Accelerated whole‐heart MR angiography using a variable‐density poisson‐disc undersampling pattern and compressed sensing reconstruction

Moghari, Mehdi H.; Uecker, Martin; Roujol, Sébastien; Sabbagh, Majid; Geva, Tal; Powell, A.

doi:10.1002/mrm.26730

Cited by 10 publications

(3 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work we have not explored the possibility of parallel imaging. Accelerated 3D image acquisitions with a 2D Poissondisc undersampling pattern in phase and partition encoding direction have been shown to work well with regularized reconstructions [54][55][56]. In this work, however, acquisitions using a twofold undersampled poisson disc and reconstructed using an additional l1-wavelet regularization along spatial image dimensions could not reach the image clarity visible in the reconstructions where all k-space points are acquired even if acquisition time was kept the same (intentional).…”

Section: Discussionmentioning

confidence: 84%

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding

Fischer

Özen

İlbey

et al. 2021

Magn Reson Mater Phy

View full text Add to dashboard Cite

Objective The slow spatial encoding of MRI has precluded its application to rapid physiologic motion in the past. The purpose of this study is to introduce a new fast acquisition method and to demonstrate feasibility of encoding rapid two-dimensional motion of human vocal folds with sub-millisecond resolution. Method In our previous work, we achieved high temporal resolution by applying a rapidly switched phase encoding gradient along the direction of motion. In this work, we extend phase encoding to the second image direction by using single-point imaging with rapid encoding (SPIRE) to image the two-dimensional vocal fold oscillation in the coronal view. Image data were gated using electroglottography (EGG) and motion corrected. An iterative reconstruction with a total variation (TV) constraint was used and the sequence was also simulated using a motion phantom. Results Dynamic images of the vocal folds during phonation at pitches of 150 and 165 Hz were acquired in two volunteers and the periodic motion of the vocal folds at a temporal resolution of about 600 µs was shown. The simulations emphasize the necessity of SPIRE for two-dimensional motion encoding. Discussion SPIRE is a new MRI method to image rapidly oscillating structures and for the first time provides dynamic images of the vocal folds oscillations in the coronal plane.

show abstract

Section: Discussionmentioning

confidence: 84%

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding

Fischer

Özen

İlbey

et al. 2021

Magn Reson Mater Phy

View full text Add to dashboard Cite

show abstract

“…Cartesian undersampled k‐space trajectories for 3D TOF‐MRA with CS reconstruction are commonly designed using 2D undersampling covering the 2 phase‐encode directions (k y , k z ), with each sampled point in the (k y , k z ) plane representing a continuously sampled line in the frequency‐encode direction (k x ). Such undersampling masks are often created using pseudorandom variable‐density Poisson disks 13 with a fully sampled calibration region in the center of the (k y , k z ) plane 9,12–17 . Variable‐density Poisson disk undersampling distributions are characterized by 3 parameters: (1) the undersampling factor ( R ), (2) the polynomial order of the sampling density variation ( pp ), and (3) the size of the fully sampled calibration region ( calib ).…”

Section: Introductionmentioning

confidence: 99%

“…Such undersampling masks are often created using pseudorandom variable-density Poisson disks 13 with a fully sampled calibration region in the center of the (k y , k z ) plane. 9,[12][13][14][15][16][17] Variable-density Poisson disk undersampling distributions are characterized by 3 parameters: (1) the undersampling factor (R), (2) the polynomial order of the sampling density variation (pp), and (3) the size of the fully sampled calibration region (calib).…”

Section: Introductionmentioning

confidence: 99%

Optimization of undersampling parameters for 3D intracranial compressed sensing MR angiography at 7 T

Buck

Jezzard

Hess

2022

Magnetic Resonance in Med

View full text Add to dashboard Cite

Purpose: 3D time-of-flight MRA can accurately visualize the intracranial vasculature but is limited by long acquisition times. Compressed sensing reconstruction can be used to substantially accelerate acquisitions. The quality of those reconstructions depends on the undersampling patterns used. In this work, we optimize sets of undersampling parameters for various acceleration factors of Cartesian 3D time-of-flight MRA. Methods: Fully sampled datasets, acquired at 7 Tesla, were retrospectively undersampled using variable-density Poisson disk sampling with various autocalibration region sizes, polynomial orders, and acceleration factors. The accuracy of reconstructions from the different undersampled datasets was assessed using the vessel-masked structural similarity index. Identified optimal undersampling parameters were then evaluated in additional prospectively undersampled datasets. Compressed sensing reconstruction parameters were chosen based on a preliminary reconstruction parameter optimization.Results: For all acceleration factors, using a fully sampled calibration area of 12 × 12 k-space lines and a polynomial order of 2 resulted in the highest image quality. The importance of parameter optimization of the sampling was found to increase for higher acceleration factors. The results were consistent across resolutions and regions of interest with vessels of varying sizes and tortuosity. The number of visible small vessels increased by 7.0% and 14.2% when compared to standard parameters for acceleration factors of 7.2 and 15, respectively. Conclusion:The image quality of compressed sensing time-of-flight MRA can be improved by appropriate choice of undersampling parameters. The optimized sets of parameters are independent of the acceleration factor and enable a larger number of vessels to be visualized. K E Y W O R D SMR angiography, time-of-flight MRA, compressed sensing, undersampling, lenticulostriate arteries, ultra-high fieldThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

show abstract

Innovations in Cardiovascular MR and PET-MR Imaging

Muñoz

Cruz

Prieto

et al. 2021

Hybrid Cardiac Imaging

View full text Add to dashboard Cite

Accelerated whole‐heart MR angiography using a variable‐density poisson‐disc undersampling pattern and compressed sensing reconstruction

Cited by 10 publications

References 31 publications

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding

Optimization of undersampling parameters for 3D intracranial compressed sensing MR angiography at 7 T

Innovations in Cardiovascular MR and PET-MR Imaging

Contact Info

Product

Resources

About