Accurate Quantification in Physiologic Phosphorus MR Spectroscopy

生理磷 MR 光谱的准确定量

• 批准号: 7964093
• 负责人: Richard Spencer
• 金额: $ 14.26万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7964093
• 关键词: Biological; Chemicals; Data; Heart; Ischemia; Lead; Magnetic Resonance Spectroscopy; Measurement; Metabolic; Methods; Mitochondria; Monitor; NMR Spectroscopy; Noise; Phosphorus; Physiological; Procedures; Rattus; Recovery; Reperfusion Therapy; Sampling; Signal Transduction; Stress; Time; base; chemical kinetics; improved; research study; simulation

We find that alternations in data acquired at alternating flip angles from the perfused rat heart are eliminated by the O-DAM correction. Corresponding simulations demonstrate that accurate saturation correction can be performed when metabolite changes are modest. Using typical parameters, we find that, as expected, greater degrees of accuracy can be achieved for smaller fractional changes in PCr. A decrease in PCr of less than 12% permits accuracy in PCr/Pi measurement to within 20%. For TR = 2 s, PCr can decrease by over 50% with accuracy of the corrected ratio remaining within 20%. Simulation of an ischemia-reperfusion experiment indicates the high degree of accuracy obtainable except at times of rapid concentration changes. Thus, the O-DAM procedure may permit accurate monitoring of metabolite concentrations even in the setting of chemical exchange and T1 changes. In addition, due to the ability to more accurately quantify PCr recovery after the cessation of stress, the O-DAM method permits a more accurate measurement of the time constant for metabolic recovery, a widely-used marker for mitochondrial synthetic capability.

我们发现，在交替翻转角度从灌注大鼠心脏采集的数据中的交替被O-DAM校正消除。 相应的模拟表明，准确的饱和校正时，代谢物的变化是温和的。 使用典型的参数，我们发现，正如预期的那样，更大程度的准确性，可以实现较小的分数变化PCr。 PCr降低小于12%允许PCr/Pi测量的准确度在20%以内。对于TR = 2 s，PCr可以降低50%以上，而校正比率的精度保持在20%以内。 缺血-再灌注实验的模拟表明，除了在快速浓度变化的时候，可获得的准确度高。 因此，即使在化学交换和T1变化的情况下，O-DAM程序也可以准确监测代谢物浓度。 此外，由于能够更准确地量化压力停止后的PCr恢复，O-DAM方法允许更准确地测量代谢恢复的时间常数，这是线粒体合成能力的广泛使用的标志物。