New Imaging Technologies Make Surgery Easier
By Michael Lasalandra
Beth Israel Deaconess Medical Center Correspondent
New imaging technologies are allowing brain and spine surgeons to get better pictures of their targets, particularly during operations, so they can see if the images done beforehand are still accurate, determine if there has been any shifting of tissue during the operation and, at the conclusion, find out if they have done what they set out to do.
"Surgeons since the beginning of time have used their knowledge of the anatomy to help guide the course of an operation," says
Dr. Michael Groff, Director of the Neurosurgical Spine Service and Co-Director of the
Spine Center at
Beth Israel Deaconess Medical Center. "In recent times, there has been an explosion of imaging technology. As a result, our understanding of the anatomy, preoperatively, is much greater than ever before. Now, new technologies are allowing us to refine imaging to see what happens at the time of surgery."
Intraoperative three-dimensional imaging allows surgeons to use MRI (Magnetic Resonance Imaging) or CT (computed tomography) technology during surgery to compare images taken during the course of the surgery to those taken prior to the surgery.
"It allows you to identify a structure in the surgical field and have the computer tell you which point it corresponds to on the preoperative image," Dr. Groff says.
In addition, it allows to directly visualize the surgical field in all dimensions and is able to account for any patient or organ motion, which can skew image accuracy. It can help, for example, guide the surgeon to precisely insert a tiny pin into a bone during spine surgery, Dr. Groff says.
Intraoperative imaging also uses the MRI or CT technology towards the end of the operation to tell the surgeon if the task has been accomplished.
For example, if the surgery is designed to remove a brain tumor, the imaging technology can be used to assess the extent of surgery, which is important for further treatment and to establish an objective baseline to a evaluate all following treatments. Otherwise, that information might not be known until a post-surgery image is taken and those images, depending on when they are taken after surgery, may be less reliable, says
Dr. Peter Warnke, Chief of Neurosurgery at BIDMC and Visiting Professor of Surgery at Harvard Medical School.
This technology will make surgery more concise and, with the integration of functional images that show brain function in relation to the intraoperative anatomy, will make surgery less prone to complications, Dr. Warnke says.
Another advance is known as stereotactic imaging in which a previously taken MRI or CT scan image can be fused with an image taken by a PET (Positron Emission Tomography) scanner, a type of nuclear medicine imaging. This can be integrated into a three-dimensional reference system equivalent to a 3D map of the brain. This system allows surgical approaches with greater precision, Dr. Warnke says.
The fused scan can show active tumors as three-dimensional, making it easier to pinpoint exactly what tissue must be removed,
"It tells us where the biologically active tumor parts are," he says. "It is more precise and far superior to a regular MRI which never shows the real extent of a brain tumor but only the areas with leaky vessels or different water content."
The technology also allows for the surgeon to see if there has been any shifting of the brain tissue during the actual procedure.
The improvements in imaging technology "allow you to plan the surgery much more carefully and the more carefully you plan, the safer it is for the patient," he says.
Above content provided by Beth Israel Deaconess Medical Center.
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Posted July 2011