• John Koivukangas

Intra-operative MRI (iMRI)



Ultrasound, navigation and MRI were next combined in a surgical MRI suite at Oulu University Hospital in my quest for surgical image of brain to ensure safer surgery for the patient.


A Finnish low-field 0.23T open configuration MRI scanner uniquely could be turned off, with a ramp-up time of only six minutes. It had automatic registration of images to the patient’s anatomy. It was one of only eight concepts in the world in the 1990's (picture: scanner, optical navigator, display). We operated on Wednesdays. On other days, radiological procedures and routine imaging studies allowed for continual full use.


On Tuesday afternoons I would accompany my patient to the suite for a full navigation session: MR imaging and surgical planning: drawing site of the tumor, scalp incision and craniotomy onto the scalp. The patient saw an augmented reality display of the surgical plan, considered to be reassuring.


At first, we used our arm-based navigator (Elekta), then an optical navigator was provided by Philips based on our visualization solution. Philips also licensed our proprietary Onesys Navigator software (picture) for text and 3D images. As a formal hospital roll-out, it was interfaced to the EMR (ESKO) of Oulu University Hospital, Oulu, Finland.


The picture below shows the overall graphical user interface (GUI) on the left, a representative 3D image in the center, and pertinent 2D images on the right. The session is stored in the hospital server for rapid retrieval and review. It should be noted also, that while today it is typical to refer to the graphics on the computer as the "G" in GUI, this is a mistaken notion. A single screen with the world's best "G"UI is inferior to a multi-screen workstation.


Reference:


Tuominen J, Yrjänä SK, Katisko JP, Heikkilä J, Koivukangas J (2003) Intraoperative imaging in a comprehensive neuronavigation environment for minimally invasive brain tumour surgery. Acta Neurochir Suppl 85: 115-20.


Workstation 1999, clinical workflow: EMR on the left, PACS opened from EMR in the middle, specific isolated images bookmarked and selected on the right. The why, the where and the what.

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