Use of decrease in apparent diffusion coefficient values to predict infarct age.

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Accurate infarct age determination is crucial for stroke management and treatment decisions.
• Magnetic resonance diffusion-weighted imaging (DWI) is a key tool for acute stroke detection.
• Apparent diffusion coefficient (ADC) values decrease in acute ischemic stroke, offering potential for age estimation.

Purpose of the Study:

• To evaluate the accuracy of apparent diffusion coefficient (ADC) decrease thresholds in predicting the age of ischemic infarcts.
• To assess the ability of DWI-derived ADC values to differentiate between infarcts younger than 24 hours and 48 hours.

Main Methods:

• Retrospective analysis of 94 patients with reliably determined infarct age (<1 hour).
• Measurement of ADC values in infarct cores and contralateral normal tissue.
• Evaluation of four ADC decrease thresholds (>50%, >40%, >30%, >20%) for predicting infarct age (<24h and <48h).

Main Results:

• Sensitivity for predicting infarct age <24h ranged from 25% to 94%, with very low positive predictive values (18-25%).
• Sensitivity for predicting infarct age <48h ranged from 23% to 98%, with positive predictive values of 46-56%.
• Overall test performance characteristics for predicting infarct age were found to be relatively poor across all tested thresholds.

Conclusions:

• Apparent diffusion coefficient (ADC) decrease thresholds demonstrate limited accuracy for predicting infarct age, particularly for recent infarcts (<24 hours).
• The low positive predictive values suggest that relying solely on ADC decrease may lead to misclassification of infarct age.
• Further research is needed to identify more reliable biomarkers or imaging techniques for precise infarct age determination in clinical practice.