[The peripheral circulation: ECG-gated magnetic resonance angiography]

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Peripheral vascular disease diagnosis relies on accurate imaging.
• Magnetic Resonance Angiography (MRA) is a key non-invasive imaging modality.
• Optimizing MRA techniques for peripheral vessels is crucial for clinical diagnosis.

Purpose of the Study:

• To compare the efficacy of MRA with and without electrocardiogram (ECG) gating for peripheral vessel imaging.
• To evaluate the impact of different trigger delays on image quality and vessel visualization.
• To determine the optimal MRA technique for studying femoral, popliteal, and tibial arteries.

Main Methods:

• Ten healthy volunteers underwent MRA of lower limb vessels using a 1.5-T magnet and 2D Time-of-Flight (TOF) technique.
• MRA was performed both without cardiac gating and with varying trigger delays (0, 20, 40, 70, 200 ms).
• Image analysis included counting visualized vessels and calculating signal-to-noise (S/N) ratios for each segment.

Main Results:

• MRA with cardiac gating consistently visualized more vessels across all peripheral segments (femoral, popliteal, tibial) compared to non-gated MRA.
• While non-gated MRA showed higher S/N ratios, gated MRA provided superior vessel delineation.
• Specific trigger delays in gated MRA demonstrated comparable, high vessel counts, indicating robustness of the technique.

Conclusions:

• Electrocardiogram (ECG) gated MRA significantly enhances the visualization of peripheral vessels.
• Cardiac gating is recommended for improved diagnostic accuracy in peripheral MRA studies.
• The TOF 2D technique with cardiac gating offers superior peripheral vessel assessment.