Magnetic resonance imaging (MRI) with dual agent characterization

Patent metadata

Field	Value
Publication number	US-9508256-B2
Application number	US-201314068537-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Mar 31, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

Example apparatus and methods concern determining whether a target material appears in a region experiencing nuclear magnetic resonance. One method acquires a baseline value for a magnetic resonance parameter (MRP) while the region is not exposed to a molecular imaging agent that affects the MRP, acquiring a non-specific uptake value for the MRP while the sample is influenced by a non-specific molecular imaging agent and acquiring a specific uptake value for the MRP while the sample is influenced by a specific molecular imaging agent. The non-specific masking problem is solved by characterizing the region as a function of the baseline value, the non-specific uptake value, and the specific uptake value. The function relies on the similarities and differences between non-specific uptake of the non-specific molecular imaging agent, non-specific uptake of the specific molecular imaging agent, and specific uptake of the specific molecular imaging agent.

First claim

What is claimed is:

1. A method, comprising:
acquiring a baseline value for a magnetic resonance (MR) parameter from a region in a sample while the sample is not exposed to a molecular imaging agent that affects the MR parameter in the sample;
acquiring a non-specific uptake value for the MR parameter while the sample is influenced by a non-specific molecular imaging agent that does not recognize a target material and where the non-specific molecular imaging agent may affect the MR parameter due to non-specific uptake of the non-specific molecular imaging agent;
acquiring a specific uptake value for the MR parameter while the sample is influenced by a specific molecular imaging agent that does recognize the target material and where the specific molecular imaging agent may affect the MR parameter due to non-specific uptake of the specific molecular imaging agent and due to specific uptake of the specific molecular imaging agent, and characterizing the region as a function of the baseline value, the non-specific uptake value, and the specific uptake value,
where the baseline value, the non-specific uptake value, and the specific uptake value are a function of magnetic resonance experienced in the sample as excited by an NMR apparatus,
where non-specific uptake of the non-specific molecular imaging agent in an area that does not include the target material and non-specific uptake of the specific molecular imaging agent in an area that does not include target material do not produce a measurably different effect on the MR parameter,
where specific uptake of the specific molecular imaging agent in an area that includes the target material and non-specific uptake of the non-specific molecular imaging agent in an area that does include the target material produce a measurably different effect on the MR parameter in the region, and
where specific uptake of the specific molecular imaging agent in an area that includes the target material and non-specific uptake of the specific molecular imaging agent in an area that does not include the target material produce a measurably different effect on the MR parameter in the region.

2. The method of claim 1 , where the MR parameter is T1 relaxation or T2 relaxation.

3. The method of claim 1 , where the region is bounded by a voxel used in magnetic resonance imaging (MRI) reconstruction, and where the voxel size is less than 2×2×2 mm 3 .

4. The method of claim 1 , where the region is bounded by a voxel used in magnetic resonance imaging (MRI) reconstruction, and where the voxel size is greater than or equal to 2×2×2 mm 3 .

5. The method of claim 1 , where the sample is excited by and where the baseline value, the non-specific uptake value, and the specific uptake value are acquired in response to a Drive Equilibrium Single Pulse Observation of T1 (DESPOT1) MR approach or a Magnetic Resonance Fingerprinting (MRF) approach.

6. The method of claim 1 , where the sample is a human tissue.

7. The method of claim 1 , where the target material is a protein associated with a disease.

8. The method of claim 1 , where the target material is a protein associated with cancer.

9. The method of claim 1 , where the target material is a protein tyrosine phosphatase μ associated with glioblastoma multiforme.

10. The method of claim 1 , where the specific molecular imaging agent recognizes the target material by binding to the target material in a protein:protein interaction.

11. The method of claim 6 , where the specific molecular imaging agent is a first peptide conjugated to a contrast agent.

12. The method of claim 11 , where the first peptide is SBK2.

13. The method of claim 12 , where the non-specific molecular imaging agent is the contrast agent, a material that changes T1 in the sample, a molecule containing Gadolinium, a second peptide conjugated to the contrast agent, or the second peptide conjugated to a molecule containing Gadolinium.

14. The method of claim 13 , where the second peptide is a randomized version of the first peptide or a scrambled version of the first peptide.

15. The method of claim 1 , where the baseline value is acquired before both the non-specific uptake value and the specific uptake value, and where the non-specific uptake value is acquired before the specific uptake value.

16. The method of claim 15 , comprising acquiring the non-specific uptake value after the non-specific molecular imaging agent has been applied to the sample and after an effect on the MR parameter associated with the non-specific molecular imaging agent has reached a first threshold level.

17. The method of claim 16 , comprising acquiring the specific uptake value after an effect on the MR parameter associated with the non-specific molecular imaging agent has fallen below the first threshold level, after the specific molecular imaging agent has been applied, and after an effect on the MR parameter associated with the specific molecular imaging agent has reached a second threshold level.

18. The method of claim 1 , comprising:
reconstructing a magnetic resonance image from magnetic resonance signals received from the sample, where the magnetic resonance image includes information that is a function of the baseline value, the non-specific uptake value, or the specific uptake value.

19. The method of claim 1 , where the non-specific uptake value is a function of the concentration of the non-specific molecular imaging agent in the region and where the specific uptake value is a function of the concentration of the specific molecular imaging agent in the region.

20. The method of claim 1 , comprising:
controlling a signal detection apparatus to generate a signal that indicates that the target material is present in the sample.

21. The method of claim 20 , where the signal identifies a phenotype of the target material.

22. The method of claim 1 , the method being configured to detect a tumor that is less than 100% the size of the region.

23. The method of claim 1 , where the baseline value, the non-specific uptake value, or the specific uptake value are acquired using a handheld magnetic resonance detector.

24. The method of claim 1 , where characterizing the region as a function of the baseline value, the non-specific uptake value, and the specific uptake value is based, at least in part, on magnetic resonance fingerprinting.

25. An apparatus for use with a magnetic resonance (MR) apparatus, comprising:
a processor;
a memory;
a set of logics; and
an interface to connect the processor, the memory, and the set of logics, the set of logics comprising:
a first logic configured to measure a baseline T1 in a sample when no T1 altering molecular imaging agent is present in the sample;
a second logic configured to measure a change in T1 in the sample from the baseline T1 due to the presence of a non-specific molecular imaging agent in the sample;
a third logic configured to measure a change in T1 in the sample from the baseline T1 due to the presence of a specific molecular imaging agent in the sample; and
a fourth logic configured to generate a signal upon identifying that a target material is present in the sample, where the identifying is performed as a function of the baseline T1, the change in T1 due to the non-specific molecular imaging agent, and the change in T1 due to the specific molecular imaging agent,

where non-specific uptake of the non-specific molecular imaging agent in an area that

Assignees

• Univ Case Western Reserve

Inventors

• Brady-Kalnay Susann
• Gulani Vikas
• Griswold Mark

Classifications

• G08C23/06 Primary

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• A61B5/4244

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• G01R33/3692

  involving signal transmission without using electrically conductive connections, e.g. wireless communication or optical communication of the MR signal or an auxiliary signal other than the MR signal · CPC title

• G01R33/4822

  in three dimensions · CPC title

• G01R33/56366

  Perfusion imaging · CPC title