From the Department of Radiology, NYU Grossman School of Medicine, New York, NY (M.E.M., T.M.S., D.L., S.W.); Division of General and Pediatric Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria (M.E.M., M.W.); Florey Institute of Neuroscience and Mental Health, Melbourne, Australia (H.R.P.); Comprehensive Epilepsy Center, Department of Neurology, NYU Grossman School of Medicine, New York, NY (H.R.P.); and Department of Radiology, University of Missouri Columbia, Columbia, MO (J.W.P.).
Invest Radiol. 2024 Nov 1;59(11):782-786. doi: 10.1097/RLI.0000000000001088. Epub 2024 Jun 14.
The aim of this study was to determine whether MRI radiomic features of key cerebral structures differ between women and men, and whether detection of such differences depends on the image resolution.
Ultrahigh resolution (UHR) 3D MP2RAGE (magnetization-prepared 2 rapid acquisition gradient echo) T1-weighted MR images (voxel size, 0.7 × 0.7 × 0.7 mm 3 ) of the brain of 30 subjects (18 women and 12 men; mean age, 39.0 ± 14.8 years) without abnormal findings on MRI were retrospectively included. MRI was performed on a whole-body 7 T MR system. A convolutional neural network was used to segment the following structures: frontal cortex, frontal white matter, thalamus, putamen, globus pallidus, caudate nucleus, and corpus callosum. Eighty-seven radiomic features were extracted respectively: gray-level histogram (n = 18), co-occurrence matrix (n = 24), run-length matrix (n = 16), size-zone matrix (n = 16), and dependence matrix (n = 13). Feature extraction was performed at UHR and, additionally, also after resampling to 1.4 × 1.4 × 1.4 mm 3 voxel size (standard clinical resolution). Principal components (PCs) of radiomic features were calculated, and independent samples t tests with Cohen d as effect size measure were used to assess differences in PCs between women and men for the different cerebral structures.
At UHR, at least a single PC differed significantly between women and men in 6/7 cerebral structures: frontal cortex ( d = -0.79, P = 0.042 and d = -1.01, P = 0.010), frontal white matter ( d = -0.81, P = 0.039), thalamus ( d = 1.43, P < 0.001), globus pallidus ( d = 0.92, P = 0.020), caudate nucleus ( d = -0.83, P = 0.039), and corpus callosum ( d = -0.97, P = 0.039). At standard clinical resolution, only a single PC extracted from the corpus callosum differed between sexes ( d = 1.05, P = 0.009).
Nonnegligible differences in radiomic features of several key structures of the brain exist between women and men, and need to be accounted for. Very high spatial resolution may be required to uncover and further investigate the sexual dimorphism of brain structures on MRI.
本研究旨在确定女性和男性之间关键脑结构的 MRI 放射组学特征是否存在差异，以及检测这种差异是否取决于图像分辨率。
回顾性纳入 30 名受试者（18 名女性和 12 名男性；平均年龄 39.0±14.8 岁）的大脑超高分辨率（UHR）3D MP2RAGE（磁化准备 2 快速获取梯度回波）T1 加权磁共振图像（体素大小 0.7×0.7×0.7mm3），这些受试者的 MRI 检查均无异常。MRI 检查在全身 7T MR 系统上进行。使用卷积神经网络分别对以下结构进行分割：额叶皮层、额叶白质、丘脑、壳核、苍白球、尾状核和胼胝体。分别提取 87 个放射组学特征：灰度直方图（n=18）、共生矩阵（n=24）、游程长度矩阵（n=16）、大小区矩阵（n=16）和依赖矩阵（n=13）。在 UHR 进行特征提取，此外，还在重新采样至 1.4×1.4×1.4mm3 体素大小（标准临床分辨率）后进行特征提取。计算放射组学特征的主成分（PC），并使用独立样本 t 检验和 Cohen d 作为效应量测量指标，评估不同脑结构中女性和男性之间 PC 的差异。
在 UHR，至少有一个 PC 在 7 个脑结构中的 6 个结构中在女性和男性之间存在显著差异：额叶皮层（d=-0.79，P=0.042 和 d=-1.01，P=0.010）、额叶白质（d=-0.81，P=0.039）、丘脑（d=1.43，P＜0.001）、苍白球（d=0.92，P=0.020）、尾状核（d=-0.83，P=0.039）和胼胝体（d=-0.97，P=0.039）。在标准临床分辨率下，只有胼胝体的一个 PC 在性别之间存在差异（d=1.05，P=0.009）。
女性和男性之间存在一些关键脑结构的放射组学特征的显著差异，需要加以考虑。可能需要非常高的空间分辨率来揭示和进一步研究 MRI 上的脑结构性别二态性。
