To compare the linear dimensions (width) of the foetal atrium and occipital horns to their areas, 31 foetuses (15-24 weeks, C-R 12.5-23.5 mm) from spontaneous abortions were evaluated. Images of the axial sections of the brains were transferred to computer and Scion for Windows 98 software was used for image analysis. 11 brains appeared normal and 20 were abnormal (leukomalacia in 9 cases, periventricular and intraventricular haemorrhage in 6 cases, ventriculomegaly in 3 cases, colpocephaly in 1 case, vascular malformation in 1 case). High-range linear and planar asymmetries in the atrium and occipital horns were observed both in normal and abnormal brains. There was no close correlation between the width and the area of the structures under investigation, although it was stronger in case of the occipital horns. The wider occipital horns and atria often had a smaller area than the narrower ones. Some abnormal cerebral hemispheres had relatively narrow atria and occipital horns in comparison with their large areas. Further investigation should be carried out to assess the utility and potential superiority of planar measurements over linear in the image diagnosis of foetal ventricles.