1. Intraoperative MRI Imaging Strategies to Evaluate for Complications during DBS Surgery
Olivia Huston
Kendall Lee MD, PhD
Robert Watson MD, PhD
Matt Bernstein PhD
John Huston MD
Kiaran McGee PhD
Mayo Clinic Rochester, MN

2. Intraoperative MRI During DBS Surgery Purpose
To determine the optimal imaging sequences, the imaging findings and the clinical consequences of those findings for MRI performed during DBS surgery.

3. Intraoperative MRI During DBS Surgery Methods
143 patients underwent 152 DBS surgeries utilizing intraoperative 1.5T MRI.
MRI sequences utilized:
- T1 MP-RAGE pre and intra-op
- T2* GRE intra-op
- T2 FLAIR selectively
- T2 FSE selectively
FLAIR and T2 FSE used ……
FLAIR – T2 weighted – shows extraaxial hyperacute blood subarachnoid and subdural
FSE – Fast Spin Echo

4. Intraoperative MRI During DBS Surgery Results
Number of Surgeries: 152
Subdural Hematomas: 5
Subarachnoid Hemorrhages: 3
Intraparenchymal Hemorrhage: 1
Subarachnoid Air: 4
Brain Shift: 144

5. Intraoperative MRI During DBS Surgery Subdural Hematoma
Number of SDH: 5
Average thickness: 5.2 mm
Range: 4-8 mm

6. Subdural Hematoma A GRE - isointense B MP-RAGE - iso
C FLAIR – high signal intensity
D CT – high attenuation
Subdural Hematoma

7. Intraoperative MRI During DBS Surgery Subarachnoid Hemorrhage
Number of SAH: 3
One patient experienced headache and disorientation requiring 2 additional days of hospitalization. Symptoms cleared prior to discharge.
This is the only patient in our study that had acute clinical changes associated with intracranial air or hemorrhage

8. Subarachnoid Hemorrhage
A – pre operative MP-RAGE
B – MPRAGE – iso – CSF displaced by iso
C – FRE - iso
D – FLAIR – high signal in subarachnoid space
E – CT – high attenuation in the subarachnoid space
Subarachnoid Hemorrhage

9. Intraoperative MRI During DBS Surgery Intraparenchymal Hemorrhage
Number Hemorrhages: 1
5 x 5 mm

10. Intraparenchymal HemorrhageB
C – GRE – slightly high signal compared to the adjacent brain tissue
D – FSE – clear high signal
E – confirmed on CT
Intraparenchymal Hemorrhage

11. Intraoperative MRI During DBS Surgery Subarachnoid Air
Number of SA Air: 4

12. Subarachnoid Air * Left lead replacement surgery
A pre-operative – solcus is large b/c of previous surgery
B postop – MP-RAGE – air is replaceing CSF but both are very low signal
C – GRE – low signal – mimicks acute blood
D – CT confirms air – low attenuation
Subarachnoid Air

13. Intraoperative MRI During DBS Surgery Brain Shift
Number with Shift: 144
Average: 0.6 cm
Range: cm

14. Brain Shift

15. Intraoperative MRI During DBS Surgery Conclusions
Intracranial hemorrhage is occasionally identified but is rarely clinically significant. One delayed SDH required evacuation.
Brain shift during DBS surgery is common.
Subarachnoid air mimics subarachnoid blood on GRE.
Selective use of T2 FLAIR and T2 FSE imaging can confirm the presence hemorrhage or air and precludes the need for CT exams.