The Images below are shown from another young patient's awake surgery to debulk this tumour involving movement and speech areas. The various types of scans we obtain prior to this kind of surgery are shown below, and highlight the need for as much "structural, biochemical and functional" information as possible in order to make the surgery as safe and an effective as possible. We have done many of these surgeries now at The Canberra Hospital, all of them with excellent neurological outcomes.
Above left: Typical magnetic resonance imaging (MRI) scan of the brain. The tumour (Tu) is relatively large and infiltrative -- it sends "fingers" of abnormal tumour cells into various regions of the brain, including those that subserve the functions of speech (S) and limb movement (M). Above right: Magnetic resonance tractography (MRT) shows the relationship of the tumour (Tu) to certain white matter tracts (bundles of nerve cell processes call axons) that carry information relating to limb movement (M). The section of the tract shown in dark blue in that image is part of a critical movement tract known as the "corticospinal tract".
Above left: A functional magnetic resonance imaging (fMRI) scan of the brain. The relationship of the speech centre (S; surrounded by red pixels) to the tumour (Tu) can be appreciated clearly now. The patient was asked to carry out various language/speech tasks during this scan, in order to accurately locate parts of his speech centre. The scanner automatically colour-codes those areas that activate during such tasks, in this case highlighting them in red. Above right: A magnetic resonance spectroscopy (MRS) scan of the brain. Various regions of the tumour can be analysed for tumour versus swelling (oedema), making it easier for a surgeon to appreciate which areas of the brain should be removed (tumour) versus which surrounding areas should be preserved (oedema). On the MRS scan, regions that are comprised of tumour show high levels of the biochemical compound "choline" (Cho; circled in red).
Top left: A look at the tumour as it bulges out of the skull opening (craniotomy). The biopsy forceps shown here facilitate early removal of a piece of the tissue on view, in order for a surgical pathologist to confirm that the sample is "tumour", what type of tumour it is and/or if it has high-grade (aggressive, malignant) features. The remainder of the tumour shown above was removed using a more precise instrument called an "ultrasonic aspirator". Top right: One of the surgeon's instruments or a "probe" (represented by the dark blue line in the lower right box of this image) is shown as it navigates through the brain, allowing the surgeon to precisely determine (centre of the green "cross-hair" his or her location in the brain as the surgery continues. This is the neurosurgeon's equivalent of the "GPS road navigation system" commonly used in cars. We use Medtronic's Stealth Navigation system for this purpose. Lower image: Dr Khurana looking at the "Stealth display" to confirm his landmarks as the awake surgery continues. Through the efforts of our engineer colleagues from Medtronic and Leica-Microsystems, these images can now be "injected" into the eye pieces of our operating microscope, to reduce the need to have to look up and away during certain critical times of the operation. It is through the use of advanced technologies such as these that we endeavour to make our work safer and our outcomes as optimal as possible.
