• John Koivukangas

Our Solution: The Birth of Modern Neuronavigation

Päivitetty: 2. maalis 2020

M.Curie was once asked why she studied radium. She answered: "Because the bibliography is so short."

Our early work in navigation was based on intraoperative ultrasound imaging since 1980. Surgerical imaging consists of three parts: Preoperative, intraoperative, and postoperative imaging. Intraoperative ultrasound and MR imaging continue to be to this day the very cutting edge of modern technologies, some 40 years later.

When MRI came, we wanted reformats in the plane (X, Y, Z) of the ultrasound image. One helped to understand the other. And we used ultrasound imaging to verify the accuracy of our new navigation system, one of the earliest in the world.

Watanabe had reported on a mechanical arm, while optical tracking would come later. Others, including peer reviewers of our manuscript in 1991 concluded that surgeons will want orthogonal images, the familiar axial, coronal and sagittal ones of atlases.

We insisted that the surgeon wants to know where he or she is going, hence our seminal "principle of the common axis" for all instruments, now used in image-guided surgery the world over (and in all contemporary VR-AR applications--you may substitute for the sake of simplicity "the common axis" with Point-of-View POV or Field-of-View FOV, that is, where you are looking determines what you see.

To demonstrate our work and in our own small way to disprove the notions of our esteemed colleagues in peer review, we brought the system to the operating rooms of the Department of Neurosurgery, University of Minnesota, during 1992-93.

Our paper was finally accepted in 1993.

The image above shows the first known actual surgical demonstration of one aspect of the principle of the common axis, namely coplanar MRI/US navigation: the intraopeative ultrasound and reformatted preoperative MR images are from the identical plane. The common axis can be seen in both images - this is to give the surgeon, once again, an intuitive understanding of where exactly s/he is going.

Benefit? US shows in real time that we are avoiding vascular structures. MRI shows the contrast enhancing tumor part for biopsy. This method is used in image-guided surgery centers the world over.

Credits: Oulu University Hospital, Oulu, Finland.

Reference: Koivukangas J, Y Louhisalmi, J Alakuijala, J Oikarinen (1993) Ultrasound-controlled neuronavigator-guided brain surgery. J Neurosurg 79: 36-42.

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