What is phase contrast MR angiography?

What is phase contrast MR angiography?

Phase contrast angiography relies on dephasing the moving spins submitted to a bipolar gradient. For a bipolar gradient of a given intensity and time, the moving spins will dephase in proportion to their velocity. Similar to spatial encoding in the phase direction, the possible phase values range from – π to + π.

What are the different types of MRI contrast?

According to biodistribution and applications, MRI contrast agents may be categorised into three types: extracellular fluid, blood pool and target/organ-specific agents.

What is contrast enhanced MRA?

Contrast-enhanced MR angiography (MRA) is a technique involving 3D spoiled gradient-echo (GE) sequences, with administration of gadolinium-based contrast agents (GBCA). It can be used to assess vascular structures of almost any part of the body.

What is a phase contrast MRI scan?

Phase contrast imaging is an MRI technique that can be used to visualize moving fluid. Spins that are moving in the same direction as a magnetic field gradient develop a phase shift that is proportional to the velocity of the spins. This is the basis of phase-contrast angiography.

What is intracranial phase-contrast imaging?

phase-contrast imaging for our brain angiographic studies, in which bipolar gradients are applied along the x, y,and zaxes sequentially and velocity components along each direction are computed. Intracranial phase-contrast MR angiography is superior to TOF MRI for the evaluation of arteriovenous malformations and the workup

Is intracranial phase-contrast MR angiography superior to TOF MRI?

Intracranial phase-contrast MR angiography is superior to TOF MRI for the evaluation of arteriovenous malformations and the workup of patients with aneurysms in the presence of 132 January-February 2020 radiographics.rsna.org Figure 15. Sagittal TOF (a) and phase-contrast (b) maximum intensity projection reconstruction MR venograms.

What is the difference between a bipolar gradient and Phase Contrast angiography?

A bipolar gradient pulse with equal magnitude and opposite direction is used to diminish signal from the stationary tissue. Phase contrast angiography (PCA) utilises the transverse magnetization vector. In phase difference images, the signal is linearly proportional to the velocity of the spins.