Intraoperative magnetic resonance imaging (iMRI) is a procedure to create images of the brain during surgery. Neurosurgeons rely on iMRI technology to create accurate pictures of the brain that guide them in removing brain tumors and other abnormalities during operations.

Advantages of iMRI

Though doctors use imaging tests to plan brain surgery, real-time images created with iMRI are crucial to:

  • Locate abnormalities if the brain has shifted. The brain often shifts during surgery, which makes pre-surgical imaging no longer exactly precise. Imaging with iMRI during the operation gives surgeons the most accurate information.
  • Distinguish abnormal brain tissue from normal brain tissue. It can be difficult to distinguish the edges of a brain tumor and separate normal tissue from abnormal tissue. Imaging with iMRI during surgery helps confirm successful removal of the entire brain tumor.

    Intraoperative MRI allows surgeons to achieve a more complete removal of some brain tumors. For this reason, iMRI has become the standard of care for operations to remove certain brain tumors.

How iMRI works

MRI uses a magnetic field and radio waves to create detailed images of the organs and tissues in your body. MRI is especially helpful for imaging the brain.

To utilize MRI technology during surgery, doctors use special imaging systems and operating rooms, including:

  • Portable iMRI devices, which are moved into the operating room to create images
  • Nearby iMRI devices, which are kept in a room adjacent to the operating room so that doctors can easily move you to the adjacent room for imaging during your surgery

At certain points in your operation, the surgeon may request imaging with iMRI. When and how often iMRI images are created during surgery depends on your procedure and your condition.

Uses for iMRI

Doctors use iMRI to assist in surgery to treat:

Intraoperative magnetic resonance imaging (iMRI) care at Mayo Clinic

Jan. 13, 2018
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  2. Barone DG, et al. Image guided surgery for the resection of brain tumors (review). Cochrane Database of Systematic Reviews. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD009685.pub2/abstract. Accessed May 20, 2014.
  3. Parney IF, et al. Awake craniotomy, electrophysiologic mapping and tumor resection with high-field intraoperative MRI. World Neurosurgery. 2010;73:547.
  4. Wharen RE (expert opinion). Mayo Clinic, Jacksonville, Fla. June 17, 2014.

Intraoperative magnetic resonance imaging (iMRI)