Download
topics in magnetic resonance angiography research and some potential new directions n.
Skip this Video
Loading SlideShow in 5 Seconds..
Topics in Magnetic Resonance Angiography Research and Some Potential New Directions PowerPoint Presentation
Download Presentation
Topics in Magnetic Resonance Angiography Research and Some Potential New Directions

Topics in Magnetic Resonance Angiography Research and Some Potential New Directions

120 Views Download Presentation
Download Presentation

Topics in Magnetic Resonance Angiography Research and Some Potential New Directions

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Topics in Magnetic Resonance Angiography Researchand Some Potential New Directions Dennis L. Parker et al.

  2. Goal – Increase Vessel Signal • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  3. Outline • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  4. MRA - TOF : Time-Of-Flight Blood Flow Signal Partially Saturated Spins v1 >v2 >v3 Saturated Static Tissue v1 v2 v3 tn = THK / vn (n=1,2,3) TR Slab THK t1 t2 t3 Fresh Inflow d=v TR Static Tissue Signal vessel v TR blood flow TR : Repetition time

  5. Acquisition Techniques • RF Coils • Reduce electric coupling, reduce noise figure • Pulse Sequences • Variable echo time • Double echo 3D TOF • Segment blood from tissue • Post processing noise reduction • 3D PR for ultrashort echo time (TE) • Novel Black-Blood sequences for carotid artery

  6. MRI Projects:3D TOF Complete FC + Variable Echo Time (VTE) • Eun Kee Jeong Non-VTE with Complete FC VTE with Complete FC

  7. Efficient Double Inversion FSE • DL Parker, EK Jeong, SE Kim, Eugene Kholmovski

  8. MRI Projects: Carotid Imaging Free Slices • Triple Double FSE: Interleaved Double Inversion Double Echo Non-interleaved acquisition. Interleaved acquisition.

  9. MRI Research: Carotid Imaging • Triple Double FSE: Interleaved Double Inversion Double Echo • Eugene: Triple Contrast: Interleaved Double Inversion Double Echo with interleaved T1

  10. Outline • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  11. Post ProcessingBrian Chapman • Noise Reduction • Vessel Enhancement Filtering

  12. Original vs. Filtered vs. Noise

  13. Post ProcessingEugene Kholmovski • Noise Reduction • Image Redundancy

  14. Original PD Original T2 Corrected PD Corrected T2 Spectral energy (non-image support) Double Echo FSE Motion Artifact Reduction • Eugene Kholmovski

  15. Standard Image POCS SENSE Reduction = 2, Ncoils = 4 Eugene Kholmovski

  16. Standard SENSE POCS SENSE Reduction = 4, Ncoils = 4 Eugene Kholmovski

  17. Outline • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  18. Conventional MIP Depth (Z-)Buffer Image Z-Buffer Segmentation (ZBS) Algorithm

  19. Future Segmentation • Incorporate Additional Information • Directionality • Signal intensity continuity • Segment the segmentation • Centerline recognition • Label vessel segments • Shape descriptors (tortuosity) • Use sparse vessel locations to speedup 3D PC and 2D PC techniques.

  20. Outline • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  21. High Resolution MRA Applications to Aneurysm Screening 3 Aneurysms, without (left) and with (right) Gadolinium Contrast. Parker, Tsuruda, et al., University of Utah

  22. Aneurysm Screening Pedigrees

  23. MRA Aneurysm Screening Results • Screening of high risk families • 143 high-risk intracranial aneurysm pedigrees found • 3400 total members • 340 relatives screened with MRA (29 aneurysms detected) • Evidence for a gene detected Dennis L. Parker, University of Utah

  24. Outline • Acquisition Techniques • RF coils, Pulse sequences, Field strength • Post Processing • Vessel enhancement, noise reduction techniques • Vessel Segmentation • Aneurysm Screening • New contrast agents

  25. General Focus • Goal to increase visibility of vascular disease • Aneurysms, embolic disease, atherosclerosis • Improve efficiency in MRA • Increase signal, post processing for noise reduction. • Use MRA for longitudinal studies of disease • Aneurysm Screening, carotid disease • New contrast agents • Blood pool, targeted agents

  26. Signal Regrowth Mz T1 (slow ~ 1s) Blood T2 should appear Longer than tissue T2 Mx My T2 (fast ~ 100ms)