• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.3
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• pp.219-226
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• 2023

Transcranial doppler ultrasonography (TCD) applies a low frequency of 2 MHz to measure the blood flow velocity and waveform within the skull. Medical technologists at several hospitals are conducting these examinations, and education is being imparted in many schools and academic societies. However, the skill of the tester is of utmost importance when performing TCD. Technicians who are conducting the procedure for the first time have trouble locating the blood vessels, and some experienced personnel are worried because too many blood vessels are present. Since this procedure does not directly look at and measure blood vessels, there are several limitations and difficulties. Therefore, this study aims to provide some help by introducing precautions and suggestions for TCD technicians conducting the test.

• The Journal of Internal Korean Medicine
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• v.29 no.4
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• pp.950-961
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• 2008

Objectives : The purpose of this study was to compare cerebral biood flow between hypertensives and normotensives using transcranial doppler ultrasonography (TCD). Methods : I investigated cerebral blood flow of 72 hypertensives and 127 normotensives. To evaluate the cerebral blood flow, I measured the systolic peak velocity(Vs) and mean How velocity (Vm) of the middle cerebral artery(MCA), anterior cerebral artery(ACA), posterior cerebral artery(PCA), basilar artery(BA), and internal carotid artery(ICA) in the two groups using TCD. Result : 1. There was a decrease in the Vs and Vm of all examined vessels of hypertensives in comparison with normotensives. There was a significant difference in the Vs of ACA and Vm of ACA, PCA, ICA. 2. In males, there was a decrease in the Vs of ACA, PCA, ICA and Vm of MCA, ACA, PCA, ICA of hypertensives in comparison with normotensives. However, there was no significant difference in the Vs or Vm of all examined vessels. 3. In females, there was a decrease in the Vs and Vm of all examined vessels of hypertensives in comparison with normotensives. There was a significant difference in the Vs of MCA, ACA and BA and Vm of ACA, PCA and BA. 4. In 30-49 year-olds, there was a decrease in the Vs and Vm of all examined vessels of hypertensives in comparison with normotensives. There was a significant difference in the Vs of ACA and Vm of ACA. 5. In 50-69 year-olds, there was a decrease in the Vs of ACA, PCA, BA, ICA and Vm of all examined vessels of hypertensives in comparison with normotensives. However, there was no significant difference in the Vs or Vm of all examined vessels. 6. In 70-89 vests old. there was a decrease in the Vs. Vm of PCA, BA, ICA of hypertensives in comparison with normotensives. But, there was no significant difference in the Vs, Vm of all examined vessels. Conclusions : There was a significant difference in the cerebral blood now velocity between hypertensives and normotcnsives. These results suggest that blood pressure has influence on cerebral blood flow.

• 대한예방의학회:학술대회논문집
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• 1993.10a
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• pp.63-64
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• 1993

• Annals of Clinical Neurophysiology
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• v.7 no.1
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• pp.61-62
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• 2005

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.70-75
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• 1999

Trancranial Doppler(TCD) monitoring is a new application of ultrasonography which allows the nonivasive detection of blood flow velocity in the horizontal (M1) segment of the middle cerebral artery (MCA) and detects microembolic phenomena in the cerebral circulation. Recent studies emphasized the potential of using this technique in vascular surgery (carotid endarterectomy, cardiopulmonary bypass), interventional and intensive care setting. Although the disparity between CBF and blood flow velocity and number of microemboli could be used to prevent cerebral ischemic and embolism based on clinical studies. A reduction of more than 60% of MCA can reflex hemodynamic ischemic state and acoustic feedback of high intensity transient signals(HITS) from the TCD monitoring unit has a direct influence on surgical technique. TCD monitoring can immediately provide information about thromboembolism and hemodynamic changes, which may be a useful tool in the study and prevention of stroke.

• Journal of Acupuncture Research
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• v.27 no.3
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• pp.83-92
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• 2010

Objectives : The aim of this study is to research the trend of the TCD-related studies in Korean medicine and to establish the hereafter direction for the study on celebral blood flow. Methods : We reviewed the domestic papers searched by search engine of Korean Acupuncture & Moxibustion Society and Korea Institute of Oriental Medicine etc. Results : We have searched 42 articles in 14 journals. 1. There were 2 or more articles every year. In 2004 there were 5 articles. 2. 11 studies were associated with the usefulness of TCD as a diagnostic tool for CVA. 3. 8 studies were associated with the effect of acupuncture on cerebral blood flow. 5 studies were about acupuncture, 2 studies were about electro-acupuncture, and 1 study was about pharmacopuncture. Conclusions : These results suggest that acupuncture could have a specific effect on cerebral blood flow. But we need more studies about the effect of various acupuncture point on cerebral blood flow.

• Journal of Korean Neurosurgical Society
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• v.40 no.6
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• pp.434-440
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• 2006

Objective : The purpose of this study is to examine the influence of cranioplasty on dynamics of cerebral blood flow[CBF] and cerebrovascular reserve capacity[CVRC], and to investigate the usefulness of single photon emission computed tomography [SPECT] as a prognostic factor for neurological improvement after cranioplasty. Methods : Between March 2003 and December 2005, a prospective study was performed on 24 patients who had undergone total 25 cranioplasty operations. Cerebral blood flow velocities in the middle cerebral artery[MCA] and internal carotid artery[ICA] were obtained by transcranial Doppler ultrasonography[TCD]. The CVRC was assessed by SPECT in the natural state and after stimulation with 1g of acetazolamide. Neurological improvement after cranioplasty was compared between patients who showed hyperactivity to acetazolamide-activated SPECT [Group 1, n=7] and hypoactivity to acetazolamide-activated SPECT [Group 2, n=17]. These measurements were obtained two weeks prior to and two weeks after cranioplasty. Results : The blood flow velocities at the opposite site to the cranioplasty as well as at the cranioplasty site were significantly increased [P<0.05]. Compared with Group 2, there was significant increase in CBF and neurological improvement after cranioplasty in Group 1. Conclusion : Among patients with surgical bony defects, the patients who had normal reactivity of the CVRC showed a significant increase in CBF and neurological improvement after cranioplasty. The authors suggest that CVRC measurement prior to surgery may be an important prognostic factor for neurological improvement after cranioplasty.

• Annals of Clinical Neurophysiology
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• v.20 no.2
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• pp.79-84
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• 2018

Background: Pulsatility of cerebral arteries and aortic stiffness have been associated with white matter hyperintensities (WMH). We explored which is better correlated with the severity of WMH in a population with acute lacunar infarct. Methods: We included patients with acute small subcortical infarcts who underwent transcranial Doppler (TCD) and brachial ankle pulse wave velocity (baPWV). Exclusion criteria were any stenosis or occlusion on major cerebral arteries on magnetic resonance angiography; poor temporal insonation windows; ankle brachial index < 0.9; and atrial fibrillation. We assessed the performance of the pulsatility index of bilateral middle cerebral arteries (PI-MCA) and baPWV for predicting moderate-to-severe WMH, defined as an Age Related White Matter Changes score > 5, and then sought to find independent predictors using binary logistic regression analysis. Results: Eighty-three patients (56 males, mean age $61.5{\pm}11.4$) participated in the study. Uni-variate analysis showed old age and high PI-MCA were significantly correlated with moderate-to-severe WMH. However, baPWV was not associated with the severity of WMH. Multivariate analysis revealed old age (odds ratio per 1-year increase, 1.068; p = 0.044) and upper tertile of PI-MCA (odds ratio, 5.138; p = 0.049) were independently associated with moderate-to-severe WMH. Receiver-operating characteristics showed PI-MCA differentiated those with and without moderate-to-severe WMH with an area under the curve of 0.719. Conclusions: PI-MCA derived from TCD was better correlated with the severity of WMH than baPWV in a population with lacunar infarction. Pulsatility of cerebral arteries may better predict cerebral small vessel disease than the aortic stiffness index.

• Journal of Korean Neurosurgical Society
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• v.39 no.5
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• pp.347-354
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• 2006

Objective : We evaluate the role of multislice computerized tomographic angiography[MCTA] in the diagnosis of intracranial vasospasm following subarachnoid hemorrhage[SAH] in patients suspected of having vasospasm on clinical ground. Methods : Between October 2003 and June 2005, patients with ruptured cerebral aneurysms of the anterior circulation clipped within 3 days of the onset were included. We performed follow-up MCTAs in patients who were suspected to have vasospasm on transcranial doppler sonography[TCD] findings and clinical grounds. Based on the clinical presentation of symptomatic vasospasm, we investigated the correlation between clinical, TCD, and MCTA signs of vasospasm and evaluated the role of MCTA in vasospasm. Results : One hundred one patients met the inclusion criteria and symptomatic vasospasm developed in 25 patients [24.8%]. We performed follow-up MCTAs in 28 patients. MCTA revealed spasm in the vessels of 26 patients. The sensitivity of MCTA was 100%. Among the 26 patients with MCTA evidence of vasospasm, 3 patients had TCD signs of vasospasm after symptomatic vasospasm presentation. Another 3 patients with symptomatic vasospasm had no TCD signs of vasospasm in daily serial recordings. Six other patients without symptomatic vasospasm showed MCTA evidence of vasospasm [false positive result] but these patients had also positive TCD signs of vasospasm. Volume rendering[VR] images tended to show significantly more exaggerated vasospasm than maximum intensity projection[MIP] images. The mean cerebral blood flow velocity of both proximal segment of the middle cerebral artery [M1] was significantly correlated with each reduced M1 diameter on MCTA [P<005]. Conclusion : MCTA could be a useful tool for evaluation and planning management of critically ill patients suspected of having vasospasm; however, more randomized controlled trials are necessary to assess these points definitively.