Cerebral Venous Thrombosis: Diagnostic Accuracy of Combined, Dynamic and Static, Contrast-Enhanced 4D MR Venography

Abstract

BACKGROUND AND PURPOSE: MR including MRV is an established method to diagnose CVT. However, it remains unsettled which MR imaging modalities offer the highest diagnostic accuracy. We evaluated the accuracy of a combined, dynamic (1.5 seconds per dataset) and static (voxel size, 1.1 ϫ 0.9 ϫ 1.5 mm), contrast-enhanced MRV method (combo-4D MRV) relative to other established MR/MRV modalities.

Diagnosis and Management of Cerebral Venous Thrombosis

“…© 2011 American Heart Association, Inc. [2,10,42,70,71,73,74,91,[98][99][100]105,106,108,[113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128] 。随着血栓的演变， 静脉窦内出现脱氧血红蛋白和氧化血红蛋白的顺磁 性代谢产物。此时硬膜窦或静脉内血栓在梯度回波 和磁敏感加权磁共振成像上呈低信号 [70,119,129] [196,197,209] 。 几项研究报告了 CVT 病人抽搐发作的发生率和 特征。一项研究报道 [218] ，在 91 例病人中，32% 以 抽搐发作就诊， 2% 在住院期间出现抽搐发作， 仅 9.5% 出现晚期抽搐发作，此外，抽搐发作并不是 1 年预 后的预测指标。早期抽搐发作在有 CT/MRI 上脑实 质病变的病人中发生的可能性高达 3.7 倍 (95% CI 1.4-9.4) 而在有感觉缺失的病人中的可能性增加 7.8 倍 (95% CI 0.8-74.8)。来自 ISCVT 的一项更近的报 告 [197] 显示，624 例病人中的 245 例 (39%) 以抽搐发 作就诊，而 43 例 (6.9%) 在诊断后 2 周内出现早期 抽搐发作。除了就诊时抽搐发作，仅诊断时 CT/MRI 上有幕上脑实质病变 ( 见于 58%) 与早期抽搐发作的 发生有关 (OR 3.1, 95% CI 1.6-9.6)。此外，在有幕上 病变而起病时没有抽搐发作的病人中，应用抗癫痫 药物可使 2 周内抽搐发作的风险降低 70%，尽管这 并没有统计学上的显著性 (OR 0.3, 95% CI 0.04-2.6)。 在这些结果的基础上，作者建议对表现为抽搐发作 的有幕上病变的急性 CVT 病人使用抗癫痫药物 [197] 。 脑积水 上矢状窦和横窦是通过横跨静脉窦壁突入到 蛛网膜下腔并引流到静脉系统的高度血管化结构的 蛛网膜颗粒进行脑脊液 (CSF) 吸收的主要部位。在 CVT，蛛网膜颗粒的功能可能受到障碍，潜在地导 致 CSF 吸收的衰竭和交通性脑积水 (6.6%) [14,198] 。 梗阻性脑积水是 CVT 的一个少见的并发症，可 由出血破入脑室系统所致。通常与累及大脑内静脉的 血栓有关，还可以与丘脑出血有关。此综合征在新生 儿已有很好的描述但可以发生在所有年龄组 …”

“…By the second week, thrombus contains methemoglobin, which results in hyperintensity on T1-and T2-weighted images ( Figure 5). 2 70,119,129 The principal early signs of CVT on non-contrast-enhanced MRI are the combination of absence of a flow void with alteration of signal intensity in the dural sinus. MRI of the brain is suggestive of CVT by the absence of a fluid void signal in the sinus, T2 hypointensity suggestive of a thrombus, or a central isodense lesion in a venous sinus with surrounding enhancement.…”

“…2,71,72,95,97,106,108,109,125,[142][143][144][145][146][147][148][149][150] Despite the challenges, other sequences such as gradient echo, susceptibilityweighted imaging, and contrast MRI/MRV may assist in these situations. 129,151 Nonthrombosed hypoplastic sinus will not have abnormal low signal in the sinus on gradient echo or susceptibility-weighted images. The chronic thrombosed hypoplastic sinus will have marked enhanced sinus and no flow on 2-dimensional TOF venography.…”

Cerebral Venous and Dural Sinus Thrombosis*

“…Furthermore, there exist new, promising MRA techniques such as time-resolved MRA [59,60], which might further improve the value of MR for the evaluation of the cerebral veins and sinuses. A very recent study on 20 CVST patients and 19 controls demonstrated that the combination of a dynamic and a static three-dimensional combined MR venography -the so-called combo 4-D MRV -was superior to TOF-MRA [61]. Future studies should address the potential value of these sequences as well as the impact of higher field strengths for the diagnosis of CVST.…”

Nontraumatic Neuroemergencies

“…The diagnosis must be confi rmed with gradient-echo techniques or MR angiography. Phasecontrast or Gd-enhanced time-of-fl ight MRAs are the preferred techniques because they are not adversely affected by intraluminal clot [ 2 ]. Associated parenchymal infarcts are found in the areas of venous abnormalities, and the infarcts are often hemorrhagic because arterial perfusion is maintained to the damaged tissue.…”