成人のChiari奇形に対するCT診断—特にReconstruction CTの効果について

Computed Tomographic Metrizamide Myelography in Chiari Malformation in Adult:Special reference to the diagnostic values of reconstruction CT

I．はじめに

　metrizamideを脊髄くも膜下腔に注入してのちCTを行う方法（computer-assisted myelography，以下CAMGと略す）はDi Chiroら^7）により紹介され，今日では種々の脊髄疾患に対し有力な補助診断法として諸家に認められるようになった．

　成人のChiari奇形では，多くの場合，脊髄水腫（hy-dromyelia）を合併するため^19），脊髄撮影では髄内腫瘍との鑑別は極めて困難であり，また通過する造影剤が少ないとChiari奇形そのものが見落される可能性も多い．

Three adult patients with a clinical diagnosis of Chiarimalformation were examined by computed tomographyafter intrathecal injection of metrizamide via the lumbarroute. In all patients Chiari malformation was demonstratedas a soft tissue oval mass at the level of C₁-C₂ vertebralbody that was intradural and posterior to the medulla andthe upper cervical spinal cord. These findings were moreaccurately visualized in saggital and in frontal reconstructedCTs. In one patient the spinal cord was measurably enlargedat the upper thoracic level.