Frequency response of multi‐phase segmented k‐space phase‐contrast

A theoretical analysis of the temporal frequency response of multi‐phase segmented k‐space phase‐contrast was developed. This includes the effects of both segment duration and the number of cardiac phases that are reconstructed. An increase in the number of views per segment and the corresponding increase in segment duration results in an increased smoothing or low‐pass filtering of the time‐resolved flow waveform. Reconstruction of all intermediate cardiac phases makes the Nyquist sampling frequency independent of the number of views per segment. This analysis was verified experimentally using a multi‐phase phase‐contrast segmented k‐space MR pulse sequence. This sequence reconstructs all intermediate cardiac phases and uses fractional segments at the end of the cardiac cycle if an entire segment does not fit. The use of fractional segments increases the portion of the cardiac cycle over which data are acquired.

[1]  N J Pelc,et al.  A rapid-gated cine MRI technique. , 1988, Magnetic resonance annual.

[2]  R R Edelman,et al.  Flow velocity quantification in human coronary arteries with fast, breath‐hold MR angiography , 1993, Journal of magnetic resonance imaging : JMRI.

[3]  A. Fenster,et al.  Computer‐controlled flow simulator for MR flow studies , 1992, Journal of magnetic resonance imaging : JMRI.

[4]  R. Edelman,et al.  Cineangiography of the heart in a single breath hold with a segmented turboFLASH sequence. , 1991, Radiology.

[5]  Michael H. Buonocore,et al.  Experimental study of the effects of “Fractional” gating on flow measurements , 1994, Magnetic resonance in medicine.

[6]  H Liu,et al.  Magnetic resonance imaging kappa-space segmentation using phase-encoding groups the accuracy of quantitative measurements of pulsatile flow. , 1995, Medical physics.

[7]  William H. Press,et al.  Numerical recipes in C. The art of scientific computing , 1987 .

[8]  E. Haacke,et al.  Pseudo‐gating: Elimination of periodic motion artifacts in magnetic resonance imaging without gating , 1987, Magnetic resonance in medicine.

[9]  N J Pelc,et al.  Simultaneous acquisition of phase‐contrast angiograms and stationary‐tissue images with Hadamard encoding of flow‐induced phase shifts , 1991, Journal of magnetic resonance imaging : JMRI.

[10]  G. Glover,et al.  Encoding strategies for three‐direction phase‐contrast MR imaging of flow , 1991, Journal of magnetic resonance imaging : JMRI.

[11]  B. Rutt,et al.  Frequency response of prospectively gated phase‐contrast MR velocity measurements , 1995, Journal of magnetic resonance imaging : JMRI.

[12]  T K Foo,et al.  Improved ejection fraction and flow velocity estimates with use of view sharing and uniform repetition time excitation with fast cardiac techniques. , 1995, Radiology.

[13]  N J Pelc,et al.  Minimizing TE in moment‐nulled or flow‐encoded two‐and three‐dimensional gradient‐echo imaging , 1992, Journal of magnetic resonance imaging : JMRI.

[14]  B. Rutt,et al.  Frequency response of retrospectively gated phase‐contrast MR imaging: Effect of interpolation , 1993, Journal of magnetic resonance imaging : JMRI.

[15]  R R Edelman,et al.  Segmented turboFLASH: method for breath-hold MR imaging of the liver with flexible contrast. , 1990, Radiology.

[16]  T A Spraggins,et al.  Wireless retrospective gating: application to cine cardiac imaging. , 1990, Magnetic resonance imaging.

[17]  D N Firmin,et al.  Blood flow imaging by cine magnetic resonance. , 1986, Journal of computer assisted tomography.

[18]  Jennifer Keegan,et al.  The application of breath hold phase velocity mapping techniques to the measurement of coronary artery blood flow velocity: Phantom data and initial in vivo results , 1994, Magnetic resonance in medicine.