頸静脈球高位の2症例—画像診断上の特徴について

Two Cases of High Jugular Bulb

I．緒言

　頸静脈球高位は内頸静脈の走行異常であり，中耳手術，鼓膜切開のさいの偶発的出血の原因としてよく知られている^1〜3）。今回私どもは中耳疾患に伴って発見された頸静脈球高位を2例経験したので報告し，その画像診断上の特徴について若干の考察を加える。

The first case was a 36-year-old female with a central perforation of the left tympanic membrane, and the other was a 37-year-old female with cholestcatoma of the right. CT scans were very useful for diagnosis in both cases.

Positions of the jugular bulb were classified according to relations to the tympanic cavity based on temporal bone CT scans and frontal tomo-graphics.

Type I; lies beneath the bottom of the tym-panic cavity (T.C.).

Type II; lies over the bottom of the T.C., but not protruded in the T.C.

Type III; protrudes in the T.C. without bone defects of the bottom of T.C. or with bone defects (IIIb)