MRI's new role: assessing obscure fetal abnormalities

CHICAGO - The advent of ultrafast MRI techniques in fetal imaging is enabling radiologists to diagnose or confirm problems in the lungs, brain, genitourinary region and other areas where ultrasound images are inconclusive or nonspecific.

Among 45 pregnant women referred to MRI after ultrasound at the University of California, San Francisco, MRI findings changed patient management in six cases. In one case, where the MRI diagnosed congenital hemochromatosis, a premature birth was induced to prevent the fetus from progressing to liver failure that might have required a transplant.

UCSF has now used MRI in a series of around 75 cases, with only three exams being compromised by fetal movement, according to Dr. Fergus Coakley, who presented MRI fetal images showing vein of Galen aneurysm and congenital diaphragmatic hernia (CDH).

Fetal MRI is also making a difference for patients at Brigham and Women's in Boston, according to Dr. Mary Frates of Harvard Medical School. In two cases of women who had previously lost fetuses due to serious brain abnormalities, the MRI was able to reassure them with confirmation of healthy fetuses.

"We have found MRI to be useful in confirming questioned diagnoses on ultrasound, and in cases where the ultrasound is limited, possibly by the size of the mother (or) by gestational age of the fetus," Frates said. "In addition, it has been very useful to us in fetuses who are potentially unstable once they are born."

Using MRI to evaluate such fetuses in the womb is advantageous, she noted, as "it's difficult to put a baby on a ventilator in the MRI."