Nelson Erik, Medina Jorge, Cusack Chris, Caveney John, Tello Richard
Boston University Medical School, Department of Radiology, Boston Medical Center, 88 East Newton Street, Boston, MA 02118, USA.
MAGMA. 2003 Nov;16(3):149-53. doi: 10.1007/s10334-003-0014-8. Epub 2003 Sep 2.
The purpose of this study was to determine the ability of postgadolinium time-of-flight (TOF) MR angiography to image the foot of patients compared to conventional TOF MR angiography.
Six feet in five patients were included in this prospective study. Standard two-dimensional axial TOF sequences of the lower extremities, followed by three-dimensional (3D) contrast-enhanced moving-table images of the aorta to the foot during the intravenous bolus administration of gadolinium, were obtained in all patients. Two-dimensional axial respiratory-compensated TOF sequences were then obtained over the foot. Axial images and maximum intensity projections (MIP) reconstructions were evaluated by two blinded radiologists and images rated with respect to overall image quality, large-vessel and small-vessel visualization, degree of venous overlap, and extent of vessel stenosis.
The 2D postgadolinium TOF technique resulted in an improvement in all areas of image quality compared with the noncontrast acquisition method, with very good interobserver agreement (kappa 0.67). Postcontrast images provided superior vessel visualization ( p=0.024, Wilcoxon signed rank test), with minimal artifact (84% with none, kappa 1.0), and excellent agreement on grading of dorsalis pedis stenosis (kappa 0.78). Vessel-to-background signal intensity ratio was doubled compared to the standard technique (mean 19.5, SD 6.5 versus 8.8, SD 4.5; p=0.016).
Postgadolinium TOF MR angiography of the foot demonstrates significantly improved image quality over noncontrast techniques.
本研究旨在确定钆增强时间飞跃（TOF）磁共振血管造影与传统TOF磁共振血管造影相比，对患者足部成像的能力。
本前瞻性研究纳入了5例患者的6只脚。所有患者均先获取下肢标准二维轴向TOF序列，然后在静脉推注钆剂期间获取从主动脉到足部的三维（3D）对比增强移动台图像。随后在足部获取二维轴向呼吸补偿TOF序列。由两名盲法放射科医生评估轴向图像和最大强度投影（MIP）重建图像，并根据整体图像质量、大血管和小血管可视化、静脉重叠程度以及血管狭窄程度对图像进行评分。
与非对比采集方法相比，二维钆增强TOF技术在图像质量的各个方面均有改善，观察者间一致性非常好（kappa值为0.67）。对比剂注射后的图像提供了更好的血管可视化效果（p = 0.024，Wilcoxon符号秩检验），伪影极少（84%无伪影，kappa值为1.0），并且在足背动脉狭窄分级方面一致性极佳（kappa值为0.78）。与标准技术相比，血管与背景信号强度比提高了一倍（平均值分别为19.5，标准差6.5与8.8，标准差4.5；p = 0.016）。
足部钆增强TOF磁共振血管造影显示出比非对比技术显著改善的图像质量。
