Apparent diffusion coefficient of different areas of brain in foetuses with intrauterine growth restriction

Introduction
This study aimed to compare the apparent diffusion coefficient (ADC) values of different brain areas between two groups of intrauterine growth restricted (IUGR) foetuses and control cases.

Material and methods
A total of 38 foetuses with IUGR and 18 normal control foetuses with similar gestational age were compared using a 3T magnetic resonance scanner. IUGR cases included 23 foetuses with clinical severity signs (group A) and 15 foetuses without clinical severity signs (group B). ADC values were measured in different brain regions and compared among groups. Foetuses with structural brain abnormalities were excluded from the study.

Results
All foetuses had normal foetal structural brain anatomy. Head circumference (HC) < 5% was more common in IUGR group A compared to IUGR group B (56.5% vs. 13.3%, p < 0.0001). In comparison to the normal group, the ADC values in IUGR foetuses were significantly lower in cerebellar hemispheres (CH) (1.239 vs. 1.280.5  10–3 mm²/s, p = 0.045), thalami (1.205 vs. 1.285  10–3 mm²/s, p = 0.031) and caudate nucleus (CN) (1.319 vs. 1.394  10–3 mm²/s, p = 0.04). However, there were no significant differences in ADC values between IUGR subtypes. Among all brain regions, pons had the lowest ADC values.

Conclusions
ADC values of thalami, CN, and CH were significantly lower in IUGR than control foetuses, while there was no significant difference among IUGR groups. Further studies are needed to evaluate the prognostic value of ADC changes in IUGR foetuses.