Point of Care Transcranial Color-Coded Duplex Ultrasound of the Middle Cerebral Artery
August 9th, 2024
Transcranial ultrasound is an essential tool for monitoring patients with various neurological conditions. Although it is commonly used in a protocolized fashion in consultative studies, the brain has been overlooked in many protocols utilizing point-of-care ultrasound (PoCUS). This study proposes a PoCUS image acquisition protocol.
Our question is trying to answer whether PoCUS can be used as a bedside screening tool to aid in the diagnosis and management of acute neurological dysfunction. Recent advancements in robotic transcranial ultrasound technology focusing on its utility in neuromonitoring enhance our ability to monitor neurological functions in real time, providing more precise and reliable data for our studies. Our protocol offers a simplified step-by-step PoCUS approach for bedside screening of neurological dysfunction.
It provides a quicker, more accessible assessment, compared to other techniques, and enables timely diagnosis and intervention in critical situations. To begin, select the phased array probe for the TCCD scan to provide the smallest footprint for the insonation of the transtemporal window. Set the ultrasound machine to the transcranial preset to position the indicator to the right of the screen.
Now, set the initial mode to B-mode and adjust the depth to 13 to 16 centimeters. Position the machine so that the ultrasound screen is directly in line with the ultrasound probe for optimal scanning ergonomics. Then, place the patient in a supine position with the head of the bed elevated to 30 degrees.
Now, apply ultrasound gel to the phased array probe. Place the probe on the transtemporal window, parallel to the ground with the index mark aimed toward the patient's anterior. Use a sliding motion to scan through the nearby brain tissue until the relevant intracranial structures are identified.
These structures serve as starting points to identify the landmarks needed for PoCUS TCCD. Identify the ipsilateral temporal bone, typically seen at a depth of around one centimeter. Then, identify the contralateral temporal bone observed at a depth of 14 to 16 centimeters.
Next, locate the third ventricle, which appears as two hyperechoic lines with a thin hypoechoic structure in between, representing cerebrospinal fluid. Begin with the view obtained from the previous steps. Reduce the depth so that the far field is set to 10 centimeters.
Then, locate the large color flow sampling box on the left side of the top half of the ultrasound screen. Initiate pulse-wave Doppler and center the box over the red color flow signal of the MCA. To obtain a spectral Doppler waveform, trace its contour to measure the velocity time integral for one cardiac cycle.
Ensure that the mean flow velocity, time average velocity, time-adjusted peak velocity, or time average maximum velocity is displayed. Also, verify that the pulsatility index is shown. Finally, review the acquired images in Doppler spectra to ensure they meet diagnostic quality standards.
Ensure that all images in Doppler data are properly saved and labeled for future reference and analysis. Inform the patient about any follow-up steps or additional tests, if required.
Overview
This study explores the use of point-of-care ultrasound (PoCUS) as a bedside screening tool for diagnosing and managing acute neurological dysfunction. It presents a simplified protocol for transcranial ultrasound, enhancing real-time neuromonitoring capabilities.
Key Study Components
Area of Science
- Neurology
- Ultrasound Imaging
- Patient Monitoring
Background
- Transcranial ultrasound is vital for monitoring neurological conditions.
- Point-of-care ultrasound has been underutilized in brain assessments.
- Robotic advancements in ultrasound technology improve monitoring accuracy.
- Timely diagnosis is crucial in acute neurological cases.
Purpose of Study
- To evaluate PoCUS as a bedside tool for neurological dysfunction.
- To provide a step-by-step protocol for ultrasound image acquisition.
- To enhance accessibility and speed of neurological assessments.
Methods Used
- Select the phased array probe for TCCD scans.
- Set the ultrasound machine to the transcranial preset.
- Position the indicator correctly on the screen.
- Follow the simplified protocol for image acquisition.
Main Results
- PoCUS provides quicker assessments compared to traditional methods.
- Real-time monitoring enhances data reliability.
- The protocol facilitates timely diagnosis and intervention.
- Robotic advancements improve the utility of transcranial ultrasound.
Conclusions
- PoCUS is a valuable tool for acute neurological assessments.
- The proposed protocol simplifies the process for clinicians.
- Further studies are needed to validate its effectiveness in various settings.
Frequently Asked Questions
Executive Industry Relevance
Point-of-care transcranial color-coded duplex (TCCD) ultrasound offers rapid, bedside neurological assessment, addressing critical gaps in acute neuromonitoring workflows. Standardized TCCD protocols enable timely detection of intracranial pathologies, supporting predictive confidence and risk-adjusted decision-making in neurocritical care. Consistent training and reproducible image acquisition are essential for integrating TCCD into enterprise-level R&D and clinical innovation pipelines.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables real-time interrogation of cerebral hemodynamics for mechanistic de-risking in neurovascular research.
- Supports functional validation of neurological targets by quantifying blood flow and pulsatility indices.
- Facilitates hypothesis-driven studies on acute neurological dysfunction and intervention effects.
Screening & Assay Development
- Provides standardized protocols for reproducible acquisition of quantitative Doppler and flow velocity data.
- Enables rapid screening of neurological status in preclinical and translational models.
- Supports assay development for evaluating interventions targeting cerebral circulation.
Translational & Preclinical Research
- Aligns with disease-relevant endpoints such as vasospasm, intracranial pressure, and cerebral circulatory arrest.
- Ensures continuity from discovery-stage mechanistic studies to preclinical validation of neuroprotective strategies.
- Reduces translational risk by enabling early detection of neurological compromise in model systems.
Pipeline & Workflow Integration
TCCD ultrasound integrates into the discovery-to-preclinical continuum by enabling hypothesis testing, quantitative readouts, and standardized data acquisition for neurological endpoints.
- Discovery Biology: Supports pathway clarification and biological de-risking through real-time cerebral flow assessment.
- Screening: Delivers reproducible, quantitative Doppler outputs for cross-condition comparison.
- Analytics: Provides velocity, pulsatility, and spectral waveform data for robust statistical analysis.
- Translational Research: Bridges early discovery with preclinical validation of neurovascular interventions.
- Enterprise Reuse: Establishes a scalable, protocol-driven capability for ongoing neurological research and screening.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in neurovascular studies.
- Operational Value: Promotes standardization, reproducibility, and rapid deployment in critical care and research settings.
- Strategic Value: Enables informed go/no-go decisions and capital-efficient advancement of neurotherapeutic programs.
- Portfolio Impact: Supports risk-adjusted prioritization and cross-functional collaboration in neurological R&D.
Implementation Considerations
- Requires specialized training in TCCD image acquisition and interpretation.
- Needs access to phased array probes and Doppler-capable ultrasound systems.
- Demands cross-team standardization for protocol adherence and data comparability.
- May require adaptation for different patient populations or preclinical models.
- Image quality and diagnostic thresholds depend on operator expertise and equipment calibration.
