Appenzeller S, Amorim B J, Ramos C D, Rio P A, de C Etchebehere E C S, Camargo E E, Cendes F, Costallat L T L
Rheumatology Unit, State University of Campinas, Campinas-SP, Brazil.
Rheumatology (Oxford). 2007 Mar;46(3):467-72. doi: 10.1093/rheumatology/kel255. Epub 2006 Aug 10.
To determine the value of voxel-based morphometry (VBM) of brain SPECT (single-photon emission computed tomography) images (BSI) in discriminating active central nervous system (CNS) manifestations in systemic lupus erythematosus (SLE) patients.
Forty SLE patients (mean age 33 yrs) and 33 normal volunteers were submitted to BSI. SLE patients were screened for the presence of CNS involvement following the American College of Rheumatology (ACR) case definition. Patients with CNS infections, uraemia, diabetes and previous ischaemic or haemorrhagic stroke were excluded. Magnetic resonance imaging (MRI) scans were obtained in a 2T scanner (Elscint Prestige) with T1- and T2-weighted images. BSI were performed after injection of 1110 MBq (30 mCi) of (99m)Tc-ECD (ethyl-cysteinate-dimer). BSI were analysed using the statistical parametric mapping. After normalization, segmentation and smoothing the groups of SLE patients with active and inactive CNS manifestations and healthy volunteers were compared using VBM. Post-processed images were compared voxel-by-voxel using t-test in order to determine differences of intensity between groups. This analysis included grand mean scaling, proportional threshold masking (set to 0.4) and implicit masking. A P-value of 0.001 and cluster size of 32 were taken into consideration.
VBM analyses of BSI did not show any differences between SLE patients with inactive CNS involvement and normal controls. However, the group of SLE patients with active CNS involvement had a global hypoperfusion, more intense in the frontal, dorsolateral and medial temporal lobe when compared with SLE patients without CNS involvement (P = 0.001) and healthy volunteers (P = 0.001).
VBM of BSI is a useful and objective method for detecting perfusion abnormalities in SLE patients, which is indicative of active CNS involvement. However, it is not helpful in differentiating the clinical sub-types of CNS involvement according to the ACR classification.
确定基于体素的脑单光子发射计算机断层扫描（SPECT）图像（BSI）形态测量法在鉴别系统性红斑狼疮（SLE）患者中枢神经系统（CNS）活动期表现中的价值。
40例SLE患者（平均年龄33岁）和33名正常志愿者接受了BSI检查。按照美国风湿病学会（ACR）病例定义对SLE患者进行CNS受累情况筛查。排除患有CNS感染、尿毒症、糖尿病以及既往有缺血性或出血性卒中的患者。在一台2T扫描仪（Elscint Prestige）上进行磁共振成像（MRI）扫描，获取T1加权和T2加权图像。注射1110 MBq（30 mCi）的（99m）Tc-ECD（乙二胺半胱氨酸二聚体）后进行BSI检查。使用统计参数映射分析BSI。在对SLE患者有活动期和非活动期CNS表现的组以及健康志愿者进行归一化、分割和平滑处理后，采用基于体素的形态测量法进行比较。使用t检验对后处理图像逐体素进行比较，以确定组间强度差异。该分析包括总体均值缩放、比例阈值掩蔽（设定为0.4）和隐式掩蔽。考虑P值为0.001和簇大小为32。
BSI的基于体素的形态测量分析显示，CNS无活动期受累的SLE患者与正常对照之间无任何差异。然而，CNS有活动期受累的SLE患者组存在整体灌注不足，与无CNS受累的SLE患者（P = 0.001）和健康志愿者（P = 0.001）相比，在额叶、背外侧和颞叶内侧更为明显。
BSI的基于体素的形态测量法是检测SLE患者灌注异常的一种有用且客观的方法，这表明存在CNS活动期受累。然而，它无助于根据ACR分类区分CNS受累的临床亚型。
