Thornhill Scientific Inc.

Tbi Innovations, LLC

Thornhill Research, Inc.

Joseph Arnold Fisher

James Duffin

Olivia Sobczyk

David J Mikulis

Ece Su Sayin

Julien Poublanc

David Smith

The present specification discloses a method for measuring brain tissue oxygenation in a subject. The method comprises the following steps: measuring a magnetic signal in a reference voxel of the subject's brain while imposing a series of arterial oxygen saturation changes using sequential gas delivery; calculating a relationship between the magnetic signal and the arterial oxygen saturation in the reference voxel; measuring a magnetic signal in a target voxel; and calculating the hemoglobin saturation in the target voxel based on the established relationship between the magnetic signal and the SaO2 in the reference voxel. This calibration of magnetic signal for SaOenables the conversion of magnetic signal to SaOthroughout blood-containing voxels throughout the brain.

Method and system of measuring brain oxygenation using deoxyhemoglobin contrast

Conventionally, the arterial input function is determined by administering a contrast agent and measuring the responsive magnetic signal in a reference voxel located in a large artery such as the middle cerebral artery. By instead measuring the signal in a voxel of the choroid plexus, a more accurate profile for the arterial input function may be obtained. The metabolic activity in the choroid plexus is negligible, which provides greater certainty for signal sampling.

System and method for determining arterial input function based on susceptibility contrast in the choroid plexus

A method of implementing changes in deoxyhemoglobin concentration, the method comprising: targeting a sequence of partial pressures of oxygen in arterial blood (PaCh) values in a subject using a sequential gas delivery device in a periodic input pattern; measuring a blood-oxygen level dependent (BOLD) signal in a voxel of the subject's brain using a magnetic resonance imaging device while targeting the sequence of values; comparing the pattern to the signal; and determining a vascular tissue characteristic (vessel type, vessel orientation, or pathological condition) for the voxel based on the comparison.

Implementing a periodic deoxyhemoglobin signal

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Thornhill, Canada

Joseph Arnold Fisher