Abstract:
Objective.Image quality in whole-body MRI (WB-MRI) may be degraded by faulty radiofrequency (RF) coil elements or mispositioning of the coil arrays. Phantom-based quality control (QC) is used to identify broken RF coil elements but the frequency of these acquisitions is limited by scanner and staff availability. This work aimed to develop a scan-specific QC acquisition and processing pipeline to detect broken RF coil elements, which is sufficiently rapid to be added to the clinical WB-MRI protocol. The purpose of this is to improve the quality of WB-MRI by reducing the number of patient examinations conducted with suboptimal equipment.Approach.A rapid acquisition (14 s additional acquisition time per imaging station) was developed that identifies broken RF coil elements by acquiring images from each individual coil element and using the integral body coil. This acquisition was added to one centre\'s clinical WB-MRI protocol for one year (892 examinations) to evaluate the effect of this scan-specific QC. To demonstrate applicability in multi-centre imaging trials, the technique was also implemented on scanners from three manufacturers.Main results. Over the course of the study RF coil elements were flagged as potentially broken on five occasions, with the faults confirmed in four of those cases. The method had a precision of 80% and a recall of 100% for detecting faulty RF coil elements. The coil array positioning measurements were consistent across scanners and have been used to define the expected variation in signal.Significance. The technique demonstrated here can identify faulty RF coil elements and positioning errors and is a practical addition to the clinical WB-MRI protocol. This approach was fully implemented on systems from two manufacturers and partially implemented on a third. It has potential to reduce the number of clinical examinations conducted with suboptimal hardware and improve image quality across multi-centre studies.
摘要:
目的:全身MRI(WB-MRI)中的图像质量可能因射频(RF)线圈元件故障或线圈阵列错位而降低。基于幻影的质量控制(QC)用于识别损坏的RF线圈元件,但是这些采集的频率受到扫描仪和工作人员可用性的限制。这项工作旨在开发扫描特定的QC采集和处理管道,以检测损坏的RF线圈元件,这是足够快被添加到临床WB-MRI协议。这样做的目的是通过减少使用次优设备进行的患者检查的数量来提高WB-MRI的质量。
方法:开发了一种快速采集(每个成像站额外采集时间14秒),通过从每个单独的线圈元件采集图像并使用整体线圈来识别损坏的RF线圈元件。该采集被添加到一个中心的临床WB-MRI方案中,为期一年(892次检查),以评估该扫描特异性QC的效果。为了证明在多中心成像试验中的适用性,该技术也在三家制造商的扫描仪上实施。
主要结果:在研究过程中,射频线圈元件被标记为可能损坏的情况有5次,在其中四个案例中确认了故障。该方法具有80%的精度和100%的召回率,用于检测故障的RF线圈元件。线圈阵列定位测量在扫描仪上是一致的,并已用于定义信号的预期变化。
意义:此处演示的技术可以识别故障的RF线圈元件和定位误差,并且是临床WB-MRI协议的实用补充。这种方法在三个制造商的系统上完全实施,在第三个制造商上部分实施。它有可能减少使用次优硬件进行的临床检查的数量,并提高多中心研究的图像质量。