MRI 'promising' in evaluating fetal, intracranial lesions, but challenges remain: the technology is costly and its availability is limited; false-positive and false-negative diagnoses also at issue.(Obstetrics)

ORLANDO -- MRI for evaluating fetal and intracranial lesions shows promise, but challenges remain, Asad U. Sheikh, M.D., said at the annual meeting of the American Institute of Ultrasound in Medicine.

"MRI has become more useful for evaluating fetal and intracranial lesions. We're starting to see application as the technology advances for abdominal lesions as well. But still, we have considerable difficulty with interpretation," explained Dr. Sheikh, director of the division of maternal-fetal medicine at the University of South Alabama.

Dr. Sheikh reported on two specific cases of schizencephaly, a brain lesion characterized by abnormal choronal migration.

The first case was of a 20-year-old woman at 19 weeks' gestation who presented with maternal serum alpha fetoprotein (AFP) elevated by 4.4 multiples of the median (MOM). Initial ultrasound evaluation indicated a left-sided intracranial cyst, Dr. Sheikh said. Investigators found that tests for karyotype and infection proved negative.

When they performed another sonogram, they found a large cystic structure replacing the left frontal temporal region. After the 35th week of gestation, they performed MRI, which showed bilateral schizencephaly. The patient delivered vaginally at term.

The second case was a 27-year-old woman at 21 weeks' gestation with an elevated AFP of 3.6 MOM; she was in her fourth pregnancy. Ultrasound revealed bilateral ven-triculomegaly.

Amniocentesis was declined, and infection ...