Reducing view-sharing using compressed sensing in time-resolved contrast-enhanced magnetic resonance angiography

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• K-space view-sharing in time-resolved MR angiography (MRA) can introduce temporal and spatial blurring artifacts.
• These artifacts can affect image quality and diagnostic accuracy, particularly in dynamic vascular imaging.

Purpose of the Study:

• To investigate temporal and spatial blurring artifacts caused by k-space view-sharing in time-resolved MRA.
• To introduce and evaluate a novel technique, compressed sensing with time-resolved imaging with stochastic trajectories (CS-TWIST), for artifact reduction.

Main Methods:

• Acquisition of k-space data using a 3D time-resolved MRA view-sharing sequence.
• Retrospective reconstruction into two frameworks: standard TWIST (full view-sharing) and CS-TWIST (minimal view-sharing with compressed sensing).
• Qualitative and quantitative comparison of artifacts and image quality in phantom and patient studies (n=9).

Main Results:

• CS-TWIST achieved a two- to three-fold reduction in temporal footprint compared to TWIST.
• CS-TWIST demonstrated significantly higher subjective image quality (P < 0.05).
• CS-TWIST reduced delays in small vessel visualization and improved thoracic MRA vessel sharpness by 8.8% (P < 0.05).

Conclusions:

• View-sharing in time-resolved MRA inherently causes temporal and spatial artifacts due to an extended temporal footprint.
• CS-TWIST effectively mitigates these artifacts, leading to improved image quality and reduced motion sensitivity.
• CS-TWIST represents a promising advancement for artifact reduction in time-resolved MRA.