Validity of transcranial doppler measurement of cerebral artery blood flow velocity during selective cerebral perfusion —An experimental study and clinical experiences-

Abstract OBJECTIVE The goal of this study was to quantify the effects of endovascular therapy on vasospastic cerebral vessels. METHODS We reviewed the medical records for 387 patients with ruptured intracranial aneurysms who were treated at a single institution (University of California, Los Angeles) between May 1, 1993, and March 31, 2001. Patients who developed cerebral vasospasm and underwent cerebral arteriographic, transcranial Doppler ultrasonographic, and cerebral blood flow (CBF) studies before and after endovascular therapy for cerebral arterial spasm (vasospasm) were included in this study. RESULTS Forty-five patients fulfilled the aforementioned criteria and were treated with either papaverine infusion, papaverine infusion with angioplasty, or angioplasty alone. After balloon angioplasty (12 patients), CBF increased from 27.8 ± 2.8 ml/100 g/min to 28.4 ± 3.0 ml/100 g/min (P = 0.87); the middle cerebral artery blood flow velocity was 157.6 ± 9.4 cm/s and decreased to 76.3 ± 9.3 cm/s (P < 0.05), with a mean increase in cerebral artery diameters of 24.4%. Papaverine infusion (20 patients) transiently increased the CBF from 27.5 ± 2.1 ml/100 g/min to 38.7 ± 2.8 ml/100 g/min (P < 0.05) and decreased the middle cerebral artery blood flow velocity from 109.9 ± 9.1 cm/s to 82.8 ± 8.6 cm/s (P < 0.05). There was a mean increase in vessel diameters of 30.1% after papaverine infusion. Combined treatment (13 patients) significantly increased the CBF from 33.3 ± 3.2 ml/100 g/min to 41.7 ± 2.8 ml/100 g/min (P < 0.05) and decreased the transcranial Doppler velocities from 148.9 ± 12.7 cm/s to 111.4 ± 10.6 cm/s (P < 0.05), with a mean increase in vessel diameters of 42.2%. CONCLUSION Balloon angioplasty increased proximal vessel diameters, whereas papaverine treatment effectively dilated distal cerebral vessels. In our small series, we observed no correlation between early clinical improvement or clinical outcomes and any of our quantitative or physiological data (CBF, transcranial Doppler velocities, or vessel diameters).

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Objective Assessment of Beat Quality in Transcranial Doppler Measurement of Blood Flow Velocity in Cerebral Arteries

10.1101/554568 ◽

2019 ◽

Author(s):

Kian Jalaleddini ◽

Nicolas Canac ◽

Samuel G. Thorpe ◽

Benjamin Delay ◽

Amber Y. Dorn ◽

...

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Transcranial Doppler ◽

Blood Flow Velocity ◽

Cerebral Blood Flow Velocity ◽

Objective Assessment ◽

Detection Algorithm ◽

Machine Learning Algorithms ◽

Doppler Measurement ◽

Waveform Cross Correlation

AbstractObjectiveTranscranial Doppler (TCD) ultrasonography measures pulsatile cerebral blood flow velocity in the arteries and veins of the head and neck. Similar to other real-time measurement modalities, especially in healthcare, the identification of high quality signals is essential for clinical interpretation. Our goal is to identify poor quality beats and remove them prior to further analysis of the TCD signal.MethodsWe selected objective features for this purpose including Euclidean distance between individual and average beat waveform, cross-correlation between individual and average beat waveform, ratio of the high frequency power to the total beat power, beat length, and variance of the diastolic portion of the beat waveform. We developed an iterative outlier detection algorithm to identify and remove the beats that are different from others in a recording. Finally, we tested the algorithm on a dataset consisting of more than 16 hours of TCD data recorded from 48 stroke and 35 in-hospital control subjects.ResultsWe assessed the performance of the algorithm in estimating clinically important TCD parameters by comparison to those identified from beats hand-annotated by an expert. The results show that there is strong correlation between the two that delineates the algorithm has successfully recovered clinically important features. We obtained significant improvement in estimating the TCD parameters using the algorithm accepted beats compared to using all beats (r>0.78, p<0.01).SignificanceOur algorithm provides a valuable tool to the clinicians for automated detection of the reliable portion of the data. Moreover, it can be used as a pre-processing tool to improve the data quality for machine learning algorithms for automated diagnosis of pathologic beat waveform.

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Cerebrovascular Reactivity in Migraineurs as Measured by Transcranial Doppler

Cephalalgia ◽

10.1046/j.1468-2982.1990.1002095.x ◽

1990 ◽

Vol 10 (2) ◽

pp. 95-99 ◽

Cited By ~ 42

Author(s):

T Darrell Thomas ◽

Gary J Harpold ◽

B Todd Troost

Keyword(s):

Blood Flow ◽

Middle Cerebral Artery ◽

Flow Velocity ◽

Doppler Ultrasound ◽

Cerebral Artery ◽

Transcranial Doppler ◽

Blood Flow Velocity ◽

Transcranial Doppler Ultrasound ◽

Cerebrovascular Reactivity ◽

Artery Blood Flow

Transcranial Doppler ultrasound is a relatively new diagnostic modality which allows the non-invasive assessment of intracranial circulation. A total of 10 migraine patients were studied and compared to healthy controls without headaches. Migraineurs during the headache-free interval demonstrated excessive cerebrovascular reactivity to CO2, evidenced by an increase in middle cerebral artery blood flow velocity of 47% ± 15% compared to 28% ± 14% in controls ( p = 0.026). Differences between the two study groups revealed no significant decrease in middle cerebral artery blood flow velocity with hypocapnia. However, the differences between middle cerebral artery blood flow velocity during hyperventilation and CO2 inhalation were significantly different ( p = 0.004) comparing migraineurs and controls. Instability of the baseline blood flow velocities was also noted in migraineurs during the interictal period. Characteristics which may allow differentiation of migraineurs from other headache populations could possibly be obtained from transcranial Doppler ultrasound flow studies.

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