頭蓋内石灰化と加齢—CTによる検討

EVALUATION OF THE INTRACRANIAL CALCIFICATION ASSOCIATED WITH AGING ON COMPUTERIZED TOMOGRAPHY

　抄録　CT上の頭蓋内石灰化の出現頻度と加齢との関係について報告した。対象として，頭部CT撮影にて正常と診断された患者1,371名より，無作為抽出にて年齢別に10歳毎に各年代層ごと男性25名，女性25名の計50名ずつの集団を作り，9組計450名を対象群とした。頭蓋内石灰化としては松果体部，脈絡叢，脳動脈，大脳鎌，大脳基底核，錐体後床突起靱帯について判定を行った。松果体部の石灰化は10歳以下ではまれで30歳以降は約70％で横這いとなった。脈絡叢の石灰化は加齢にほぼ比例して増加し加齢の良い指標となるものと思われた。大脳鎌の石灰化はやはり加齢と共に増加傾向をしめした。脳動脈の石灰化は70台までは加齢と共に増加し40台で15％，70台で26％に認めたが80歳以上の高齢長寿者群ではその保有率が10％と少なく，高齢長寿者は脳動脈硬化の程度が少ないことを示唆する興味深い所見と思われた。大脳基底核の石灰化は2.2％に認めた。また全例をまとめた頭蓋内石灰化保有率では40歳台以上の症例の90％以上に何らかの石灰化の存在をみとめた。

Computerized tomography (CT) scans of 450 standardized normal persons from 5000 consecutivepatients were examined to study the relationship between the incidence of intracranial calcification and aging process. The 450 subjects were clas-sified into 9 groups according to age.

In people older than 30 years, calcification in the pineal region including pineal body and ha-benular commissure was found in about 70%. Cal-cified choroid plexus seems to be chracteristic of aging process because the rate of its calcification increased in proportion to aging. Calcification of the falx cerebri was also found to increase in proportion to aging. Calcified cerebral arteries were observed in advanced-aged groups. The fact that people in the ninth decade had a smaller incidence in calcification of the cerebral artery than those in the eighth decade indicates the pos-sibility that longer-lived people had less incidence of cerebral arterial calcification.