Patients become image-conscious
THE R E HAS b e e n a surge i n public interest i n health s c r e e n i n g , wi t h increasingly sophisticated techniques available. Among the most advanced is diagnosticimaging,aspioneeredbythe national programme for breast screening, using mammography to pick up early breast cancer since 1987.
Other imaging techniques have also been developed to detect organsystem diseases before the individual becomes aware of symptoms.
Dexa bone densitometry uses a very low dose of x-rays to diagnose osteoporosis, so a combination of lifestyle advice and treatment can be given to reduce the risk of hip fracture in the elderly, or others at risk.
Ultrasound can screen for conditions in the unborn. In adults, it can spot aortic aneurysms which, if undiagnosed, can lead to catastrophic haemorrhage and sudden death. Ultrasound can also measure the thickness of the inner wall of the carotid arter- ies, on which the brain depends for its blood supply. Increased inner arterial wall thickening at this site may be associated with greater cardiovascular risk, which can be reduced through lifestyle changes and treatment of raised cholesterol and high blood pressure.
Cardiovascular disease, in the form of heart attacks and stroke, remains the biggest cause of adult mortality. CT scanning techniques have been developed to look at the deposits inside arteries and calculate the risk of heart attack; it also allows us to evaluate coronary artery narrowing without invasive catheter angiography (an imaging method that involves inserting a plastic tube and passing a coloured liquid along it).
CT scanning can also reveal early lung cancers in individuals at high risk, such as smokers, at a potentially curable stage. Similarly CT techniques have been developed to detect polyps in the large bowel at a precancerous stage when they can often be removed by minimally invasive procedures.
Increasingly MRI (magnetic resonance imaging) is augmenting or replacing CT. MRI has the advantage of not using x-rays (although the risk Screening expert at Highgate Private Hospital takes a medical history associated with CT scanning is very small). A recent development has been the use of MRI to identify prostate cancer — the commonest cancer in men. MRI can be performed in men who have an elevated level of PSA, a protein produced by the prostate gland but often abnormally increased in the presence of prostate cancer. This helps the urologist to biopsy the abnormal areas of the prostate more accurately and increases the likelihood of optimal treatment.
Screening offers reassurance, when findings are normal, or early detection and treatment of disease if it is present. This is infinitely preferable to the late presentation of such diseases, when the chance of a cure or successful treatment may be dramatically reduced. Jeevan Kumaradevan is a consultant radiologist at Highgate Private Hospital, north London