De Ciantis A, Barkovich A J, Cosottini M, Barba C, Montanaro D, Costagli M, Tosetti M, Biagi L, Dobyns W B, Guerrini R
From the Pediatric Neurology Unit (A.D.C., C.B., R.G.), Meyer Children's Hospital, University of Florence, Florence, Italy.
Department of Radiology and Biomedical Imaging (A.J.B.), University of California San Francisco, San Francisco, California.
AJNR Am J Neuroradiol. 2015 Feb;36(2):309-16. doi: 10.3174/ajnr.A4116. Epub 2014 Sep 25.
Polymicrogyria is a malformation of cortical development that is often identified in children with epilepsy or delayed development. We investigated in vivo the potential of 7T imaging in characterizing polymicrogyria to determine whether additional features could be identified.
Ten adult patients with polymicrogyria previously diagnosed by using 3T MR imaging underwent additional imaging at 7T. We assessed polymicrogyria according to topographic pattern, extent, symmetry, and morphology. Additional imaging sequences at 7T included 3D T2* susceptibility-weighted angiography and 2D tissue border enhancement FSE inversion recovery. Minimum intensity projections were used to assess the potential of the susceptibility-weighted angiography sequence for depiction of cerebral veins.
At 7T, we observed perisylvian polymicrogyria that was bilateral in 6 patients, unilateral in 3, and diffuse in 1. Four of the 6 bilateral abnormalities had been considered unilateral at 3T. While 3T imaging revealed 2 morphologic categories (coarse, delicate), 7T susceptibility-weighted angiography images disclosed a uniform ribbonlike pattern. Susceptibility-weighted angiography revealed numerous dilated superficial veins in all polymicrogyric areas. Tissue border enhancement imaging depicted a hypointense line corresponding to the gray-white interface, providing a high definition of the borders and, thereby, improving detection of the polymicrogyric cortex.
7T imaging reveals more anatomic details of polymicrogyria compared with 3T conventional sequences, with potential implications for diagnosis, genetic studies, and surgical treatment of associated epilepsy. Abnormalities of cortical veins may suggest a role for vascular dysgenesis in pathogenesis.
多小脑回是一种皮质发育畸形，常见于癫痫或发育迟缓的儿童。我们在体研究了7T成像在多小脑回特征描述中的潜力，以确定是否能识别出更多特征。
10例先前经3T磁共振成像诊断为多小脑回的成年患者接受了7T额外成像检查。我们根据地形模式、范围、对称性和形态对多小脑回进行评估。7T的额外成像序列包括3D T2* 磁敏感加权血管造影和2D组织边界增强快速自旋回波反转恢复序列。使用最小强度投影评估磁敏感加权血管造影序列描绘脑静脉的潜力。
在7T时，我们观察到6例患者为双侧外侧裂周多小脑回，3例为单侧，1例为弥漫性。6例双侧异常中有4例在3T时被认为是单侧的。虽然3T成像显示出两种形态学类别（粗糙型、精细型），但7T磁敏感加权血管造影图像显示出一种均匀的带状模式。磁敏感加权血管造影显示所有多小脑回区域有大量扩张的浅表静脉。组织边界增强成像显示一条对应于灰白质界面的低信号线，清晰显示了边界，从而提高了对多小脑回皮质的检测。
与3T传统序列相比，7T成像能揭示多小脑回更多的解剖细节，对相关癫痫的诊断、遗传学研究及手术治疗可能具有重要意义。皮质静脉异常可能提示血管发育异常在发病机制中的作用。
