Associations Between Diffusion Dynamics and Functional Outcome in Acute and Early Subacute Ischemic Stroke

Area of Science:

• Neurology
• Radiology
• Biomedical Imaging

Background:

• Ischemic stroke significantly impacts patient functional outcomes.
• Accurate prediction of stroke recovery is crucial for clinical management.
• Diffusion imaging offers insights into tissue microstructure changes post-stroke.

Purpose of the Study:

• To investigate the association between diffusion dynamics of ischemic lesions and clinical functional outcomes in acute and early subacute stroke.
• To determine if diffusion parameters can predict long-term functional recovery.
• To assess the influence of lesion volume and stroke timing on these associations.

Main Methods:

• 80 patients with middle cerebral artery infarcts underwent multi-b-values diffusion-weighted imaging and diffusion kurtosis imaging.
• Diffusion parameters (ADCst, FA, MK ratios) were calculated using various diffusion models.
• Functional outcome was assessed using the modified Rankin scale (mRS) at 6 months; partial correlation analyzed significant parameters.

Main Results:

• Fractional anisotropy (FA) ratio in acute stroke, and apparent diffusion coefficient (ADCst) and mean kurtosis (MK) ratios in early subacute stroke, correlated with functional outcome.
• These correlations remained significant after controlling for lesion volume.
• Specific diffusion parameters showed distinct associations depending on the stroke phase (acute vs. early subacute).

Conclusions:

• Diffusion dynamics of ischemic lesions are significantly correlated with clinical functional outcomes.
• This relationship is independent of lesion volume and specific to the time post-stroke onset.
• Diffusion kurtosis imaging shows promise for predicting stroke recovery, warranting further investigation.