April Spotlight: Neuroradiology and the fMRI exam

April is host to Neurodiagnostic Week, a time to honor and celebrate the contributions of our neurodiagnostic professionals.

Our Neuroradiology department is an integral part of the diagnostic evaluation process and collaborates with all OHSU clinical and medical teams including but not limited to neurosurgery, interventional neuroradiology, ENT surgery, orthopedic surgery, and vascular surgery.

One of the most advanced techniques we use is a functional magnetic resonance imaging (fMRI) exam. This exam is tailored to the location of the brain lesion, regions of clinical concern, and the normal brain adjacent to it.axial fmri and dti

The goal is to allow the neurosurgeon or clinician to plan the optimal, least invasive approach, and to allow the surgeon to more completely excise a mass or portion of the brain while preserving as much normal function as possible.

How it works:.

Functional MRI is based on changes in blood flow to regions of the brain associated with an activity.

For example, when you move your fingers, the neurons in your brain that tell your finger to move need more oxygenated blood and the body delivers more blood to these cells.

The MRI scanner can measure these very small changes in blood flow and display them on an image. The test is designed to evaluate different tasks such as tapping your fingers or reading/thinking of words.

These tasks allow the MRI to identify these critical areas of the brain cortex before surgery. To identify the “wiring of the brain” or the connections between the cortex and your extremities, we use a technique called diffusion tensor imaging (DTI).

3d dtiThis complex MRI sequence allows visualization of the white matter of the brain and shows where regions of the brain are connected.

The fMRI and DTI images are then incorporated together into the operating room so the neurosurgeon can navigate around these critical areas and perform the surgery without damaging these areas.

An fMRI is often indicated for presurgical planning for many conditions including but not limited to epilepsy and brain tumors.

fMRI allows a patient to better understand the potential risks of having surgery. Many studies have shown reduced morbidity and increased survival rates in patients who have had preoperative fMRI.

I started the current fMRI program in 2008 when I arrived at OHSU from Wake Forest University. In the beginning of the program, all the fMRI exams were audio based. Patients would have to listen to words being read to them while in the scanner.

While the fMRI was often successful, the MRI environment is quite loud so some patients had difficulty hearing the words. The potential of the technology was still demonstrated and many patients had great results.

OHSU realized the potential and made significant investments in hardware and software which allowed patients to see the fMRI data with a large MRI compatible LCD monitor.

Now patients will silently read words or follow instructions on the screen to move their fingers. The visual based fMRI system has allowed many more patients to benefit from the technology. In addition to the hardware upgrade, the new software allowed for seamless integration of the fMRI and DTI data into the surgical environment.

Over 300 patients have since been successfully scanned making OHSU one of the most active fMRI programs on the west coast.

What do our providers have to say about this technology?

“There is no doubt that fMRI has revolutionized our approach to patients with a number of brain conditions.

  1.  Notably, fMRI has allowed a much less invasive and specific evaluation of hemispheric dominance for language which in years past required cerebral arteriography and Wada testing.
  2.  fMRI brain mapping has now completely changed epilepsy surgery and tumor surgery such that the surgeon is now armed with knowledge of the discrete functional areas adjacent to tumors or epileptogenic foci.
  3.  DTI has facilitated tumor surgery by allowing the surgeon to avoid vital tracts.
  4.  DTI has allowed us to begin to understand the behavior of implanted brain electrodes (DBS) with respect to dense fiber tracts such as the internal capsule.

Having been here for almost twenty years before this project was instituted, I could see in 2007 how far fMRI had to go to be to even be on a par with other academic medical centers in the area of functional imaging.  To now be in the forefront of this field on the west coast shows how much has been accomplished.  I am very thankful that we have come so far.”

Dr. Kim Burchiel is an OHSU neurosurgeon and pioneer in deep brain stimulation surgery.


Kim J. Burchiel, M.D., F.A.C.S.

John Raaf Professor and Head
Division of Functional Neurosurgery
Department of Neurological Surgery
Professor, Dept. of Anesthesiology and Perioperative Medicine

“Recent AAN guidelines for use of fMRI in epilepsy surgery evaluation will lead to increased utilization of this technology (and fewer Wada tests).”

Spencer,David_12

 

David Spencer, M.D.
Director, Comprehensive Epilepsy Center

 

 

 

“fMRI is crucial to delivering the most advanced neurosurgical care in the world, curing disease while preserving function. As part of our new intra-operative MRI brain surgery program at OHSU, we can now bring functional MRI into the operating room itself, offering the most powerful capabilities to the patients who need our advanced care.”
Selden-2

 

Nathan R. Selden, M.D., Ph.D., F.A.C.S, F.A.A.P.
Campagna Professor and Chair of the OHSU Department of Neurological Surgery.

 

 

 

The Neuroradiology section of Diagnostic Radiology offers a full range of state of the art computed tomography (CT) and magnetic resonance imaging (MRI) services for the neuroaxis including the brain, spinal cord, skull, orbits, sinuses, temporal bone, and neck of the adult and pediatric patient. 

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Pollock,Jeffrey_10

 

Jeffrey M. Pollock, M.D. is an Associate Professor of Radiology

 

 

 

Interested in seeing more images from our neurodiagnostic technicians as well as other examples of #neuroart?
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