Article ID Journal Published Year Pages File Type
6268088 Journal of Neuroscience Methods 2016 12 Pages PDF
Abstract

•We present a novel method for lesion delineation in individual T1 MRI scans.•We compared our method with manual delineation for a large group of stroke patients.•Our method reliably predicted lesion extents and volumes.•Our method identified lesion effects that pose challenges for manual delineation.•Our method can be used for lesion-symptom mapping and clinical volume estimation.

BackgroundManual lesion delineation by an expert is the standard for lesion identification in MRI scans, but it is time-consuming and can introduce subjective bias. Alternative methods often require multi-modal MRI data, user interaction, scans from a control population, and/or arbitrary statistical thresholding.New methodWe present an approach for automatically identifying stroke lesions in individual T1-weighted MRI scans using naïve Bayes classification. Probabilistic tissue segmentation and image algebra were used to create feature maps encoding information about missing and abnormal tissue. Leave-one-case-out training and cross-validation was used to obtain out-of-sample predictions for each of 30 cases with left hemisphere stroke lesions.ResultsOur method correctly predicted lesion locations for 30/30 un-trained cases. Post-processing with smoothing (8 mm FWHM) and cluster-extent thresholding (100 voxels) was found to improve performance.Comparison with existing methodQuantitative evaluations of post-processed out-of-sample predictions on 30 cases revealed high spatial overlap (mean Dice similarity coefficient = 0.66) and volume agreement (mean percent volume difference = 28.91; Pearson's r = 0.97) with manual lesion delineations.ConclusionsOur automated approach agrees with manual tracing. It provides an alternative to automated methods that require multi-modal MRI data, additional control scans, or user interaction to achieve optimal performance. Our fully trained classifier has applications in neuroimaging and clinical contexts.

Related Topics
Life Sciences Neuroscience Neuroscience (General)
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