We measured simultaneously the flow velocity curves of the common carotid artery and the middle cerebral artery to evaluate the relationship between the systemic and cerebral circulations in the early neonatal period. Eligible for inclusion in this study were 20 healthy full-term neonates. Doppler ultrasound examinations were performed at 1, 2, 3, and 4 days after birth. The flow velocity curves of both arteries were recorded using a multi-channel Doppler system. Systolic maximal velocities and end-diastolic velocities were measured, and resistance indices (RIs) were calculated. The flow velocity of the middle cerebral artery increased during the first three days after birth, but that of the common carotid artery did not change. The RI of the middle cerebral artery remained constant, but that of the common carotid artery decreased on the third day after birth. These data suggest that the cerebral arteries might work as resistance vessels.

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Transcranial Doppler sonography (TCD) is a useful method for investigating the hemodynamics of cerebral arteries. Phase-contrast (PC) MRA measures a vector quantity that contains information about blood flow direction and velocity. The purpose of this study was to evaluate the clinical usefulness of these modalities for investigating the hemodynamics of the ophthalmic artery (OA) and superior ophthalmic vein (Soy) . Between 1991 and 1996, ten patients with moyamoya disease and 6 patients with carotid-cavernous fistula (CCF) were evaluated using both methods. TCD was carried out through the orbital window. On the other hand, three-dimensional PC MRA and two-dimensional PC cine MRI were used with various velocity encoding gradient, and the flow direction in the OA and SOV was evaluated from the phase image. The results were as follows: (1) In moyamoya disease, the mean flow velocity (MFV) in the ophthalmic artery was relatively high, and reverse flow was seen in 3 of the 20 affected sides in both the TCD and PC MRA. (2) In CCF, the MFV in the SOV by TCD was elevated, although the level of the optimal velocity by PC MRA was relatively low. In conclusion, both TCD and PC MRA are clinically useful for evaluating the hemodynamics of the OA and SOV in moyamoya disease and CCF. Comprehensive evaluation using these two modalities should be done to understand the hemodynamics of these diseases.

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近年, 卵円孔開存 (PFO) を介する右左シャントによる奇異性塞栓が, 従来原因不明とされていた脳梗塞の発症機転に関与している可能性が注目されている.卵円孔開存の診断は経胸壁心エコー図検査, 経食道心エコー図検査, および経頭蓋超音波ドプラ検査でValsalva法とコントラスト法を用いて診断される.一方, 1996年に心房中隔欠損症 (ASD) 例で特徴的な心電図所見 (II, III, aVF誘導におけるR波のノッチ, “crochetage”) が報告された.ASDとPFOは部位が似ているので, PFOに於いても心電図上の“crochetage”が見られる可能性がある.そこで, 脳血管障害もしくは一過性脳虚血発作の初回発作例1470症例のうち, 一定の診断基準を満たすPFOを有す原因不明の脳梗塞28例 (PFO群) とPFOを有さない原因不明の脳梗塞32例 (コントロール群) 間で背景因子や心電図所見を比較検討した.
PFOの診断は経胸壁カラードプラ心エコー, コントラスト経胸壁心エコー, もしくはコントラスト経食道心エコー図検査で行われた.PFO群 (45±16歳) はコントロール群 (52±10歳) より若く (p<0.05) , 合併する動脈硬化危険因子 (高血圧, 糖尿病, 高脂血症, 肥満, 喫煙) の数が少なかった (0.5±0.7v.s.1.0±0.9) .心電図上の“crochetage”はPFO群が28例中10例 (36%) , コントロール群が32例中3例 (9%) でPFO群の方が有意に多かった (p<0.05) .原因不明の脳梗塞におけるPFO陽性への心電図上のcrochetageのsensitivityは36%, specificityは91%, positive predictive valueは77%, negative predictive valueは62%であった.
これらの結果から, 著者らは心電図上の“crochetage”はsensitivityが低いのでPFO診断のスクリーニングとしては向かないが, positive predictive valueが比較的高いことから心電図上のcrochetageが見られたら, コントラスト経食道心エコー図検査やコントラスト経頭蓋超音波検査で早急に確認するべきであろうと考察している.

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We studied the relationship between carotid plaques and plasma endothelin-1 concentration (ET-1) in patients with essential hypertension.
A total of 212 patients (83 males, 129 females, 36-84 yr, mean age 63 yr) with essential hypertension (WHO stage I-II), and 109 age-matched control subjects (35-79 yr, mean 61 yr) were enrolled in this study. Plaque (defined as intima-media thickness 50% thicker than neibour intima-media thickness) in the both side of common carotid artery and the both side of internal carotid artery were measured by B-mode ultrasonography. Plaques were classified into soft plaque (without calcification) and hard plaque (with calcification) . ET-1 was measured by enzyme immunoassay.
ET-1 levels were significantly higher in hypertensive patients than in control subjects. The frequency of plaque in patients with high ET-1 levels (ET-1≥1.71 pg/ml) was signficantly higher than those with normal ET-1 levels (ET-1<1.71 pg/ml) . The frequency of soft plaque in patients with high ET-1 levels was signficantly higher than those with normal ET-1 levels. But there was no difference between the frequency of hard plaque in patients with high ET-1 levels and that with normal ET-1 levels.
These results indicate that high ET-1 levels with essential hypertension may play a role in the progression of carotid plaque without calcification.

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A rare case of duplicated spinal dural arteriovenous fistulae is reported. A 31-year-old woman suffering from congestive myelopathy was admitted. Spinal angiography demonstrated dural arteriovenous fistulae at the T10/11 intervertebral foramen. Surgical interruption of the fistulae was performed using micro-Doppler monitoring. Intraoperative micro-Doppler monitoring was performed on the dorsal redundant perimedullary vein, which showed an arterial spectrum. After ligation of the retrogradely irrigating radiculomedullary vein along the right T10 dorsal root, the arterial spectrum diminished, but was restored with time. Repeated temporary clipping under micro-Doppler monitoring disclosed a second dural arteriovenous fistula fed by the anterior spinal canal artery. The arterialized vein proximal to the coronal plexus was coagulated. After this procedure, the arterial spectrum disappeared on the dorsal perimedullary vein. Postoperatively, the patient's neurological deficits improved gradually.
In this case, a second arteriovenous fistula located ventrally was found in addition to the usual radiculomeningeal arteriovenous fistula around the dorsal root. Intraoperative micro-Doppler monitoring was effective for detecting the residual arteriovenous shunting through the second arteriodural venous fistula.
Microdoppler monitoring is an easily available and noninvasive monitoring technique. Use of this monitoring method will yield excellent results in surgery for spinal dural arteriovenous fistulae, and it is especially useful in rare cases such as duplicated arteriovenous fistulae.

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The goal of acoustic neuroma surgery is to accomplish total removal of the tumor with functional preservation of the facial and cochlear nerves. A conventional ultrasonic aspirator is too large and heavy for performance of fine and delicate surgical maneuvers. We developed a compact and light-weight handpiece suitable for acoustic neuroma surgery. The handgrip is designed to fit the surgeon's hand, and is well balanced. Suction pressure can be controlled with a finger by closing or opening a hole set in the handpiece. The horn portion is exchangeable for one with a different tip diameter; the smallest diameter is 1.5 mm. This ultrasonic aspirator has been used in 48 acoustic neuroma operations. The aspirator enabled removal of a relatively hard tumor including one in the internal auditory canal quickly, without damage to the surrounding tissue. The maneuverability of the aspirator is similar to the conventional suction tube, in view of the suction-pressure control system and handgrip. Holding a regular suction tube in one hand and the ultrasonic aspirator in the other is the most convenient method for removing a tumor safely because the surgeon can always confirm the amount and nature of the residual tumor by touching the tumor with the regular suction tip.

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Three-dimensional echo (3D-Echo) technology has been under development in the world for 10 years, and great progress has been made in both echographic equipment and personal computers. The principles of 3D-Echo have not changed, but now three-dimensional calculation has become practical. Current 3D-Echo systems have the following merits, and also demerits which must be improved.
Merits
1. Wide area of view
2. Solid form
3. Feasibility of volume and weight measurements
Demerits
1. No real-time display
2. No 2D image information
3D-Echo diagnostic ability and technology will be available in the near future. We need to develop performance, including highspecd (realtime), ease of operation, and various forms of measurement such as dynamic imaging, and also reduce the cost.

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