To discuss time-resolved MR angiography (TR-MRA) sequences according to its physical bases and differences . To review clinical scenarios where TR-MRA can be the best noninvasive tool. To depict how to perform and report time-resolved MRA. To show some interesting cases using this technique.
Conventional contrast enhanced MR angiography (MRA) techniques are widely used in routine practice.
although with a superb spatial resolution,
have limited temporal resolution because of long acquisition times.
breath-hold is also needed,
which can be difficult in some frequent clinical scenarios where angiography is planned. Recent development both in hardware and software have brought us time-resolved MRA (TR-MRA) imaging,
which can obtain real time fluoroscopic...
Findings and procedure details
TR-MRA delivers vascular imaging with enough temporal resolution to assess contrast flow dynamics in arteries and veins (and requiring only a small contrast dose).
A typical TR- MRA study may contain more than twenty images obtained at rates as rapid as 1-5 frames per second. As we all know (and suffer),
spatial and temporal cannot usually be obtained at the same time.
TR-MRA techniques balance this,
using a process called view-sharing .
Remember the distribution of the k-space: The center of...
TR-MRA is a technique with very high temporal and spatial resolution which allow to capture the multiple arterial,
venous phase images during the passage of a contrast agent through the vascular anatomy The method is particularly useful for evaluating collateral or retrograde flow around stenoses and in the work up of arteriovenous malformations. Prior knowledge is key to perform and report TR-MRA studies.
New developments in MRA: time-resolved MRA. Neuroradiology , 46 (2),
Time-resolved projection MRA: clinical application in intracranial vascular malformations. Neuroradiology , 42 (2),
Contrast-enhanced time-resolved MRA for pre-angiographic evaluation of suspected spinal dural arterial venous...