Collie Donald A, Summers David M, Sellar Robin J, Ironside James W, Cooper Sarah, Zeidler Martin, Knight Richard, Will Robert G
Department of Neuroradiology, Western General Hospital, Edinburgh, Scotland.
AJNR Am J Neuroradiol. 2003 Sep;24(8):1560-9.
Variant Creutzfeldt-Jakob disease (vCJD) is a rare but important cause of dementia and death in young patients and is causally linked to bovine spongiform encephalopathy. Symmetrical hyperintensity in the pulvinar (posterior) nuclei of the thalamus (pulvinar sign) on brain MR images was described as a specific, noninvasive, diagnostic sign of vCJD in a previous small series. This purpose of this larger study was to evaluate this sign prospectively and further define the MR imaging characteristics of vCJD.
As part of the ongoing surveillance program in the United Kingdom, MR images of suspected cases of vCJD were collected during a 6-year period. All available images were assessed prospectively by one observer for the presence of the pulvinar sign. Images of neuropathologically confirmed cases were then assessed independently by two neuroradiologists for the degree of hyperintensity of the pulvinar on images of different MR sequences, and for the presence of abnormal hyperintensity in other areas of the brain. Discrepancies were reviewed jointly and a consensus opinion formed.
Prospective analysis identified the pulvinar sign in 74 of 82 cases of vCJD. In the retrospective study, the pulvinar sign, as defined by hyperintensity of the pulvinar relative to the anterior putamen, was present on seven (9%) of 75 T1-weighted, 77 (71%) of 108 T2-weighted, 47 (81%) of 58 proton density-weighted, and 30 (100%) of 30 fluid-attenuated inversion-recovery (FLAIR) images. Diffusion-weighted images were available in two cases and were positive for the pulvinar sign in one. Other features were hyperintensity of the dorsomedial thalamic nuclei (93%), caudate head (40%), and periaqueductal gray matter (83%) on FLAIR images.
In the appropriate clinical context, demonstration of the pulvinar sign on MR images is a highly accurate diagnostic sign for vCJD. FLAIR sequence is more sensitive than other sequences. Positive MR images may obviate more invasive diagnostic tests in most cases.
变异型克雅氏病（vCJD）是导致年轻患者痴呆和死亡的一种罕见但重要的病因，且与牛海绵状脑病存在因果关联。在先前的一项小型研究系列中，脑磁共振成像（MR）图像上丘脑枕（后部）核的对称性高信号（枕征）被描述为vCJD的一种特异性、非侵入性诊断征象。这项规模更大的研究旨在前瞻性评估该征象，并进一步明确vCJD的MR成像特征。
作为英国正在进行的监测项目的一部分，在6年期间收集了疑似vCJD病例的MR图像。由一名观察者对所有可用图像进行前瞻性评估，以确定是否存在枕征。然后，两名神经放射科医生独立评估经神经病理学确诊病例的图像，观察不同MR序列图像上丘脑枕的高信号程度，以及脑内其他区域是否存在异常高信号。对存在的分歧进行联合审查并形成共识意见。
前瞻性分析在82例vCJD病例中的74例发现了枕征。在回顾性研究中，以丘脑枕相对于壳核前部的高信号定义的枕征，在75例T1加权像中有7例（9%）出现，在108例T2加权像中有77例（71%）出现，在58例质子密度加权像中有47例（81%）出现，在30例液体衰减反转恢复（FLAIR）像中有30例（100%）出现。有2例可获得扩散加权图像，其中1例显示枕征阳性。其他特征包括FLAIR像上丘脑背内侧核高信号（93%）、尾状核头部高信号（40%）和导水管周围灰质高信号（83%）。
在适当的临床背景下，MR图像上显示枕征是vCJD的一种高度准确的诊断征象。FLAIR序列比其他序列更敏感。在大多数情况下，MR图像阳性可能无需进行更具侵入性的诊断检查。
