Time-of-Flight Magnetic Resonance Angiography to Visualize Blood Vasculature

Position the patient's head inside the radiofrequency, or RF, coil of a magnetic resonance imaging, or MRI, machine.

Initiate the time-of-flight magnetic resonance angiography or TOF MRA, a non-invasive technique for visualizing blood vessels.

Select a tissue slice for imaging to visualize arteries and veins.

Apply an RF pulse to excite the protons within the selected imaging slice. These protons release energy, which is detected as an MR signal.

Repeated application of RF pulses saturates the MR signal from stationary tissue, resulting in a darkened background.

Fresh blood flowing into the imaging slice contains unsaturated protons that, upon RF excitation, produce strong signals.

Next, apply a saturating pulse proximal to the imaging slice to saturate protons in the venous flow returning to the imaging slice, ensuring the signal comes exclusively from arterial blood outflow.

The resulting high-contrast image exhibits bright arteries against a dark background.