Longo Maria G, Fagundes Joana, Huang Susie, Mehan William, Witzel Thomas, Bhat Himanshu, Heberlein Keith, Rosen Bruce R, Rosenthal Daniel, Gonzalez Ramon G, Schaefer Pamela W, Rapalino Otto
Department of Radiology, Massachusetts General Hospital, Boston, MA.
CDPI (Clínica de Diagnóstico por Imagem), Rio de Janeiro, Brazil.
J Neuroimaging. 2017 Sep;27(5):442-446. doi: 10.1111/jon.12453. Epub 2017 Jun 2.
Previous studies have used parallel imaging (PI) techniques to decrease spine magnetic resonance imaging (MRI) protocol acquisition times. Recently developed MRI sequences allow even faster acquisitions. Our purpose was to develop a lumbar spine MRI protocol using PI with GRAPPA (generalized autocalibrating partially parallel acquisition) and a simultaneous multislice (SMS)-based sequence and to evaluate its diagnostic performance compared to a standard lumbar spine MRI protocol.
Ten patients were scanned in a 3-Tesla scanner (MAGNETOM Skyra, Siemens Healthcare). Each patient was imaged using a standard protocol and an optimized fast protocol acquiring the same contrasts and planes. The fast protocol included sagittal T1, T2, and fat suppressed T2 sequences accelerated with GRAPPA and an SMS-based axial T2-weighted sequence using a high-density spine coil (Siemens MR, 30 channel spine). Two blinded neuroradiologists independently assessed image quality and diagnostic accuracy for clinically relevant imaging findings.
The fast protocol acquisition time was 5:28 minutes, compared with 16:30 minutes for the standard protocol. Both protocols had a similar performance for definition of anatomical structures, diagnostic quality, and identification of clinically relevant imaging findings. There were more artifacts in the SMS Turbo Spin Echo (P = .014) sequence without compromising diagnostic performance. Artifacts in the remaining non-SMS sequences were similar in both protocols (P > .180). The sensitivity, specificity, and accuracy of the 5-minute protocol were 92.3%, 100.0%, and 99.6%, respectively, for the clinically relevant findings (P = 1.0, interrater agreement .57).
A 5-minute SMS-based MRI protocol for lumbar spine imaging is feasible and can be achieved without significant impact in the overall diagnostic quality.
以往研究采用并行成像（PI）技术来缩短脊柱磁共振成像（MRI）检查方案的采集时间。最近开发的MRI序列能实现更快的采集。我们的目的是开发一种使用具有GRAPPA（广义自校准部分并行采集）的PI和基于同时多切片（SMS）序列的腰椎MRI检查方案，并与标准腰椎MRI检查方案相比评估其诊断性能。
10名患者在3特斯拉扫描仪（MAGNETOM Skyra，西门子医疗）中进行扫描。每位患者分别使用标准方案和优化的快速方案进行成像，两种方案采集相同的对比度和层面。快速方案包括采用GRAPPA加速的矢状位T1、T2及脂肪抑制T2序列，以及使用高密度脊柱线圈（西门子MR，30通道脊柱线圈）的基于SMS的轴位T2加权序列。两名盲法神经放射科医生独立评估图像质量以及临床相关影像表现的诊断准确性。
快速方案的采集时间为5分28秒，而标准方案为16分30秒。两种方案在解剖结构清晰度、诊断质量以及临床相关影像表现的识别方面具有相似的性能。在不影响诊断性能的情况下，SMS快速自旋回波序列中的伪影更多（P = 0.014）。其余非SMS序列中的伪影在两种方案中相似（P > 0.180）。对于临床相关表现，5分钟方案的敏感性、特异性和准确性分别为92.3%、100.0%和99.6%（P = 1.0，评分者间一致性0.57）。
基于SMS的5分钟腰椎成像MRI检查方案是可行的，且不会对整体诊断质量产生显著影响。
