Combined arterial spin labeling and magnetic resonance fingerprinting

1. A magnetic resonance imaging system for imaging a subject, wherein the magnetic resonance imaging system comprises:

a memory for storing machine executable instructions and pulse sequence commands,

wherein the pulse sequence commands comprise:

tagging pulse sequence commands comprising a tagging inversion pulse portion for spin labeling a tagging location within the subject, a first background suppression portion, and a first image acquisition portion,

wherein the first background suppression portion comprises first magnetic resonance fingerprinting (MRF) pulse sequence commands for acquiring a first portion of fingerprinting magnetic resonance data according to a magnetic resonance fingerprinting protocol; and

control pulse sequence commands comprising a control inversion pulse portion, a second background suppression portion, and a second image acquisition portion,

wherein the second background suppression portion comprises second MRF pulse sequence commands for acquiring a second portion of fingerprinting magnetic resonance data according to the magnetic resonance fingerprinting protocol;

and a processor for controlling the magnetic resonance imaging system, wherein execution of the machine executable instructions causes the processor to:

acquire tagged magnetic resonance data by controlling the magnetic resonance imaging system with the tagging pulse sequence commands according to a conventional arterial spin labeling protocol, and

execute the first background suppression portion to acquire the first portion of fingerprinting magnetic resonance data;

acquire control magnetic resonance data by means of a conventional arterial spin labeling protocol by controlling the magnetic resonance imaging system with the control pulse sequence commands according to the conventional arterial spin labeling protocol, and

execute the second background suppression portion to acquire the second portion of fingerprinting magnetic resonance data;

reconstruct tagged magnitude images using the tagged magnetic resonance data;

reconstruct control magnitude images using the control magnetic resonance data;

construct an arterial spin labeling (ASL) ASL image by subtracting the control magnitude images from the tagged magnitude images from each other;

reconstruct a series of magnetic resonance fingerprinting images using the first portion of fingerprinting magnetic resonance data and/or the second portion of fingerprinting magnetic resonance data; and

generate at least one magnetic resonance parametric map by comparing the series of magnetic resonance fingerprinting images with a magnetic resonance fingerprinting dictionary.

2. The magnetic resonance imaging system of claim 1 , wherein at least one of the first background suppression portion or second background suppression portion further comprises background suppression pulse sequence commands.

3. The magnetic resonance imaging system of claim 2 , wherein the background suppression portion is discretely divided into regions of the background suppression pulse sequence commands and at least one region of the MRF pulse sequence commands.

4. The magnetic resonance imaging system of claim 3 , wherein the tagging pulse sequence commands and control pulse sequence commands comprise a delay between a last portion of the at least one region of the MRF pulse sequence commands and the image acquisition portion.

5. The magnetic resonance imaging system of claim 1 , wherein the MRF pulse sequence commands comprise a flip angle portion.

6. The magnetic resonance imaging system of claim 5 , wherein the flip angle portion in the MRF pulse sequence commands of the tagging pulse sequence commands and the MRF pulse sequence commands of the control pulse sequence commands are identical.

7. The magnetic resonance imaging system of claim 5 , wherein the flip angle portion is configured for generating flip angles below any one of the following: 10 degrees, 8 degrees, 7 degrees, 6 degrees, and 5 degrees.

8. The magnetic resonance imaging system of claim 1 , wherein the at least one magnetic resonance parametric map comprises angiography data.

9. The magnetic resonance imaging system of claim 1 , wherein the MRF pulse sequence commands of the tagging pulse sequence commands comprise a first gradient encoding portion, wherein the MRF pulse sequence commands of the control pulse sequence commands comprise a second gradient encoding portion, wherein the first gradient encoding portion and the second gradient encoding portion encode identical portions of k-space.

10. The magnetic resonance imaging system of claim 9 , wherein execution of the machine executable instructions further cause the processor to calculate averaged magnetic resonance data by averaging corresponding elements of the first portion of the fingerprinting magnetic resonance data with the second portion of the fingerprinting magnetic resonance data, wherein the series of magnetic resonance fingerprinting images is reconstructed using the averaged magnetic resonance data.

11. The magnetic resonance imaging system of claim 1 , wherein the MRF pulse sequence commands of the tagging pulse sequence commands comprise a first gradient encoding portion, wherein the wherein the MRF pulse sequence commands of the control pulse sequence commands comprise a second gradient encoding portion, wherein the first gradient encoding portion and the second gradient encoding portion encode interleaving portions of k-space.

12. The magnetic resonance imaging system of claim 1 , wherein the ASL image comprises a cerebral blood flow map, wherein the magnetic resonance fingerprinting dictionary is a function of cerebral blood flow, wherein execution of the machine executable instructions causes the processor to use the cerebral blood flow map to provide the cerebral blood flow to the magnetic resonance fingerprinting dictionary during determination of the at least one magnetic resonance parametric map.

13. The magnetic resonance imaging system of claim 12 , wherein the at least one magnetic resonance parametric map comprises any one of the following: a T2 map, a T1 map, an MTT map, and combinations thereof.

14. A computer program product comprising machine executable instructions stored on a non-transitory computer readable medium for execution by a processor controlling a magnetic resonance imaging system, wherein execution of the machine executable instructions causes the processor to:

acquire tagged magnetic resonance data by controlling the magnetic resonance imaging system with tagging pulse sequence commands according to a conventional arterial spin labeling protocol, wherein the tagging pulse sequence commands include a tagging inversion pulse portion for spin labeling a tagging location within the subject, a first background suppression portion, and a first image acquisition portion, wherein the first background suppression portion comprises first magnetic resonance fingerprinting (MRF) pulse sequence commands for acquiring a first portion of fingerprinting magnetic resonance data according to a magnetic resonance fingerprinting protocol;

acquire control magnetic resonance data by controlling the magnetic resonance imaging system with the control pulse sequence commands according to the conventional arterial spin labeling protocol, wherein the control pulse sequence commands include a control inversion pulse, a second background suppression portion, and a second image acquisition portion, wherein the second background suppression portion comprises second MRF pulse sequence commands for acquiring a second portion of fingerprinting magnetic resonance data according to the magnetic resonance fingerprinting protocol;

reconstruct tagged magnitude images using the tagged magnetic resonance data;

reconstruct control magnitude images using the control magnetic resonance data;

construct an ASL image by subtracting the control magnitude images and the tagged magnitude images from each other;

reconstruct a series of magnetic resonance fingerprinting images using the first portion of the fingerprinting magnetic resonance data and/or the second portion of the fingerprinting magnetic resonance data; and

generate at least one magnetic resonance parametric map by comparing the series of magnetic resonance fingerprinting images with a magnetic resonance fingerprinting dictionary.

15. A method of operating a magnetic resonance imaging system for imaging a subject, wherein the method comprises:

acquiring tagged magnetic resonance data by controlling the magnetic resonance imaging system with tagging pulse sequence commands according to a conventional arterial spin labeling protocol, wherein the tagging pulse sequence commands include a tagging inversion pulse portion for spin labeling a tagging location within the subject, a first background suppression portion, and a first image acquisition portion, wherein the first background suppression portion comprises first magnetic resonance fingerprinting (MRF) pulse sequence commands for acquiring a first portion of fingerprinting magnetic resonance data according to a magnetic resonance fingerprinting protocol;

acquiring control magnetic resonance data by controlling the magnetic resonance imaging system with the control pulse sequence commands according to the conventional arterial spin labeling protocol, wherein the control pulse sequence commands include a control inversion pulse, a second background suppression portion, and a second image acquisition portion, wherein the second background suppression portion comprises second MRF pulse sequence commands for acquiring a second portion of fingerprinting magnetic resonance data according to the magnetic resonance fingerprinting protocol;

reconstructing tagged magnitude images using the tagged magnetic resonance data;

reconstructing control magnitude images using the control magnetic resonance data;

constructing an ASL image by subtracting the control magnitude images and the tagged magnitude images from each other;

reconstructing a series of magnetic resonance fingerprinting images using the first portion of the fingerprinting magnetic resonance data and/or the second portion of the fingerprinting magnetic resonance data; and

generating at least one magnetic resonance parametric map by comparing the series of magnetic resonance fingerprinting images with a magnetic resonance fingerprinting dictionary.