Diffusion-weighted MR imaging and apparent diffusion coefficient of the normal fetal lung: preliminary experience.

Objective To assess if a correlation is present between apparent diffusion coefficient (ADC) values and normal lung maturation during gestation to define potential reference values as indicators of the lung development. Methods Our study included 50 pregnant women (gestational age, GA: 18–36 weeks), with normal fetal development of lungs assessed by a previous obstetric ultrasound (US), and then confirmed by our magnetic resonance (MR) examination. We used T2-weighted sequences, diffusion-weighted imaging sequences (DWI) and ADC maps for studying pulmonary tissue. In all cases the resulting ADC values were related to GA using Pearson correlation. Results ADC values ranged from 1,2 µm2/ms at 18 weeks' gestation to 3,9 µm2/ms at 36 weeks' gestation with a mean value, regardless for the gestational age, of 2, 352 ± 0,623106 µm2/ms. We found a significant correlation between ADC and gestational age (Pearson correlation = 0,816). Conclusion The ADC values correlate with gestational age since alveolar fluid secretion and angiogenesis increase gradually. Therefore, ADC can be considered as a new parameter for studying lung maturity. Copyright © 2008 John Wiley & Sons, Ltd.