CLINICAL ASSESSMENT OF CBF FROM PERFUSION MRI

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。 本研究的目的是为斯坦福大学P41 RR09784先进磁共振技术中心的研究人员和合作者完善和改进血流和灌注成像(DTI)方法。努力(核心3)。使用磁共振灌注成像(PWI)的基本原理是，脑缺血时功能缺陷的灌注阈值略高于表观弥散系数(ADC)的降低。因此，如果没有弥散加权成像的损害，脑缺血仍可能是导致患者S症状的根本原因，而磁共振弥散加权成像可以揭示这一点。在这些患者中(血流灌注不足，但没有DWI异常)，血流似乎受到了损害，但还没有严重到导致受影响区域能量衰竭的程度，这表明大多数或所有受影响组织仍然有可能挽救。我们假设，测量的灌注(CBF、MTT值和CBV)值将揭示呈现时可逆事件的不可逆组织，后续的测量将对此进行测试。我们使用我们在这里开发的CBF标测PWI方法的改进来研究使用PWI和Ostergaard CBF方法校正的CBF严重减少的患者的临床和放射学相关性。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，严重的脑血流量下降超过50%会导致更严重的脑缺血，表现为更高的NIHSS，更低的TRACE-ADC，更大的DWI病变和更大的血流灌注不足。我们现在正试图？滴定？观察到的ADC随着从MRI和连续患者的XeCT研究中获得的CBF值而减少。

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.