Abstract:
The purpose of this study is to determine the feasibility of using a single scan ramped hybrid-encoding (RHE) method for rapid bicomponent T2* analysis of the human knee joint. The proposed method utilizes RHE to acquire ultrashort echo time (UTE) and subsequent gradient echo images at 16 different echo times ranging between 40 μs and 30 ms in a single scan. In the proposed RHE technique, UTE imaging was followed by acquisition of 14 gradient recalled echo images, where an additional UTE image was obtained within the first readout by oversampling single point imaging (SPI) encoding. The single scan RHE method with a 9-minute scan time was performed on human cadaveric knee joints from six donors and in vivo knee joints from four healthy volunteers at 3 T. A bicomponent signal model was used to characterize the short T2* and long T2* water components. Mean bicomponent T2* parameters for patellar tendon, anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and meniscus were calculated. In the experimental results, the RHE technique provided bicomponent T2* parameter estimations of tendon, ACL, PCL and meniscus, which were similar to previously reported values in the literature. In conclusion, the proposed single scan RHE technique provides rapid bicomponent T2* analysis of the human knee joint with a total scan time of less than 9 minutes.
摘要:
这项研究的目的是确定使用单扫描斜坡混合编码(RHE)方法对人体膝关节进行快速双组分T2*分析的可行性。所提出的方法利用RHE在单次扫描中以40μs和30ms之间的16个不同回波时间采集超短回波时间(UTE)和随后的梯度回波图像。在提出的RHE技术中,UTE成像后采集14张梯度回波图像,其中通过过采样单点成像(SPI)编码在第一读出内获得额外的UTE图像。在3T下对来自六个供体的人尸体膝关节和来自四个健康志愿者的体内膝关节进行9分钟扫描时间的单扫描RHE方法。使用双组分信号模型来表征短T2*和长T2*水成分。髌腱的平均双组分T2*参数,前交叉韧带(ACL),计算后交叉韧带(PCL)和半月板。在实验结果中,RHE技术提供了肌腱的双组分T2*参数估计,ACL,PCL和弯月面,与文献中先前报道的值相似。总之,提出的单扫描RHE技术提供了人膝关节的快速双组分T2*分析,总扫描时间少于9分钟。