There is growing evidence that psychosis is characterized by brain network abnormalities. Analyzing morphological abnormalities with T1-weighted structural MRI may be limited in discovering the extent of deviations in cortical associations. We assess whether structural associations of either cortical white-gray contrast (WGC) or cortical thickness (CT) allow for a better understanding of brain structural relationships in first episode of psychosis (FEP) patients. Principal component and structural covariance analyses were applied to WGC and CT derived from T1-weighted MRI for 116 patients and 88 controls, to explore sets of brain regions that showed group differences, and associations with symptom severity and cognitive ability in patients. We focused on 2 principal components: one encompassed primary somatomotor regions, which showed trend-like group differences in WGC, and the second included heteromodal cortices. Patients' component scores were related to general psychopathology for WGC, but not CT. Structural covariance analyses with WGC revealed group differences in pairwise correlations across widespread brain regions, mirroring areas derived from PCA. More group differences were uncovered with WGC compared with CT. WGC holds potential as a proxy measure of myelin from commonly acquired T1-weighted MRI and may be sensitive in detecting systems-level aberrations in early psychosis, and relationships with clinical/cognitive profiles.

中文翻译：

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首发性精神病的皮质对比度和厚度的结构性关联。

越来越多的证据表明，精神病的特征是脑网络异常。用T1加权结构MRI分析形态异常可能会限制发现皮层关联偏差的程度。我们评估皮质白灰色对比（WGC）或皮质厚度（CT）的结构关联是否有助于更好地了解精神病患者（FEP）首发中的大脑结构关系。将主要成分和结构协方差分析应用于来自T1加权MRI的WGC和CT，共116例患者和88例对照，探讨了显示出群体差异以及与患者症状严重程度和认知能力相关的大脑区域集。我们专注于2个主要组成部分：一个包含主要的躯体运动区域，在WGC中显示出趋势样的群体差异，第二个包括异质皮质。患者的成分评分与WGC的一般精神病理学有关，但与CT无关。使用WGC进行的结构协方差分析揭示了在广泛的大脑区域中成对相关性的组差异，反映了源自PCA的区域。与CT相比，WGC发现了更多的组差异。WGC具有潜力，可以作为通常通过T1加权MRI获得的髓磷脂的替代指标，并且在检测早期精神病的系统级像差以及与临床/认知特征之间的关系时可能很敏感。使用WGC进行的结构协方差分析揭示了在广泛的大脑区域中成对相关性的组差异，反映了源自PCA的区域。与CT相比，WGC发现了更多的组差异。WGC具有潜力，可以作为通常通过T1加权MRI获得的髓磷脂的替代指标，并且在检测早期精神病的系统级像差以及与临床/认知特征之间的关系时可能很敏感。使用WGC进行的结构协方差分析揭示了在广泛的大脑区域中成对相关性的组差异，反映了源自PCA的区域。与CT相比，WGC发现了更多的组差异。WGC具有潜力，可以作为通常通过T1加权MRI获得的髓磷脂的替代指标，并且在检测早期精神病的系统级像差以及与临床/认知特征之间的关系时可能很敏感。