Cortical demyelinating lesions are clinically important in multiple sclerosis, but notoriously difficult to visualize with MRI. At clinical field strengths, double inversion recovery MRI is most sensitive, but still only detects 18% of all histopathologically validated cortical lesions. More recently, phase-sensitive inversion recovery was suggested to have a higher sensitivity than double inversion recovery, although this claim was not histopathologically validated. Therefore, this retrospective study aimed to provide clarity on this matter by identifying which MRI sequence best detects histopathologically-validated cortical lesions at clinical field strength, by comparing sensitivity and specificity of the thus far most commonly used MRI sequences, which are T₂, fluid-attenuated inversion recovery (FLAIR), double inversion recovery and phase-sensitive inversion recovery. Post-mortem MRI was performed on non-fixed coronal hemispheric brain slices of 23 patients with progressive multiple sclerosis directly after autopsy, at 3 T, using T₁ and proton-density/T₂-weighted, as well as FLAIR, double inversion recovery and phase-sensitive inversion recovery sequences. A total of 93 cortical tissue blocks were sampled from these slices. Blinded to histopathology, all MRI sequences were consensus scored for cortical lesions. Subsequently, tissue samples were stained for proteolipid protein (myelin) and scored for cortical lesion types I–IV (mixed grey matter/white matter, intracortical, subpial and cortex-spanning lesions, respectively). MRI scores were compared to histopathological scores to calculate sensitivity and specificity per sequence. Next, a retrospective (unblinded) scoring was performed to explore maximum scoring potential per sequence. Histopathologically, 224 cortical lesions were detected, of which the majority were subpial. In a mixed model, sensitivity of T₁, proton-density/T₂, FLAIR, double inversion recovery and phase-sensitive inversion recovery was 8.9%, 5.4%, 5.4%, 22.8% and 23.7%, respectively (20, 12, 12, 51 and 53 cortical lesions). Specificity of the prospective scoring was 80.0%, 75.0%, 80.0%, 91.1% and 88.3%. Sensitivity and specificity did not significantly differ between double inversion recovery and phase-sensitive inversion recovery, while phase-sensitive inversion recovery identified more lesions than double inversion recovery upon retrospective analysis (126 versus 95; P < 0.001). We conclude that, at 3 T, double inversion recovery and phase-sensitive inversion recovery sequences outperform conventional sequences T₁, proton-density/T₂ and FLAIR. While their overall sensitivity does not exceed 25%, double inversion recovery and phase-sensitive inversion recovery are highly pathologically specific when using existing scoring criteria and their use is recommended for optimal cortical lesion assessment in multiple sclerosis.

中文翻译：

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经组织病理学验证的多发性硬化症皮层病变影像学建议。

皮质脱髓鞘病变在多发性硬化症中具有重要的临床意义，但众所周知难以通过MRI进行可视化。在临床领域的优势下，双反转恢复MRI最敏感，但仍仅能检测到所有经组织病理学验证的皮质病变的18％。最近，尽管相声学未在组织病理学上得到证实，但有人提出相敏感的反转恢复比双重反转恢复具有更高的灵敏度。因此，这项回顾性研究旨在通过比较迄今最常用的MRI序列T _2的敏感性和特异性，确定哪种MRI序列最能在临床场强下检测经组织病理学验证的皮层病变，从而对此问题进行澄清。，流体衰减反演恢复（FLAIR），双重反演恢复和相敏反演恢复。尸检后直接在3 T下使用T ₁和质子密度/ T ₂对23例进行性多发性硬化的非固定冠状动脉半球脑切片进行死后MRI检查加权以及FLAIR双重反转恢复和相敏反转恢复序列。从这些切片中总共采样了93个皮质组织块。盲目进行组织病理学检查，所有MRI序列均对皮质病变进行了共识评分。随后，对组织样本进行蛋白脂蛋白（髓磷脂）染色，并对I-IV型皮损（分别为混合灰质/白质，皮层内，乳突下和跨皮质皮损）评分。将MRI得分与组织病理学得分进行比较，以计算每个序列的敏感性和特异性。接下来，进行回顾性（无盲）评分，以探索每个序列的最大评分潜力。在组织病理学上，发现了224个皮层病变，其中大多数是皮下病变。在混合模型中，灵敏度为T ₁，质子密度/ T ₂，FLAIR，双重反转和相敏反转恢复分别为8.9％，5.4％，5.4％，22.8％和23.7％（20、12、12、51和53个皮层病变）。预期得分的特异性为80.0％，75.0％，80.0％，91.1％和88.3％。两次反转和相敏反转恢复之间的敏感性和特异性无显着差异，而回顾性分析显示，相敏反转恢复比二次反转恢复识别出更多的病变（126 vs 95；P  <  0.001）。我们得出的结论是，在3 T时，双重反转恢复和相敏反转恢复序列的性能优于常规序列T ₁，质子密度/ T ₂和FLAIR。尽管它们的整体敏感性不超过25％，但在使用现有评分标准时，双重反转恢复和相敏反转恢复在病理上具有高度的特异性，建议将它们用于多发性硬化症的最佳皮层病变评估。