MRI based objective ischemic core-penumbra quantification in adult clinical stroke

Objective and non-invasive quantification of ischemic stroke and differentiation of salvageable from non-salvageable tissue is critical to treatment planning. However current Magnetic Resonance Imaging(MRI) techniques are time consuming and rely on manual detection methods. Computer aided preliminary screening of the injured tissue could assist neuroradiologists in performing more detailed analysis of the lesion components. An established Hierarchical Region Splitting (HRS) method was extended to segment lesions from adult patients who suffered a clinical stroke using diffusion- and perfusion weighted image (DWI-PWI) maps and associated computed maps. Apart from lesion quantification PWI-DWI based HRS was also able to automatically quantify core (irrecoverable) the penumbra (potentially recoverable) which helped to estimate salvageable tissue. The PWI-DWI/HRS results were validated by comparing with manually demarcated ground truth in terms of performance indices like lesion volume (82.1% accuracy), sensitivity (78.8%), specificity (99.3%) and similarity (78.54%) for a dataset of 10 acute adult stroke patients. Data sets were classified into severe, moderate and mild injuries based on total lesion volume. Proposed PWI-DWI/HRS method demonstrated accuracy close to manual lesion demarcation with high performance indices for core and penumbra in severe and moderate classes.