Diagnosis: The Trouble with Hot Spots

For all the painstaking care he puts into the pictures he takes, Dr. Jacob Gershon-Cohen could be one of the arti est of arty photographers. In his darkened studio, the temperature has to be just right-a steady 68° to 72°. He insists that subjects stretch out and relax for 15 minutes before the first picture is snapped. But Dr. Gershon-Cohen, a radiologist at Albert Einstein Medical Center in Philadelphia, is the extremely careful scientist, not the temperamental artist. Borrowing a technique space researchers use to take temperature readings of Venus, he photographs the human body's surface heat with a novel infra-red camera.

Highs & Lows. The procedure is called thermography, and Dr. R. Bowling Barnes, president of Barnes Engineering Corp., which developed the camera, describes the picture taken on photographic film as a "thermal map of the skin." The instrument does not ir radiate the subject in any way. Instead, it scans the body surface for six to twelve minutes to register the invisible infra-red rays emitted by the body itself. Where blood concentrates close to the surface-in veins, infections or abnormally rapid growths-the skin runs a higher temperature and the thermogram shows a light spot. Where there are areas of low metabolism-such as hair and scars or inactive growths close to the surface-the bodv temperature is slightly lower, and -',e thermogram is proportionately darker. Routine thermometer readings might show a fever, but they would not pinpoint its cause.

In a study of the camera's potential for diagnosis, Dr. Gershon-Cohen took almost 1,000 thermograms of breast lesions alone, also photographed suspected appendicitis cases and arterial disorders. The breast thermograms often aided a more definite diagnosis.

Picture of Illness. There was no way of telling from examination of one typical subject if the lump in her left breast was benign or malignant. But the thermogram left little doubt. The picture of the left breast came out lighter than normal; the temperature was about 3° higher than in the other breast. Surgery proved that the lump was cancer. A thermogram of another patient, a 68-year-old man with arteriosclerosis, showed his right leg black from the knee down. Its temperature was below normal. The patient had a blocked artery, was dangerously close to gangrene.

Additional diagnosis is usually required to determine the exact cause of the hot spots and cold spots discovered by thermography. But the new procedure, says Dr. Gershon-Cohen, "holds much promise as another, ancillary approach to more accurate diagnosis of diseases of the breast, particularly carcinoma." The camera is already "valuable in differentiating benign from malignant lesions."

* Photographs are reversed, right and left, as a thermogram is made from a mirror reflection of patient.