Bergamino Maurizio, Burke Anna, Baxter Leslie C, Caselli Richard J, Sabbagh Marwan N, Talboom Joshua S, Huentelman Matthew J, Stokes Ashley M
Barrow Neuroimaging Innovation Center, Barrow Neurological Institute, Phoenix, Arizona, USA.
Department of Neurology, Barrow Neurological Institute, Phoenix, Arizona, USA.
J Magn Reson Imaging. 2022 Dec;56(6):1845-1862. doi: 10.1002/jmri.28172. Epub 2022 Mar 23.
Advanced diffusion-based MRI biomarkers may provide insight into microstructural and perfusion changes associated with neurodegeneration and cognitive decline.
To assess longitudinal microstructural and perfusion changes using apparent diffusion coefficient (ADC) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in cognitively impaired (CI) and healthy control (HC) groups.
Prospective/longitudinal.
Twelve CI patients (75% female) and 13 HC subjects (69% female).
FIELD STRENGTH/SEQUENCE: 3 T; Spin-Echo-IVIM-DWI.
Two MRI scans were performed with a 12-month interval. ADC and IVIM-DWI metrics (diffusion coefficient [D] and perfusion fraction [f]) were generated from monoexponential and biexponential fits, respectively. Additionally, voxel-based correlations were evaluated between change in Montreal Cognitive Assessment (ΔMoCA) and baseline imaging parameters.
Analysis of covariance with sex and age as covariates was performed for main effects of group and time (false discovery rate [FDR] corrected) with post hoc comparisons using Bonferroni correction. Partial-η and Hedges' g were used for effect-size analysis. Spearman's correlations (FDR corrected) were used for the relationship between ΔMoCA score and imaging. P < 0.05 was considered statistically significant.
Significant differences were found for the main effects of group (HC vs. CI) and time. For group effects, higher ADC, IVIM-D, and IVIM-f were observed in the CI group compared to HC (ADC: 1.23 ± 0.08 10 vs. 1.09 ± 0.07 10 mm /sec; IVIM-D: 0.82 ± 0.01 10 vs. 0.73 ± 0.01 10 mm /sec; and IVIM-f: 0.317 ± 0.008 vs. 0.253 ± 0.009). Significantly higher ADC, IVIM-D, and IVIM-f values were observed in the CI group after 12 months (ADC: 1.45 ± 0.05 10 vs. 1.50 ± 0.07 10 mm /sec; IVIM-D: 0.87 ± 0.01 10 vs. 0.94 ± 0.02 10 mm /sec; and IVIM-f: 0.303 ± 0.007 vs. 0.332 ± 0.008), but not in the HC group at large effect size. ADC, IVIM-D, and IVIM-f negatively correlated with ΔMoCA score (ρ = -0.49, -0.51, and -0.50, respectively).
These findings demonstrate that longitudinal differences between CI and HC cohorts can be measured using IVIM-based metrics.
2 TECHNICAL EFFICACY STAGE: 2.
基于扩散的先进磁共振成像生物标志物可能有助于深入了解与神经退行性变和认知衰退相关的微观结构和灌注变化。
使用认知障碍（CI）组和健康对照（HC）组的表观扩散系数（ADC）和体素内不相干运动扩散加权成像（IVIM-DWI）参数评估纵向微观结构和灌注变化。
前瞻性/纵向研究。
12例CI患者（75%为女性）和13例HC受试者（69%为女性）。
场强/序列：3T；自旋回波-IVIM-DWI。
间隔12个月进行两次磁共振成像扫描。ADC和IVIM-DWI指标（扩散系数[D]和灌注分数[f]）分别通过单指数拟合和双指数拟合生成。此外，还评估了蒙特利尔认知评估变化（ΔMoCA）与基线成像参数之间基于体素的相关性。
以性别和年龄作为协变量进行协方差分析，以评估组和时间的主要效应（错误发现率[FDR]校正），并使用Bonferroni校正进行事后比较。部分η和Hedges'g用于效应大小分析。Spearman相关性分析（FDR校正）用于评估ΔMoCA评分与成像之间的关系。P<0.05被认为具有统计学意义。
发现组（HC与CI）和时间的主要效应存在显著差异。对于组效应，与HC组相比，CI组观察到更高的ADC、IVIM-D和IVIM-f（ADC：1.23±0.08×10⁻³vs.1.09±0.07×10⁻³mm²/sec；IVIM-D：0.82±0.01×10⁻³vs.0.73±0.01×10⁻³mm²/sec；IVIM-f：0.317±0.008 vs.0.253±0.009）。12个月后，CI组观察到显著更高的ADC、IVIM-D和IVIM-f值（ADC：1.45±0.05×与1.50±0.07×10⁻³mm²/sec；IVIM-D：0.87±0.01×10⁻³vs.0.94±0.02×10⁻³mm²/sec；IVIM-f：0.303±0.007 vs.0.332±0.008），但在HC组中未观察到较大效应大小。ADC、IVIM-D和IVIM-f与ΔMoCA评分呈负相关（ρ分别为-0.49、-0.51和-0.50）。
这些发现表明，基于IVIM的指标可以测量CI和HC队列之间的纵向差异。
2级。技术效能阶段：2级。
