MR Brain Pre DBS - GPI Neuro Protocol

Scan notes:

  • If the target isn’t specified in the order for pre-DBS, contact the RDO to verify if the “GPI” or “STN” or "VIM" protocol should be used.
  • OK to use padding and headphones for all DBS patients.
  • No angles on any sequences.
  • No compressed sense.
  • YOU MUST GET THE IMAGES CHECKED prior to letting the patient go. These need to be checked either by a radiologist or someone from Neurosurgery. If the motion is too excessive, we need to get the ball started for arranging to have the exam done with GA, as many of these patients have surgery scheduled within days of the MRI.
  • As of 10/16/2019, DTI is no longer needed.
  • All Pre- DBS exams are ordered with anxiolytics.  Radiology RNs are to evaluate the patient if you note that the patient cannot hold still.

Last updated: 8/17/2020
Charge as: Brain WO
Scanner preference: 3T only
Coil: Head

POSITIONING

  • Positioning is very important in obtaining a study that fuses. 
  • If the patient is laying with the head going too far backwards, it is important to raise the head so the chin is down.
  • The head coil can be tilted or a sponge can be used under the patients head, which allows for better coverage.
  • OK to add slices for coverage. Slices should be from top of vertex to as low as you can go. 
  • You need to be below the acoustic nerves for best outcome.

GPI SEQUENCE NOTES FOR SIEMENS SCANNERS

as of 8/6/2020

Adding Slices:
The GPI series on MR3 is very temperamental. Please do not change the number of slices on this sequence. If you add or remove slices to the series, it will change the weighting and make the series un-usable for Neurosurgery due to the forced changes in TR/TE that result from changing the number of slices. This is an issue specific to the Siemens Scanner.

Coverage:
For the GPI sequence, the images need to cover at a minimum from the vertex through the Globus Pallidus. If the number of slices on the Siemens does not provide full brain coverage, you can clip the Cerebellum and lower brain stem structures.

RAD TO CHECK IMAGES AND TECH TO NOTIFY SURGEONS BEFORE PT LEAVES THE DEPARTMENT

  1. Neuro Radiologist must be paged to check the images. Make a note of the Rad's name.
  2. Page Dr. Burchiel x11292, Anne Mitchell x12996, and Antonia Gragg x16703 in the following format:
    1. Patient last name, GPI, VIM or STM for study type, comment (Pass or fail) and the Radiologist name.
      1. Example if comment is "Pass": "Smith, GPI, Pass, Checked by neuro rad Hamilton"
      2. Example if comment is "Fail": "Smith, GPI, Fail, Checked by neuro rad Hamilton, patient waiting in MRI"
    2. If it fails, the patient needs to remain in department (add to page that patient is waiting). 
    3. We are required to reschedule the patient with GA using a callback
MRI GPI image quality examples for MRI technologists
Plane Weighting Mode Slice Gap FAT SAT FOV Notes
AXIAL 3D T1 FFE None 26cm DO NOT ANGLE. Cover above the vertex of the brain at least 1 cm. Cover the nose.
AXIAL (GPI) MPRAGE 3D Ok to change on Philips only. Do not increase slices on MR3 (Siemens) ISO None DO NOT CHANGE DO NOT ANGLE. FULL BRAIN COVERAGE. SEE NOTES FOR INSTRUCTIONS ON POSITIONING, COVERAGE AND HOW TO GET THE IMAGES CHECKED.
Radiologist must check images. Neurosurgeons must be paged. See notes.

RAD TO CHECK IMAGES AND TECH TO NOTIFY SURGEONS BEFORE PT LEAVES THE DEPARTMENT

  1. Neuro Radiologist must be paged to check the images. Make a note of the Rad's name.
  2. Page Dr. Burchiel x11292, Anne Mitchell x12996, and Antonia Gragg x16703 in the following format:
    1. Patient last name, GPI, VIM or STM for study type, comment (Pass or fail) and the Radiologist name.
      1. Example if comment is "Pass": "Smith, GPI, Pass, Checked by neuro rad Hamilton"
      2. Example if comment is "Fail": "Smith, GPI, Fail, Checked by neuro rad Hamilton, patient waiting in MRI"
    2. If it fails, the patient needs to remain in department (add to page that patient is waiting). 
    3. We are required to reschedule the patient with GA using a callback