Prospective Self-Gated Nonenhanced Magnetic Resonance Angiography of the Peripheral Arteries

Most nonenhanced MRA techniques for evaluating peripheral artery disease (PAD) require cardiac synchronization through physiological gating. Electrocardiographic (ECG) gating is the most popular method for cardiac synchronization; however, it is subject to interference from switching magnetic field gradients and radiofrequency pulses. A method is described for self-gated nonenhanced MRA that does not require the use of ECG gating. Imaging was prospectively triggered by detecting the acceleration of blood flow during systole with a reference-less phase contrast navigator. The technique was implemented for non-subtractive nonenhanced MRA using quiescent-interval single-shot (QISS) MRA. The lower extremity peripheral arteries of eight healthy subjects were imaged using ECG-, pulse-, and self-gated QISS. Self-gated QISS triggered with 99% accuracy. There were no significant differences in relative contrast, contrast-to-noise ratio, or image quality between self-gated and ECG-gated QISS MRA (p > 0.05). Image quality with pulse gating was inferior.