Objective        To demonstrate the regional anatomy features of jugular foramen region in suboccipito-retrosigmoidal approach simulated by virtual reality technique.       Methods         CT and MRI scanning were performed to 5 adult cadaver heads

and then

silicone mixed with contrast agent was injected into the arterial and venous systems respectively. CT scanning were performed again after above 2 times of injection. Brainstem and cranial nerves were exposed after resecting partial cerebellar hemisphere by suboccipito-retrosigmoidal approach in the bilateral dissection of cadaver head. MRI scaning were performed again. Image data was inputted into Vitrea virtual reality system to establish three-dimensional anatomy model of jugular foramen region and simulate suboccipito-retrosigmoidal approach. Superior margin of inner acoustic canal entrance

anterior and posterior margin of jugular foramen were selected as osseous mark points to measure the distance in cadaver heads and computed models respectively. Bland-Altman method was used for the uniformity of checking.       Results        Spacial relationships of nerves

vessels and osseous structures were displayed well in virtual reality three-dimensional model of jugular foramen region. Comparative analysis between cadaver heads and computed models by Bland-Altman method showed that bias for distance between superior margin of inner acoustic canal entrance and anterior margin of jugular foramen

superior margin of inner acoustic canal entrance and posterior margin of jugular foramen

anterior and posterior margin of jugular foramen were 0.060

0.062

and 0.017

respectively

and 95% confidence intervals were -0.255 to 0.375

-0.357 to 0.481

and -0.265 to 0.299

  respectively. Good consistency was demonstrated in scatter diagram.       Conclusion        Data measured in three-dimensional anatomic model of jugular foramen region is proven to be accurate by cadaver dissection

which is helpful to launch research for protection of nerves and vessels.