Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, Japan.
Radiographics. 2010 Jan;30(1):111-25. doi: 10.1148/rg.301095052.
When a vascular disease is suspected, the focus is usually on morphologic features seen at contrast material-enhanced multidetector computed tomography (CT). However, unenhanced CT also plays an important role in revealing so-called hyperattenuating signs, which represent a slight increase in the focal attenuation of a vessel. Hyperattenuating signs are occasionally observed when an acute clot has formed in a vessel and can be seen in various vascular diseases, including acute arterial occlusion, acute arterial dissection, aneurysm rupture, and acute venous thrombosis. The attenuation of these signs tends to increase because the concentration of hemoglobin increases as water content decreases. Hyperattenuating signs are a transient phenomenon, as the attenuation gradually decreases. Therefore, they can serve as unique findings indicating an acute state. Although hyperattenuating signs are not well understood, recognition of these signs is important because they can help reveal serious acute vascular diseases even at unenhanced CT.
当怀疑存在血管疾病时，重点通常是观察对比增强多排 CT（CT）上的形态特征。然而，未增强 CT 在揭示所谓的高信号征象方面也起着重要作用，这些征象代表血管局灶性衰减略有增加。当血管内形成急性血栓时，偶尔会观察到高信号征象，并且可以在各种血管疾病中看到，包括急性动脉闭塞、急性动脉夹层、动脉瘤破裂和急性静脉血栓形成。由于血红蛋白浓度增加，水分含量减少，这些征象的衰减往往会增加。高信号征象是一种短暂的现象，因为衰减逐渐降低。因此，它们可以作为指示急性状态的独特发现。尽管高信号征象尚未得到很好的理解，但识别这些征象很重要，因为即使在未增强 CT 上，它们也可以帮助揭示严重的急性血管疾病。
