OBJECTIVES We investigated whether prenatal magnetic resonance imaging (MRI) within 26 weeks of gestation (GW) may predict the fate of isolated upward rotation of the cerebellar vermis (URCV). METHODS This retrospective multicentre observational study included foetuses diagnosed with isolated URCV in prenatal MRI performed within 26 GW. Isolated URCV was defined by a brainstem-vermis angle (BVA) ≥ 12° in the MR midline sagittal view without abnormalities of the supratentorial structures, brainstem, or cerebellum hemispheres. The assessments included the BVA, clival-supraoccipital angle, transverse diameter of the posterior cranial fossa, tentorial angle, width of the cisterna magna (WCM), ventricular width, vermian diameters, hypointense stripes, and cerebellar tail sign. Late prenatal or postnatal MRI was used as a reference standard to assess the final vermian fate (rotated/de-rotated). RESULTS Forty-five foetuses (mean GW at prenatal MRI = 21.5 ± 1.4 weeks) were included. In the reference standard, the vermis was de-rotated in 26 cases (57.7%). At least two of the following criteria were used to predict the persistence of URCV at imaging follow-up: BVA ≥ 23°, WCM ≥ 9 mm, and the cerebellar tail sign. The results were a sensitivity of 84.21% (95% CI, 60.4-96.6%), specificity of 80.8% (95% CI, 60.6-93.4%), positive predictive value of 76% (95% CI, 58.7-87.8%), and negative predictive value of 87.5% (95% CI, 70.9-95.2%). CONCLUSIONS MRI within 26 GW on foetuses diagnosed with isolated URCV may predict delayed cerebellar vermis de-rotation, which is associated with good neurodevelopmental outcome in most cases. KEY POINTS • Foetal MRI is a valuable tool in predicting the fate of isolated upward-rotated cerebellar vermis. • A wider angle between the brainstem and vermis is associated with higher risk of persistence of vermian rotation. • The presence of ≥ 2 factors among a brainstem-to-vermis angle ≥ 23°, width of the cisterna magna ≥ 9 mm, and the presence of the "cerebellar tail sign" has a sensitivity of 84.21% (95% CI, 60.4-96.6%) and specificity of 80.8% (95% CI, 60.6-93.4%) in predicting the persistence of the vermian rotation at imaging follow-up.

中文翻译：

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妊娠 26 周内的产前磁共振成像可以预测小脑蚓部孤立向上旋转的命运：来自多中心研究的见解。

目标 我们调查了妊娠 26 周内的产前磁共振成像 (MRI) (GW) 是否可以预测小脑蚓部 (URCV) 的孤立向上旋转的命运。方法 这项回顾性多中心观察研究包括在 26 GW 以内进行的产前 MRI 诊断为孤立性 URCV 的胎儿。孤立的 URCV 定义为 MR 中线矢状面脑干-蚓部角 (BVA) ≥ 12°，无幕上结构、脑干或小脑半球异常。评估包括 BVA、斜枕上角、后颅窝横径、小脑幕角、小脑池宽度 (WCM)、脑室宽度、蚓部直径、低信号条纹和小脑尾征。晚期产前或产后 MRI 被用作评估最终蚯蚓命运（旋转/去旋转）的参考标准。结果 包括 45 个胎儿（产前 MRI 的平均 GW = 21.5 ± 1.4 周）。在参考标准中，26 例 (57.7%) 的蚓部发生旋转。以下标准中至少有两项用于预测影像学随访时 URCV 的持续存在：BVA ≥ 23°、WCM ≥ 9 mm 和小脑尾征。结果的敏感性为 84.21%（95% CI，60.4-96.6%），特异性为 80.8%（95% CI，60.6-93.4%），阳性预测值为 76%（95% CI，58.7-87.8%） ，阴性预测值为 87.5%（95% CI，70.9-95.2%）。结论 对诊断为孤立性 URCV 的胎儿进行 26 GW 以内的 MRI 可以预测延迟的小脑蚓部去旋转，这在大多数情况下与良好的神经发育结果相关。要点 • 胎儿 MRI 是预测孤立的上旋小脑蚓部命运的重要工具。• 脑干和蚓部之间的角度越大，蚓部持续旋转的风险越高。• 脑干与蚓部角度 ≥ 23°、小脑池宽度 ≥ 9 mm 和“小脑尾征”中存在 ≥ 2 个因素的敏感性为 84.21%（95% CI，60.4 -96.6%）和 80.8%（95% CI，60.6-93.4%）的特异性预测成像随访中蚓部旋转的持续性。