Q: When a person has a small aneurysm of the abdominal lTC aorta, is it necessary to have a CAT scan every six months if the aneurysm has not grown? Our internist and heart specialist disagree on how frequently these scans must be done. Is there any unnecessary danger from regular scans?
A: CAT scans can be used to track the course of an abdominal aneurysm. However, sonography (ultrasound) is the method generally recommended to follow such aneurysms because CAT scans are more costly and time-consuming. Sonography is the most practical and cost-effective way to determine whether an aneurysm is growing. The only possible danger of frequent CAT scans is that of radiation -- a very small risk in comparison with the danger of not detecting growth in an aneurysm that might precede its rupture. There is, of course, no radiation associated with sonograms.
A common approach is to carry out sonography every six months for a period of 12 to 18 months to determine the rate of growth of the aneurysm. If these examinations document little or no growth, the procedure may then be repeated only once a year. The patient's physicians will use the size and growth rate of the aneurysm, along with other information about the patient, to decide on the frequency of examinations.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine and associate dean for faculty affairs at the school.