Neurosonology
Print ISSN : 0917-074X
ISSN-L : 0917-074X
Volume 9, Issue 3
Displaying 1-5 of 5 articles from this issue
  • Kazutoshi NISHITANI, Shin UEDA, Keizo MATSUMOTO, Masahito AGAWA, Kensa ...
    1996 Volume 9 Issue 3 Pages 68-73
    Published: August 31, 1996
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    Ultrasonography was applied to 24 carotid arteries in 22 patients prior to carotid endarterectomy (CEA) . The relationships between the histology of the plaque removed by CEA, especially the presence or absence of plaque hemorrhage (PH) and the echogenicity in B-mode imaging, and between clinical symptoms and turbulent flow (TF) around the plaque revealed by color flow imaging, were examined. The echogenicity of the plaque was divided into 3 grade based on comparison with that of the intimal layer: Low, in which echogenicity was hypoechoic relative to the intimal layer (5 plaques), Iso, in which echogenicity was the same as that of the intimal layer (6 plaques), High, in which echogenicity was hyperechoic relative to the intimal layer (13 plaques) . PH was found in 7 of the 24 plaques. All 5 of the hypoechoic plaques showed PH, whereas none of the 13 hyperechoic plaques didso. TF was detected in 11 of the 24 carotid arteries. Clinical symptoms occurred in 7 of the 11 patients with TF and 3 of those without TF. In conclusion, we have shown that this technique is capable of predicting the occurrence of PH due to its echogenicity in B-mode imaging. We also suggest that TF may play a role in the production of clinical symptoms.
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  • Takeshi KOHNO, Kenki NISHIDA, Masayuki BAN, Koichiro SOGABE, Shin UEDA ...
    1996 Volume 9 Issue 3 Pages 74-79
    Published: August 31, 1996
    Released on J-STAGE: December 10, 2010
    JOURNAL FREE ACCESS
    A study was conducted to evaluate the severity of reduction of middle cerebral artery flow velocity (FVmca) during cross-clamping of the cervical carotid artery using transcranial Doppler ultrasound (TCD), and to compare the reduction rate of FVmca with internal carotid artery back-pressure (BPica) during carotid endarterectomy (CEA) .
    Subjects and methods: Among 56 patients (46 men, 10 women) who underwent CEA during a period of 2.5 years, 43 (38 men, 5 women) were evaluable for FVmca measurement during CEA (detection rate: 78%) . The internal carotid artery (ICA) was occluded for 70 sec, and four measurements of FVmca were taken: 1) prior to ICA occlusion, 2) 10 sec after occlusion, 3) 60 sec after occlusion, and 4) immediately following the restoration of ICA flow. The rate of reduction in FVmca and the blood flow pattern during occlusion as well as the rate of increase in FVmca following the restoration of ICA were examined. Then the correlation of these factors with BPica was studied by inserting a three-way shunt tube.
    Results: The degrees of FVmca resulting from ICA occlusion were classified as a percentage of the preocclusion value: 1) severe (FVmca≤15%; 10 patients), 2) moderate (FVmca=16-40%; 12 patients), and 3) mild or no ischemia (FVmca ≥ 41%; 21 patients) . The BPica (mmHg) in each of the groups was 6.9±2.3, 20.1±5.6, and 51.1±18.3, respectively. Nearly all the patients with severe or moderate ischemia showed a blood flow pattern of the plateau type in FVmca during ICA occlusion (i.e., flow velocity was unchanged), whereas most patients in the mild or no ischemia group showed a gradual increase of blood flow velocity (i.e., an increasing pattern) .
    Conclusion: A high correlation was shown between the rate of reduction in FVmca and BPica during ICA occlusion. The reduction rate of FVmca and the flow pattern observed with ICA occlusion provided useful information for deciding on the use of the shunt procedure intraoperatively.
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  • Houtetsu SHIMAMOTO, Jun MIYAGI, Kazuya MORIMOTO, Minoru SHIGEMORI, Yuk ...
    1996 Volume 9 Issue 3 Pages 80-84
    Published: August 31, 1996
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    We studied TCD findings in six patients with occlusion of the internal carotid artery (ICA), including two with bilateral ICA occlusion. Their ages ranged from 60 to 70 yr with mean of 64 yr. All patients had superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Mean flow velocity (MFV) and pulsatility index (PI) in the middle cerebral artery (MCA), anterior cerebral artery (ACA) and STA were measured pre-and postoperatively. Two of three patients demonstrated a decrease of MFV and a slight increase of PI in the MCA postoperatively. All three showed decreased MFV in the ACA after surgery. Five patients demonstrated a significant increase of MFV and a decrease of PI in the STA after the procedure.
    These results indicate that TCD is clinically useful for assessing hemodynamic changes induced by bypass surgery.
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  • Kunihiko EBINA, Shigeharu SUZUKI
    1996 Volume 9 Issue 3 Pages 85-90
    Published: August 31, 1996
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    We have developed an originally designed ultrasonic surgical aspirator unit for a newly developed stereotactic neuro-endoscopic surgical system. It has a maximum power output of 35 W, maximum amplitude of 90 μm, a resonance frequency of 23 kHz, capability for fine adjustment using 12 levels, and oscillating probes prepared in three sizes, 2.0×1.2×310 mm (external diameter × internal diameter × effective length), 2.0×1.3×310 mm, and 1.8×1.1×295 mm.
    This unit fragments and aspirates hard blood clots, viscous fluid and tumors, thus facilitating efficient CT-guided stereotactic neuro-endoscopic brain surgery. We have applied this unit to 40 cases of intracerebral hematoma, 26 cases of brain tumor, and 5 other cases. This unit appears to be less invasive and safer, as it can be applied to removal of not only intracerebral hematomas but also deep-seated brain tumors, and also neuronal transplantation.
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  • Showa AOKI, Toshiyuki HATA, Hiromi WATANABE, Daisaku SENOH, Kohkichi H ...
    1996 Volume 9 Issue 3 Pages 91-93
    Published: August 31, 1996
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    We present a case of exencephaly with amniotic band syndrome at 12 weeks of gestation. Ultrasonographic examination showed absence of the fetal cranium, and the brain appeared to be exposed in the amniotic cavity. In addition, a string-shaped structure originating from the brain and extending to the placenta was noted. At 13 weeks of gestation, induced abortion was carried out, and the diagnosis was confirmed. To our knowledge, this is the first case of its kind to be diagnosed by transvaginal ultrasonography in the first trimester of pregnancy.
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