Kalc Polona, Hoffstaedter Felix, Luders Eileen, Gaser Christian, Dahnke Robert
Structural Brain Mapping Group, Department of Neurology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany.
Forschungszentrum Jülich, Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Jülich, Germany.
Imaging Neurosci (Camb). 2024 Dec 6;2. doi: 10.1162/imag_a_00390. eCollection 2024.
Bones and brain are intricately connected and scientific interest in their interaction is growing. This has become particularly evident in the framework of clinical applications for various medical conditions, such as obesity and osteoporosis. The adverse effects of obesity on brain health have long been recognised, but few brain imaging studies provide sophisticated body composition measures. Here, we propose to extract the following bone- and adiposity-related measures from T1-weighted MR images of the head: an approximation of skull bone mineral density (BMD), skull bone thickness, and two approximations of subcutaneous fat (i.e., the intensity and thickness of soft non-brain head tissue). The reliability and validity of these four distinct measures were tested in two large-scale databases, the UK Biobank and OASIS-3. The measures pertaining to skull BMD, skull bone thickness, and intensity-based adiposity proxy proved to be reliable (ICC = .95/.83/.66, < .001) and valid, with high correlations to DXA-derived head BMD values (rho = .70,< .001) and MRI-derived abdominal subcutaneous adipose volume (rho = .62,< .001). Thickness-based adiposity proxy had only a low retest reliability (ICC = .53,< .001). The outcomes of this study constitute an important step towards extracting relevant non-brain features from available brain scans.
骨骼与大脑有着复杂的联系，科学界对它们之间相互作用的兴趣与日俱增。这在各种医学病症（如肥胖症和骨质疏松症）的临床应用框架中尤为明显。肥胖对大脑健康的不利影响早已得到认可，但很少有脑成像研究提供精确的身体成分测量方法。在此，我们提议从头部的T1加权磁共振图像中提取以下与骨骼和肥胖相关的测量指标：颅骨骨矿物质密度（BMD）的近似值、颅骨厚度以及皮下脂肪的两种近似值（即非脑组织的软组织强度和厚度）。在两个大型数据库——英国生物银行和OASIS - 3中测试了这四种不同测量指标的可靠性和有效性。与颅骨BMD、颅骨厚度以及基于强度的肥胖指标相关的测量结果被证明是可靠的（组内相关系数ICC分别为0.95/0.83/0.66，P < 0.001）且有效，与双能X线吸收法（DXA）得出的头部BMD值高度相关（rho = 0.70，P < 0.001），与磁共振成像（MRI）得出的腹部皮下脂肪体积也高度相关（rho = 0.62，P < 0.001）。基于厚度的肥胖指标重测可靠性较低（ICC = 0.53，P < 0.001）。本研究结果是朝着从现有的脑部扫描中提取相关非脑特征迈出的重要一步。
