Object ID: 00000018WIA30025C80GYZ
Topic ID: id_2036502 Version: 1.3
Date: Mar 3, 2022 1:47:01 PM

Silenz: acquire a MRA scan

About this task

Use these steps to acquire and process Silenz MRA axial, sagittal or coronal neurological MRA images with ASL and without the use of contrast agents on your MR system. Silenz MRA is compatible with:

Warning

IEC 60601-2-33: 201.7.9.2.101 (d) Hearing protection is required for all people in the magnet room during a scan to prevent hearing impairment. Acoustic levels may exceed 99 dB(A)

Step-by-step instructions

Position the patient for a head exam.
- Provide the patient with hearing protection. Although the Silenz MRA scan is very quiet, hearing protection is still required because any other prescribed scans including prescan and non-Silenz sequences may have acoustic levels exceeding 99 dB(A).
- Silenz MRA is compatible with a limited number of coils:
Open a scan session.
From the workflow Manager, click Add Task > Add Sequence.
1. Silenz MRA is a neurological application, so typically the protocol is located under the Head tab.
2. From the Protocol list, click the Silenz MRA series and add it to the Multi-Protocol basket.
3. Click Accept.
Acquire the 3-plane localizer.
From the Workflow Manager, select the Silenz MRA series and click Setup.
1. Confirm that Silenz is selected on the PSD/Imaging Options Application area.
2. Confirm that Bright Blood (ASL) is selected on the Imaging Option area.
3. From the scan parameter screen, select Slice Thickness and Slices per Slab.
To view the Details screen, click the of the scan parameters screen. Make scan parameter adjustments as needed.
1. Silenz MRA images can be acquired in the axial, sagittal, and coronal plane.
2. From the scan parameter screen, review the Acq Voxel Size display. For more details, see Advisory area.
  Figure 1. Silenz advisory area
3. See the following Silenz specific topics for scan parameter details: Spokes per Segment
Click the Advanced tab and for details see, SAR Optimization.
Graphically deposit and position the 3D slab to cover the region of interest.
Silenz is a non spatially selective sequence and therefore the imaging volume needs to be large enough to encompass all anatomy visible to the coils.
Select an option from the Auto IR Band menu: On or Off. The IR Band is used to determine the position of the ASL tagging and control planes.
- Select On to automatically prescribe the IR band.
- Select Off, to manually position the IR band and complete the following steps:
1. From the Graphic Rx toolbar, click IR.
2. From the IR menu, click IR A. Only one IR saturation band is allowed with Silenz MRA.
3. Place the cursor on the localizer image and click to deposit the IR saturation band.
  - The position of ASL tagging plane is determined by the inferior boundary of the IR band.
  - The position of ASL control plane is determined by the superior boundary of the IR band.
4. Adjust the IR band so that superior/inferior edges are outside the 3D slab.
  - Placement of the IR band edges is critical in order to avoid signal suppression in the final images.
    Figure 2. Example of IR saturation band placement
If desired, see Add post-process task. Compatible post-process tasks include:
1. Maximum Intensity Projection. Typically select Automatic.
2. MultiPlanar Reconstruction (MPR).
When the prescription is finished, click Save Rx > Scan.
- It is only the Silenz MRA scan that is quiet. The prescan portion of the Silenz MRA scan is quieter than prescan for other sequences but the prescan sound and subsequent series require that all patients have hearing protection.
- Due to the very quiet nature of the Silenz MRA scan, remind the patient to hold very still when the scan is about to start and inform the patient when the scan is completed.
- It is useful to observe the scan countdown on the AutoView screen to check the scan's progress.
When the Silenz MRA series is completed, execute the following steps to view the reformatted images:
1. Select the scanned series from the Workflow Manager task list.
2. Click View.