7T PROTON RESONANT FREQUENCY SHIFT & R2* IN FROZEN EXVIVO RENAL TISSUE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 简介 影像引导冷冻消融是治疗肾癌的一种微创治疗方法。为此，在低场介入系统上用超短TE MR成像测量了冷冻组织的MR参数[1，2]，但对质子共振频率漂移对观察到的相变的贡献的理解受到低场下冷冻组织的SNR的限制。 目标 本研究的目的是在高场光谱仪上测量冷冻组织的MR参数(PRF位移和R2*)。 方法 新鲜切取的肾脏样本用瓦里安INOVA 300 MHz核磁共振系统进行成像。组织温度逐步降至30℃。为了计算1H频率随温度的变化，从每个温度下的1H频率减去基线频率。R2*是根据线宽计算得出的。

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. ntroduction Image-guided cryoablation is a minimally invasive therapy for renal cancer. To this end, MR parameters of frozen tissue have been measured with ultrashort TE MR imaging on a low field interventional system [1,2], but understanding of the contribution of the proton resonant frequency shift to the observed phase changes have been limited by the SNR of the frozen tissue at low field. Aims The purpose of this study was to measure the MR parameters of frozen tissue (PRF shift and R2*) on a high field spectrometer. Methods Freshly excised kidney samples were imaged with the Varian INOVA 300 MHz NMR system. Tissue temperature was decreased to 30¿C in steps. To calculate 1H frequency shift with temperature, the baseline frequency was subtracted from the 1H frequency at every temperature. The R2* was calculated from the linewidth.