US 12,336,783 B2
Identifying the vascularity of cerebral tissue in subjects using deoxyhemoglobin contrast
Jacob B. Schulman, Toronto (CA); Kamil Uludag, Toronto (CA); Joseph Arnold Fisher, Thornhill (CA); David Mikulis, Oakville (CA); Olivia Sobczyk, Etobicoke (CA); Ece Su Sayin, Windsor (CA); Julien Poublanc, Toronto (CA); and James Duffin, Toronto (CA)
Assigned to THORNHILL SCIENTIFIC INC., North York (CA)
Appl. No. 18/694,505
Filed by THORNHILL SCIENTIFIC INC., North York (CA)
PCT Filed Sep. 29, 2022, PCT No. PCT/IB2022/059311
§ 371(c)(1), (2) Date Mar. 22, 2024,
PCT Pub. No. WO2023/053066, PCT Pub. Date Apr. 6, 2023.
Claims priority of provisional application 63/249,779, filed on Sep. 29, 2021.
Prior Publication US 2024/0389856 A1, Nov. 28, 2024
Int. Cl. A61B 5/00 (2006.01); A61B 5/055 (2006.01)
CPC A61B 5/0042 (2013.01) [A61B 5/0036 (2018.08); A61B 5/055 (2013.01); A61B 5/4884 (2013.01); A61B 5/489 (2013.01); A61B 2576/026 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of identifying the vascularity of cerebral tissue in a subject, the method comprising:
inducing a first change in partial pressure of oxygen in arterial blood (ΔPaO2) in the subject using a sequential gas delivery device;
wherein inducing the first change in partial pressure of oxygen in arterial blood (ΔPaO2) comprises targeting a first baseline partial pressure of oxygen in arterial blood (PaO2) in the subject and subsequently targeting a first signal partial pressure of oxygen in arterial blood (PaO2) in the subject; and
wherein the first signal partial pressure of oxygen in arterial blood (PaO2) is lower than the first baseline partial pressure of oxygen in arterial blood (PaO2);
determining a first change in magnetic signal (ΔSI) in a voxel of the subject's brain using a magnetic resonance imaging device while inducing the first change partial pressure of oxygen in arterial blood (ΔPaO2);
inducing a second change in partial pressure of oxygen in arterial blood (ΔPaO2) in the subject using the sequential gas delivery device;
wherein inducing the second change in partial pressure of oxygen in arterial blood (ΔPaO2) comprises targeting a second baseline partial pressure of oxygen in arterial blood (PaO2) in the subject and subsequently targeting a second signal partial pressure of oxygen in arterial blood (PaO2) in the subject; and
wherein the second signal partial pressure of oxygen in arterial blood (PaO2) is lower than the second baseline partial pressure of oxygen in arterial blood (PaO2); and
wherein the second baseline partial pressure of oxygen in arterial blood (PaO2) is lower than the first baseline partial pressure of oxygen in arterial blood (PaO2); determining a second change in magnetic signal (ΔSI) in the voxel of the subject's brain using the magnetic resonance imaging device while inducing the second change partial pressure of oxygen in arterial blood (ΔPaO2);
comparing the first and second changes in magnetic signal (ΔSI); and
based on the comparison, outputting a signal at a user interface connected to the magnetic resonance imaging device, the signal indicating whether the voxel is extravascular or intravascular.