Myocardial perfusion MRI with an undersampled 3D stack‐of‐stars sequence

Abstract

Purpose:To determine the feasibility of three-dimensional (3D) hybrid radial (stack-of-stars) MRI with spatiotemporal total variation (TV) constrained reconstruction for dynamic contrast enhanced myocardial perfusion imaging. Methods: An ECG-triggered saturation recovery turboFLASH sequence with undersampled stackof-stars sampling with spatiotemporal TV constrained reconstruction was developed for dynamic contrast enhanced myocardial perfusion imaging. Simulations were performed to study the dependence of the approach to steady state on flip angle and saturation recovery time for this stack-of-stars acquisition. Phantom studies were used to show the effect of the flip angle selection and imperfect spoiling on image qualities. Studies were done in three humans to test the feasibility of the approach for myocardial perfusion imaging. Results: The simulation and phantom studies showed that imperfect spoiling and magnetization changes during the readout were a function of flip angle and nonoptimized selection of flip angle could degrade the images. Low flip angle acquisitions in the human subjects result in images with good quality similar to multislice radial 2D images. Conclusions: 3D stack-of-stars sampling with spatiotemporal TV constrained reconstruction provides a promising alternative for myocardial perfusion imaging.

Accelerated cardiac MR stress perfusion with radial sampling after physical exercise with an MR‐compatible supine bicycle ergometer

“…However, the highly undersampled radial data in this study result in relatively wide streaks and the TV reconstruction penalizes oscillations while preserving sharp edges . Because prior CS‐based reconstruction for perfusion imaging exploited the temporal correlation of perfusion data, we cannot directly compare our results with those of prior studies. Further studies to investigate other CS‐based reconstruction are needed.…”

Smoothly clipped absolute deviation (SCAD) regularization for compressed sensing MRI using an augmented Lagrangian scheme

“…By dropping the terms independent of ()i in Eq. (15), completing the square in Eq. (10) and defining the intermediate variable iJ = DXk+1 + yk /p, we can rewrite the problem (10) as follows:…”

“…In this context, total variation (TV) regularization has been widely used to exploit and promote the sparsity of the solution [14][15][16]. TV regularization is based on the L, norm and makes use of discrete gradients as a sparsifying transform.…”

Advanced Cardiovascular Magnetic Resonance Myocardial Perfusion Imaging

“…23,25 Other promising acceleration techniques, such as spiral imaging, are in early development, but their clinical utility has yet to be assessed. [26][27][28] With the techniques listed above, it is possible to accelerate image acquisition up to a factor of ≥10 times. This speed-up has been used to improve spatial resolution (high-resolution perfusion CMR) or to acquire 3D myocardial perfusion data within a single acquisition shot facilitating greater spatial coverage.…”