Health Engineering SL, Getxo, Spain.
Institut d'Investigacions Biomèdiques August Pi Sunyer - Hospital Clinic, University of Barcelona, Spain.
Neuroimage Clin. 2021;30:102653. doi: 10.1016/j.nicl.2021.102653. Epub 2021 Mar 29.
Fractal geometry measures the morphology of the brain and detects CNS damage. We aimed to assess the longitudinal changes on brain's fractal geometry and its predictive value for disease worsening in patients with Multiple Sclerosis (MS).
We prospectively analyzed 146 consecutive patients with relapsing-remitting MS with up to 5 years of clinical and brain MRI (3 T) assessments. The fractal dimension and lacunarity were calculated for brain regions using box-counting methods. Longitudinal changes were analyzed in mixed-effect models and the risk of disability accumulation were assessed using Cox Proportional Hazard regression analysis.
There was a significant decrease in the fractal dimension and increases of lacunarity in different brain regions over the 5-year follow-up. Lower cortical fractal dimension increased the risk of disability accumulation for the Expanded Disability Status Scale [HR 0.9734, CI 0.8420-0.9125; Harrell C 0.59; Wald p 0.038], 9-hole peg test [HR 0.9734, CI 0.8420-0.9125; Harrell C 0.59; Wald p 0.0083], 2.5% low contrast vision [HR 0.4311, CI 0.2035-0.9133; Harrell C 0.58; Wald p 0.0403], symbol digit modality test [HR 2.215, CI 1.043-4.705; Harrell C 0.65; Wald p 0.0384] and MS Functional Composite-4 [HR 0.55, CI 0.317-0.955; Harrell C 0.59; Wald p 0.0029].
Fractal geometry analysis of brain MRI identified patients at risk of increasing their disability in the next five years.
分形几何可测量大脑形态并检测中枢神经系统损伤。我们旨在评估多发性硬化症（MS）患者脑分形几何的纵向变化及其对疾病恶化的预测价值。
我们前瞻性分析了 146 例连续的复发缓解型 MS 患者，这些患者在 5 年内接受了临床和脑部 MRI（3T）评估。使用盒计数法计算脑区的分形维数和空隙度。在混合效应模型中分析纵向变化，并使用 Cox 比例风险回归分析评估残疾累积风险。
在 5 年的随访中，不同脑区的分形维数显著降低，空隙度增加。皮质分形维数降低增加了扩展残疾状态量表[HR 0.9734，CI 0.8420-0.9125；Harrell C 0.59；Wald p 0.038]、9 孔钉测试[HR 0.9734，CI 0.8420-0.9125；Harrell C 0.59；Wald p 0.0083]、2.5%低对比视力[HR 0.4311，CI 0.2035-0.9133；Harrell C 0.58；Wald p 0.0403]、符号数字模态测试[HR 2.215，CI 1.043-4.705；Harrell C 0.65；Wald p 0.0384]和 MS 功能综合 4[HR 0.55，CI 0.317-0.955；Harrell C 0.59；Wald p 0.0029]的残疾累积风险。
脑 MRI 的分形几何分析确定了未来五年内残疾风险增加的患者。
