Investigating Lesion Size and Neuroimaging Methods with Magnetic Resonance Imaging in People With Aphasia

Lesion size and tracing methods with MRI Lesion size and tracing methods with MRI Brown, Filion, Keith, Massar Page 1 of 29 The aim of this study was to investigate the effect of lesion size on performance on various cognitive and linguistic tasks in three individuals with left-hemisphere stroke. Findings from previous research studies have indicated mixed results, with some studies arguing that the location of the lesion has a greater impact on recovery after stroke. Researchers were also interested in determining which method of lesion mapping generated the most accurate measure of the individual’s lesion size while reducing mapping duration. Subjects underwent an MRI scan, after which lesions were mapped onto brain images using the MRIcron program. Graphs were generated that plotted lesion size against participant performance on each task and data was analyzed through visual inspection and slope analysis of graphed lines. No consistent pattern of decline in task performance was observed with increasing lesion size across linguistic and cognitive tasks. In addition, it was determined that the manual method of mapping (MTM) was superior to the semi-automated technique (STM), as it provided greater flexibility and a higher level of accuracy, especially for larger lesions