Myocardial First-Pass Perfusion: Influence of Spatial Resolution and Heart Rate on the Dark Rim Artifact
Myocardial First-Pass Perfusion: Influence of Spatial Resolution and Heart Rate on the Dark Rim Artifact
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DOI：
10.1002/mrm.22969
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发表时间：
2011-12-01
影响因子：
3.3
通讯作者：
Lombardi, Massimo
中科院分区：
文献类型：
--
作者：
Meloni, Antonella;Al-Saadi, Nidal;Lombardi, Massimo
心肌灌注图像会受到暗边缘伪影的影响。本研究旨在评估空间分辨率和心率对伪影跨壁范围的影响。采用超声平面成像/快速梯度回波序列和非选择性饱和准备脉冲在1.5T下对6头麻醉猪进行扫描。在第一次注射造影剂时，每一次心跳都要获得三张短轴切片。使用两种不同的平面内空间分辨率（2.65和3.75 mm）和两种不同的心率（正常和心动过速），产生一组四次灌注扫描。提取心内膜下相对于心外膜的信号下降百分比和伪影的跨壁范围。此外，还评估了信噪比和噪声对比比。信号衰减和暗边缘伪影的宽度随着空间分辨率的降低和心率的增加而增加。在四个考虑组中，没有检测到明显的信号下降和边缘宽度的切片差异。随着空间分辨率的增加，信噪比（SNR）和噪声对比比（CNR）降低。综上所述，低时空分辨率与暗边缘伪影的增加、较低的信噪比和信噪比相关。中华医学杂志（英文版），2011。(C) 2011 Wiley期刊公司
Myocardial perfusion images can be affected by the dark rim artifact. This study aimed to evaluate the effects of the spatial resolution and heart rate on the transmural extent of the artifact. Six pigs under anesthesia were scanned at 1.5T using an echo-planar imaging/fast gradient echo sequence with a nonselective saturation preparation pulse. Three short-axis slices were acquired every heart beat during the first pass of a contrast agent bolus. Two different in-plane spatial resolutions (2.65 and 3.75 mm) and two different heart rates (normal and tachycardia) were used, generating a set of four perfusion scans. The percentage drop of signal in the subendocardium compared to the epicardium and the transmural extent of the artifact were extracted. Additionally, the signal-to-noise and the contrast-to-noise ratios were evaluated. The signal drop as well as the width of the dark rim artifact increased with decreased spatial resolution and with increased heart rates. No significant slice-to-slice variability was detected for signal drop and width of the rim within the four considered groups. signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) ratios decreased with increasing spatial resolution. In conclusion, low spatial and temporal resolution could be correlated with increased extent of the dark-rim artifact and with lower SNR and CNR. Magn Reson Med 66:1731-1738, 2011. (C) 2011 Wiley Periodicals, Inc.