Cardiac late gadolinium enhancement MRI for patients with implanted cardiac devices
Disclosed herein are methods and systems for clinical practice of medical imaging on patients with metal-containing devices, such as implanted cardiac devices. In particular, Disclosed herein are methods and systems for improved late gadolinium enhancement (LGE) MRI for assessing myocardial viability for patients with implanted cardiac devices, i.e., cardiac pacemakers and implantable cardiac defibrillators.
1. A method for acquiring an image of a subject using a magnetic resonance imaging (MRI) system, the method comprising:
selecting an inversion time (TI) to null signal from a desired tissue type during the performance of a pulse sequence designed to acquire late-gadolinium enhanced (LGE) T1-weighted images from a region of interest in the subject;
selecting a series of inversion recovery (IR) pulses to cover a spectral bandwidth that is designed to invert the desired tissue type and other tissue that are experiencing off-resonance effects caused by implants;
performing the pulse sequence using the selected TI and the series of IR pulses to acquire MRI data from the subject; and
reconstructing the MM data to create an image of the subject having hyper-intensity image artifacts induced by the off-resonance effects reduced; and
displaying the image on a display.
2. The method of claim 1 , wherein each of the IR pulses within the series of IR pulses have a spectral bandwidth that ranges from 1 kHz to 5 kHz.
3. The method of claim 2 , wherein the series of IR pulses includes a first IR pulse having a first spectral bandwidth and a second IR pulse having a second spectral bandwidth, wherein the first spectral bandwidth and the second spectral bandwidth are different.
4. The method of claim 1 , wherein the series of IR pulses are performed in a back-to-back arrangement.
5. The method of claim 1 , wherein the series of inversion pulses includes interleaved on-resonance and off-resonance inversion pulses.
6. The method of claim 1 , wherein the series of inversion pulses include adiabatic pulses.
7. The method of claim 1 , wherein the series of inversion pulses includes non-adiabatic pulses.
8. The method of claim 1 further comprising performing a self-gating technique to achieve respiratory gating when reconstructing the image of the subject.
9. A method for acquiring an image of a subject using a magnetic resonance imaging (Mill) system, the method comprising:
selecting an inversion time (TI) to null signal from a desired tissue type during the performance of a pulse sequence designed to acquire late-gadolinium enhanced (LGE) T1-weighted images from a region of interest in the subject;
selecting an inversion recovery (IR) pulse having a spectral bandwidth that is designed to invert the desired tissue type and other tissue that are experiencing off-resonance effects caused by implants;
performing the pulse sequence using the selected TI and the IR pulse, wherein only a single IR pulse is used in each spectral bin prior to a multi-spectral acquisition to allow full longitudinal signal relaxation for the spectral bin;
performing the multi-spectral acquisition to acquire MM data from the subject; and
reconstructing the MM data to create an image of the subject having hyper-intensity image artifacts induced by the off-resonance effects reduced; and
displaying the image on a display.
10. The method of claim 9 , wherein the multi-spectral acquisition includes interleaving on-resonance and off-resonance acquisitions.
11. The method of claim 10 , wherein the interleaving of the on-resonance and the off-resonance acquisitions is triggered between successive heartbeats, wherein the heartbeats are defined by an R-R interval.
12. The method of claim 10 , wherein the off-resonance acquisitions acquire signal from a series of off-resonance spectral bins while the on-resonance spins continue to relax during the off-resonance acquisitions.
13. The method of claim 11 , wherein the off-resonance acquisition includes from two to three off-resonance spectral bins.
14. The method of claim 9 , wherein the IR pulse is a non-selective IR pulse.
15. The method of claim 9 , wherein the IR pulse has a spectral bandwidth that ranges from 1.5 kHz to 5 kHz.
16. A method for acquiring an image of a subject using a magnetic resonance imaging (MRI) system, the method comprising:
performing a wideband late-gadolinium enhanced (LGE) pulse sequence to acquire MRI data from the subject, the LGE pulse sequence having an inversion time (TI) to null signal from a desired tissue type in a region of interest of the subject, and an inversion recovery (IR) pulse having a spectral bandwidth that is sufficient to invert the desired tissue type and other tissue in the region of interest that are experiencing off-resonance effects caused by implants;
reconstructing the MM data to create an image of the subject having hyper-intensity image artifacts induced by the off-resonance effects reduced, wherein the wideband late-gadolinium enhanced (LGE) pulse sequence has a specific absorption rate (SAR) that ranges from 0.01 W/kg to 0.2 W/kg; and
displaying the image on a display.
17. The method of claim 16 , wherein the IR pulse has a spectral bandwidth that ranges from 1.5 kHz to 5 kHz.
18. The method of claim 16 , wherein the wideband IR pulse has a SAR that ranges from 0.01 W/kg to 0.07 W/kg.
19. The method of claim 16 , wherein the image is a cardiac image.
20. The method of claim 16 further comprising performing a self-gating technique to achieve respiratory gating when reconstructing the image of the subject.