My son has been having stomach pains that are quite severe, and his doctor wants him to have a CAT scan of the abdomen, but because he has diabetes and allergies, I fear he may be at risk from such a scan. Could you please explain the complications and risks involved?
A CAT (computerised axial tomography) scan is merely a form of X-ray, a very sophisticated X-ray, in which dozens of low dose X-rays are taken at different angles of the area of the body being examined, to produce a detailed cross-sectional view. There are no more complications from a CAT scan than from a normal chest X-ray.
The exception to this rule is when contrast dyes are used. These dyes show up areas that are not normally visible on a normal CAT scan or X-ray. An example would be the Barium meal, where a mixture of Barium is swallowed so that the stomach and intestine can be seen. In some CAT scans, dyes may be injected into the bloodstream and travel to areas of particular interest.
Some people can be allergic to these dyes, and because your son has many allergies, it is possible that he may react adversely to a dye being used for an X-ray or CAT scan. It is probable that no dye will be used in a CAT scan of the abdomen, but they are commonly used in brain CAT scans. You should discuss this with the radiologist performing the scan, and if a dye is essential for the examination, a very small test dose of the dye may be given to see if your son reacts.
There are no risks associated with diabetes and CAT scans. Your doctor would not advise your son to have this test without good reason, and I therefore suggest that you proceed as outlined above.

My husband recently underwent a CAT scan, but suffered severely with diarrhea for two weeks afterwards, and was at one stage considered at risk of dying. A doctor told him that he had an allergic reaction to the dye injected for the CAT scan. Can you warn people of these risks?
The contrast dyes that are injected into some patients before an X-ray or CAT scan to get a better picture can cause rare fatal reactions but are 20 times less risky than travelling by car.
There is no evidence that new contrast dyes recently introduced are safer, even though they cost up to six times as much.
In one recent study, only eight deaths occurred after more than 600,000 dye injections—an extraordinarily low risk, considering that many of those injected were critically ill. In those under 65 years of age, the risk was far less than in those over 65, and there was a close relationship to the health of the patient. Survival after a severe reaction depended upon the availability of resuscitation equipment.
There has been much public anxiety over this issue, but when the benefits are weighed against the risks, proceeding with a potentially disease-identifying and therefore life-saving procedure is far safer than waiting until the disease becomes more obvious.

My obstetrician wants me to have a scan to check on the size of my baby. I am only 4 months pregnant. Are these scans safe in pregnancy?
YES! There is absolutely no doubt that an ultrasound scan is safe in pregnancy. Thousands of experiments into its safety have been carried out, and millions of women have had the procedure during pregnancy with no evidence of problems.
Ultrasound is not an X-ray, but actual waves of sound, rather like the dog whistle that animals can hear but which humans cannot.
A greasy substance is rubbed onto your abdomen, and an instrument that contains a miniature high-frequency sound-producing element is then rubbed across your tummy. The sound waves pass through your body, but are reflected and distorted in different ways by different types of tissue, fluid and bone. These distortions can be picked up and measured to give a detailed picture of the growing baby.
The size, shape, position, development and sometimes the sex of the child can all be determined, so it is a very useful tool for measuring the progress of a pregnancy, and making pregnancy safer for both mother and child.

I am 66 years old and the report on a recent X-ray of my chest says that ‘the aorta is unfolded’. Could you please explain in a good old-fashioned way what takes place with this complaint, and are there any exercises that could help?
There is absolutely no reason for you to be concerned about this problem, and there is no need to undertake any specific exercises, as I will explain.
The aorta is the main artery of the body and is about 2 cm across. It starts from the top of the heart, bends (or folds) over, and then runs down the back of the chest and belly along the inside of the backbone. It looks like an upside down ‘J’. Just below your umbilicus (tummy button) it splits into two slightly smaller arteries that continue through the pelvis and down each leg.
In an X-ray of the chest, the heart and aorta can be seen quite clearly. As you age, the bend in the aorta as it curls around from the top of the heart to run down the back of the chest becomes a less sharp bend. The aorta does not fold over on itself as much as it did before, and so in medical jargon, the aorta is said to be ‘unfolded’.
In your case it is a sign that you are no longer 21, and nothing more. In some people the aorta is unfolded and dilated by an aneurysm, which is quite a serious condition, but this can usually be seen on the X-ray and there is no sign that this was the case with you.