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Direct-seeding culture without tillage and covering soil using the Y-shaped seeding furrow was examined in 1997 and 1998 at a poorly drained paddy field in Hachirogata(Akita Pref., Japan). The percentage of seedling establishment in the plots of polyolefin coated urea(CU)and sigmoid type of CU(SCU)were 50.3% and 44.7%, respectively, in 1997, and 35.7% and 35.3%, respectively, in 1998. The cumulative effective temperature from seeding to the establishment time was 147.6°C and l24.0°C in 1997 and 1998, respectively. The number of established seedling per m2 in the CU and SCU plots was 167 and 149, respectively, in 1997, and 119 and 118, respectively, in 1998. The brown grain yield per m2 in CU and SCU plots was 645 g and 621 g in 1997, and were 501 g and 472 g, respectively, in 1998. These results suggested that the direct seeding of rice on Y-shaped furrow without tillage and covering soil is highly feasible to keep the same level of the yield in the transplanted cultivation of rice in cool and clayey paddy fields in the Tohoku District.

A 67-year-old woman without organic heart, disease had symptomatic ventricular premature contractions. Because class Ia, Ib and IV antiarrhythmic drugs did not prevent the premature contractions, the patient was treated with flecainide acetate at a dose of 50 mg t.i.d. Adverse reactions were noted. After measurement of the blood drug level, the dose was reduced to 50 mg b.i.d. The adverse reactions disappeared, and the arrhythmia was controlled. Flecainide acetate has a relatively long blood elimination half-life and a narrow safety margin. When some antiarrhythmic drugs are used in elderly patients, blood drug level monitoring is useful in preventing adverse reactions and in designing appropriate therapy.

Paying attention to the sound of breaking sea bottom depending on the magnitude of TSUNAMI, we examined the acquisition of a sea sound wave at Japan waters. We considered the traveling route of the sea sound wave radiated from the hypocenter of the Tohoku-Pacific Ocean Earthquake, and estimated the propagation loss, which has a characteristic that the diffusion loss depending on distance is dominant. Thus, the sound pressure level of the hypocenter was presumed being at least 252 dB. (0 dB = 1u Pa). A sea sound wave radiation from the earthquake with the tsunami in Japanese waters is expected to attenuate the receiving about 55 dB at an area along the shore.

Clinical records of 128 non-selected patients with esophageal cancer treated by radiation were reviewed to investigate reasons why treatment had to be discontinued, relationship between age and survival, and factors influencing prognosis. Radiation therapy was completed in 77 patients but was discontinued in 27 patients. Preoperative radiation was attempted in 24 patients. An overall median survival of 128 patients was 6.4 months, with 8.5 and 3.3 percent surviving 3 and 5 years. Median survivals of incomplete RT, completed Rt and RT + Surgery were 1.3, 7.7 and 11.3 months. By Kaplan-Meier analysis significant difference was observed in survival rate between incomplete RT and the other two groups, but not between RT and RT + surgery. T1 tumor cases with incomplete RT were characterized by a higher C-Score (higher incidence of comorbidity and complications), lower albumin concentration and poor performance status. Median survivals of 60 years, 70 and 80 were 12, 5.4 and 6.2 months, respectively. Performance status and C-score were significantly different between the 60 yr and 80 yr groups. Survival rates were also apparently affected by the size of the primary tumor and metastasis. Thus important factors influencing prognosis were performance status, albumin concentration, and comorbidity and complications, in addition to stage of tumor itself. Although performance status and albumin concentration were considered directly related to tumor stage, old age may have an adverse effect on these factors through increase of comorbidity and complication. The data may be useful for decision making for treatment of esophageal cancer of the aged.

This paper describes a diagonal autostereoscopic three-dimensional (3-D) television system with a liquid-crystal video projector, the picture of which could be observed without the need to use special glasses. As the representation method of 3-D images of this system, the pixels from four television cameras are composed electronically to make stripe images which are projected onto the rear surface of a lenticular screen by a high-quality HDTV liquid-crystal video projector. In this way, clear full-color diagonal stereoscopic 50-inch television pictures could be displayed. Besides the lack of obligation to use special glasses, the advantages of this system are: the observation range is broadened, compared to the previous stereoscopic 3-D television; and the pictures are more natural and easier to observe. The newly realized diagonal autostereoscopic 3-D television system, the lenticular screen, the diagonal autostereoscopic 3-D cameras, the recording equipment of 3-D pictures, etc., are discussed in this paper.

自然発生条件下におけるコウキヤガラ (Scirpus planiculmis Fr. Schm.) 塊茎の休眠覚醒, 萌芽・出芽の経過について調査し, またこれらに関与する2, 3の要因について検討した。1. 塊茎は自発休眠性があり低温によって休眠から覚醒した。自然下では11月下旬から覚醒が始まり1月中にほぼ完全に覚醒した。変温条件も塊茎の萌芽を促進する効果があった。2. コウキヤガラの出芽開始は融雪期の早晩によって変動し, 融雪期が早い年は出芽開始が早まり, 遅い年は遅れた。また, 融雪後出芽開始までの積算温度は融雪期が早い年は高く (約100℃), 遅い年は低くなる (約40℃) という関係が認められた。3. 塊茎からの出芽は乾燥した圃場の方が低湿な圃場よりも遅かった。

Findings in patients in whom brain stem lesions were suspected were studied by a high-field-strength (1.5 T) MR imager. MR scans were obtained in 97 patients over a 10-month period. The mean age was 71 years (range, 39-94 years). A high incidence of infarction and lesions showing a high signal on T2-weighted image, but an almost normal signal on the T1-weighted image were observed at the pons in elderly cases. Furthermore, cases in which these two findings were observed, had a high incidence of lesion at other regions than pons. Cases with a past history of hypertension had higher incidence of lesions at the pons than normotensive patients (alpha less than 0.01). These findings suggest that MRI examination in the elderly could detect a high incidence abnormal lesions at the brain stem as well as in basal ganglia.

コウキヤガラ (Scirpus planiculmis Fr. Schm.) 種子の発芽特性, 水田における実生の発生および除草剤による実生の防除等について検討した。1. コウキヤガラの主要な繁殖器官は塊茎であるが, 水田で種子からの発生も一部認められた。2. 種子は堅い種皮に覆われており吸水が緩慢であるが, 種子基部の切除や硫酸処理によって吸水が促進された。3. 種子は明所・変温下で発芽し, また種子基部を切除することによつて発芽が著しく促進された。4. 水田埋土1年目の種子より2年, 3年と長期間埋土したものの方が発芽率が高かった。5. 実生は塊茎から発生した株に比べて生育が著しく劣った。6. 除草剤は種子発生に対して高い防除効果を示した。

コウキヤガラ (Scirpus planiculmis Fr. Schm.) の防除法確立のための基礎的知見を得るため, 塊茎からの発生に及ぼす耕種操作の影響および種々な条件下での塊茎の寿命等について検討した。1. 代かき後は土中15cm以内に塊茎がほぼ均一に分布するようになった。また, 耕耘前よりも深層まで塊茎の分布範囲が拡大した。2. 同一塊茎を毎年水田の表層に置くと数年間萌芽が続き, 地表下30～40cmに埋められた場合には20年経過しても塊茎の半数は生存した。3. コウキヤガラの塊茎は低温および乾燥に対する耐性が比較的高い。4. 耕種操作は生長中の芽を土中に埋没して死滅させる効果があるが, 塊茎が作土の深層に移動した場合には, 繁殖源を後年度に持ち越してコウキヤガラの発生を長期化させるという一面もある。

コウキヤガラの水稲に対する雑草害および両者の競合について検討し, 以下の結果を得た。1. 収穫期にコウキヤガラ風乾重が100g/m2あると水稲は約20%減収し, 単位重量あたりの減収程度は水田雑草の中ではかなり高い方に属する。2. コウキヤガラの水稲穂数への影響は, 分げつ期には茎数の増加の抑制, 最高分げつ期～出穂期には無効茎の増加, さらに1穂粒数の減少として現れた。3. 水稲およびコウキヤガラのCGRは, ともに生育が進むにつれ増大し, 最高分げつ期から出穂期にかけて最大となった。RGRは両者ともに生育前期において高いが, コウキヤガラでは特に高い値を示した。NARは生育前期においてはコウキヤガラが高く, 中～後期においては水稲の方が高かった。4. 水稲とコウキヤガラは養分と光の双方で競合するが, まず養分の競合が先行し, ついで光の競合も起こる。水稲収穫期におけるコウキヤガラの窒素吸収総量は, コウキヤガラの密度が特に高い場合約5.0kg/10aであった。

99mTc-EHIDAを用いて各種甲状腺疾患症例の肝胆道シンチグラフィを施行し, deconvolution法により肝での平均通過時間 (mean transit time; 以下MTT) を算出した。その結果, (1) 健常成人4人のMTTは全例10分以下であった。 (2) 甲状腺疾患のうち, 血清のTSHの濃度が4.6μU/ml以上の症例のうち, 半数の症例ではMTTが13分以上を示す高度排泄遅延型であった。他方, TSHの濃度が0.34μU/ml以下の甲状腺機能亢進症ではMTTが13分以上を示した症例はなかった。以上の結果より甲状腺ホルモンは99mTc-EHIDAの肝での代謝, 排泄に密接に関与していることが示唆された。

メガネが不要な50インチ液晶投写型の多眼式3次元カラーテレビジョン装置を試作した.この装置は被写体を4台のテレビカメラで同時に撮像し, 信号処理によって縦縞のストライプ像に合成したあと, 1台の高性能液晶プロジェクタを用いてレンチキュラスクリーンに背面投写する方式である.試作した4眼式3次元テレビジョン装置は, 従来の2眼式に比べて立体視できる観察範囲が拡大し, 自然で見やすい立体カラー動画像を表示することができた.

Radionuclide angiocardiograpy (RNA)における局所壁運動による梗塞診断率を剖検所見と対比して求めた. RNAの有病正診率は84.1%,無病正診率58.8%,総合正診率70.1%であつた.梗塞のない症例においても,壁運動異常が半数に認められ,特に広範囲壁運動異常を認めうものが多かつた.広範囲壁運動異常を示すものには,心筋梗塞症以外に, cardiacamyloidosisやうつ血型心筋症などの心疾患が認められた.心筋梗塞症例で, LVEF 30%未満のものでは,心臓死が87%に認められ,予後は9.3カ月と他の群に比し有意に短かつた. RNAは心筋梗塞の部位,心室瘤の有無,心機能を把握できるばかりでなく,安静時LVEFは心筋梗塞の予後の推定に有用であると思われた.

Two sets of discordant rate constants reported recently for the high-temperature reactions of NH3 with O and OH were examined by comparing the calculated concentration profiles of NH3 and OH with experiments by the shock tube technique forNH3-N2O-Ar mixtures. The rate constants were confirmed tobe: k4 = 3.1 × 1012exp(−25.5 kJ/RT) cm3 mol−1 s−1 for NH3 + O → NH2 + OH and k5 = 3.2×1012 exp(−8.4 kJ/RT) for NH3 + OH → NH2 + H2O.

In a series of 1,000 consecutive autopsy cases, we evaluated the clinical utility of thallium-201 (Tl-201) myocardial scintigraphy and electrocardiography (ECG) in 101 patients who had been studied while alive. Fifty-five cases had myocardial infarctions (MI) at autopsy. The Tl-201 scintigram and ECG in diagnosis of MI showed sensitivities of 68% and 60%, specificities of 87% and 83%, and diagnostic accuracies of 76% and 70%, respectively. The sensitivity of the Tl-201 scintigram was 70% in anterior MI, 80% in postero-inferior MI, 25% in lateral and subendocardial infarction. The sensitivity was 88% for large massive MI, but was low in scattered (50%) or middle-sized MI (17%). The diagnostic limit of the resolution of Tl-201 scintigrams was 4.5 cm in long diameter. All 8 cases with MI of less than 4 cm could not be diagnosed with the technique. There were 48 cases of large MI (more than 5 cm), but 8 cases could not be diagnosed by scintigraphy because of non-transmural or scattered MI. A comparison of the Tl-201 scintigram and ECG showed that 27 cases out of 60 cases were diagnosed by both methods, 14 only by the Tl-201 scintigram, 9 only by ECG and 10 by neither method.

Fatigue tests were conducted on the moulded joints of aluminum and an epoxide adhesive material, and the debond growth behavior at its moulded interface pretreated in two different ways was observed. As the basic data, the fatigue crack propagation characteristics of the adhesive itself were experimentally obtained. The debond growth behavior at the interface by fatigue was predicted under the following conditions;(1) The stress intensity factor of an interface crack is approximately equal to that of a crack in homogenious material as derived from the no-slip model proposed by Mak et al.1).(2) The debond growth rate per cycle is equal to the crack propagation rate of the adhesive material.(3) The residual stress on the moulded interface estimated by a photoelastic experiment and FEM analysis is taken into account as an influential factor for the stress ratio of fatigue load.Fairly good agreement between the experimental and analytical results was found for the interface pretreated with sand-blast and chromic-acid. However the debond growth rate for the interface with no chromic-acid pretreatment was faster nearly by a factor of one order of magnitude than the prediction. Microscopic analyses of the debonded interfaces were conducted with SEM and X-ray microanalyzer and the debond growth mechanism was discussed.

コウキヤガラの薬剤による防除法を検討したところ, 次のような結果を得た。1. 茎葉処理試験において薬害がなく, かつ防除効果が高かった薬剤は bentazon であった。2. Bentazon の茎葉処理は, 親株の草丈が10cm未満の場合は効果が低いため, 大多数の親株が10cmを越してから行うのがよい。八郎潟干拓地では田植後30～40日頃が適当と考えられる。コウキヤガラ多発田の場合は2回処理が望ましい。3. Bentazon の茎葉処理により親株が枯死すると, その親塊茎は以後萌芽能力を失った。4. 土壌処理剤の中では bensulfuron methyl が水稲に対して薬害がなく, かつ有効であった。

CT検査の導入により明確な脳の解剖学的所見が得られるようになった. これらの所見を加味して脳槽シンチグラフィーを再評価することが必要と思われる. そこで, 脳槽シンチグラフィーを行った患者201例について, 脳室内逆流の程度を, (1) 非逆流型 (Type I), (2) 一過性逆流型 (Type II), (3) 遅延逆流型 (Type III), (4) 逆流下降型 (Type IV), (5) 低濃度停滞型 (Type V), (6) 高濃度停滞型 (Type VI) の6つの型に分類し, それらの型と脳血管障害, 側脳室の型, 脳室の大きさ, 脳溝の拡大度などのCT所見, 脳脊髄液および臨床症状等との関係について検討を加えた.全症例中, 何らかの逆流を示す症例は約50%を占め, 高濃度停滞型は約6%, 低濃度停滞型は約9%の症例に見られた. 脳血管障害 (CVD) の有無により, これらの型の出現頻度には殆ど差は認められなかった. 正常圧水頭症 (NPH) を高頻度に起こすクモ膜下出血 (SAH) 群では, 高濃度停滞型が全体の40%と高い割合を示し, NPHと高濃度停滞型が深い関連を有することを示唆した. 高濃度停滞型では, CT所見上, 非逆流型の症例に比し, 側脳室が有意に拡大しており (p

Gallbladder emptying after intramuscular injection of cerulein was investigated by 99mTc-EHIDA hepatobiliary scintigraphy in 23 patients with biliary disease, 55 patients with chronic liver disease, and 21 normal controls. The mean gallbladder ejection fraction in patients with gallstones and liver cirrhosis was significantly reduced compared with normal controls. (gallstones: 56.3 +/- 21.3%, LC with gallstones: 50.8 +/- 29.6%, LC without gallstones: 55.9 +/- 26.7%, vs. normal controls: 74.4 +/- 12.9%, p less than 0.01). The mechanism for sluggish gallbladder emptying in liver cirrhosis is unknown, however impaired emptying with bile stasis provides a potential pathophysiologic basis for the high frequency of pigment stones.

過去4カ年間に65歳以上の高齢者を対象とする慢性硬膜下血腫21例を経験したので, その臨床症状と予後について報告する. 対象者の平均年齢は77.1歳で性差は認めない. 本症の既往で大切なのは頭部外傷95%, 高血圧症52%, 糖尿病19%, そして慢性アルコール中毒14%である. 入院前の発症および初発症状を家族から聞くと, 一番多いのは歩行障害43%で (下肢脱力, 半身不全麻痺, 片麻痺), 精神障害及び人格変化24%, 失禁29%, 頭痛24%, 痴呆24%, 意識障害24%, さらに痙攣や目まい5%である. 本院入院前の診断名は脳梗塞43%, 脳動脈硬化症14%, 脳出血14%, 老年痴呆10%そして頭部外傷, 脳腫瘍, 髄膜炎など同じように5%である. 入院前の種々様々な診断名から老齢者において慢性硬膜下血腫を老年痴呆, 脳血管障害, 他の血管系痴呆などと鑑別診断することは極めて難しい. 入院時の主症状は意識障害43%, 精神障害38%, 半身不全麻痺と片麻痺71%, 失禁29%, 頭痛24%, 言語障害24%そして Aphasia が10%である. 瞳孔不同とウッ血乳頭は非常に少なく3%であった. 髄液所見では180mmH2O以上は7例で33%, 120mmH2O以下は8例で38%であった. 髄液蛋白が50ml/dl以上のものは陳旧性脳卒中と脳梗塞の例であった. 脳血管撮影を施行した17例の全例に無血管領野を認めて確定診断ができた. 予後判定は臨床症状とCBFの結果を観察した. CBFの改善を示したのは術後3カ月目であった. 改善が成大に較べて, 老人の本症が遅延するのは, 脳血行障害がすでに存在し, 脳実質圧迫がより少なくても, 脳萎縮もあり, しかも頭蓋内腔の拡大が存在するからである.

著者らは当院で過去5年間に生前脳スキャンを受け, のち剖検され, その病理組織像が明らかにされている62例 (脳硬塞55・脳出血7) を対象とし, retrospective study を行い脳スキャンによるCVDの予後判定が可能かどうかを予後の違いによるグループ別に, 脳スキャン陽性度, 陽性病巣サイズ, 病巣部位について検討した. CVD発症後1カ月以内, 2カ月目～6カ月, 7カ月目～12カ月, 2年目以上に死亡した例を各々1群 (6例), 2群 (28例), 3群 (12例), 4群 (16例) とした.脳硬塞においては陽性症例は55%, 陽性スキャン頻度は58%, 経過観察平均スキャン回数は1.5回, 陽性度平均は1.9±1.2度, 陽性サイズ平均5.9±3.2cmであった. 脳出血においては上記の順に夫々43%, 44%, 1.3回, 1.7±1.1度, 6.5±1.7cmの結果であり陽性サイズのみ脳硬塞より高い値を示した.脳硬塞例では発症5カ月後迄が陽性期であり陽性度よりみると発症後4週目に陽性ピークがあった. 脳スキャン陽性度平均は第1群で2.3±1.1, 第2群で2.3±1.2, 第3群1.7±1.0, 第4群で1.3±1.1度と差がみられた. 即ち脳スキャン陽性度平均と予後の長短は相関が認められた. 予後の悪い第1群, 第2群では最初から高い陽性度を示し予後のよい第4群では急速な陰性化を示すことが特長的であった. しかし4群別に検討した経時的陽性度平均の最大値は上記の順に3.0, 3.2, 2.7 3.0度と差はみられなかった. 陽性スキャンの頻度は上記の順に各々75, 68, 68, 33%であった. 陽性病巣サイズ平均は上記の順に各々7.0±5.0, 6.8±3.7, 4.8±1.4, 5.1±2.1cmと重症例程陽性病巣サイズが大きい傾向はみられたがSDが大きく平均値による検討は意味付けが難しかった. 陽性度と陽性サイズに相関があるかどうかを検討した所, 両者の相関はなく陽性度と病巣の大きさの持つ臨床的意義は別である事が分った.

老年者に骨シンチグラムを施行した結果, 胸, 腰椎部に bone seeking agent, 99m Tc-MDP の異常集積の多発するのを経験した. その成因を解明する目的で骨の剖検所見と骨CT所見との比較検討を行なった. 悪性疾患で胸, 腰椎部に radionuclide (以下RNと略す.) の異常集積像を呈した症例は49% (85症例中42症例) であった. 特に腰椎部にRNの異常集積像をみた25症例の剖検所見では13症例で明らかな悪性腫瘍の転移性骨病変を認めたが, 残りの症例では認めなかった. 良性疾患群でも28%の症例に胸, 腰椎部にRNの異常集積像をみとめた. 胸, 腰椎部にRNの異常集積像をみとめた18症例の骨CT検査では同部に顕著な骨硬化像, 骨粗鬆性変化および圧迫骨折などを認めた. これらの事実は, 老年者の骨シンチグラムにおける胸, 腰椎部のRNの異常集積像は悪性疾患の転移性病変のみならず, 加齢に伴う骨の諸変化等が原因となることが多いことを示し, 診断上考慮する必要があると考えられる.

With the improvement of the ear surgery, the congenital middle ear malformation, found occas-ionally in the operations, incidence of, have increased making middle ear malformation fairly common.The vast majority of the ear malformation in literature mention no obvious cause, although the etiologic consideration is very difficult to decide in malformation of any part. Logically, however, heredity must be considered to be a strong etiologic posibility.We encountered a rare case of 3 patients with the external and middle ear malformations in one family. They were a man, 39 years old, his daug-hter of 10 and his son of 9, whose bilateral deafn-ess were congenital.The otoscopic examination did not reveal any obvious inflammatory findings in their ears, but the functional examination showed the conductive deafness with the moderate impairment of perce-ptive hearing. Exploratory examinatin of the middle ear cavities of the father and son were carried out and the deformities of the stapes were observed.Stapes mobilization was performed on the father's left ear and stapes surgeries on his son's ears.The former didnot gain as better hearing as the latter.The embryologic considerations of the cases were also discussed.

The purpose of this paper is to determine the standard use of hearing aids in children with sensorineural hearing loss. Follow up studies on the audiograms were carried out in 62 children with perceptive hearing loss making use of hearing aids.The results were summarized as follows:1. About 10per cent of the subjects showed more than 10dB aggravation in hearing after entrance to the special class for hearing impaired children.2. There was tendency in those cases that he aggravation in hearing was improved in some cases.3. No definite evidence of acoustic trauma due to the use of hearing aid was found in the residual hearing.4. Adequate guidance and superintendance are essential for hearing impaired children to use hearing aid effectively.

For the purpose of determining standard use of hearing aids by young children, a series of investigations regarding the models, the range of frequency response characteristics and the volume control of hearing aids were conducted on 22 sensorineural hearing impaired children who were skilful user of hearing aids and whose age ranged from eight to fourteen years.The results obtained are briefly summarized in the following.1. If the average hearing levels in speech range are not worse than 80dB, hearing aids in Japanese make (R Co.) may be helpful, but U. S. make (Z Co.) are more helpful for those children.2. Type of broad frequency response characteristics (300-4000cps) is more suitable than narrow (500-4000cps) for those hearing impaired children.3. In respect of volume control, comfortable level setting for normal ear is suitable even to those with impaired hearing.4. To obtain good speech discrimination by hearing aid, input sound level must be set as high as 70-80dB (P0=0.000204 dyne/cm2).

Determination methods of small amounts of lead and bismuth, contained in molybdenum trioxide briquette which is charged into the steelmaking furnace as a substitute for the ferromolybdenum, have been studied. Crashed and powdered sample are dissolved in aqua regia and organic matters present are decomposed completely by the addition of perchloric acid. After being cooled, the molybdenum acid anhydride deposited is dissolved either with ammonia water in the presence of tartric acid or with sodium hydroxide. Lead is extracted with dithizone-tetrachloride solution in advance from the solution of pH 10, containing tartarate and cyanide, and then, separated from bismuth by shaking with 0.05 N nitric acid. Finally, lead is extracted and measured as dithizonate in dithizone-benzene solution. Bismuth is extracted and determined photometrically as diethyldithio carbamate in the carbon tetrachloride solution, after being separated and concentrated according to the ferric hydroxide coprecipitation procedure. In the use of the spectrographic detection, conbined with the dithizonate extraction, it is confirmed that the samples do not contain any amount of thallium, which is interfered with the determination of lead and bismuth. Analytical results some commercial briquettes and ferromolybdenums are shown in Tables I and II.

正常例と痴呆例の脳のCT所見を比較する場合, 老年者においては脳血管障害 (CVD) の有無により, 分けて検討しなければならない, そこで痴呆を主症状とする100名の老年痴呆患者と, 139名の健常老人ボランティアに対し, それぞれCVDの有無により二群に分類し, 年齢構成別に頭部CT所見の比較検討を行った結果, 以下のような結論が得られた.1. 健常老人ボランティアにおいても silent stroke をしめすものが約20%に見られ, これらを除くCVD (-) の健常老人のCT像を, 狭義の健常老人として, 痴呆脳のCT像の検討に際して対比することが必要と思われる.2. 狭義の健常老人においては側脳室拡大, 脳溝拡大, シルビウス溝の拡大の出現頻度は, 加齢と共に増大するが, PVL, 第三脳室拡大の頻度は加齢とともに増加せず, 80歳でも低値であった.3. 老人脳におけるPVLの出現頻度は血管障害の有無と関係が深いが, CVD (-) の痴呆患者においても, 加齢とともに増加した.4. 痴呆患者では側脳室拡大, 脳溝拡大, シルビウス溝拡大, 第三脳室拡大の頻度は, 年齢と関係なく, 脳溝拡大, 第三脳室拡大を除き一般にCVDを伴うものに高い傾向がみられた. これらの変化を健常老人と比較すると, 一般に80歳老人のそれにほぼ近かった.5. medial temporal lobe の萎縮を示す所見は50歳代のCVD (-) の痴呆例に最も高頻度に見られた. 60歳代以上の痴呆例においてはCVDの有無による差はなかった.6. 痴呆患者のCT像においては, PVL, 第三脳室拡大を除き, 加齢に伴う変化が早期より出現したり, より著明な変化を示すものが多いと言えるが, ほぼ年齢相応の変化を示すものも認められた.