Abstract：
OBJECTIVE: The current study aims to explore the utility of novel synthetic MRI-derived quantitative parameters including myelin-correlated volume (MyC) in identifying active MS lesions without injecting gadolinium contrast.
METHODS: 43 MS patients underwent institutional MS protocol including 3D FLAIR and post-contrast 3D T1VIBE sequence on a 1.5 T MR Scanner in addition to synthetic MRI sequence. MS plaques were categorised into enhancing (C) and non-enhancing (N) lesions. They were also sub-categorised based on location into periventricular WM lesions (P), deep WM lesions (D), infratentorial lesions (I) and cortical-juxtacortical (C) lesions. ROIs were placed on Synthetic FLAIR images in MS lesions and quantitative parameters of R1, R2, PD and myelin-correlated volume (MyC) obtained. Sensitivity and specificity for various cut-off values to differentiate enhancing from non-enhancing multiple sclerosis lesions were calculated by performing ROC curve analysis and logistic regression analysis.
RESULTS: Contrast enhancing lesions demonstrated significantly higher mean R1, R2 values and lower mean PD values in comparison to non-enhancing lesions (p < 0.05) but with limited specificity. Region-wise analysis revealed high AUC values for mean R1 and R2 at cortical-juxtacortical lesions (p < 0.001) followed by periventricular lesions (p < 0.003) for differentiating enhancing from non-enhancing lesions with no significant contribution from MyC and PD values.
CONCLUSIONS: Synthetic MRI-derived quantitative parameters of mean R1, R2, MyC and PD hold value in differentiating contrast enhancing and non-enhancing MS lesions without administering gadolinium-based contrast agent. However, the current study did not achieve significant specificity for establishing the same.
METHODS: 43 MS patients underwent institutional MS protocol including 3D FLAIR and post-contrast 3D T1VIBE sequence on a 1.5 T MR Scanner in addition to synthetic MRI sequence. MS plaques were categorised into enhancing (C) and non-enhancing (N) lesions. They were also sub-categorised based on location into periventricular WM lesions (P), deep WM lesions (D), infratentorial lesions (I) and cortical-juxtacortical (C) lesions. ROIs were placed on Synthetic FLAIR images in MS lesions and quantitative parameters of R1, R2, PD and myelin-correlated volume (MyC) obtained. Sensitivity and specificity for various cut-off values to differentiate enhancing from non-enhancing multiple sclerosis lesions were calculated by performing ROC curve analysis and logistic regression analysis.
RESULTS: Contrast enhancing lesions demonstrated significantly higher mean R1, R2 values and lower mean PD values in comparison to non-enhancing lesions (p < 0.05) but with limited specificity. Region-wise analysis revealed high AUC values for mean R1 and R2 at cortical-juxtacortical lesions (p < 0.001) followed by periventricular lesions (p < 0.003) for differentiating enhancing from non-enhancing lesions with no significant contribution from MyC and PD values.
CONCLUSIONS: Synthetic MRI-derived quantitative parameters of mean R1, R2, MyC and PD hold value in differentiating contrast enhancing and non-enhancing MS lesions without administering gadolinium-based contrast agent. However, the current study did not achieve significant specificity for establishing the same.
摘要：
目的：本研究旨在探索新型合成MRI衍生的定量参数（包括髓鞘相关体积（MyC））在不注射钆造影剂的情况下识别活动性MS病变的实用性。
方法：43例MS患者在1.5TMR扫描仪上接受了包括3DFLAIR和对比后3DT1VIBE序列的机构MS方案，以及合成MRI序列。MS斑块分为增强(C)和非增强(N)病变。他们也根据位置到脑室周围的WM病变（P），深部WM病变（D），幕下病变（I）和皮质-皮质（C）病变。将ROI放置在MS病变的合成FLAIR图像上，并获得R1，R2，PD和髓鞘相关体积（MyC）的定量参数。通过进行ROC曲线分析和逻辑回归分析，计算了区分增强与非增强多发性硬化病变的各种临界值的敏感性和特异性。
结果：对比增强病变显示与非增强病变相比，显著较高的平均R1、R2值和较低的平均PD值（p<0.05），但特异性有限。分区域分析显示，在皮质近区病变处，平均R1和R2的AUC值较高（p<0.001），然后是脑室周围病变（p<0.003），用于区分增强与非增强病变，而MyC和PD值没有显着贡献。
结论：合成MRI衍生的定量参数的平均R1，R2，MyC和PD在不使用基于钆的造影剂的情况下区分对比增强和非增强MS病变方面具有价值。然而,目前的研究没有达到建立相同的显著特异性.
方法：43例MS患者在1.5TMR扫描仪上接受了包括3DFLAIR和对比后3DT1VIBE序列的机构MS方案，以及合成MRI序列。MS斑块分为增强(C)和非增强(N)病变。他们也根据位置到脑室周围的WM病变（P），深部WM病变（D），幕下病变（I）和皮质-皮质（C）病变。将ROI放置在MS病变的合成FLAIR图像上，并获得R1，R2，PD和髓鞘相关体积（MyC）的定量参数。通过进行ROC曲线分析和逻辑回归分析，计算了区分增强与非增强多发性硬化病变的各种临界值的敏感性和特异性。
结果：对比增强病变显示与非增强病变相比，显著较高的平均R1、R2值和较低的平均PD值（p<0.05），但特异性有限。分区域分析显示，在皮质近区病变处，平均R1和R2的AUC值较高（p<0.001），然后是脑室周围病变（p<0.003），用于区分增强与非增强病变，而MyC和PD值没有显着贡献。
结论：合成MRI衍生的定量参数的平均R1，R2，MyC和PD在不使用基于钆的造影剂的情况下区分对比增强和非增强MS病变方面具有价值。然而,目前的研究没有达到建立相同的显著特异性.
