垂体微腺瘤磁共振图像假阴性表现分析

Analysis of false-negative manifestation of pituitary microadenoma on MRI

关键词:  磁共振  垂体  微腺瘤

Key words:  magnetic resonance  pituitary  microadenoma

摘要:

［目的］ 分析垂体微腺瘤磁共振图像假阴性表现的原因，探讨对这类微腺瘤的诊断方法。［方法］ 回顾性分析经手术证实垂体微腺瘤患者54例，男9例，女45例，患 者平均年龄34.5岁（16～57岁），所有患者手术前均行磁共振平扫及动态增强。分析平扫与增强检查均为假阴性表现的垂体微腺瘤的特点，探讨磁共振对这类微腺瘤的诊断方法。［结果］经手术证实垂体微腺瘤患者54例中正常垂体形态的微腺瘤18例，其中12例形态与信号均正常，动态增强检查后18例垂体表现为正常形态的微腺瘤中14例可以明确诊断， 4例磁共振平扫及增强检查均为阴性，该4例患者3～6个月后复查磁共振均明确诊断。［结论］部分垂体微腺瘤患者垂体形态可以表现为正常，甚至表现为形态与信号均正常，动态增强可以提高垂体微腺瘤检出率，应列为常规检查，对于临床高度怀疑垂体微腺瘤而磁共振平扫及增强均表现为正常的患者，结合临床表现、相关化验结果并定期复查可以进一步提高垂体微腺瘤的检出率。

Abstract:

［Objective］To analyze the reasons of false-negative manifestation in microadenoma, and to detect the MR diagnostic method for them.［Methods］ Retrospectively analyze 54 cases (9 males and 45 females) of microadenomas demonstrated by surgery, whose average age was 34.5 (16-57) year. All patients underwent MRI plan scan and dynamic enhancement before operation. Analyze the character of microadenoma that showed fault-negative manifestation in plan scan and even fault-negative in plan and enhance scan. Detect diagnostic method of these microadenomas by MRI. ［Results］ Among the 54 cases of microadenoma demonstrated by surgery, 18 cases had normal morphology, and among them, 12 cases had not only normal morphology ,but also normal signal. After dynamic enhancement, 14 microadenomas of the 18 cases with normal pituitary shape could be definitely diagnosed. 4 cases showed negative both in plan scan and enhancement. They were diagnosed after 3 to 6 months follow-up.［Conclusion］ The morphology of pituitary in part of patients with microadenoma maybe normal, no matter in morph ology or in signal. Dynamic enhancement could increase positive rate of it and should be acted as routine method. To patients highly suspected of pituitary microadenoma in clinics, while showed normal both in MRI plan scan and enhancement, combining its clinical manifestation, relevant tests and time reexamination may further elevate the positive rate of pituitary manifestation.