Whole-body MR angiography using variable density sampling and dual-injection bolus-chase acquisition

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Conventional bolus-chase angiography has limitations in peripheral runoff imaging, including low spatial resolution, limited slice coverage, and venous contamination.
• These issues are particularly problematic in distal vascular segments, hindering accurate diagnosis and assessment.
• Improved imaging techniques are needed to overcome these challenges in magnetic resonance angiography (MRA).

Purpose of the Study:

• To present and evaluate a novel whole-body magnetic resonance angiography (WB-MRA) technique using a dual-contrast-injection, four-station acquisition protocol.
• To address the limitations of conventional methods in generating high-resolution peripheral runoff images.
• To demonstrate the feasibility of the proposed WB-MRA technique in phantom and human volunteer studies.

Main Methods:

• Implementation of a four-station acquisition protocol with dual contrast injections for WB-MRA.
• Utilized bolus sharing between stations: abdomen/calf (first bolus) and thorax/thigh (second bolus).
• Applied variable density sampling and elliptical centric acquisition order for abdomen/thorax; extended scan time for high-resolution calf/thigh imaging.

Main Results:

• The dual-injection WB-MRA technique successfully generated peripheral runoff images with improved characteristics.
• Demonstrated feasibility in phantom studies, indicating technical viability.
• Validated in vivo in human volunteers, showing promising results for clinical application.

Conclusions:

• The presented dual-contrast-injection WB-MRA technique offers a viable solution to overcome limitations of conventional angiography for peripheral runoff imaging.
• This protocol enhances spatial resolution and slice coverage, particularly in distal stations.
• The technique shows potential for improved diagnostic accuracy in vascular imaging.