The past decade has seen an unprecedented increase in the use of
radiologic exams on pregnant women, according to a study presented
Tuesday at the annual meeting of the Radiological Society of North
America (RSNA).
"Through medical imaging examinations, we are exposing pregnant
women to twice the amount of radiation as we did 10 years ago,"
said Elizabeth Lazarus from Brown University in Rhode Island.
"Overall, the levels of radiation to which we are exposing pregnant
women are low, however even low levels of radiation have been shown
to carry a small risk of harm to a developing fetus."
The researchers conducted a retrospective review of selected
imaging examinations -- nuclear medicine, computed tomography
(CT)and plain-film x-rays -- performed at Brown to determine how
often these imaging exams were utilized in pregnant women and the
estimated resulting radiation dose to the fetus. Data were compiled
for the years 1997 through 2006 and compared to the number of
infant deliveries per year.
They found that from 1997 to 2006, the number of imaging studies
performed on pregnant women increased by 121 percent. The greatest
increases were in the number of CT exams, which deliver more
radiation than many other radiologic procedures.
CT is not routinely used in pregnancy, but pregnant women may
undergo CT to detect suspected life-threatening conditions such as
bleeding in the brain, blood clots in the lungs or
appendicitis.
The average estimated fetal radiation exposure for CT was 0.69
rads, compared to 0.04 rads for nuclear medicine and 0.0015 rads
for plain-film x-rays.
Dr. Lazarus cautioned healthcare consumers to be aware of this
trend. "I want to assure patients that CT can be a safe, effective
test for pregnant patients," she said. "However, there are
alternatives that should at least be explored. Pregnant patients
should ask their doctors about other imaging or diagnostic tests
that may not expose the fetus to radiation."
(Xinhua News Agency November 28, 2007)