Enhanced fat saturation in myocardial infarction MRI

1. A magnetic resonance imaging (MRI) system comprising:

an MRI gantry having static and gradient magnet assemblies and at least one radio frequency (RF) coil defining an image volume into which a patient region of interest (ROI) can be disposed;

MRI control circuits connected to control components within said MRI gantry and configured to effect MRI data acquisition sequences of RF and gradient magnetic pulses which elicit MRI signals from patient tissue when an ROI is disposed therein, to acquire and process said elicited MRI signals into MR image data;

said MRI control circuits being configured to:

(a) acquire k-space data of a patient ROI during an MRI data acquisition sequence including a nuclear magnetic resonance (NMR) signal readout period, said MRI data acquisition sequence using at least one water-specific RF NMR magnetization inversion pulse, a first fat-specific inversion pulse and at least one second fat-specific RF NMR magnetization inversion pulse imposed prior to said readout period, said at least one water-specific inversion pulse and said at least one second fat-specific inversion pulse each being respectively timed to cause a substantial null in NMR magnetization of fat tissue protons inverted by the at least one second fat-specific RF NMR magnetization inversion pulse and a substantial null in NMR magnetization of normal tissue protons inverted by the water-specific RF NMR magnetization inversion pulse to occur during said readout period when MRI data in a center portion of k-space is being acquired;

(b) process said acquired k-space data into MR image data in the spatial domain; and

(c) store, transfer and/or display said processed MR image data, with the processed MR image data representing a contrast enhanced image of tissues within the ROI but having substantially suppressed normal and fat nuclei components therein.

2. An MRI system as in claim 1 wherein said MRI control circuits are configured to use a late gadolinium enhanced (LGE) data acquisition sequence including at least one fat-specific RF NMR magnetization inversion pulse imposed (i) after a water-specific RF NMR magnetization inversion pulse timed to cause a substantial null in NMR magnetization of normal tissue protons during said readout period when MRI data for a center portion of k-space is being acquired and (ii) before MRI data for a center portion of k-space is acquired, which fat-specific inversion pulse is also timed to cause a substantial null in NMR magnetization during said readout period when MRI data for a center portion of k-space is being acquired.

3. An MRI system as in claim 2 , wherein said MRI control circuits are configured to also impose an initial fat-specific inversion pulse substantially concurrent with imposition of said water-specific RF NMR magnetization inversion pulse.

4. An MRI system as in claim 2 , wherein said patient ROI includes myocardium and wherein said contrast enhanced image depicts substantially only infarct myocardium.

5. An MRI system as in claim 3 wherein said patient ROI includes myocardium and wherein said contrast enhanced image depicts substantially only infarct myocardium.

6. A magnetic resonance imaging (MRI) method, with the acquiring, processing and storing, transferring and/or displaying steps being performed with a magnetic resonance imaging system, comprising:

acquiring k-space data of a patient ROI during an MRI data acquisition sequence including a nuclear magnetic resonance (NMR) signal readout period, said MRI data acquisition sequence using at least one water-specific RF NMR magnetization inversion pulse, a first fat-specific inversion pulse and at least one second fat-specific RF NMR magnetization inversion pulse imposed thereafter, said water-specific inversion pulse and the at least one second fat specific inversion pulse each being respectively timed to cause a substantial null in NMR magnetization of fat tissue protons inverted by the at least one second fat-specific RF NMR magnetization inversion pulse and a substantial null in NMR magnetization of normal tissue protons inverted by the water-specific RF NMR magnetization inversion pulse to occur during said readout period when MRI data in a center portion of k-space is being acquired;

(b) processing said acquired k-space data into MR image data in the spatial domain; and

(c) storing, transferring and/or displaying said processed MR image data, with the processed MR image data representing a contrast enhanced image of tissues within the ROI but having substantially suppressed normal and fat nuclei components therein.

7. An MRI method as in claim 6 wherein said data acquisition sequence comprises a late gadolinium enhanced (LGE) data acquisition sequence including at least one fat-specific RF NMR magnetization inversion pulse imposed (i) after a water-specific RF NMR magnetization inversion pulse timed to cause a substantial null in NMR magnetization of normal tissue protons during said readout period when MRI data for a center portion of k-space is being acquired and (ii) before a time said readout period when MRI data for a center portion of k-space is being acquired, which fat-specific inversion pulse is also timed to cause a substantial null in NMR magnetization during said readout period when MRI data for a center portion of k-space is being acquired.

8. An MRI method as in claim 7 , wherein an initial fat-specific inversion pulse is imposed substantially concurrent with imposition of said water-specific RF NMR magnetization inversion pulse.

9. An MRI method as in claim 7 , wherein said patient ROI includes myocardium and wherein said contrast enhanced image depicts substantially only infarct myocardium.

10. An MRI system as in claim 8 wherein said patient ROI includes myocardium and wherein said contrast enhanced image depicts substantially only infarct myocardium.