Figure 2.

Fibre orientation in the PV region. (a) Anterior view of the PV region, showing the main fibre bundles in several areas (an arbitrary colour is chosen to distinguish each bundle). (b) Details of the main fibre tracts near the sleeve of the LSPV. Most of the fibres wrap around the vein's ostium in an oblique direction. An area of sharp changes in the fibre directions between the LSPV and IPA is shown with a black circle. (c) Detail of the main fibre tracts along the sleeve of the RIPV. It can be seen that most of the fibres are oriented longitudinally or obliquely in relation to the vein. Fibre orientation patterns in (b) and (c) are in good agreement with anatomical observations [17]. (d) and (e) Main fibre directions shown in the same view as (b) and (c), respectively. Colours are the same as in figure 1d,e.