• Object ID: 00000018WIA30356970GYZ
  • Topic ID: id_40025584 Version: 1.4
  • Date: Aug 21, 2022 6:25:09 PM

PC: 2D scan

Uses for 2D Phase Contrast include:

  • indicating flow direction and velocity for intracranial and extracranial vasculature
  • detecting slow flow states in arterial venous malformations and aneurysms, using variable velocity encoding
  • assessing portal and hepatic vein anatomy
  • generating a vascular localizer prior to more lengthy 3D Phase Contrast angiography
  • acquiring several quick images at various VENCs, in order to get a rough idea of the range of flows represented
  • as an alternative to 3D Phase Contrast collapsed images when the imaging plane for anatomy is known and the exam does not need to be re-projected into different planes at a later date

Consider this information when modifying 2D Phase Contrast scan parameters. For specific scan parameter values, select a protocol from your GE or Site library.

  • Scan selections: 2D mode, Vascular family, Phase Contrast pulse.

General

  • Images to be used for Flow Analysis cannot exceed 20 mm.
  • It is not compatible with projection images, nor with MRA.
  • Oblique imaging requires a localizer
    • single-axis and double-axis obliques (an oblique scan prescribed from an oblique localizer) can be used.
    • single-axis oblique images are sometimes referred to as simple obliques or one-angle obliques.

Scan Parameters

  • Flip angle
    • Moderate flip angles (20 to 40) improve signal in flowing vessels and improve the background vessel contrast.
    • Larger flip angles may increase the severity of pulsatile flow artifacts.
    • As flip angle increases, there is greater saturation of small vessels that have slower flow.
    • In areas of fast flow, flip angle increases may cause pixel overranges and thus reduce the measured flow rate and velocity in Flow Analysis.
  • Slabs
    • Single slab imaging does not allow a collapsed image to be created in addition to projection images.
    • Single, thick slab (3 to 5 mm) or smaller multiple slices can be prescribed.
  • Slice thickness
    • Acquisitions with a slice thickness > 20 mm should use Complex Difference reconstruction for optimal background suppression.
    • Thin slices increase partial volume effects and decrease intravoxel dephasing.
  • PC tab:
    • Select Complex Diff with 2D Phase Contrast thick slab scans.
    • Select Phase Diff and Flow Analysis On if the images are used for flow analysis.

User CVs

Click the Advance tab to view the available User CVs. The CVs may vary based on the field strength and selected scan and imaging parameters.

Post-process tasks

There are multiple compatible post-process tasks. For details, see Add post-process task.

  • Image Enhancement Filters
  • Negative Enhancement Integral MRSTD
  • Pasting (only if series are linked)