and peripheral vascular disease.
Computed tomography combines x-rays with computing to build up x-ray “slices”, creating detailed pictures of anatomy and pathology. This helps doctors to visualise the pathology of disease, and the location of abnormalities better and to understand how internal organs function in health and disease. CT can represent blood supply to malignant tumours visually and enable treatment strategies to be developed. Drugs can be delivered via specially-designed catheters through blood vessels to target diseased organs. Respiratory doctors use high-resolution CT for patients with vasculitis, cancer and other lung disease. 3D reconstruction of contrast-enhanced scans are already replacing conventional angiography in a number of situations in clinical practice.
Magnetic resonance (MR) imaging, 10 years ago restricted to large teaching hospitals, can be found in most hospitals today – the NHS has seen a 60 per cent increase in the number of MR scans in the past six years. Complex mathematical research is finding smarter ways of performing calculations on raw data to obtain better images. Research at Hammersmith has led to new ways of imaging tissue that does not show using standard MR sequences, such as cartilage and tendon, and a scanner dedicated to the neonatal age group is revealing the secrets of brain development. There is a never-ending list of conditions for which MR is being used – the challenge for government and hospital administrators is to increase staff numbers to enable these machines to be used for longer hours.
Ultrasound, originally developed to detect enemy submarines, has many medical uses, including its most familiar: allowing mothers to see their unborn children. One of the biggest leaps forward was made with the discovery that tiny gas bubbles injected into the body contract and expand rapidly when ultrasound is applied. Originally developed to improve image techniques in general, our researchers are developing the technology in a range of powerful applications. Microbubbles are taken up strongly by the liver, enabling tumours and other growths to be shown with remarkable clarity. Research has also shown that they have considerable potential for delivering gene therapy and drugs to diseased tissues.
Hammersmith Hospital was the first in the world to have a medical cyclotron unit – a reactor that produces radioactive isotopes for use in positron emission tomography (PET). This provides scientists with a window on real-time chemical processes in human organs such as the brain, heart and lungs. Following the discovery that cancerous tumours metabolise sugar in a different way to normal tissue, patients with cancer can be injected with a radioactive sugar called F-18 fluorodeoxyglucose that shows up cancerous cells under PET scanning. By providing information about what is happening at a molecular level in the body, imaging data from PET can even help speed up drug discovery and development. As well as diagnosing the disease, PET could also help design the drugs to treat it.
It’s been only 100 years since the “new light” of x-rays has been with us. It’s hard to see how the next 100 will be any less exciting.
