Isensee C, Reul J, Thron A
Department of Neurology, Klinikum RWTH Aachen, Germany.
Stroke. 1994 Jan;25(1):29-34. doi: 10.1161/01.str.25.1.29.
Magnetic resonance imaging should have the potential to replace angiography in the diagnosis of dural sinus thrombosis. Concerning time-dependent signal changes of the thrombus, we intended to develop a standardized examination protocol for routine use in suspected dural sinus thrombosis.
The time-dependent signal changes of thrombosed dural sinuses were studied in 23 consecutive patients by multiplanar spin-echo and flow-sensitive sequences. Signal intensities and thrombus homogeneity were graded and related to the time after clinical onset and the results of the magnetic resonance angiography.
Four stages of the thrombus evolution could be observed. The acute thrombosis (days 1 to 5) appeared strongly hypointense in T2-weighted images and isointense in spin density- and T1-weighted images. In the subacute stage (up to day 15) the thrombus signal was strongly hyperintense in T1- and T2-weighted images. The third stage began in the third week after clinical onset. The thrombus signal was decreased in all sequences and showed an increasing inhomogeneity. The fourth (late) stage was characterized by either the restitution of blood flow or the persistence of a residual thrombus.
Each stage requires a different diagnostic approach. With the combined use of spin-echo and gradient-echo sequences, it is possible to make the diagnosis of acute thrombosis; in the second stage, multiplanar spin-echo sequences are sufficient. Diagnosis of dural sinus thrombosis can be established accurately with magnetic resonance imaging in the first two stages. However, the diagnosis of the later stages is difficult because of inhomogeneous signs of recanalization and flow phenomena. Therefore, a suspected older dural sinus thrombus still requires intra-arterial angiography as the primary diagnostic tool.
磁共振成像在硬脑膜窦血栓形成的诊断中应具有取代血管造影的潜力。关于血栓随时间的信号变化，我们旨在制定一种标准化检查方案，用于疑似硬脑膜窦血栓形成的常规检查。
通过多平面自旋回波和血流敏感序列，对23例连续患者的血栓形成硬脑膜窦的随时间信号变化进行了研究。对信号强度和血栓均匀性进行分级，并与临床发病后的时间以及磁共振血管造影结果相关联。
可观察到血栓演变的四个阶段。急性血栓形成（第1至5天）在T2加权图像上呈明显低信号，在自旋密度加权和T1加权图像上呈等信号。在亚急性期（至第15天），血栓信号在T1加权和T2加权图像上呈明显高信号。第三阶段始于临床发病后的第三周。血栓信号在所有序列中均降低，且不均匀性增加。第四（晚期）阶段的特征是血流恢复或残留血栓持续存在。
每个阶段需要不同的诊断方法。联合使用自旋回波和梯度回波序列，可以诊断急性血栓形成；在第二阶段，多平面自旋回波序列就足够了。在前两个阶段，磁共振成像可以准确诊断硬脑膜窦血栓形成。然而，由于再通和血流现象的不均匀征象，晚期的诊断较为困难。因此，疑似较陈旧的硬脑膜窦血栓仍需要动脉血管造影作为主要诊断工具。
