MR Imaging Grading System for Skull Base Chordoma
MR Imaging Grading System for Skull Base Chordoma
复制标题
颅底脊索瘤磁共振成像分级系统
DOI：
10.3174/ajnr.a5152
复制
发表时间：
2017-06-01
影响因子：
3.5
通讯作者：
Zhang, J.
中科院分区：
文献类型：
--
作者：
Tian, K.;Wang, L.;Zhang, J.
背景和目的：颅底脉络膜肿瘤近年来已被广泛研究，但其影像学特征尚未得到很好的阐述。本研究旨在建立颅底脉络膜病变的MR影像分级系统。材料和方法：在这项研究中，156例颅底脊索瘤患者进行了回顾性评估。根据治疗前MR图像RT 1（T1 FLAIR序列中肿瘤与脑桥信号强度的比值）、RT 2（T2序列中肿瘤与脑桥信号强度的比值）和REN（增强T1 FLAIR序列中肿瘤与脑桥信号强度的比值）计算肿瘤与脑桥信号强度比值，并选择总生存期和无进展生存期的显著比值建立分级系统。然后分析不同MR成像分级之间的临床变量，以评估分级系统的有用性。结果：RT 2（P <0.001）和REN（P = 0.04）被确定为影响无进展生存期的重要变量。分析后，将分类标准设定为：MR I级，RT 2> 2.49且REN ≤ 0.77; MR II级，RT 2> 2.49且REN > 0.77，或RT 2 ≤ 2.49且REN ≤ 0.77; MR III级，RT 2 ≤ 2.49且REN > 0.77。MR III级肿瘤比MR I级肿瘤有更丰富的肿瘤血供（P < .001），MR III级肿瘤的术中失血量高于MR I级肿瘤（P = .002）。此外，MR分级每增加一级，颅底脉络膜进展风险增加2.071倍（P <0.001）。结论：较高的RT 2值是肿瘤进展的阴性指标，而较高的REN值是肿瘤进展的阳性风险因素。MR III级肿瘤显示出比MR I级肿瘤更丰富的血供，并且颅底脉络膜进展的风险随着每一个MR级别的增加而增加。
BACKGROUND AND PURPOSE: Skull base chordoma has been widely studied in recent years, however, imaging characteristics of this tumor have not been well elaborated. The purpose of this study was to establish an MR imaging grading system for skull base chordoma. MATERIALS AND METHODS: In this study, 156 patients with skull base chordomas were retrospectively assessed. Tumor-to-pons signal intensity ratios were calculated from pretreatment MR images RT1 (ratio of tumor to pons signal intensity in T1 FLAIR sequence), RT2 (ratio of tumor to pons signal intensity in T2 sequence) and REN (ratio of tumor to pons signal intensity in enhanced T1 FLAIR sequence), and significant ratios for overall survival and progression-free survival were selected to establish a grading system. Clinical variables among different MR imaging grades were then analyzed to evaluate the usefulness of the grading system. RESULTS: RT2 (P < .001) and REN (P = .04) were identified as significant variables affecting progression-free survival. After analysis, the classification criteria were set as follows: MR grade I, RT2 > 2.49 and REN ≤ 0.77; MR grade II, RT2 > 2.49 and REN > 0.77, or RT2 ≤ 2.49 and REN ≤ 0.77; and MR grade III, RT2 ≤ 2.49 and REN > 0.77. MR grade III tumors had a more abundant tumor blood supply than MR grade I tumors (P < .001), and the intraoperative blood loss of MR grade III tumors was higher than that of MR grade I tumors (P = .002). Additionally, skull base chordoma progression risk increased by 2.071 times for every single MR grade increase (P < .001). CONCLUSIONS: A higher RT2 value was a negative indicator of tumor progression, whereas a higher REN value was a positive risk factor of tumor progression. MR grade III tumors showed a more abundant blood supply than MR grade I tumors, and the risk of skull base chordoma progression increased with every single MR grade increase.