Highly Accelerated T1-Weighted Abdominal Imaging Using 2-Dimensional Controlled Aliasing in Parallel Imaging Results in Higher Acceleration

Abstract

The CAIPRINHA-VIBE with an acceleration factor of R = 2 × 2 is feasible in a clinical setting and is characterized by fast and robust imaging with an image quality comparable with a 2-fold acceleration with GRAPPA.

Feasibility of free-breathing dynamic contrast-enhanced MRI of the abdomen: a comparison between CAIPIRINHA-VIBE, Radial-VIBE with KWIC reconstruction and conventional VIBE

“…15 On the other hand, in a scan accelerated by parallel imaging, such as 3D CAIPIRINHA, loss of SNR is a well-known limitation of undersampling. 19,20 On the other hand, the lack of fidelity of the time-intensity curve obtained from KWIC-Radial-VIBE is a known drawback in the quantification of perfusion analysis. 3 In our study, six individual subframe images were generated every 5 s with 54 radial views for the central k-space filling.…”

Shortened breath-hold contrast-enhanced MRI of the liver using a new parallel imaging technique, CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration): a comparison with conventional GRAPPA technique

“…They depend heavily on the geometry of the coil array used and various vendor-specific parallel imaging reconstruction algorithms, and the generalized autocalibrating partially parallel acquisition (GRAPPA) technique is now standard [2,4,8]. In addition, an AF of 2 is preferred clinically at 1.5 T with an acquisition time of longer than 20 s [2,4]. However, a long breath-hold time leads to patient discomfort and increased respiratory motion artifacts.…”

“…domen and is now a crucial component of almost all abdominal MRI examinations [1,2]. However, long breath-holding times are needed, and the spatial resolution of MRI is lower than that of CT [3].…”

“…The well-known limitations of parallel imaging reconstructions are a decrease in signal-to-noise ratio (SNR) and residual aliasing artifacts at a high acceleration factor (AF) compared with a fully sampled k-space data, which lead to a loss of image quality [3,[8][9][10]. They depend heavily on the geometry of the coil array used and various vendor-specific parallel imaging reconstruction algorithms, and the generalized autocalibrating partially parallel acquisition (GRAPPA) technique is now standard [2,4,8]. In addition, an AF of 2 is preferred clinically at 1.5 T with an acquisition time of longer than 20 s [2,4].…”

“…It has been generally used together with the parallel imaging technique for decreasing the acquisition time or improving the spatial resolution [4]. The principle of the parallel imaging technique is to reconstruct the image from the reduced number of sampled k-space data, using the inherent spatial information of different coil elements of multiple independent radiofrequency receiver coils [2]. The well-known limitations of parallel imaging reconstructions are a decrease in signal-to-noise ratio (SNR) and residual aliasing artifacts at a high acceleration factor (AF) compared with a fully sampled k-space data, which lead to a loss of image quality [3,[8][9][10].…”