During the month of November the research and development team made a field trip to a local medical CT scanning service, taking with them two recent neuro patients. Due to circumstances surrounding their death, one patient was cryoprotected and the other was not.
Patient safety is Alcor’s main objective, and with that in mind our neuro patients were transported inside individual liquid nitrogen dewars securely tied down and well padded against vibration in the back of our Rescue Vehicle.
Having safely returned from our trip and taking care of returning the patients to the patient care bay, Steve Graber opened up the first of the patient scan files in our 3-D visualization software. This is where the team could really see some interesting things. First, using the ‘Slice’ tool to remove a small section of the skull (Fig. 1) and looking into the brain cavity we could make out the sensor wires which were previously placed into the brain cavity during surgery. Through the slice we can see variations in brain density which is visible in the red and purple range. NOTE: Color designations are entirely arbitrary.
A direct comparison of two brains digitally enhanced in software (Fig. 2) highlights unusual density variations between brains. When one compares these identically composed, sectioned and displayed images of a cryoprotected brain (top image) vs non-cryoprotected brain it is clear that there is a big difference in overall density between these two brains. A-1546 displays a significantly greater electron density than A-1088 throughout the majority of the brain. Overall the A-1546 brain is much more electron dense and we believe this to be evidence that perfusion did occur, at least in certain areas. It is important to note that we do not feel that complete perfusion of cryoprotectant was achieved across the entire brain. This may be due to the fact patient A-1546 was pronounced out of state and experienced a travel time of 18 hours from pronouncement to the beginning of the cryoprotective ramp in the Alcor O.R.
A future test of a variety of substances under the CT scanner in LN2 is expected to help to identify electron density specifics of cryoprotectants, which in turn will make our analysis that much more complete. We also expect to test a locally pronounced patient vs an out of state pronounced patient to determine the quality differences in cryoprotection caused by the time-lag to cryoprotection between these two scenarios.