椎骨動脈造影による脳幹部腫瘍の診断—特にparadoxical signについて

VERTEBRAL ANGIOGRAPHY OF BRAIN STEM TUMORS WITH SPECIAL EMPHASIS ON PARADOXICAL SIGNS

　10例の1悩幹部腫瘍の椎骨動脈造影所見を分折し，椎骨動脈造影法のみでも，本腫瘍の1診断の可能なことを強調した。本腫瘍は対称的な遠心性発育を示し，このために特徴のある血管造影所見が得られる。動脈が腫瘍に囲繞されて反対方向へ偏位するparadoxical signについても言及し，この所見が存在しても腫瘍の遠心性発育の所見に注目すれば診断は可能であることをのべた。また，本腫瘍と他の部位の後頭蓋窩腫瘍との鑑別は動脈相，静脈相にsubtractionを用いて詳細な検討を行なえば鑑別診断が可能である。

Ten cases of brain stem tumors have been re-viewed and their angiographic findings have been analysed. The angiographic characteristics are produced by enlargement of the pons, midbrain and medulla. Vascular displacements primarily base upon central location and symmetric expansion of tumors.

The most important findings include anterior displacements of the basilar artery, anterior pon-tomesencephalic vein, and transverse pontine vein as well as posterior displacements of the precentral cerebellar vein and posterior medullary segmentof the posterior inferior cerebellar artery. Pseudo-axial or paradoxical displacements of the basilar, superior cerebellar, and posterior cerebral arteries are discribed as one of the important angiographic features of brain stem tumors.

Brain stem tumors can be differentiated fromother posterior fossa tumors by angiographic find-ings when detailed evaluation is made with sub-tracted arterial and venous phases of serial verte-bral angiography.