From the Departments of Neuroscience, Imaging and Clinical Sciences (M.C., R.N., E.P., V.P., M.C.)
National Institutes of Health (H.C.), Bethesda, Maryland.
AJNR Am J Neuroradiol. 2023 Feb;44(2):150-156. doi: 10.3174/ajnr.A7765. Epub 2023 Jan 19.
Surgical resection of cerebral cavernous malformations close to eloquent regions frequently uses fMRI and DTI for surgical planning to best preserve neurologic function. This study investigates the reliability of fMRI and DTI near cerebral cavernous malformations.
Consecutive patients with cerebral cavernous malformations undergoing presurgical fMRI and DTI mapping were identified. Each cerebral cavernous malformation was hand-contoured; 2 sequential 4-mm expansion shells (S1 and S2) were created, generating 2 ROIs and 2 contralateral controls. Fractional anisotropy and regional homogeneity measurements were then extracted from each ROI and compared with the contralateral controls. Reliability, accuracy, and precision were compared as appropriate.
Fifty-four patients were identified and included. Errors of fractional anisotropy were significantly lower than those of regional homogeneity in S1 and S2 (< .001), suggesting that fractional anisotropy is more reliable than regional homogeneity near cerebral cavernous malformations. Proximity to cerebral cavernous malformations worsened the reliability of regional homogeneity (S1 versus S2, < .001), but not fractional anisotropy ( = .24). While fractional anisotropy was not significantly biased in any ROI (> .05), regional homogeneity was biased toward lower signals in S1 and S2 (< .05), an effect that was attenuated with distance from cerebral cavernous malformations (< .05). Fractional anisotropy measurements were also more precise than regional homogeneity in S1 and S2 (< .001 for both).
Our findings suggest that hemosiderin-rich lesions such as cerebral cavernous malformations may lead to artifactual depression of fMRI signals and that clinicians and surgeons should interpret fMRI studies near cerebral cavernous malformations with caution. While fMRI is considerably affected by cerebral cavernous malformation-related artifacts, DTI appears to be relatively unaffected and remains a reliable imaging technique near cerebral cavernous malformations.
在靠近语言功能区的情况下，对脑内海绵状血管畸形进行手术切除时，通常会使用 fMRI 和 DTI 进行手术规划，以最大程度地保留神经功能。本研究旨在探讨 fMRI 和 DTI 在脑内海绵状血管畸形附近的可靠性。
本研究连续纳入了接受术前 fMRI 和 DTI 定位的脑内海绵状血管畸形患者。手动勾画每个脑内海绵状血管畸形，并创建了两个连续的 4mm 扩展壳（S1 和 S2），生成 2 个 ROI 和 2 个对侧对照。然后从每个 ROI 中提取各向异性分数和局部均一性测量值，并与对侧对照进行比较。适当比较可靠性、准确性和精密度。
共确定并纳入了 54 例患者。在 S1 和 S2 中，各向异性分数的误差明显低于局部均一性的误差（<.001），表明在脑内海绵状血管畸形附近，各向异性分数比局部均一性更可靠。靠近脑内海绵状血管畸形会降低局部均一性的可靠性（S1 与 S2 比较，<.001），但不会降低各向异性分数的可靠性（=0.24）。在任何 ROI 中，各向异性分数均无显著偏倚（>.05），而局部均一性在 S1 和 S2 中均呈低信号偏倚（<.05），这种偏倚随距离脑内海绵状血管畸形的增加而减弱（<.05）。在 S1 和 S2 中，各向异性分数的测量精度也高于局部均一性（均<.001）。
本研究结果表明，富含含铁血黄素的病变（如脑内海绵状血管畸形）可能导致 fMRI 信号的人为压低，临床医生和外科医生在解读脑内海绵状血管畸形附近的 fMRI 研究时应持谨慎态度。虽然 fMRI 受到脑内海绵状血管畸形相关伪影的严重影响，但 DTI 似乎相对不受影响，并且仍然是脑内海绵状血管畸形附近可靠的成像技术。
