Park Jaeseok, Larson Andrew C, Zhang Qiang, Simonetti Orlando, Li Debiao
Department of Radiology, Northwestern University, Chicago, Illinois, USA.
Magn Reson Med. 2005 Oct;54(4):833-40. doi: 10.1002/mrm.20627.
Coronary artery data acquisition with steady-state free precession (SSFP) is typically performed in a single frame in mid-diastole with a spectrally selective pulse to suppress epicardial fat signal. Data are acquired while the signal approaches steady state, which may lead to artifacts from the SSFP transient response. To avoid sensitivity to cardiac motion, an accurate trigger delay and data acquisition window must be determined. Cine data acquisition is an alternative approach for resolving these limitations. However, it is challenging to use conventional fat saturation with cine imaging because it interrupts the steady-state condition. The purpose of this study was to develop a 4D coronary artery imaging technique, termed "cine angiography with phase-sensitive fat suppression" (CAPS), that would result in high temporal and spatial resolution simultaneously. A 3D radial stacked k-space was acquired over the entire cardiac cycle and then interleaved with a sliding window. Sensitivity-encoded (SENSE) reconstruction with rescaling was developed to reduce streak artifact and noise. Phase-sensitive SSFP was employed for fat suppression using phase detection. Experimental studies were performed on volunteers. The proposed technique provides high-resolution coronary artery imaging for all cardiac phases, and allows multiple images at mid-diastole to be averaged, thus enhancing the signal-to-noise ratio (SNR) and vessel delineation.
采用稳态自由进动（SSFP）进行冠状动脉数据采集时，通常在舒张中期的单帧中进行，并使用频谱选择性脉冲抑制心外膜脂肪信号。数据采集是在信号接近稳态时进行的，这可能会导致SSFP瞬态响应产生伪影。为避免对心脏运动敏感，必须确定准确的触发延迟和数据采集窗口。电影数据采集是解决这些限制的另一种方法。然而，在电影成像中使用传统的脂肪饱和技术具有挑战性，因为它会中断稳态条件。本研究的目的是开发一种4D冠状动脉成像技术，称为“具有相位敏感脂肪抑制的电影血管造影”（CAPS），该技术将同时实现高时间和空间分辨率。在整个心动周期内采集3D径向堆叠k空间，然后与滑动窗口交织。开发了具有重新缩放功能的灵敏度编码（SENSE）重建技术，以减少条纹伪影和噪声。采用相位敏感SSFP通过相位检测进行脂肪抑制。对志愿者进行了实验研究。所提出的技术为所有心脏相位提供高分辨率冠状动脉成像，并允许对舒张中期的多个图像进行平均，从而提高信噪比（SNR）和血管轮廓清晰度。
