Quantification of Blood Velocity with 4D Digital Subtraction Angiography Using the Shifted Least-Squares Method

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Fluid Dynamics

Background:

• Four-dimensional digital subtraction angiography (4D-DSA) offers high temporal and spatial resolution for visualizing blood flow.
• Accurate quantification of blood velocity is crucial for diagnosing and managing vascular diseases.

Purpose of the Study:

• To investigate a shifted least-squares method for estimating blood velocity using 4D-DSA data.
• To validate the accuracy of this novel method against established techniques.

Main Methods:

• Determined vascular centerlines and time-concentration curves from 4D-DSA datasets.
• Calculated temporal shifts along centerlines to derive velocity, fitting the data to a straight line.
• Validated the method using a flow phantom and compared results with 3D phase-contrast MRI in human internal carotid arteries.

Main Results:

• 4D-DSA-derived mean velocities in a flow phantom showed excellent agreement with ultrasonic flow probe measurements (11% RMSE).
• Blood velocities in internal carotid arteries estimated via 4D-DSA correlated well with 3D phase-contrast MRI (r = 0.835).

Conclusions:

• The shifted least-squares method effectively estimates blood velocity from 4D-DSA.
• This technique provides a valuable tool for quantitative vascular analysis within a 3D volume.