Noncontrast 3D steady state free precession magnetic resonance angiography of the thoracic central veins using nonselective radiofrequency excitation over a large field of view - Initial experience
Noncontrast 3D steady state free precession magnetic resonance angiography of the thoracic central veins using nonselective radiofrequency excitation over a large field of view - Initial experience
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DOI：
10.1097/rli.0b013e31816be927
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发表时间：
2008-05-01
影响因子：
6.7
通讯作者：
Krishnam, Mayil S.
中科院分区：
文献类型：
--
作者：
Tomasian, Anderanik;Lohan, Derek G.;Krishnam, Mayil S.
目的：目的：探讨非选择性射频激发三维稳态自由旋进（SSFP）磁共振血管成像（MRA）对胸部中央静脉的可行性。年龄范围22-76岁），患有各种心脏和胸部血管疾病，在1.5 T条件下接受了自由呼吸心电图门控非造影SSFP MRA和常规高分辨率3D对比增强（CE）胸部MRA。两名阅片者评价了两个数据集的结果：静脉可见性和清晰度（从0，不可见到3，清晰度极佳）;伪影，信噪比（SNR）; 8个静脉段的对比度噪声比（CNR），包括上级腔静脉（SVC）、上腔静脉（supra-surgical inferior vena cava）。双侧头臂静脉近端锁骨下静脉和下颈内静脉结果：3D SSFP和CE-MRA均成功完成，图像质量和血管清晰度采用Wilcoxon检验，SNR和CNR采用t检验，观察者间变异性采用kappa系数。SSFP MRA的扫描时间范围为5 - 10分钟（平均值+/-标准差，7 +/- 2分钟）。阅片人1（2）分别将23（25）例和7（5）例患者的SSFP MRA以及22（23）例和8（9）例患者的CE-MRA的整体图像质量评定为优和良。在SSFP MRA上，阅片者1和阅片者2分别对234（97.5%）和233（97.1%）个静脉节段进行了诊断定义（2级和3级）分级（kappa = 0.69）。在常规CE-MRA上，读片者1和2分别对231个（96.3%）和232个（96.7%）静脉节段进行了诊断定义（2级和3级）分级（kappa = 0.68）。对于每位读片者来说，CE-MRA上下颈内静脉的节段可见性和清晰度更高（P < 0.001）。两种技术在静脉可见性和其他静脉段的清晰度评分方面无显著性差异（P > 0.05）。颈内静脉在SSFP MRA上的SNR和CNR值较低（P < 0.001）。SSFP和CE-MRA上其他静脉段的SNR和CNR值差异均无统计学意义（均P > 0.05）。2名阅片者在两个数据集上均显示SVC Glenn分流至主肺动脉通畅（n = 3），下腔静脉至肺动脉汇合处的心外Fontan分流通畅（n = 2），SVC（n = 1）和右头臂静脉（n = 1）扩张和血栓形成。采用非选择性射频激发的自由呼吸导航仪门控非对比3D SSFP MRA可提供高图像质量和足够的SNR和CNR，可用于胸部中心静脉的可靠评价。
Purpose: To evaluate the feasibility of three-dimensional (3D) steady state free precession (SSFP) magnetic resonance angiography (MRA) using nonselective radiofrequency excitation for the assessment of thoracic central veins.Materials and Methods: Thirty consecutive patients (17 males, 13 females. age range 22-76) with various cardiac and thoracic vascular diseases underwent free-breathing electrocardiogram-gated non-contrast SSFP MRA and conventional high-resolution 3D contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers evaluated both datasets for findings: venous visibility and sharpness (from 0, not visualized to 3, excellent definition); artifacts-, signal-to-noise ratio (SNR); and contrast-to-noise ratio (CNR) in 8 venous segments including superior vena cava (SVC), supra-diaphragmatic inferior vena cava. bilateral brachiocephalic, proximal subclavian, and lower internal jugular veins. Statistical analysis was performed using Wilcoxon test for overall image quality and vessel visibility, t test for SNR and CNR analysis, and kappa coefficient for inter-observer variability.Results: 3D SSFP and CE-MRA were successfully performed in all patients. Scan time for SSFP MRA ranged from 5 to 10 minutes (mean +/- standard deviation, 7 +/- 2 minutes). Reader 1 (2) graded the overall image quality as excellent and good on SSFP MRA in 23 (25) and 7 (5) patients, and on CE-MRA in 22 (23) and 8 (9) patients, respectively. On SSFP MRA, readers 1 and 2 graded 234 (97.5%) and 233 (97.1%) venous segments with diagnostic definition (grades 2 and 3) (kappa = 0.69), respectively. On conventional CE-MRA, readers 1 and 2 graded 231 (96.3%) and 232 (96.7%) venous segments with diagnostic definition (grades 2 and 3) (kappa = 0.68), respectively. Segmental visibility and sharpness were higher for lower internal jugular veins on CE-MRA for each reader (P < 0.001). No significant difference existed for venous visibility and sharpness scores for other venous segments between the 2 techniques for both readers (P > 0.05). SNR and CNR values were lower for internal jugular veins on SSFP MRA (P < 0.001). No significant difference existed between SNR and CNR values for the other venous segments on SSFP and CE-MRA (P > 0.05 for all). The 2 readers demonstrated patent SVC Glenn shunt to main pulmonary artery (n = 3), patent extra cardiac Fontan shunt from inferior vena cava to pulmonary artery confluence (n = 2), and dilatation and thrombosis of SVC (n = 1) and right brachiocephalic vein (n = 1) on both datasets.Conclusion: Free breathing navigator-gated noncontrast 3D SSFP MRA with nonselective radiofrequency excitation provides high image quality and sufficient SNR and CNR for confident evaluation of thoracic central veins.