System for the noninvasive determination of tracer concentration in blood
AssigneeKoninklijke Philips N.V.
InventorsDragos-Nicolae Peligrad, Lothar Spies, Timo Paulus
Life of this patent
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Abstract
The invention relates to a general composite compartmental model and a compartmental analysis procedure to extract non-invasively the concentration (Cp) of the imaging agent in plasma (301), in metabolites (304, 504) and in blood elements (303) (like red cells, platelets, plasma protein etc.) from time signal curves measured within a reference tissue region (200). This is made possible by deploying an injection function (SINJ(t)) as input which models the amount of imaging agent administered to the patient as a function of time. The invention allows the presentation of the plasma input function to the medical practitioner without the need for invasively drawing blood samples.
Claims18
A method for evaluating image data that represent concentration of an imaging agent in a body volume, the method comprising:
- determining an injection function (SINJ(t)) that models an injection of the imaging agent into a reference region as a function of time;
- determining a concentration of free imaging agent in plasma (CP) in the reference region;
- determining a time signal in the reference region via convolution and summing using the injection function, the concentration of the free imaging agent in plasma, impulse response functions of blood elements (GB) and metabolites (GMB) within a blood volume fraction (VB) of a blood subsystem in the reference region, partial volume fractions of the blood elements (GB) and the metabolites (GMB), respectively, within the blood subsystem, impulse response functions of tissue (GT) and metabolites (GMT) within a tissue volume fraction (VT) of a reference tissue subsystem in the reference region, and a partial volume fraction of the metabolites (GMT) within the reference tissue subsystem, determining the time signal being executed by a processor;
- and
- estimating a distribution of the imaging agent in blood of a patient using the time signal,
- wherein the injection function is expressed as a volume flow of the imaging agent through one of a syringe and an infusion system into a vein of the patient.
A non-transitory computer readable medium that stores programming code, executable by a computer, for evaluating image data that represent concentration of at least one imaging agent in a body volume, the computer readable medium comprising:
- injection determining code for determining an (SINJ(t)) injection function that models an injection of the imaging agent into a reference region as a function of time;
- free imaging agent concentration determining code for determining a concentration of free imaging agent in plasma (CP) in the reference region;
- time signal determining code for determining a time signal in the reference region via convolution and summing using the injection function, the concentration of the free imaging agent in plasma, impulse response functions of blood elements (GB) and metabolites (GMB) within a blood volume fraction (VB) of a blood subsystem in the reference region, partial volume fractions of the blood elements (GB) and the metabolites (GMB), respectively, within the blood subsystem, impulse response functions of tissue (GT) and metabolites (GMT) within a tissue volume fraction (VB) of a reference tissue subsystem in the reference region, and a partial volume fraction of the metabolites (GMT) within the reference tissue subsystem;
- and
- estimating code for estimating a distribution of the imaging agent in blood of a patient using the time signal,
- wherein the injection function is expressed as a volume flow of the imaging agent through one of a syringe and an infusion system into a vein of the patient.
Dependencies are inferred from the claim text.