Apparent diffusion coefficient determination in normal fetal brain: a prenatal MR imaging study.
OBJECTIVE
Diffusion-weighted MR imaging studies of normal brain development have focused on premature babies who were free of focal lesions on conventional MR images. The condition of prematurity, however, is dissimilar to intrauterine life. We sought to establish normal values of fetal brain apparent diffusion coefficient (ADC) to highlight its abnormal changes in pathologic conditions and to obtain information about normal brain development.


METHODS
We measured the ADC, in utero, by using an echo-planar three-axes diffusion-sensitized sequence (b factor, 0 and 600 s/mm(2)), in frontal and occipital white matter and basal ganglia gray matter of 15 fetuses. Their gestational ages ranged from 22 to 35 weeks, and the postnatal MR images or sonograms revealed normal brain.


RESULTS
Mean ADC value was 1.96 +/- 0.1 micro m(2)/ms (SD) in frontal white matter, 1.95 +/- 0.1 micro m(2)/ms in occipital white matter, and 1.56 +/- 0.1 micro m(2)/ms in basal ganglia. A significant negative correlation between ADC and gestational age was found for basal ganglia, whereas only a trend was present for frontal white matter.


CONCLUSIONS
Although moderately higher, the ADC determinations we obtained are consistent with those reported in the literature in postnatal studies performed in premature babies.
Department of Neuroradiology, Istituti Clinici di Perfezionamento, Milan, Italy.
Andrea
A
Righini
Elena
E
Bianchini
Cecilia
C
Parazzini
Patrizia
P
Gementi
Luca
L
Ramenghi
Cristina
C
Baldoli
Umberto
U
Nicolini
Fabio
F
Mosca
Fabio
F
Triulzi
D000328:Adult; D001921:Brain / Q000196:embryology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012016:Reference Values