We propose to use our recently-conceived HYPR method to develop an easy-to-implement, time-resolved, multi-station, contrast-enhanced peripheral MR angiography protocol that provides high spatial resolution angiograms with dramatically higher temporal resolution than is possible with current MR techniques. The HYPR method permits great improvements to temporal resolution in radial k-space acquisitions by producing time frames using only a very small subset of the total number of radial k-space lines necessary to satisfy the Nyquist criterion. Streak artifacts that would ordinarily result from constructing images using a severely reduced number of projections are ameliorated by constraining unfiltered back projected data to regions in which objects, in this case vessels, are known to exist. In order to determine the location of the vessels, a vessel map, or composite image, is produced using data from multiple time frames. This is possible because the data for each of the time frames is produced from radial k-space lines that are acquired at slightly different angles. The high SNR in the composite images dictates the SNR in the individual time frames, providing improved image quality relative to accelerated methods that are based solely on undersampling. Preliminary simulations suggest that good image quality may be achieved even when undersampling factors greater than 100 are used. In order to achieve our goal, we propose to develop three MRA techniques - 3D hybrid HYPR, 3D HYPR TRICKs, and 3D HYPR VIPR - and to evaluate and optimize the performance of these techniques using a series of simulation, phantom, and volunteer studies. Following this, the most successful HYPR peripheral vascular protocol will be compared with conventional x-ray DSA in a cohort of patients. Our central hypothesis is that HYPR will permit acquisition of very high temporal resolution contrast-enhanced multi-station peripheral MR angiograms, in which spatial resolution, SNR, and image quality are maintained at high levels.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB006882-03
Application #
7568198
Study Section
Medical Imaging Study Section (MEDI)
Program Officer
Liu, Guoying
Project Start
2007-04-01
Project End
2011-01-31
Budget Start
2009-02-01
Budget End
2010-01-31
Support Year
3
Fiscal Year
2009
Total Cost
$325,828
Indirect Cost
Name
University of Wisconsin Madison
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
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Keith, Lauren; Rahimi, Mahdi; Holmes, James et al. (2014) Use of a computer-controlled motion phantom to investigate the temporal and spatial fidelity of HYPR processing. Magn Reson Med 71:702-10
Wang, Kang; Schiebler, Mark L; Francois, Christopher J et al. (2013) Pulmonary perfusion MRI using interleaved variable density sampling and HighlY constrained cartesian reconstruction (HYCR). J Magn Reson Imaging 38:751-6
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Wu, Yijing; Kecskemeti, Steven R; Johnson, Kevin et al. (2011) HYPR TOF: time-resolved contrast-enhanced intracranial MR angiography using time-of-flight as the spatial constraint. J Magn Reson Imaging 33:719-23
Wu, Yijing; Johnson, Kevin; Kecskemeti, Steven R et al. (2011) Time resolved contrast enhanced intracranial MRA using a single dose delivered as sequential injections and highly constrained projection reconstruction (HYPR CE). Magn Reson Med 65:956-63
Velikina, Julia V; Johnson, Kevin M; Wu, Yijing et al. (2010) PC HYPR flow: a technique for rapid imaging of contrast dynamics. J Magn Reson Imaging 31:447-56
Wu, Yan; Korosec, Frank R; Mistretta, Charles A et al. (2009) CE-MRA of the lower extremities using HYPR stack-of-stars. J Magn Reson Imaging 29:917-23