NCIGT Project Week Fast Imaging Library

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NCIGT Project WeekFast Imaging Library
W. Scott Hoge and Bruno Madore
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Overview

• Fast Imaging reconstruct MR images from limited
  data
• MR applications limited by time
• Reduce data aquired reduce acquisition time
• Can be used to increase spatial resolution,
  temporal resolution,
• or both.
• Aims to fill the gaps left by scanner
  manufacturers
• Library currently supports
• Parallel MR Imaging (SENSE, GRAPPA, )
• Temporal Processing (UNFOLD)
• plus additional utility functions (Partial
  Fourier, DICOM, )
• Linux, Windows, and Mac distributions available
• Link from stand-alone C/C applications or call
  from Matlab scripts

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Library Functions Parallel Imaging

• pMRI Parallel MR Imaging employs spatial
  encoding to complement Fourier encoding and
  reduce image data requirements.
• SENSE and GRAPPA are
• widely known variants
• Library supports
• Variable-density sampling
• Sophisticated regularization
• 2D and 3D acquisitions

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Library Functions UNFOLD

• Temporal encoding can tag acquisition artifacts
• One can then suppress the artifacts by applying
  temporal filters to an image series.
• Library provides both time domain and frequency
  domain Fermi filters for UNFOLD

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Library Functions Utility Routines

• Partial Fourier reconstruction (homodyne)
• Basic building blocks
• FFT, SVD, Conjugate Gradient, LSQR
• Magnetic field corrections (GradWarp)
• Basic DICOM reader/editor/writer

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Applications

• A wide variety of applications have been
  supported to date
• Accelerated Cardiac Perfusion CINE
• Real-time cardiac imaging
• Accelerated temperature monitoring
• Real-time self-calibrated EPI
• Accelerated PROPELLER EPI for perfusion imaging

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App Cardiac Perfusion

• Utilizing library building blocks, one can
  mix-and-match algorithms for best image quality

Credit B. Madore
UNFOLD GRAPPA (lo) SPACE RIP (mid)
UNFOLD SPACE RIP (lo) SPACE RIP (mid)
UNFOLD GRAPPA (lo) GRAPPA (mid)
3.5x acceleration, 8 channel cardiac coil, 1.5T,
SSFP sequence
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App Real-time Cardiac Tracking
Credit E. Samset, R. Chu

• 3.2x acceleration, 128x128, 8 channel coil, SSFP
• Completely self-referenced
• 6 images/sec with 1 frame of latency

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App Temperature Monitoring

• 8x acceleration using 2DRF, SENSEUNFOLD

Credit C-S Mei, J. Yuan, N. McDannold, L.
Panych, B. Madore
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App Real-time self-cal EPI

• Phase-labeling w/ UNFOLD for Nyquist ghost
  correction
• 3.2x acceleration, 128x128, SS-GE-EPI, 1.5T
• Completely self-referenced with low latency

Credit H.Tan, B. Kraft (WFU)
1x
3.2x
note Reduced Distortion
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App PROPELLER EPI for Perfusion

• 2007 before collaboration
• No parallel imaging
• Blade dimension 32 x 128
• Number of blades 64

2009 with Fast Imaging Library Acceleration
factor 2x, GRAPPA Blade dimension 96 x
128 Number of blades 64 with distortion
correction.
Credit H.Tan, B. Kraft (WFU)
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Whats in the Package?

• Linkable binary library file
• Documentation (via Doxygen)
• Quick Start Guide
• Function Reference Manual
• Demos
• Matlab MEX functions w/ test data
• C/C demos FFT, data I/O, DICOM tag editing

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Quick Setup Example

• Download from
• http//www.ncigt.org/pages/Downloads
• Imaging Toolkit
• Unzip into working directory
• Start Matlab
• Build MEX files
• Run Matlab demo scripts

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Acknowledgements

• Funding provided by NCIGT
• NIH U41 RR019703-01A2 (PIJolesz)
• For more information
• ncigt-imaging-toolkit_at_bwh.harvard.edu
• or
• shoge_at_bwh.harvard.edu