So here’s me getting an MSI – a Magnetic Source Imaging study in UCSF’s MEG machine. The helmet-like receptical contains some 200 sensors, and 3 electrodes are taped to my head for positioning. The big thing behind my head is a large, superconducting magnet, One colleague, seeing this photo, thought I looked like a Conehead.

The thing on my chest is a paper megaphone. Part of the test measures my response to pictures flashed on the screen or nouns spoken to me. The microphone that picks up my voice is sufficiently magnetic that it can be placed no closer than my feet. The megaphone helps funnel my voice. My understanding is that as I talk, or am tapped in various places or asked to repeatedly push a button, the 200 censors feed very faint RF signals generated by magnetic gradients to RF gear that hands off the signals to banks of Linux machines that crunch the data into waveforms and identify the spatial coordinates for each waveform.

The image on the screen is one of the pictures I was asked to identify: if you’re very sharp eyed you may note that the picture sits on a Linux desktop (Red Hat 7.3). Open source software, being used to save lives (or, at least in my case, mobility). The MSI data, when mapped to a high-res MRI, shows where my motor, sensory and cognitive areas are – ‘no-go’ zones for surgery and other treatment. It is amazing that whole parts of the body – my left side, for example, is contolled by a brain region the size of a peanut. One of the MEG techs gave me a screen shot of the MSI app running on her console, and printed it out via the GIMP. I’m getting good at staying still inside these machines. The MSI took more than 2 hours, and I remained still for all of the studies, even when I had a small seizure… BTW here’s a pretty good description of how the MEG, MRI et al are integrated into UCSF’s surgical procedures…

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