[Dynamic CT and its application in the diagnosis of oral and maxillofacial tumors].

Dynamic CT was used in 26 cases with oral and maxillofacial tumors. Among them, 21 were incremental dynamic CT, 4 were single level dynamic CT, and both of them were used in 1 case. Incremental dynamic CT can show not only the extent of the tumor, but also the relationship between the tumors and carotid arteries and jugular veins. It can provide important information for design of the operation. There are four types of shape of the carotid sheath in the involved side as follows: (1) a space of fat is present between the tumor and major vessels, indicating that carotid sheath is not involved by the tumor. (2) the vessel is close to the tumor although its position and shape are normal. (3) vessel is displaced by the tumor. (4) involved jugular vein is narrower than normal, with or without displacement.