Department of Medicine (Cardiology Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
J Magn Reson Imaging. 2010 Nov;32(5):1255-61. doi: 10.1002/jmri.22356.
To investigate pulmonary vein (PV) off-resonance and blood flow as causes of signal void artifacts in noncontrast steady-state-free-precession (SSFP) PV magnetic resonance angiography (MRA).
PV blood off-resonance was measured on 11 healthy adult subjects and 10 atrial fibrillation (AF) patients. Noncontrast PV MRA was performed using a 3D slab-selective SSFP sequence at 1.5T on seven healthy subjects with signal profile shifts of 0-125 Hz. The time-resolved blood flow velocity of the PVs was measured on five healthy subjects. The impact of flow was studied on six healthy subjects, on whom SSFP PV MRA was acquired twice with the electrocardiogram (ECG) trigger delay corresponding to low and high flow, respectively.
The PV off-resonances were 97 ± 27 Hz, 65 ± 20 Hz, 74 ± 25 Hz, and 52 ± 17 Hz for right inferior, left inferior, right superior, and left superior PVs, respectively, on healthy subjects, and 74 ± 20 Hz, 38 ± 9 Hz, 51 ± 20 Hz, and 28 ± 11 Hz on AF patients (P<0.01 for all). The off-resonance caused severe signal voids in the PVs. Signal acquired during mid-diastole with high PV flow caused additional signal voids in the left atrium, which was reduced by setting the ECG trigger delay to late-diastole.
PV off-resonance and flow causes signal void artifacts in noncontrast 3D slab-selective SSFP PV MRA.
探讨肺静脉（PV）失相和血流导致非对比稳态自由进动（SSFP）PV 磁共振血管造影（MRA）信号缺失伪影的原因。
在 11 名健康成年志愿者和 10 名心房颤动（AF）患者中测量 PV 血液失相。在 7 名健康志愿者中使用 3D 片状选择性 SSFP 序列进行非对比 PV MRA，信号轮廓移位 0-125Hz。在 5 名健康志愿者中测量 PV 的时间分辨血流速度。在 6 名健康志愿者中研究血流的影响，对他们进行两次 SSFP PV MRA 采集，ECG 触发延迟分别对应于低流量和高流量。
健康志愿者的右下、左下、右上和左上 PV 的 PV 失相分别为 97±27Hz、65±20Hz、74±25Hz 和 52±17Hz，AF 患者的分别为 74±20Hz、38±9Hz、51±20Hz 和 28±11Hz（所有 P<0.01）。失相导致 PV 内严重的信号缺失。在高 PV 血流期间采集的舒张中期信号在左心房内引起额外的信号缺失，通过将 ECG 触发延迟设置为舒张晚期可以减少这种缺失。
PV 失相和血流导致非对比 3D 片状选择性 SSFP PV MRA 中的信号缺失伪影。
