APPLICABILITY OF SEMIAUTOMATIC SEGMENTATION FOR VOLUMETRIC-ANALYSIS OF BRAIN-LESIONS

This project involves the development of a fast semi-automatic segment ation procedure to make an accurate volumetric estimation of brain les ions. This method has been applied in the segmentation of demyelinatio n plaques in Multiple Sclerosis (MS) and right cerebral hemispheric in farctions in patients with neglect. The developed segmentation method includes several image processing techniques, such as image enhancemen t, amplitude segmentation, and region growing. The entire program oper ates on a PC-based computer and applies graphical user interfaces. Twe nty three patients with MS and 43 patients with right cerebral hemisph ere infarctions were studied on a 0.5 T MRI unit. The MS plaques and c erebral infarctions were thereafter segmented. The volumetric accuracy of the program was demonstrated by segmenting Magnetic Resonance (MR) images of fluid filled syringes. The relative error oft he total volu me measurement based on the MR images of syringes was 1.5%. Also the r epeatability test was carried out as inter- and intra-observer study i n which MS plaques of six randomly selected patients were segmented. T hese tests indicated 7% variability in the inter-observer study and 4% variability in the intra-observer study. Average time used to segment and calculate the total plaque volumes for one patient was 10 min. Th is simple segmentation method can be utilized in the quantitation of a natomical structures, such as air cells in the sinonasal and temporal bone area, as well as in different pathological conditions, such as br ain tumours, intracerebral haematomas and bony destructions.