Objectives: To evaluate the image quality of magnetic resonance 3D-sampling perfection with application-optimized contrasts by using different filp angle evolutions (3D-SPACE) sequence combined with different fusion methods in image fusion technology and the application value of fusion technology in preoperative evaluation of pituitary macroadenoma.
Methods: We collected MRI data of 43 patients with pituitary macroadenoma confirmed by Xiangya Hospital of Central South University, including collecting conventional MRI scan+enhancement, 3D-SPACE T2WI, and 3D-SPACE T1WI+C image data. 3D-SPACE sequence fusion was used in 6 combinations of 3D-SPACE T2WI/3D-SPACE T1WI+C, which were normal phase+normal phase, reverse phase+normal phase, normal phase+reverse phase, reverse phase+reverse phase, and normal phase pseudo color+normal phase, normal phase+normal phase pseudo color. Two senior radiologists used semi-quantitative methods to evaluate and compare the image quality of different combinations to obtain the best fusion mode. According to the degree of tumor invasion of the optic chiasma, oculomotor nerve, and cavernous sinus vessels, the MRI enhancement, 3D-SPACE T2WI, 3D-SPACE T1WI+C, and 2 3D-SPACE sequence fusion images were performed according to a three-level score system. Taking the intraoperative observation as the gold standard, Fisher probability exact method was used to compare different sequences to show the difference between the degree of invasion of the pituitary macroadenoma to the surrounding tissue and the intraoperative results.
Results: The Kruskal-Wallis H rank sum test showed that among the 6 image fusion modes, 3D-SPACE T1WI+C normal phase pseudo-color and 3D-SPACE T2WI normal phase fusion images had the best quality (P<0.05). No significance was observed among the 4 groups in the evaluation of consistency between the intraoperative findings and the graphically displayed extent of tumor invasion into oculomotor nerve (both level I, II, and III, P>0.05). The 3D-SPACE T2WI/3D-SPACE T1WI+C fusion images and the 3D-SPACE T2WI images showed better performance in the evaluation of consistency between the intraoperative findings and the graphically displayed extent of tumor invasion into optic chiasma (level II and III) than that in other two kinds of imaging data of the MRI enhancement group and 3D-SPACE T1WI+C group (P<0.01, P<0.05, respectively), with no significance being observed in level I. The 3D-SPACE T2WI/3D-SPACE T1WI+C fusion images and the 3D-SPACE T1WI+C images showed better performance in the evaluation of consistency between the intraoperative findings and the graphically displayed extent of tumor invasion into cavernous sinus vessels (level II) than that in other two kinds of imaging data of the MRI enhancement group and 3D-SPACE T2WI group (P<0.01, P<0.05, respectively), with no significance being observed in level I and III.
Conclusions: Magnetic resonance 3D-SPACE sequence combined with image fusion technology is better than conventional magnetic resonance sequence for showing pituitary macroadenoma invasion of skull base vascular nerves. The invasion is better than the 3D-SPACE sequence alone, showing that the relationship between tumor and cavernous sinus vascular grade II better than the 3D-SPACE sequence alone. It has good application prospects for preoperative risk assessment and surgical plan.
目的: 评价磁共振成像(MRI)三维可变翻转角快速自旋回波(3D-sampling perfection with application-optimized contrasts by using different filp angle evolutions，3D-SPACE)序列结合不同图像融合技术获得的图像对垂体大腺瘤术前评估的应用价值。方法: 收集中南大学湘雅医院43例术后证实为垂体大腺瘤患者的MRI资料，包括常规MRI平扫+增强、3D-SPACE T2WI和3D-SPACE T1WI+C(增强)的影像资料。3D-SPACE T2WI/3D-SPACE T1WI+C序列分别采用正相+正相、反相+正相、正相+反相、反相+反相以及正相伪彩+正相、正相+正相伪彩6种组合方式融合，由两名放射科高年资主治医生采用半定量方法对不同组合方式图像质量进行评价及比较，得到最佳融合模式；并根据肿瘤对视交叉、动眼神经、海绵窦血管的侵袭程度，按照三级评分制对MRI平扫+增强(常规MRI增强组)，3D-SPACE T2WI，3D-SPACE T1WI+C及2种3D-SPACE序列融合(融合组)的图像进行评估，以术中观察结果为金标准，采用Fisher概率确切法比较4组图像显示垂体大腺瘤对周围组织侵袭程度与金标准的一致性。结果: Kruskal-Wallis H秩和检验结果显示6种图像融合模式中，以3D-SPACE T1WI+C正相伪彩与3D-SPACE T2WI正相融合图像质量最优 (P<0.05)。比较肿瘤对动眼神经侵袭程度I，II，III级关系一致性时，MRI增强组、3D-SPACE T1WI+C组、3D-SPACE T2WI组、融合组4组图像差异均无统计学意义(均P>0.05)；比较肿瘤对视交叉侵袭程度I级关系一致性时，4组图像差异均无统计学意义(均P>0.05)，比较侵袭程度II，III级关系一致性时，融合组图像与3D-SPACE T2WI组差异无统计学意义(P>0.05)，但均明显优于常规MRI增强组(均P<0.01)和3D-SPACE T1WI+C组(均P<0.05)；比较肿瘤对海绵窦血管侵袭程度I，III级关系一致性时，4组图像差异均无统计学意义(均P>0.05)，比较侵袭程度II级关系一致性时，融合组图像与3D-SPACE T1WI+C组差异无统计学意义(P>0.05)，但均明显优于常规MRI增强组(均P<0.01)和3D-SPACE T2WI组(均P<0.05)。结论: MRI 3D-SPACE序列结合图像融合技术在显示垂体大腺瘤对颅底血管神经的侵袭程度上明显优于常规MRI序列，在显示肿瘤与视交叉II，III级侵袭关系及肿瘤与海绵窦血管II级侵袭关系上明显优于单独的3D-SPACE序列，对于手术前的风险评估及手术方案的制订有良好的应用前景。.
Keywords: 3D-sampling perfection with application-optimized contrasts by using different filp angle evolutions sequence; image fusion; magnetic resonance imaging; pituitary adenoma.