Creating & Filming CISS or MP-RAGE
MPRs for Acoustic Nerves
Greg Brown Royal Adelaide Hospital
These notes describe step by step the process of creating suitably
angled Axials for the VIIth and VIIIth cranial nerves on a Siemens
Magnetom using Numaris 3 VB31 software.
The cranial nerves of the IAM angle upwards as they extend lateral and
anterior, this combined with the very thin slices of the CISS and MP-RAGE
sequences means that the scanning plane is rarely the optimal plane for
display of the nerves.
12 images parallel to the VII and VIII cranial nerves (facial & acoustic)
1 mm thick, covering from the V nerve (trigeminal) to below the CP angle
12 format sheet. Magnification factor 1.5 (presented FOV 134 mm)
Film the 12 images that start just above the Vth nerves but include a slice
below the VIII nerves
Start MPR and select appropriate Study
Click on Double Oblique, then click on sagittal image
Place the bulls eye at the brainstem insertion of VII and VIII (the
posterior inferior junction of Pons and Medulla) looking at the reconstructed
axial to find the proximal insertion.
Swing the anterior edge of the prescription line upwards. If your bulls
eye is in the right spot the proximal end of the nerves will stay in the
image and you will progressively see more of the distal nerves.
Adjust the prescription line on the coronal image to get both sides
in the same plane.
When the plane is correct go back to the sagittal image and slide the
bulls eye anterior until the IAMS appear in the coronal image.
Click back to the coronal image (segment 2) slides the prescription
line bulls eye up to just above the V nerves. Click Define Start,
Click Define End slide the bulls eye down to just clear the IAM CSF.
Check that Thick Slices is OFF and spacing set to 1 mm. There should
be 12-16 slice locations
Save images by clicking I/O Data Store study (or all) Go
Exit the MPR platform