Doyle Mark, Kortright Eduardo, Anayiotos Andreas S, Rayarao Geetha, Rathi Vikas K, Caruppannan Kethes, Li Longchuan, Biederman Robert W W
Department of Medicine, Allegheny General Hospital, 320 East North Avenue, Pittsburgh, PA 15212, USA.
J Magn Reson Imaging. 2007 Jun;25(6):1256-62. doi: 10.1002/jmri.20926.
To show that accuracy of jet flow representation by magnetic resonance (MR) phase-contrast (PC) velocity-encoded (VE) cine imaging is dominated by error terms resulting from the temporal distribution of data, and to present a generally applicable data interpolation-based approach to correct for this phenomenon.
Phase-contrast data were acquired in a stenotic orifice flow phantom using a physiologic pulsatile flow waveform. A temporally registered scan, acquired without data segmentation or interleaving was obtained (17 minutes) and taken as the reference (REF). Conventional PC data sets were acquired using segmentation and data interleaving. An enhanced temporal registration (ETR) algorithm was applied to the acquired data to temporally interpolate component sets and output data at matching time points, thereby reducing temporal dispersion.
Compared to the REF data, conventionally processed PC data consistently overestimated peak velocities in laminar jet flow regions (127% +/- 28%) and exhibited relatively weak correlations (r = 0.67 +/- 0.23). The ETR-processed data better represented peak velocities (101% +/- 13%, P < 0.001) and correlated more closely with the REF data (r = 0.94 +/- 0.05, P < 0.001).
The temporal distribution of PC data impacts the accuracy of velocity representation in pulsatile jet flow. A temporal registration postprocessing algorithm can minimize loss of accuracy.
证明磁共振（MR）相位对比（PC）速度编码（VE）电影成像对射流表示的准确性受数据时间分布产生的误差项主导，并提出一种普遍适用的基于数据插值的方法来校正这种现象。
使用生理性搏动血流波形在狭窄孔口流动模型中采集相位对比数据。获得一次未进行数据分割或交织的时间配准扫描（17分钟）并将其作为参考（REF）。使用分割和数据交织采集传统PC数据集。将增强时间配准（ETR）算法应用于采集的数据，以在时间上对分量集进行插值并在匹配时间点输出数据，从而减少时间离散。
与REF数据相比，传统处理的PC数据在层流射流区域始终高估峰值速度（127%±28%），且相关性相对较弱（r = 0.67±0.23）。经ETR处理的数据能更好地表示峰值速度（101%±13%，P < 0.001），并且与REF数据的相关性更紧密（r = 0.94±0.05，P < 0.001）。
PC数据的时间分布会影响搏动射流中速度表示的准确性。时间配准后处理算法可将准确性损失降至最低。
