INVESTIGATION OF AN ARTIFACT IN TEMPERATURE IMAGES OF FUS HEATING

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 简介：基于PRF的温度标测通常用于监测聚焦超声（FUS）消融。沿加热点的纵向方向对加热点沿着成像显示出伪影，该伪影表现为在加热区域的中间的测量温度中的下降，在该加热区域中温度被预期为最高。这项工作的目的是调查这件文物的来源。 方法和讨论：MR实验和MatLab模拟进行。这些表明，当成像切片位置相对于焦斑偏离中心时，焦斑处的陡峭温度梯度会出现伪影。对于较厚的切片，伪影较大。结果表明，切片方向上的部分容积效应和偏离中心的切片位置不会单独产生倾斜伪影，但T1随温度的变化需要包括在模拟中。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: PRF based temperature mapping is commonly used to monitor focused ultrasound (FUS) ablation. Imaging the heating spot along its longitudinal direction shows an artifact that appears as a dip in the measured temperature in the middle of the heating region where temperatures were expected to be highest. The purpose of this work was to investigate the source of this artifact. Methods and Discussion: MR experiments and MatLab simulations were performed. These showed that the artifact occurs for steep temperature gradients at the focal spot when the imaging slice location is off-center with respect to the focal spot. The artifact is larger for thicker slices. The results showed that partial volume effect in the slice direction and off-center slice position alone did not create the dip artifact, but that the T1-change with temperature needed to be included in the simulation.