A MEDICAL MARVEL

Hawera Star, Volume XLVIII, 2 March 1929, Page 9

A MEDICAL MARVEL

WHAT X-RAYS REVEAL

jp'VERYONE knows that X-rays are useful for examining broken bones and locating bullets, but it has surprised many people to learn that the King’s doctors have been using them, to discover the condition of their patient’s lungs, says the “Daily News.” Yet this is far from strange if we consider how large a part X-rays now play in the diagnosis of disease. Their usefulness depends on tlxcir being able to pass through some substances more easily than others, and in this, of course, they resemble ordinary light rays. The light from an electric lamp passes freely through glass,-but not so freely through paper. Again, some of the rays from a strong light will go through thin wood, but we know of no light (Strong enough to penetrate a plate of iron half an inch thick. In the same way X-rays will pass freely through skin, but not so freely through muscle and fibrous tissue. Only a certain proportion of the rays will penetrate the larger bones, and none at all will get through a thick plate of lead.

over this difficulty an ingenious device is now adopted. Into the patient’s windpipe, without pain or discomfort, is introduced a substauce called lipiodol, which, is opaque to X-rays. This fluid runs down into the smaller air-tubes, hud when a radiogram is taken, all the ramifications of these tubes stand out clearly, so that abnormalities are made plain. The same principle has long been employed in examining the stomach and the rest of the alimentary canal. The patient swallows a “meal” containing barium or bismuth powder, through which X-rays cannot pass, and radiograms then show the stomach in silhouette. Its shape and movements are noted, together with any signs of spasm or ulceration, and by taking photographs at intervals during the next day or two the “meal” is watched in its progress dawn the intestine. Any obstruction in the bowel is thus made manifest, and eight times out of ten it is said to be possible to ascertain the state 'of the appendix, whose cavity often fills with barium. Any part of the body into which an opaque fluid can be passed can be examined in the same way by X-rays, and the knowledge, thus obtained may be of the utmost value.

In examining fractures we use “hard” rays, corresponding to a strong light and having a high power of penetration. These will pass through all the soft tissues and throw a shadow of the thick bones on a photographic plate. But in examining the chest we use “soft” rays, whose penetrative power is weak, for these will throw a shadow which reveals the finer structure of the lung and enables conclusions to be drawn about its condition. The technical adjustment of hard and soft rays has now reached such a pitch of efficiency that shadows can often be seen if there is abnormal fibrous tissue (resulting from inflammation) in the lung; whilst cavities, patches of pneumonia or broncho-pneu-monia, areas of collapse, and effusions o? fluid may be clearly recognisable. Even the most skilful radiologist however, will be unable by these means alone to study the condition of the smaller bronchial tubes, and to' get

The height of ingenuity, however, has been reached with a new method of investigating the state of the gall bladder.

A drug has been discovered, cglled totraidophenolphthalein, which is absorbed from the alimentary canal into the circulating blood. Thence some of it passes into the gall-bladder, where it makes the bile opaque to X-rays. The patient swallows a few capsules of the drug, and after an hour or so th<; gall-bladder can be seen as a small bag casting an oval shadow on the X-ray screen. If gallstones are present, they may be seen as transparent areas in th e shaddwy mass, and the doctor may thus learn the cause of symptoms whose origin might otherwise not have been known without an operation.