Functional magnetic resonance imaging for presurgical brain mapping enables neurosurgeons to identify viable tissue near a site of operable pathology which might be at risk of surgery-induced damage. However, focal brain pathology (e.g., tumors) may selectively disrupt neurovascular coupling while leaving the underlying neurons functionally intact. Such neurovascular uncoupling can result in false negatives on brain activation maps thereby compromising their use for surgical planning. One way to detect potential neurovascular uncoupling is to map cerebrovascular reactivity using either an active breath-hold challenge or a passive resting-state scan. The equivalence of these two methods has yet to be fully established, especially at a voxel level of resolution. To quantitatively compare breath-hold and resting-state maps of cerebrovascular reactivity, we first identified threshold settings that optimized coverage of gray matter while minimizing false responses in white matter. When so optimized, the resting-state metric had moderately better gray matter coverage and specificity. We then assessed the spatial correspondence between the two metrics within cortical gray matter, again, across a wide range of thresholds. Optimal spatial correspondence was strongly dependent on threshold settings which if improperly set tended to produce statistically biased maps. When optimized, the two CVR maps did have moderately good correspondence with each other (mean accuracy of 73.6%). Our results show that while the breath-hold and resting-state maps may appear qualitatively similar they are not quantitatively identical at a voxel level of resolution.

中文翻译：

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阈值对脑血管反应的屏气和静息状态图的体素对应关系的影响。

用于术前脑映射的功能性磁共振成像使神经外科医生能够识别可手术病理部位附近的活组织，这些组织可能存在手术引起的损伤风险。然而，局灶性脑病理（例如，肿瘤）可能会选择性地破坏神经血管耦合，同时使潜在的神经元功能完好无损。这种神经血管解偶联会导致大脑激活图出现假阴性，从而影响其在手术计划中的使用。检测潜在神经血管解偶联的一种方法是使用主动屏气挑战或被动静息状态扫描来绘制脑血管反应性。这两种方法的等效性尚未完全确定，尤其是在体素分辨率水平上。为了定量比较脑血管反应性的屏气和静息状态图，我们首先确定了优化灰质覆盖率同时最小化白质中的错误反应的阈值设置。如此优化后，静息状态指标具有适度更好的灰质覆盖率和特异性。然后，我们再次在广泛的阈值范围内评估了皮质灰质内两个指标之间的空间对应关系。最佳空间对应强烈依赖于阈值设置，如果设置不当，往往会产生有统计偏差的地图。优化后，两个 CVR 地图之间确实具有中等良好的对应关系（平均准确率为 73.6%）。