利用动态磁敏感对比 MRI 可靠估计血脑屏障破坏患者的微血管血流模式。
Reliable estimation of microvascular flow patterns in patients with disrupted blood-brain barrier using dynamic susceptibility contrast MRI.
机构信息
Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark.
出版信息
J Magn Reson Imaging. 2017 Aug;46(2):537-549. doi: 10.1002/jmri.25549. Epub 2016 Nov 30.
PURPOSE
To present and quantify the performance of a method to compute tissue hemodynamic parameters from dynamic susceptibility contrast (DSC) MRI data in brain tissue with possible nonintact blood-brain barrier.
THEORY AND MATERIALS AND METHODS
We propose a Bayesian scheme to obtain perfusion metrics, including capillary transit-time heterogeneity (CTH), from DSC-MRI data in the presence of contrast agent extravasation. Initial performance assessment is performed through simulations. Next, we assessed possible over- or under correction for tracer extravasation in two patients receiving contrast agent preloading and two patients not receiving preloading. Perfusion metrics for N = 60 patients diagnosed with either grade III (N = 14) or grade IV gliomas (N = 46) were analyzed across tissue types to evaluate the ability to distinguish regions with different hemodynamic patterns. Finally, N = 4 patient cases undergoing anti-angiogenic treatment are evaluated qualitatively for treatment effects. All patient data were acquired at 3.0 Tesla.
RESULTS
The simulation studies showed good robustness against low signal-to-noise ratios, exemplified with Pearson correlations of R = 0.833 (mean transit time) and R = 0.738 (CTH) at signal-to-noise ratio = 20. Region-of-interest analysis of the N = 60 glioma patients showed that cerebral blood volume (CBV) significantly separated enhancing core from edema (grade IV: P < 10 , grade III: P < 0.05) and enhancing core from normal appearing ipsilateral white matter (NAWM) (grade IV: P < 10 , grade III: P < 0.05). The microvascular parameters were particularly good in separating edematous tissue from NAWM tissue in grade IV gliomas (P < 0.001). Finally, CTH separated grade III and grade IV core tissue (P < 0.05).
CONCLUSION
We have demonstrated robustness of the proposed Bayesian algorithm against experimental noise and demonstrated complementary value in microvascular parameters to the CBV parameter in separating tissue types in gliomas.
LEVEL OF EVIDENCE
3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:537-549.
目的
提出并量化一种从可能存在血脑屏障不完整的动态对比磁共振成像（DSC MRI）数据中计算组织血流动力学参数的方法，并对其进行定量分析。
理论、材料和方法：我们提出了一种贝叶斯方案，用于从 DSC-MRI 数据中获得灌注度量，包括毛细血管渡越时间异质性（CTH），并存在对比剂外渗的情况下。通过模拟进行初步性能评估。接下来，我们评估了在接受对比剂预加载的 2 名患者和未接受预加载的 2 名患者中，对比剂外渗的过度或不足校正。对 60 名诊断为 3 级（n=14）或 4 级（n=46）胶质瘤的患者进行了 n=60 次的组织类型分析，以评估区分不同血流模式区域的能力。最后，对 n=4 例接受抗血管生成治疗的患者进行定性评估，以评估治疗效果。所有患者数据均在 3.0T 下采集。
结果
模拟研究表明，该方法对低信噪比具有很好的稳健性，以信噪比为 20 时的 Pearson 相关系数 R=0.833（平均通过时间）和 R=0.738（CTH）为例。对 n=60 例胶质瘤患者的感兴趣区域分析表明，脑血容量（CBV）显著区分了增强核心与水肿（IV 级：P<0.001，III 级：P<0.05）和增强核心与同侧正常白质（NAWM）（IV 级：P<0.001，III 级：P<0.05）。微血管参数在区分 IV 级胶质瘤的水肿组织和 NAWM 组织方面尤其有效（P<0.001）。最后，CTH 区分了 III 级和 IV 级核心组织（P<0.05）。
结论
我们已经证明了所提出的贝叶斯算法对实验噪声的稳健性，并证明了在微血管参数方面对 CBV 参数具有补充价值，可用于区分胶质瘤中的组织类型。
证据水平
3 级技术功效：2 级。J. MAGN. RESON. IMAGING 2017；46：537-549。
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