Page Comparison

Topics covered:

1. Introduction to Verasonics Vantage 32LE Ultrasound Research System.

2. Introduction to ultrasound transducers.

3. Introduction to ultrasound imaging modes.

4. Real-time data acquisition using Verasonics.

5. Time-of-Flight measurement of common carotid artery (cca) using ultrasound and image processing.

6. Flow measurement and colour doppler imaging using ultrasound.

Experiment details:

Introduction

This experiment involves the use of the Verasonics Vantage 32LE, a sophisticated ultrasound research system, to explore various aspects of ultrasound imaging and data acquisition. Participants will gain hands-on experience with different ultrasound imaging modes, including A-Mode, B-Mode, Colour Doppler, and Power Doppler, while understanding the applications of linear array, curvilinear/convex, and phased array transducers. The experiment will also cover real-time data acquisition using the Verasonics system, focusing on measuring Time-of-Flight values for echoes and analyzing the power spectrum of ultrasound signals in Doppler mode. This comprehensive approach will provide a deeper understanding of both the technical and practical aspects of ultrasound technology.

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To find the difference in time-of-flight between the two echoes:

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Procedure

1. Introduction to Verasonics Vantage 32LE Ultrasound Research System

• Objective: Familiarize with the Verasonics Vantage 32LE system, its components, and its capabilities.

• Procedure:

  1. Begin with an overview of the Verasonics Vantage 32LE system, including the main console, transducers, and the user interface.

  2. Discuss the system's key features, such as its high-performance computing capabilities, customizable imaging modes, and real-time data acquisition.

  3. Demonstrate how to power on the system, navigate the user interface, and set up the system for imaging.

2. Introduction to Ultrasound Transducers

• Objective: Understand the different types of ultrasound transducers and their applications.

• Procedure:

  1. Present the various transducer types available with the Verasonics system, including linear array, curvilinear, and phased array transducers.

  2. Explain the physical principles behind each transducer type, focusing on beam formation and the impact of transducer geometry on imaging.

  3. Describe the common applications of each transducer type:

     • Linear Array: High-resolution imaging of superficial structures (e.g., vascular studies).

     • Curvilinear Array: Deeper imaging, commonly used in abdominal imaging.

     • Phased Array: Cardiac imaging, due to its ability to scan through narrow acoustic windows.

3. Introduction to Ultrasound Imaging Modes

• Objective: Learn about the various ultrasound imaging modes available on the Verasonics system.

• Procedure:

  1. A-Mode (Amplitude Mode):

     • Explain the concept of A-mode imaging and its historical significance.

     • Demonstrate the use of A-mode to measure distances within tissues.

  2. B-Mode (Brightness Mode):

     • Describe B-mode as the most common imaging mode for real-time 2D imaging.

     • Show how to set up and acquire B-mode images of the common carotid artery (CCA).

     • Discuss the interpretation of B-mode images, focusing on anatomical structures.

  3. Color Doppler Imaging:

     • Introduce the principles of Doppler ultrasound and how it measures blood flow velocity.

     • Demonstrate the setup and acquisition of Color Doppler images, focusing on blood flow within the CCA.

     • Discuss the interpretation of Color Doppler images, with emphasis on flow direction and velocity.

  4. Spectral Doppler Imaging:

     • Explain the concept of Spectral Doppler and its use in quantifying blood flow velocity.

     • Demonstrate how to acquire a Spectral Doppler waveform and interpret the results, focusing on the CCA.

4. Real-Time Data Acquisition Using Verasonics

• Objective: Acquire real-time ultrasound data using the Verasonics system and understand the process of data handling and storage.

• Procedure:

  1. Set up the Verasonics system for real-time data acquisition in B-mode.

  2. Position the selected transducer on the subject’s neck, over the CCA.

  3. Adjust imaging parameters (e.g., depth, gain, focus) to optimize image quality.

  4. Acquire and save real-time B-mode images of the CCA.

  5. Transition to Color Doppler mode and acquire real-time flow images.

  6. Save all acquired data for further analysis.

5. Time-of-Flight Measurement of Common Carotid Artery (CCA) Using Ultrasound and Image Processing

• Objective: Measure the time-of-flight (TOF) of ultrasound pulses reflecting off the CCA and process the data for analysis.

• Procedure:

  1. Use the B-mode images acquired previously to identify the CCA and measure the depth of the anterior and posterior walls.

  2. Calculate the TOF for ultrasound pulses reflecting from these walls using the formula:

     TOF=2dc\text{TOF} = \frac{2d}{c}TOF=c2d​

     where ddd is the depth of the wall and ccc is the speed of sound in tissue.

  3. Use image processing software (e.g., MATLAB) to analyze the B-mode images and extract TOF data.

  4. Discuss the significance of TOF measurements in clinical practice, such as assessing arterial wall thickness.

6. Flow Measurement and Color Doppler Imaging Using Ultrasound

• Objective: Measure blood flow in the CCA using Color Doppler and analyze the results.

• Procedure:

  1. Set up the Verasonics system for Color Doppler imaging of the CCA.

  2. Acquire Color Doppler images, ensuring that the flow is visualized across the vessel.

  3. Use Spectral Doppler to obtain a waveform of the blood flow velocity.

  4. Measure key parameters from the Doppler waveform, such as peak systolic velocity (PSV) and end-diastolic velocity (EDV).

  5. Analyze the flow patterns, and discuss potential clinical implications, such as identifying stenosis or other vascular conditions.

Report requirements:

The report for this part is expected to include: 

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