Color duplex measurement of cerebral blood flow volume in healthy adults

BACKGROUND AND PURPOSE: Global cerebral blood flow (CBF) is an important yet largely unknown quantity in the treatment of neurological intensive care patients. Color duplex sonography of the extracranial cerebral arteries can be used to measure global CBF volume directly at the bedside. To establish reference data on global CBF volume and to test the influence of sex and age on this parameter, a prospective study was performed in a group of 78 healthy adults aged 20 to 85 years (39 women, 39 men; mean age, 52+/-19 years in either sex). METHODS: The common, external, and internal carotid arteries and the vertebral arteries were examined with the use of a 7.0-MHz transducer of a computed sonography system. Angle-corrected time-averaged flow velocity and the diameter of the vessel were measured. Intravascular flow volumes were calculated as the product of angle-corrected time-averaged flow velocity and the cross-sectional area of the circular vessel. CBF volume was determined as the sum of flow volumes in the internal carotid and vertebral arteries of both sides. RESULTS: From 20 to 85 years of age, CBF volume decreased significantly (P相似文献   

Evaluation of the vertebrobasilar-posterior system by transcranial color duplex sonography in adults.

BACKGROUND AND PURPOSE: The transcranial color duplex sonography technique was applied to the vertebrobasilar-posterior system to provide normal data for clinical application. METHODS: The intracranial posterior circulation was studied in 49 healthy volunteers (mean +/- SD age, 35 +/- 12 years) by a transcranial and suboccipital approach with a 2.0-MHz sector transducer of a computed sonography system. RESULTS: The posterior cerebral artery and the vertebrobasilar system were depicted clearly in the color Doppler mode. Pulsed Doppler signals could be recorded in the posterior cerebral (100%), basilar (92%), and vertebral arteries (89%). The following normal values were provided for all vessels: systolic peak, end-diastolic maximum, time-averaged, and time-averaged maximum velocities; resistance and pulsatility indexes; and a spectral broadening index. Mean +/- SD values were 45.9 +/- 9.6, 45.5 +/- 10.8, and 39.2 +/- 10.6 cm/sec for time-averaged maximum velocity, and 28.3 +/- 6.5, 30.6 +/- 7.2, and 24.7 +/- 8.4 cm/sec for time-averaged velocity in the posterior cerebral, basilar, and vertebral arteries, respectively. In a reproducibility study, duplex measurements of the posterior cerebral arteries were repeated in 27 subjects. The correlation between the two examiners was high (r = 0.56, p less than or equal to 0.0001 for time-averaged maximum velocity). CONCLUSIONS: Color duplex sonography of the vertebrobasilar-posterior system is a new, noninvasive, bedside investigative technique. It permits visualization of artery flow in real time, relating these to adjacent brain and cranial structures, as well as angle-corrected duplex measurement of "true" flow velocities at defined sites of the vessels. Thus, it will open new diagnostic possibilities in disorders of the posterior circulation.     

Volume reduction in cerebral blood flow in patients with Alzheimer's disease: a sonographic study

Neuroimaging techniques such as PET and SPECT demonstrated a consistent reduction of cerebral blood flow (CBF) in Alzheimer's disease (AD). The aim of the study was to assess the potential role of ultrasonography for CBF measurement in AD patients and whether the CBF volume correlates positively with disease severity. Fifty patients who met the diagnostic criteria of probable AD (NINDS-ADRDA) were compared to 50 age-matched healthy elderly volunteers. The extracranial internal carotid arteries (ICAs) and the vertebral arteries (VAs) of the patients and controls were examined. Angle-corrected time-averaged flow velocity (TAV) and the diameter of the vessel were measured. Intravascular flow volumes were calculated as the product of TAV and the cross-sectional area of the circular vessel. CBF volume was calculated as the sum of flow volumes in the ICAs and VAs of both sides. All subjects underwent the MMSE. The mean global CBF (474.87 +/- 94.085 vs. 744.26 +/- 94.082 ml/min; p < 0.0001) was lower in AD patients than in healthy volunteers. A significant decline in global flow volumes (r = 0.48; p < 0.0007) with the degree of cognitive impairment was also present. The ability of ultrasonography to characterize flow decreases makes such a technique an attractive tool for the study of AD, for the evaluation of pharmacological therapies and, possibly, for early diagnosis.     

Volume Flow in the Common Carotid Artery does not Decrease Postprandially

BACKGROUND AND PURPOSE: A commonplace explanation for postprandial fatigue is the assumption of the redistribution of perfusion from the cerebral to the mesenterial territory. However, this assumption has never been scientifically proven. METHODS: Because approximately 70% of the blood flow in the common carotid artery (CCA) is directed to the internal carotid artery, this vessel can be seen as a major brain-supplying artery. Flow volume in the CCA can be measured by color M-mode duplex sonography. The authors investigated the flow volume rate in 20 healthy volunteers before and after the intake of a high-energy meal. Heart rate, blood pressure, and expiratory CO2 were also measured at both times. RESULTS: There was a significant (P = .001) increase in right, left, and net CCA flow volume postprandially (right: from 362.0 [interquartile range 315.5-410.5] to 401.5 [322.1-486.4] mL/min; left: from 384.5 [345.5-439.0] to 414.5 [357.9-527.7] mL/min; net: from 756.0 [683.0-822.5] to 832.4 [713.7-967.26] mL/min). This increase was paralleled by a statistically significant increase in heart rate from 66 (58-70) to 76 (63-84) bpm, but without substantial correlation (r = 0.28) with the volume flow changes. There was no correlation with any other tested parameter. CONCLUSIONS: The authors conclude that the assumption of global brain hypoperfusion in the postprandial state cannot serve as an explanation for postprandial fatigue.     

Effect of doxapram on cerebral blood flow velocity in preterm infants

BACKGROUND: Doxapram is used to treat apnea of prematurity when there is an insufficient response to methylxanthine treatment. As an unwanted side effect, reduced cerebral perfusion has been seen in methylxanthine-treated infants while effects of doxapram on the cerebral perfusion have not been studied yet. PATIENTS AND METHODS: Fifteen preterm infants treated with doxapram were included in the study. Birth weight ranged from 380 g to 1150 g (median 740 g), gestational age from 24 to 27 weeks (median 26 weeks). Infants received a doxapram loading dose (2.5 mg/kg) over a 30-minute period, followed by a continuous infusion of 0.5 mg/kg/h. Using Doppler sonography, blood flow velocities and the resistance index were measured in the anterior cerebral artery. Measurements were performed at baseline and 30 and 120 minutes after the start of doxapram. RESULTS: Maximal systolic blood flow velocity (V(max)) decreased significantly after the infants had received the loading dose (V(max) baseline: 40.7 cm/s +/- 6.9 [mean +/- SD]; V(max) 30 min: 35 cm/s +/- 8.9; p = 0.0017) but returned to near baseline values at 120 min (38.5 +/- 9.0, p = 0.22). End-diastolic, time-averaged, and time-averaged maximal velocities did not change significantly at 30 or 120 min. CONCLUSIONS: Doxapram induced a significant decrease in maximal cerebral blood flow velocity. Further studies are needed to assess whether this decrease may be critical to cerebral white matter perfusion in the vulnerable preterm infant.     

磁共振相位对比血管成像测量脑血流量的最佳速度编码

实验运用1.5-T磁共振的2D cine PC序列对10位健康志愿者C2水平感兴趣区血管进行速度编码为30~90cm/s,间隔10cm/s的7次同层扫描,探讨速度编码在磁共振相位对比血管成像中对测量脑血流量及入脑/出脑血流的影响。发现不同的速度编码对颈内动脉血流量、最大血流速度和平均血流速度影响较大,对椎动脉及颈内静脉影响不明显。当速度编码为60～80cm/s时,入脑血流量为(655±118)mL/min,出脑血流量(506±186)mL/min,入脑血流量/出脑血流量稳定在0.78～0.83,且所有血管中无混淆现象。提示在应用磁共振相位增强血管成像测量脑血流量时,应选择60～80cm/s的速度编码。     

Color-coded duplex ultrasonography of the origin of the vertebral artery: normal values of flow velocities.

The introduction of color-coded duplex ultrasonography has improved the ease of performing ultrasound investigations of the vertebral arteries. So far, normal values of flow velocities have been reported only for the intertransverse region of the vertebral artery (V2 segments). Atherosclerotic disease at the origin of the vertebral arteries (V0 segment) is frequent and is one of the risk factors for vertebrobasilar ischemic disease. Normal values of flow velocities of the vertebral artery origin are needed to assess pathologic findings, such as vertebral artery origin stenosis or dissection. The aim of this study was to describe the normal flow velocities of vertebral artery origin (V0 segment) and the pre- (V1 segment) and intertransverse (V2 segment) part in 50 age-matched neurologic patients (mean age 54) without ischemic cerebral disease. The V0 segment could be visualized in 46 persons (92%) on the right side and in 43 (86%) on the left. The peak systolic blood velocity ranged from 30 to 100 cm/s (mean 63.6 +/- 17.5 cm/s), and end-diastolic blood velocity ranged from 10 to 35 cm/s (mean 16.1 +/- 5.1 cm/s). Analysis of side-to-side differences showed no significant differences of flow velocities in all subjects. It is concluded that color duplex ultrasonography is a feasible method to insonate the origin of the vertebral artery, and that nomogram data could be established. It is suggested that color-coded duplex ultrasonography of the vertebral artery origin should be performed in all patients with clinical symptoms or signs of vertebrobasilar ischemic disease. Nevertheless, further studies are needed to determine the normal and pathologic values of flow velocities of the vertebral artery origin and their reproducibility.     

Extracranial Internal Carotid Artery Occlusion: The Role of Common Carotid Artery Volume Flow

BACKGROUND AND PURPOSE: Quantitative measurement of blood flow volume in the common carotid artery (CCA) is now possible using the color velocity imaging quantification (CVI-Q) ultrasound technique. The aim of this study was to evaluate the cerebral hemodynamic effects of unilateral internal carotid artery (ICA) occlusion on CCA blood flow volumes (FVs) using CVI-Q. METHODS: Records of ultrasound studies in our neurosonology laboratory were retrospectively reviewed to identify patients with unilateral ICA occlusions who at a minimum received both a routine color duplex carotid ultrasound examination and quantitative measurement of FV in the CCA, bilaterally, using the CVI-Q method. A total of 71 patients met criteria and were included in the cohort. A side to side comparison was performed for FV, peak systolic velocities (PSV), end-diastolic velocities (EDV), and resistance indices (RIs) in the CCA. Results correlated with any other available data such as flow direction in the ophthalmic artery and the presence of intracranial collateralization. RESULTS: The FV, PSV, and EDV were significantly reduced, and the RI was significantly increased in the CCA on the side of the occlusion. A subgroup analysis in patients who also had an examination of the ophthalmic (n = 61) and the intracranial arteries of the Circle of Willis (n = 50), showed significantly higher FV in the CCA on the side of the occlusion if there was also reversed flow in the ophthalmic artery on the side of the occlusion (344 +/- 144 ml/min versus 169 +/- 53 ml/min). CONCLUSION: Quantitative FV measurement using CVI-Q ultrasound can identify clear alterations in volume flow, collateral pathways, and cerebral hemodynamics in patients with unilateral ICA occlusion. It is a complementary tool, providing additional objective information about the cerebral hemodynamic effects of ICA occlusion that goes beyond what is available using routine flow velocity data.     

Transcranial color Doppler sonography on healthy pre-school children: flow velocities and total cerebral blood flow volume

Transcranial color Doppler sonography (TCCD) is a useful tool for intracranial investigation. Using TCCD to calculate total cerebral blood flow volume (TCBFV) can be a useful indicator for intracranial hemodynamic status. We performed a series study of TCCD on 60 healthy kindergarten students. Peak-systolic, end-diastolic, and mean blood velocities of major cerebral arteries, and depth of flow waves were measured. We also collected Gosling pulsatile index (PI) and Pourcelot resistance index (RI) of the arteries. TCBFV was calculated from the mean blood flood velocity and vessel chamber size of the internal carotid artery (ICA) and basilar artery (BA). Fifty children completed the examinations. The TCBFV was 1538+/-416 ml/min with mean cerebral blood flow volume of 571+/-241 ml/min for the ICA system and 983+/-343 ml/min for the BA system. PI, RI, and the velocities of A1, A2, M1, M2, BA, ICA, and TCBFV were not significantly different between girls and boys in this age group. In this study, we used TCCD to determine the normal data of main cerebral arteries and TCBFV of pre-school children in Taiwan. The reference data of velocities and other parameters of main cerebral arteries from our study may serve as a guide for additional pediatric cerebral hemodynamic studies.     

Toward a further elucidation: role of vertebral artery hypoplasia in acute ischemic stroke

BACKGROUND AND PURPOSE: Congenital vertebral artery (VA) hypoplasia is an uncommon embryonic variation of posterior circulation. The frequency of this congenital variation was reported to be 2-6% from autopsy and angiograms. The aim of our study was to elucidate the role of VA hypoplasia in acute ischemic stroke. METHOD: We examined 191 acute ischemic stroke patients (age 55.8 +/- 14.0 years). TOAST subtypes were determined. A cervical magnetic resonance angiogram was performed in every patient. A duplex study of bilateral VA with flow velocities and vessel diameter recording in the intertransverse (V2) segment was performed within 72 h after onset of ischemic stroke. The net VA flow volume was measured in each subject. RESULT: The overall incidence of a unilateral congenital hypoplastic VA was 11.51%, which was statistically higher especially in cases of brainstem/cerebellar infarction. Of these, subjects with VA hypoplasia had an etiological preponderance of the 'large-artery atherosclerosis' subtype and a topographic preponderance of ipsilateral posterior circulation infarction. CONCLUSIONS: Based on our results, VA hypoplasia seemed a contributing factor of acute ischemic stroke, especially in posterior circulation territories.     

Capillary flow and diameter changes during reperfusion after global cerebral ischemia studied by intravital video microscopy.

The reaction of cerebral capillaries to ischemia is unclear. Based on Hossmann's observation of postischemic "delayed hypoperfusion," we hypothesized that capillary flow is decreased during reperfusion because of increased precapillary flow resistance. To test this hypothesis, we measured cerebral capillary erythrocyte velocity and diameter changes by intravital microscopy in gerbils. A cranial window was prepared over the frontoparietal cortex in 26 gerbils anesthetized with halothane. The animals underwent either a sham operation or fifteen minutes of bilateral carotid artery occlusion causing global cerebral ischemia. Capillary flow velocities were measured by frame-to-frame tracking of fluorescein isothiocyanate labeled erythrocytes in 1800 capillaries after 1-hour reperfusion. Capillary flow velocities were decreased compared to control (0.25 +/- 0.27 mm/s vs. 0.76 +/- 0.45 mm/s; P<0.001). Precapillary arteriole diameters in reperfused animals were reduced to 76.3 +/- 6.9% compared to baseline (P<0.05). Capillary diameters in reperfused animals (2.87 +/- 0.97 microm) were reduced (P<0.001) compared to control (4.08 +/- 1.19 microm). Similar reductions of precapillary (24%) and capillary vessel diameters (30%) and absolute capillary flow heterogeneity indicate that delayed (capillary) hypoperfusion occurs as a consequence of increased precapillary arteriole tone during reperfusion.     

Ultrasonographic assessment of global cerebral blood volume in healthy adults.

The authors describe a new ultrasonographic method for analysis of global cerebral blood volume (CBV) and its application under controlled hyperventilation. CBV was determined as the product of global cerebral blood flow volume (CBF) and global cerebral circulation time. CBF was measured by duplex sonography and calculated as the sum of flow volumes in both internal carotid arteries and vertebral arteries. Extracranial Doppler assessed cerebral circulation time by determining the time interval of echo-contrast bolus arrival between internal carotid artery and contralateral internal jugular vein. Forty-four healthy volunteers (mean age 45 +/- 19 years, range 20-79 years) were studied. Mean CBV was 77 +/- 13 mL. CBV did not correlate with age, end-tidal carbon dioxide level, heart rate, or blood pressure. Hypocapnia was induced in 10 subjects by controlled hyperventilation. Mean reduction of end-tidal carbon dioxide values by 9 +/- 1 mm Hg led to a significant increase in cerebral circulation time (6.1 +/- 0.9 to 8.4 +/- 1.1 second, P < 0.0001) and a significant CBF decrease (742 +/- 85 to 526 +/- 77 mL/min, P < 0.0001), whereas CBV remained unchanged (75 +/- 6 to 73 +/- 10 mL).     

Quantitative Volumetry in Patients With Carotid Disease—Effects of Acetazolamide

The intracranial effects of acetazolamide on flow velocities can be monitored noninvasively by transcranial Doppler (TCD) sonography. Extracranial volume flow changes can now reliably be measured with color duplex M-mode systems. The authors tested the volumetric effects of acetazolamide in patients with high-grade unilateral carotid disease to quantify the amount of flow changes. Patients in group 1 had a high-grade > 70% internal carotid artery (ICA) stenosis, without collateral flow through the ophthalmic artery (OA). Patients with occluded ICA were included in group 2 (patent OA collateralization) or group 3 (no OA collateralization) (n = 6 per group). In group 1, common carotid artery (CCA) volume flow in the stenotic (normal contralateral) side increased from 271 (388) ml/min by 52 (54%) with 1 g aceta-zolamide intravenously. Simultaneously, middle cerebral artery (MCA) flow velocities increased from 54 (56) cm/s by 47 (53%). In group 2, extracranial volume flow increased from 166 (444) ml/min by 19 (52)%. MCA flow velocities increased from 43 (65) cm/s by 13 (30)%. In group 3, volume flow increased from 159 (467) ml/min by 2 (46)%. Intracranial flow velocities rose from 49 (54) cm/s by 27 (41)%. Volume flow data showed the expected decline in patients with high-grade ICA stenosis and even more pronounced in patients with occlusion of the vessel. Cerebral reserve capacity was less sufficient in patients with a patent OA, despite an additional supply of 30 ml/min, indicating a hemodynamically critical situation.     

Flow estimation using ultrasound imaging (color M-mode) and computer postprocessing

We have developed a method to calculate flow noninvasively in blood vessels using color Motion-mode (M-mode) and computer postprocessing. The velocity of each point in the cross-sectional area of the vessel was found from the color M-mode recording by correcting for angle both distances and velocities and by assuming a symmetrical circular velocity field. Volume flow was then found by integrating the velocity field at 5-ms intervals through the cardiac cycle. In a cardiovascular hydromechanical model, a correlation of 0.99 and p value of less than 0.001 were found between estimated and measured flow in the model (n = 8). In 20 healthy individuals, we made 31 investigations in the common carotid (CCA), internal carotid (ICA), and external carotid (ECA) artery, comparing flow in the CCA with the added flow in the ICA and ECA. The values (CCA versus ICA + ECA) correlated with r = 0.91 and p less than 0.01. Repeated investigations (n = 8) in one individual gave flow estimates of 495 +/- 50 ml/min in the CCA, 304 +/- 45 ml/min in the ICA, and 165 +/- 37 ml/min in the ECA (means +/- SD). This article shows that this system can make accurate estimation of blood flow to the brain noninvasively.     

磁共振电影相位对比法监测脑外伤后脑血流动力学改变的研究

目的 探讨磁共振电影相位对比法在诊断与监测脑外伤后血流动力学改变中的价值. 方法 选取解放军第一七五医院放射科自2010年9月至2010年12月行磁共振二维电影相位对比法成像(MRI 2D-PC Cine)监测的颅脑外伤患者40例,同期40例健康志愿者作为对照组,分析比较外伤组与对照组之间双侧颈内静脉、颈内动脉、椎动脉出颅段平均流速、峰值流速及平均流量速的差异. 结果 外伤组患者双侧颈内静脉平均流速均高于对照组,差异有统计学意义(P＜0.05),而2组间峰值流速、平均流量比较差异均无统计学意义(P＞0.05);2组之间双侧颈内动脉、椎动脉平均流速、峰值流速及平均流量比较差异均无统计学意义(P＞0.05). 结论 MRI 2D-PC Cine法能早期定量分析颅脑外伤患者颅脑血流动力学改变,为临床治疗提供依据.     

Variations in middle cerebral artery blood flow investigated with noninvasive transcranial blood velocity measurements

Observations on blood velocity in the middle cerebral artery using transcranial Doppler ultrasound and on the ipsilateral internal carotid artery flow volume were obtained during periods of transient, rapid blood flow variations in 7 patients. Five patients were investigated after carotid endarterectomy. A further 2 patients having staged carotid endarterectomy and open heart surgery were investigated during nonpulsatile cardiopulmonary bypass. The patient selection permitted the assumption that middle cerebral artery flow remained proportional to internal carotid artery flow. The integrated time-mean values from consecutive 5-second periods were computed. The arithmetic mean internal carotid artery flow varied from 167 to 399 ml/min in individual patients, with individual ranges between +/- 15% and +/- 35% of the mean flow. The mean middle cerebral artery blood velocity varied from 32 to 78 cm/sec. The relation between flow volume and blood velocity was nearly linear under these conditions. Normalization of the data as percent of the individual arithmetic means permitted a composite analysis of data from all patients. Linear regression of normalized blood velocity (V') on normalized flow volume (Q') showed V' = 1.05 Q' - 5.08 (r2 = 0.898).     

Fat delays emptying but increases forward and backward antral flow as assessed by flow-sensitive magnetic resonance imaging

Flow has been assessed in the gastric antrum using a velocity-sensitive version of the high-speed magnetic resonance imaging technique, echo planar imaging (EPI). Eight healthy volunteers attended fasted on three separate days and consumed 800 mL of either a 5% glucose (0.2 kcal mL-1), 10% glucose (0.4 kcal mL-1) or an isotonic mixed nutrient meal, Fresubin (1 kcal mL-1, 27.2 g fat). Gastric volumes were obtained at 10-min intervals for 1 h. Flow measurements were performed on a single slice through the antropyloric region 5 and 35 min after meal ingestion. Gastric volumes at 45 min were inversely proportional to the calorie density of the meal with (mean +/- SEM) 89 +/- 10%* of the Fresubin, 64 +/- 5%* of the 10% glucose and 41 +/- 5% of the 5% glucose remaining (*P < 0.005 vs 5% glucose). Substantial forward and backward antral flow was observed after all three meals in the initial 5-min imaging period. AT 35 min flow activity was significantly greater after both the high-calorie meals relative to the 5% meal (total number of flow events: Fresubin = 6.6 +/- 1.7,[symbol: see text] 10% glucose = 9.9 +/- 2.2, [symbol: see text] 5% glucose = 2.5 +/- 0.9,[symbol: see text] P < 0.03,[symbol: see text] P < 0.007 vs 5% glucose, n = 8). Peak forward velocities for the initial phase of emptying tended to be greater for the rapidly emptying 5% meal (5.9 +/- 0.8 cm-1) compared with the Fresubin (3.3 +/- 0.6 cm-1, P < 0.069, n = 8) and the 10% glucose (2.9 +/- 1.0 cm-1, P < 0.068, n = 8) meals. In spite of delayed gastric emptying, high-calorie meals were associated with substantial to and fro movements which may be important for meal tritruration and fat emulsification.     

Noninvasive assessment of cerebral collateral blood supply through the ophthalmic artery

We assessed the potential of 2-MHz pulsed-wave transorbital Doppler ultrasonography to delineate the role of the ophthalmic artery as a source of collateral cerebral blood supply by comparing oculopneumoplethysmography, transorbital Doppler ultrasonography, periorbital continuous-wave Doppler ultrasonography, and transcranial Doppler ultrasonography in 25 patients with unilateral internal carotid artery occlusion and five controls with 10 normal internal carotid arteries. Systolic ophthalmic artery blood velocity was reduced ipsilateral to an internal carotid artery occlusion (38.2 +/- 10.2 cm/sec) compared with the contralateral and control velocities (46.0 +/- 10.3 and 47.5 +/- 6.8 cm/sec, respectively; p less than 0.05). Ophthalmic systolic pressure measured by oculopneumoplethysmography was 94.7 +/- 13.2 mm Hg ipsilateral to an internal carotid artery occlusion compared with 108.4 +/- 15.3 mm Hg on the contralateral side (p less than 0.01). Transorbital and periorbital Doppler ultrasonography detected reversed ophthalmic artery blood flow ipsilateral to an internal carotid artery occlusion in 44.0% and 40.0% of the patients, respectively. Systolic middle cerebral artery blood velocity was 55.2 +/- 22.3 cm/sec ipsilateral to an internal carotid artery occlusion compared with 79.4 +/- 23.5 cm/sec on the contralateral side (p less than 0.05) and 101.2 +/- 18.9 cm/sec in the controls (p less than 0.05). Reversed ophthalmic artery blood flow was associated with a low middle cerebral artery blood velocity and lack of major intracerebral collaterals. Transorbital Doppler ultrasonography permits noninvasive evaluation of the ophthalmic artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intra-operative measurement of cortical arterial flow volumes in posterior circulation using Doppler sonography

Little has been reported on the flow volume of cortical arteries in the posterior circulation. During craniotomy in 28 patients, we measured the flow velocity of the arteries using microvascular Doppler sonography and recorded their arterial radii and the insonation angle. The flow velocities and radii were 25.7 cm sec-1 and 0.11 cm for the posterior cerebral artery (PCA), 19.5 cm sec-1 and 0.07 cm for the superior cerebellar artery (SCA), 19.6 cm sec-1 and 0.04 cm for the anterior inferior cerebellar artery (AICA), 14.9 cm sec-1 and 0.05 cm for the posterior inferior cerebellar artery (PICA), 28.3 cm sec-1 and 0.18 cm for the basilar artery, and 18.5 cm sec-1 and 0.16 cm for the vertebral artery, respectively. Since the flow velocities of these arteries were confined in a narrow range compared to the cross-sectional areas, the latter was considered to be the primary determinant for flow volume in these arteries. Based on certain assumptions, we estimated the flow volume of the PCA, SCA, AICA and ICA to be 60, 20, 10 and 10 ml min-1, respectively, which could be regarded as the current reference values for the arterial flow volumes.     

Intra-operative measurement of cortical arterial flow volumes in posterior circulation using Doppler sonography

Abstract

Little has been reported on the flow volume of cortical arteries in the posterior circulation. During craniotomy in 28 patients, we measured the flow velocity of the arteries using microvascular Doppler sonography and recorded their arterial radii and the insonation angle. The flow velocities and radii were 25.7 cm sec^–1 and 0.11 cm for the posterior cerebral artery (PCA), 19.5 cm sec^–1 and 0.07 cm for the superior cerebellar artery (SCA), 19.6 cm sec^–1 and 0.04 cm for the anterior inferior cerebellar artery (AICA), 14.9 cm sec^–1 and 0.05 cm for the posterior inferior cerebellar artery (PICA), 28.3 cm sec^–1 and 0.18 cm for the basilar artery, and 18.5 cm sec^–1 and 0.16 cm for the vertebral artery, respectively. Since the flow velocities of these arteries were confined in a narrow range compared to the cross-sectional areas, the latter was considered to be the primary determinant for flow volume in these arteries. Based on certain assumptions, we estimated the flow volume of the PCA, SCA, AICA and ICA to be 60, 20, 10 and 10 ml min^–1, respectively, which could be regarded as the current reference values for the arterial flow volumes. [Neurol Res 2000; 22: 194-196]