Hinman Jeffrey M, Provenzale James M
Department of Radiology, Duke University Medical Center Durham, DUMC 3808, Durham, NC 27710, USA.
Eur J Radiol. 2002 Feb;41(2):147-52. doi: 10.1016/s0720-048x(01)00365-5.
To determine the frequency of hypointense appearance of dural sinus thrombosis on T2-weighted images, which may mimic a normal flow void, and when possible correlate with appearance on T1-weighted images.
Retrospective review of radiology files showed 51 patients with a discharge diagnosis of dural sinus thrombosis who underwent MR imaging during the period 1986-1998. These images were reviewed by an experienced neuroradiologist for appearance on T2-weighted images. This process yielded five cases in which a hypointense appearance on this pulse sequence simulated a normal flow void. An additional two cases were added from the teaching files of two other institutions giving a total of seven cases (13% of studies). The resulting study population consisted of five women and two men (mean age 27.1 years). T1 weighted images were available in five patients. In two patients MR venography was available, but not T1-weighted images. The diagnosis of dural sinus thrombosis was based solely on absence of flow void on T1-weighted images in one case, solely on absence of flow void on MR venography in two cases and absence of flow void on T1-weighted images in conjunction with MR venography or gradient echo findings in 4 patients. All images were obtained on a 1.5 T magnet (GE Medical Systems; Milwaukee, Wisconsin).
In all patients hypointense signal of thrombus was isointense with normal flow voids in other dural sinuses on T2-weighted images. In all cases in which T1-weighted images were available, the signal intensity of thrombus was isointense to gray matter.
Hypointense appearance of thrombus on T2-weighted images is a potential pitfall in the MR diagnosis of dural sinus thrombosis. Because thrombus in this stage of evolution appears isointense to gray matter on T1-weighted images, careful attention must be paid to other sequences to avoid this pitfall.
确定硬脑膜窦血栓形成在T2加权图像上表现为低信号的频率，这种低信号可能会模拟正常血流空洞，并尽可能与T1加权图像上的表现相关联。
对放射学档案进行回顾性研究，发现1986年至1998年期间有51例出院诊断为硬脑膜窦血栓形成的患者接受了磁共振成像检查。一位经验丰富的神经放射科医生对这些图像进行了检查，以观察其在T2加权图像上的表现。在此过程中发现了5例，在该脉冲序列上血栓的低信号表现模拟了正常血流空洞。另外从其他两个机构的教学档案中增加了2例，共计7例（占研究的13%）。最终的研究人群包括5名女性和2名男性（平均年龄27.1岁）。5例患者有T1加权图像。2例患者有磁共振静脉造影图像，但没有T1加权图像。硬脑膜窦血栓形成的诊断在1例中仅基于T1加权图像上无血流空洞，2例中仅基于磁共振静脉造影上无血流空洞，4例中基于T1加权图像上无血流空洞并结合磁共振静脉造影或梯度回波表现。所有图像均在1.5T磁体（通用电气医疗系统公司；威斯康星州密尔沃基）上获得。
在所有患者中，血栓的低信号在T2加权图像上与其他硬脑膜窦的正常血流空洞等信号。在所有有T1加权图像的病例中，血栓的信号强度与灰质等信号。
血栓在T2加权图像上表现为低信号是硬脑膜窦血栓形成磁共振诊断中的一个潜在陷阱。由于处于这一演变阶段的血栓在T1加权图像上与灰质等信号，因此必须仔细关注其他序列以避免这一陷阱。
