Accuracy and effectiveness of self-gating signals in free-breathing three-dimensional cardiac cine magnetic resonance imaging

Abstract

Conventional multiple breath-hold two-dimensional (2D) balanced steady-state free precession (SSFP) presents many difficulties in cardiac cine magnetic resonance imaging (MRI). Recently, a self-gated free-breathing three-dimensional (3D) SSFP technique has been proposed as an alternative in many studies. However, the accuracy and effectiveness of selfgating signals have been barely studied before. Since self-gating signals are crucially important in image reconstruction, a systematic study of self-gating signals and comparison with external monitored signals are needed.Previously developed self-gated free-breathing 3D SSFP techniques are used on twenty-eight healthy volunteers. Both electrocardiographic (ECG) and respiratory bellow signals are also acquired during the scan as external signals. Self-gating signal and external signal are compared by trigger and gating window. Gating window is proposed to evaluate the accuracy and effectiveness of respiratory self-gating signal. Relative deviation of the trigger and root-mean-square-deviation of the cycle duration are calculated. A two-tailed paired t-test is used to identify the difference between self-gating and external signals. A Wilcoxon signed rank test is used to identify the difference between peak and valley self-gating triggers.The results demonstrate an excellent correlation (P = 0, R > 0.99) between self-gating and external triggers. Wilcoxon signed rank test shows that there is no significant difference between peak and valley self-gating triggers for both cardiac (H = 0, P > 0.10) and respiratory (H = 0, P > 0.44) motions. The difference between self-gating and externally monitored signals is not significant (two-tailed paired-sample t-test: H = 0, P > 0.90).The self-gating signals could demonstrate cardiac and respiratory motion accurately and effectively as ECG and respiratory bellow. The difference between the two methods is not significant and can be explained. Furthermore, few ECG trigger errors appear in some subjects while these errors are not found in self-gating signals.

Doppler ultrasound cardiac gating of intracranial flow at 7T

“…Self-gating depends on using tailored k-space readout schemes, limiting the flexibility of sequence design and requiring non-standard reconstruction algorithms. An extension of the notion of self-gating has been presented [ 20 , 21 , 37 ], where the authors show that the parallel transmit (pTx) coil scattering matrix reflects the heart beat as well as respiration, and can be used for synchronization.…”

Improved simultaneous multislice magnetic resonance imaging using total variation regularization

“…Parallel imaging is a widely used method for scan acceleration; however, it features intrinsic signal-to-noise ratio (SNR) loss due to the reduced data collection. [1][2][3][4][5] Simultaneous multislice imaging (SMS) is a promising fast imaging technique, which utilizes a multiband radio frequency (RF) pulse to excite multiple slices simultaneously. [6][7][8] Because of increased slice-field of view (FOV), the SMS has a better SNR performance as compared with typical parallel imaging techniques.…”