增强磁共振成像（MRI）是脑肿瘤诊断和治疗规划的基石。我们开发了一种新型的双回波三维暗血脉序列，称为Dixon不平衡T1弛豫增强稳态（uT1RESS），可以增强对比增强病变的可见度，同时抑制血管和脂肪组织的信号。本研究的目的是测试假设：与磁化制备快速梯度回波（MPRAGE）相比，Dixon uT1RESS会显著改善脑肿瘤的可见性，并确定该技术的潜在限制。该回顾性研究已获得医院机构审查委员会的批准。纳入了47名接受脑肿瘤MRI扫描的成年患者。使用MPRAGE和Dixon uT1RESS在3T进行脑部对比增强MRI。为了控制扫描过程中造影剂流出的影响，Dixon uT1RESS在约一半的受试者中在MPRAGE后立即进行，另一半在MPRAGE前立即进行。三个读者对图像质量、伪影和病变检测进行评分，病变表观信噪比和病变对背景的Weber对比度从感兴趣区域的测量中计算得出。与MPRAGE相比，Dixon uT1RESS使肿瘤与脑的对比度显著增加（在Dixon uT1RESS在MPRAGE之前获取时为1.60±1.18，与Dixon uT1RESS在MPRAGE之后获取时0.61±0.47相比，在前者中1.94±0.97，后者为0.82±0.55）。与MPRAGE相比，在转移性疾病患者中，Dixon uT1RESS在平均24.7％的患者中检测到至少1个增强的脑部病变，而MPRAGE未能检测到，Dixon uT1RESS未漏诊任何通过MPRAGE证实的病变。Dixon uT1RESS更好地检测了少量患者的血管和硬脑膜侵犯。总之，与MPRAGE相比，使用Dixon uT1RESS的3T脑部肿瘤更加显著，无论顺序如何，病变对背景的对比度都提高了约2.5倍。它在脑转移瘤、硬脑膜或血管侵犯的检测方面表现优异。这些结果表明，Dixon uT1RESS可能成为现有神经影像技术的有用补充或替代品，用于颅内肿瘤的造影后评估。 版权所有©2023 Wolters Kluwer Health，Inc。保留所有权利。

Contrast-enhanced magnetic resonance imaging (MRI) is the cornerstone for brain tumor diagnosis and treatment planning. We have developed a novel dual-echo volumetric dark blood pulse sequence called Dixon unbalanced T1 relaxation-enhanced steady-state (uT1RESS) that improves the visibility of contrast-enhancing lesions while suppressing the tissue signals from blood vessels and fat. The purpose of this study was to test the hypothesis that Dixon uT1RESS would significantly improve the conspicuity of brain tumors compared with magnetization-prepared rapid gradient echo (MPRAGE), as well as to determine potential limitations of the technique.This retrospective study was approved by the hospital institutional review board. Forty-seven adult patients undergoing an MRI scan for a brain tumor indication were included. Contrast-enhanced MRI of the brain was performed at 3 T using both MPRAGE and Dixon uT1RESS. To control for any impact of contrast agent washout during the scan procedure, Dixon uT1RESS was acquired in approximately half the subjects immediately after MPRAGE, and in the other half immediately before MPRAGE. Image quality, artifacts, and lesion detection were scored by 3 readers, whereas lesion apparent signal-to-noise ratio and lesion-to-background Weber contrast were calculated from region-of-interest measurements.Image quality was not rated significantly different between MPRAGE and Dixon uT1RESS, whereas motion artifacts were slightly worse with Dixon uT1RESS. Comparing Dixon uT1RESS with MPRAGE, the respective values for mean lesion apparent signal-to-noise ratio were not significantly different (199.31 ± 99.05 vs 203.81 ± 110.23). Compared with MPRAGE, Dixon uT1RESS significantly increased the tumor-to-brain contrast (1.60 ± 1.18 vs 0.61 ± 0.47 when Dixon uT1RESS was acquired before MPRAGE and 1.94 ± 0.97 vs 0.82 ± 0.55 when Dixon uT1RESS was acquired after MPRAGE). In patients with metastatic disease, Dixon uT1RESS detected at least 1 enhancing brain lesion that was missed by MPRAGE on average in 24.7% of patients, whereas Dixon uT1RESS did not miss any lesions that were demonstrated by MPRAGE. Dixon uT1RESS better detected vascular and dural invasion in a small number of patients.In conclusion, brain tumors were significantly more conspicuous at 3 T using Dixon uT1RESS compared with MPRAGE, with an approximately 2.5-fold improvement in lesion-to-background contrast irrespective of sequence order. It outperformed MPRAGE for the detection of brain metastases, dural or vascular involvement. These results suggest that Dixon uT1RESS could prove to be a useful adjunct or alternative to existing neuroimaging techniques for the postcontrast evaluation of intracranial tumors.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.