New technique provides pictures of arteries

Press, Volume CXIV, Issue 33433, 15 January 1974, Page 15

New technique provides pictures of arteries

Bi

HAROLD M. SCHMECK,

WASHINGTON

The technology that; made possible man’s first i close-up map of Mars has been coupled with the old-fashioned X-ray to give doctors a new and potentially important view of hardening of the arteries. The scientists who devel-i oped the new technique for 1 viewing human blood vessels! expect it to become, a key! tool for studying atherosclerosis, the common type of hardening of the ateries

that ranks as America's No [1 health problem. A substantial measure of, I their enthusiasm is shared. I by officers of the National' Heart and Lung Institute, ' which has supported research leading to the new technique. The method was developed . through collaboration be-1 tween the Jet Propulsion Laboratory of the California Institute of Technology and; the University of Southern p California Medical School. It; involves basically the same; computer-aided technology i for extracting information I from images that scientists; of National Aeronautics and'; Space Aministration used to i seperate the real picture from the murk of extraneous radio noise in the signals < they received via spacecraft i from the vicinity of Mars. In the case of heart re- I search the technology is I used to extract a useful pic-j ture of the irregularities p within arteries from an ordi-H nary arteriogram — an i [X-ray visualisation of an ar- i tery. i FATTY PLAQUES Atherosclerosis involves ; the formation of fatty j plaques in the interior lining of arteries. As these plaques become enlarged they reistrict the flow of blood and}' ultimately may block a ' blood vessel. The new technique pro-' 1 duces X-ray' pictures on 1 which the size and shape of; 1 irregularities representing 1 ' atherosclerotic plaques can ‘ be seen clearly within human arteries. The ability to see the size and extent of the plaques ] offers the prospect of taking pictures at yearly' intervals 1 to see whether plaques are growing or retreating under' the influence of diet, ex- p ercise or drug treatment. Heart experts say one of; the key problems in research; on atherosclerosis is the; lack of a good and timely P measure of the state of ar-p teries. Usually the effectiveness! <

of any programme for slow ing the peogress of atherorsclerosis is gauged by studying large numbers of persons for many years so that comparisons can be made in heart attack and death rates of groups with different ways of life, diet and drug treatment. If the changes in atherosclerotic plaques could he studied directly, the worth of various treatments could be determined more quick!' and economically. This is the primary hope for the new technique. A specialist at the heart institute in Washington said several other techniques i<> achieve the same objectives were under development, but they were generally not as close to utility as the new method. Dr David H. Blankenhorn. professor of medicine and head of cardiology at the University of Southern California, said in an interview that his group used the method in the last year to lake pictures of the femoral artery of 105 patients with abnormally high blood fats. Most of these will be X-rayed again soon in a fol-ow-up. FOLLOW-UP PICTURES In another project, followup pictures will be taken of about 60 male heart attack victims in the 40-to-49-year age group. All are taking part in rehabilitation programmes involving varied combinations of weight loss md exercise. The question to be answered is whether any of ihe exercise and weight loss programmes will produce detectable favourable changes in the patients’ arteries. For the current studies, the femoral artery has been chosen as the place to look because this main artery of the thigh is easy to capture in X-ray pictures and involves little risk to the patient, even though the procedure involves injecting in the artery dye that is ipaque to X-rays. Robert Selzer, the engineer who heads the Jet Propulsion Laboratory’s part of he collaboration, said the echuique depended on a eamera-coniputer system differences in shades of ;rey in the X-ray picture ire converted into numerical zalues at 600 points in ivery 1900 lines that scan a our-i;ich length of artery. With this information the omputer determines the ■dges of the artery, the iresence and extent of irrclularities and then converts t all back into a picture on vhich these irregularities how up clearly. Copyright, "New York "imes” news service).