MR灌注成像在脑膜瘤诊断中的应用价值

目的:探讨MR灌注成像对不同病理类型脑膜瘤的诊断及鉴别诊断价值.方法:对30例经手术病理证实为脑膜瘤的MR灌注成像资料进行回顾性分析,其中血管瘤型4例,上皮型11例,纤维型10例,混合型5例.分析其MR灌注曲线和伪彩图像特点,测量肿瘤实质区域相对血容积(rCBV)、平均通过时间(MTT)、时间-信号强度曲线的最大下降斜率(MSD)和最大上升斜率(MSI)并进行统计学分析.结果:所有病理类型脑膜瘤的时间-信号强度曲线表现为负性增强,上升支与下降支不对称,增强后基线水平较增强前呈缓慢上升;其中血管瘤型灌注曲线的下降支陡峭,上皮型和混合型次之,纤维型最平缓.上皮型、纤维型和混合型脑膜瘤的灌注曲线显示在信号强度恢复前出现一小的再下降波形.不同病理类型脑膜瘤的rCBV和MSD值差异均有显著性意义(P《0.05),而MTT和MSI值差异无显著性意义(P》0.05).结论:MR灌注成像测量rCBV和MSD值对不同病理类型脑膜瘤的诊断和鉴别诊断具有较高的临床应用价值.

Role of Clinical Application of Dynamic MR Perfusion Imaging in the Diagnosis of Meningiomas

Objective:To study the diagnostic and differential diagnostic values of dynamic MR perfusion imaging(DPMRI) in various types of pathologically confirmed meningiomas.Methods:The stuffs of DPMRI of 30 cases of surgically and pathologically confirmed meningiomas,including angiomatous type(n=4),epithelial type(n=11),fibrous type(n=10) and mixed type(n=5),were retrospectively analyzed.The features of MR perfusion curves and artificial color images of the meningiomas were studied and the relative regional cerebral blood volume(rCBV),the mean transit time(MTT) and the rates of maximal descending and ascending slopes of the time/signal intensity curves(MSD) of the tumor parenchyma were measured and statistically treated.Results:The time/signal intensity curves in all types of meningiomas showed negative enhancements.Their ascending and descending portions were asymmetrical and the level of the postcontrast baseline was elevated slowly in contrast to the precontrast one.The descending portion of the perfusion curves of the angiomatous type meningiomas sloped down most abruptly with those of the fibrous and mixed types sloping down less abruptly.That of the fibrous type meningiomas showed a slowly ascending and rather flat curve.The perfusion curves of the epithelial,fibrous and mixed types of meningiomas revealed a small redescending wave before the recovery of original signal intensity.The differences of rCBV and MSD values in various types of meningiomas showed remarkable significance(P<0.05),however,the differences in values of MTT and MSI demonstrated no remarkable significance(P>0.05).Conclusion:In DPMRI,the measurements and study of the rCBV and MSD values of meningiomas would have been helpful and valuable in the diagnosis and differential diagnosis for various pathological types of meningiomas.