在7特斯拉下从MP2RAGE采集的丘脑核的快速自动分割
Fast automatic segmentation of thalamic nuclei from MP2RAGE acquisition at 7 Tesla
摘要：
目的：常规MRI由于对比度差，丘脑核团在很大程度上不可见。Thalamus Optimized Multi-Atlas Segmentation（THOMAS）提供了在7 T下使用白质零化（WMn）MP3序列的12个丘脑核团的自动分割。本文研究了THOMAS在磁化制备2快速梯度回波（MP2）序列中的应用。研究方法：在费城儿童医院招募了8名健康志愿者和5名儿童多发性硬化症患者，并在Siemens 7 T上使用WMn-MP2序列和多回波MP2序列（ME-MP2序列）进行扫描。从ME-MP2序列的T1图合成白质无效对比度（MP2-SYN）。使用THOMAS联合标记融合算法从WMn-MP4和MP2-SYN数据集分割丘脑核团。修改了THOMAS管道，以使用多数表决来分割偏差校正的MP2-UNI图像。使用骰子系数、体积相似性指数（VSI）和质心之间的距离，将来自MP2-SYN和MP2-UNI图像的丘脑核与从WMn-MPTSD图像获得的相应核进行评估。结果如下：对于MP2-SYN，对于5个较大的核实现了dice > 0.85和VSI > 0.95，并且对于7个较小的核实现了dice > 0.6和VSI > 0.7。与MP2-UNI相比，MP2-SYN的方块和VSI略高，而质心之间的距离较小，这表明使用合成的WMn图像的性能有所改善。讨论内容：THOMAS算法可以成功地分割丘脑核团在常规采集的无偏见的MP2神经元图像与基本上等同的质量时，评价WMn-MP2神经元，因此有更广泛的适用性，在研究丘脑参与衰老和疾病。
英文摘要：
Purpose: Thalamic nuclei are largely invisible in conventional MRI due to poor contrast. Thalamus Optimized Multi-Atlas Segmentation (THOMAS) provides automatic segmentation of 12 thalamic nuclei using white-matter-nulled (WMn) MPRAGE sequence at 7T. Application of THOMAS to Magnetization Prepared 2 Rapid Gradient Echo (MP2RAGE) sequence acquired at 7T has been investigated in this study. Methods: 8 healthy volunteers and 5 pediatric-onset multiple sclerosis patients were recruited at the Children's Hospital of Philadelphia and scanned at Siemens 7T with WMn-MPRAGE and multi-echo MP2RAGE (ME-MP2RAGE) sequences. White-matter-nulled contrast was synthesized (MP2-SYN) from T1 maps from ME-MP2RAGE sequence. Thalamic nuclei were segmented using THOMAS joint label fusion algorithm from WMn-MPRAGE and MP2-SYN datasets. THOMAS pipeline was modified to use majority voting to segment the bias corrected MP2-UNI images. Thalamic nuclei from MP2-SYN and MP2-UNI images were evaluated against corresponding nuclei obtained from WMn-MPRAGE images using dice coefficients, volume similarity indices (VSI) and distance between centroids. Results: For MP2-SYN, dice > 0.85 and VSI > 0.95 was achieved for the 5 larger nuclei and dice > 0.6 and VSI > 0.7 was achieved for the 7 smaller nuclei. The dice and VSI were slightly higher whilst the distance between centroids were smaller for MP2-SYN compared to MP2-UNI, indicating improved performance using the synthesized WMn image. Discussion: THOMAS algorithm can successfully segment thalamic nuclei in routinely acquired bias-free MP2RAGE images with essentially equivalent quality when evaluated against WMn-MPRAGE, hence has wider applicability in studies focused on thalamic involvement in aging and disease.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
