Improved MRI Detection of Cerebral Microbleeds with Novel Susceptibility Mapping

脑微出血(CMBS)是一种小的脑出血(MRI上小于1厘米，CT上看不到)。他们的 存在可用于作出多种诊断(脑淀粉样血管病、创伤性脑损伤、急性和 慢性高血压性颅内出血、阿尔茨海默病药物并发症ARIA-H等)，以及 与更大的脑出血、认知能力下降和动脉瘤破裂的风险增加有关。他们也是 与多种疾病的不良结局有关，包括中风患者血栓后的脑出血 中风患者脑血栓清除后给予破碎性药物，与未服用药物的患者相比，残疾更严重 CMBS。根据CMBS的数量和数量，CMBS的检测在患者的治疗管理中发挥着重要作用 它们在大脑中的什么地方被发现。不幸的是，可检测到的CMB的数量和位置 根据所使用的MRI成像类型而定。例如，虽然3T SWI成像是最敏感的 临床可用的CMB成像方法，放射成像与脑组织的相关性研究 检查表明，组织中高达75%的CMBS未被3T SWI MRI检测到。 此外，SWI已被证明难以区分CMBS和钙化，后者是一种常见的 招商银行模仿。 在SWI和类似的临床使用的MRI技术中看到的许多技术变异性在 较新的磁共振成像技术称为定量磁化率图(QSM)。然而，大多数QSM成像需要 要被遮盖的头骨(MQSM)，导致在生成的图像中遗漏了大脑的随机部分。我们的 研究表明，一种不需要掩码的较新的QSM(称为pQSM)显示了许多 在mQSM图像上看不到大脑。我们还发现CMBS存在于大脑的某些区域。 它们在pQSM图像上可见，但在mQSM图像上不可见。 通常，诊断CMBS的核磁共振成像是由神经放射科医生阅读的。这个项目的目标是研究 神经放射科医生如何阅读pQSM和SWI图像来评估CMBS的差异，以及看看这些是否 差异将导致不同的患者护理，这与已确定的CMBS的数量和/或位置有关。我们 有权获得一组出血量较大的住院患者的数据，这些患者接受了核磁共振成像 他们的部分护理包括制作SWI和pQSM图像所需的原始数据，以及 显示他们的大量脑出血和钙化区域。我们计划使用这些数据来制定SWI和pQSM 供读者神经放射科专家小组为CMBS审查的图像。因为我们不能从 对于这些患者，我们聘请了额外的神经放射科医生作为专家小组，选择SWI上的区域 并将pQSM图像归类为CMB或非CMB，作为黄金标准。读者神经放射科医生 然后将审查由CMBS专家小组标记的这些领域。

Cerebral microbleeds (CMBs) are small brain bleeds (less than 1 cm on MRI, and not visible on CT). Their presence is used to make multiple diagnoses (cerebral amyloid angiopathy, traumatic brain injury, acute and chronic hypertensive intracranial hemorrhage, the Alzheimer's drug complication ARIA-H, etc.), and is associated with increased risk of larger brain bleeds, cognitive decline, and aneurysm rupture. They are also associated with worse outcomes for multiple diseases, including brain bleeds in stroke patients after clot busting drugs are given and worse disability after brain clot removal in stroke, relative to patients without CMBs. Detection of CMBs plays a major role in patient therapeutic management based on their number and where in the brain they are found. Unfortunately, the number and location of detectable CMBs are highly variable depending on the type of MRI imaging used. For example, while 3T SWI imaging is the most sensitive of clinically available CMB imaging methods, studies correlating radiology imaging with brain tissue examination have demonstrated that up to 75% of CMBs in tissue are not detected by 3T SWI MRI. Additionally, SWI has been shown to have difficulty distinguishing CMBs from calcification, which is a common CMB mimic. Much of the technical variability seen in SWI and similar clinically used MRI techniques is not present in a newer MRI technique called quantitative susceptibility mapping (QSM). However, most QSM imaging requires the skull to be masked (mQSM), resulting in omission of random parts of the brain in the resultant images. Our work has shown that a newer kind of QSM, that does not require the masking (called pQSM), shows much of the brain not seen on mQSM images. We also showed that CMBs were present in some of the areas of brain that are visible on pQSM but not mQSM images. Typically, the MRIs that diagnose CMBs are read by neuroradiologists. The goal of this project is to study differences in how neuroradiologists read pQSM and SWI images for evaluating CMBs, and to see if those differences would lead to different patient care, related to the number and / or location of CMBs identified. We have access to data from a group of patients admitted to the hospital with larger bleeds, who received MRIs as part of their care that included the raw data needed to make SWI and pQSM images as well as CT scans that show their large brain bleed and areas of calcification. We plan to use this data to make SWI and pQSM images for a panel of reader neuroradiologists to review for CMBs. Because we cannot get brain tissue from these patients, we recruited additional neuroradiologists to serve as an expert panel to select areas on the SWI and pQSM images to classify as CMB or not CMB, to serve as a gold standard. The reader neuroradiologists will then review these areas marked by the expert panel for CMBs.