The purpose of this study was to prospectively evaluate the contribution of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) for predicting outcome after ischemic stroke.

Patients with acute ischemic stroke who underwent brain MRI at 3 Tesla, including a multi-b diffusion-weighted imaging sequence were prospectively included. Mean, maximum (max) and minimum (min) of diffusion parameters, including apparent diffusion coefficient (ADC), D, D*, f, f·D* and K were extracted from the infarct core and normal-appearing parenchyma. The primary endpoint was 3-month modified Rankin scale (mRS). Associations were tested by univariable ordinal logistic regression with false discovery rate correction. Model performance was assessed using area under the receiver operating characteristic curve (AUC) analysis and the ranked probability score.

A total of 157 patients were included. There were 83 men and 74 women with a mean age of 70 ± 16 (standard deviation) years (range: 23–100 years). In univariable analyses, ADCmin in the infarct core was the strongest predictor of worse functional outcome at 3 months (OR, 0.37; P < 0.001). Within the infarct core, nine other parameters were significantly associated with mRS (one ADC, six IVIM and two DKI metrics). In the normal-appearing parenchyma, eight parameters (two ADC, four IVIM and two DKI metrics) were significantly associated with outcome. In multivariable analysis, the model combining ADCmin and Kmin in the core with ADCmax in the normal-appearing parenchyma provided the highest prognostic performance, with an AUC of 0.81 (95 % confidence interval [CI]: 0.77–0.86) compared to ADCmin alone (AUC, 0.75; 95 % CI: 0.67–0.82) ( P < 0.0001).

A combination of advanced diffusion MRI parameters could predict functional outcome in patients with ischemic stroke with higher precision than standard ADC alone.