CLINICAL ASSESSMENT OF CBF FROM PERFUSION MRI

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 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 中心，不一定是研究者的机构。 本研究的目的是完善和改进的方法，血流和灌注成像（DTI）的研究人员和合作者的P41 RR 09784？斯坦福大学的先进磁共振技术中心？核心3（Core 3）使用灌注MRI（PWI）的基本原理是缺血中功能缺陷的灌注阈值略高于表观扩散系数（ADC）降低的灌注阈值。因此，如果没有DWI病变，缺血可能仍然是患者的根本原因？的症状，PWI可以显示。在这些患者中（灌注缺损，但无DWI异常），血流似乎受损，但不足以导致受累区域的能量衰竭，这表明大部分或所有受累组织仍有可能挽救。我们假设测量的灌注（CBF、MTT和CBV）值将揭示呈现时可逆事件的不可逆组织，后续测量将对此进行测试。我们已经使用了我们的CBF映射PWI方法的改进，在这里开发的研究临床和放射学相关的患者与严重减少的CBF使用PWI与CBF校正的Ostergaard CBF的方法。我们建议进一步研究这种有趣的ADC-CBV组织模式。这些数据表明，严重的CBF减少超过50%会导致更严重的脑缺血，如较高的NIHSS，较低的traceADC，较大的DWI病变和较大的灌注缺损。我们现在正试图？滴定？观察到的ADC随着从连续患者的MRI和XeCT研究中获得的CBF测量值而降低。

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. The goal of this research is to refine and improve the methodology of flow and perfusion imaging (DTI) for the investigators and collaborators on the P41 RR09784 ?Center for Advanced MR Technology at Stanford? effort (Core3). The rationale for using perfusion MRI (PWI) is that the perfusion thresholds for functional deficits in ischemia are slightly above that for reductions in the apparent diffusion coefficient (ADC). Thus, if there is no DWI lesion, ischemia may still be the underlying cause of the patient?s symptoms, which can be revealed by PWI. In these patients (perfusion deficit, but no DWI abnormality), blood flow appears to be impaired, but not severely enough to cause energy failure in the affected region, suggesting that most or all of the affected tissue is still potentially salvageable. We hypothesize that measured perfusion (CBF, MTT, and CBV) values would reveal the irreversible tissue from the reversible events at presentation, subsequent measures will test this. We have used our refinements of the CBF mapping PWI methods developed here to study the clinical and radiological correlates of patients with a severe reduction of CBF using PWI with the CBF corrected by the Ostergaard CBF approach. We propose to further study this interesting ADC-CBV tissue pattern. These data suggest that severe CBF reductions of greater than 50% result in more severe cerebral ischemia, as measured by a higher NIHSS, a lower traceADC, a larger DWI lesion and a larger perfusion deficit. We now are attempting to ?titrate? the observed ADC decreases with measured CBF values acquired from the MRI and from XeCT studies on consecutive patients.