低场强术中磁共振成像在经鼻蝶窦垂体大腺瘤显微手术中的应用

目的 探讨低场强术中磁共振成像(iMRI)在经鼻蝶窦垂体大腺瘤显微手术中的应用.方法 在82例垂体大腺瘤的经鼻蝶窦显微手术中,采用0.15T iMRI系统进行术中实时引导.以术后早期高场强MRI为标准对照,定量分析iMRI的成像准确性,并就低场强iMRI对肿瘤切除程度和治疗结果 的影响进行分析.结果 在iMRI的辅助下,82例垂体大腺瘤的全切率从61.0%提高到81.7%.低场强iMRI的成像准确率达86.6%,但对于侵犯鞍旁结构的肿瘤的成像准确率明显低于其他类型垂体大腺瘤的成像准确率(53.3%vs 94.0%,P<0.001).结论 iMRI导航技术的应用,'为经蝶窦垂体大腺瘤手术进程的动态引导及手术结果 的实时判断提供了客观的依据,提高了肿瘤的全切率及手术的精确性与安全性.

Application of low-field intraoperative magnetic resonance imaging in transsphenoidal pituitary macroadenomas resection

Objective To evaluate the applicability of low-field intraoperative magnetic resonance imaging during transsphenoidal micresurgery of pituitary macwadenormas. Methods Tmnsnaso-sphenoidal resection of 82 pituitary macroadenomas(modified Hardy(s) grade II to IV)were performed under the guidance of real-time updated images acquired by 0.15 Tesla PoleStar N-20 iMRI In comparison with early(within 72 h)postoperative highfield MR images,the accuracy of imaging evaluation of low-field iMRI was analyzed. The definitive benefits as well as major drawbacks of low-field iMRI and its influence on transsphenoidal surgery were assessed with respect to tumor resection control and clinical outcome.Results Intraoperative imaging revealed residual tumors in 29 of 82 cases and led to extended resection in 25 cases.Complete resection was achieved in 16 Patients. As a result.the percentage of gross total removal of macroadenomas was increased from 61.0% to 81.7%.The accuracy of imaging evaluation of low-field iMRI was 86.6% ,compared with early postoperative hish-field MRL A significantly lower accuracy(53.3%)was identified in those cases with cavernous sinus invasion in contrast to 94.0% found in other sites(P<0.001).There was no iMRI-related complication.Conclusions Intraoperative magnetic resonance image-based navigation provides objective information for the guidance of surgical procedure and the real-time jedgment of surgical consequence,which leads to higher percentage of tumor removal and better clinical outcome in transsphenoidal Surgery for pituitary macroadenomas.