1) The right occipital AVM measures less than 3 cm in each orthogonal dimension. It is approximately 19 x 20 x 24 mm in the AP x trans x CC dimensions.
2) The AVM is supplied by the right P1/fetal origin R PCA.
3) Venous drainage is superficial to the right transverse sinus and separately to the superior sagittal sinus.
4) There may be a 5 mm nidal aneurysm centrally within the nidus - this is difficult to distinguish from the nidus itself.