Detection of brain tumour in 2d MRI: implementation and critical review of clustering-based image segmentation methods

Image segmentation can be defined as segregation or partitioning of images into multiple regions with the same predefined homogeneity criterion. Image segmentation is a crucial process in medical image analysis. This paper explores and investigates several unsupervised image segmentation approaches and their viability and performances in delineating tumour region in contrast enhanced T1-weighted brain MRI (Magnetic Resonance Imaging) scans. First and foremost, raw CE T1-weighted brain MR images are downloaded from a free online database. The images are then pre-processed and undergo an important process called skull stripping. Then, image segmentation techniques such as k-means clustering, Gaussian mixture model segmentation and fuzzy c-means are applied to the pre-processed MR images. The image segmentation results are evaluated using several performance measures, such as precision, recall, Tanimoto coefficient and Dice similarity index in reference to ground truth images. The highest average Dice coefficient is achieved by k-means (0.189) before post-processing and GMM (0.208) after post-processing. Unsupervised clustering-based brain tumour segmentation based on just image pixel intensity in single-spectral brain MRI without adaptive post-processing algorithm cannot achieve efficient and robust segmentation results

A Hybrid Approach of Using Symmetry Technique for Brain Tumor Segmentation

Tumor and related abnormalities are a major cause of disability and death worldwide. Magnetic resonance imaging (MRI) is a superior modality due to its noninvasiveness and high quality images of both the soft tissues and bones. In this paper we present two hybrid segmentation techniques and their results are compared with well-recognized techniques in this area. The first technique is based on symmetry and we call it a hybrid algorithm using symmetry and active contour (HASA). In HASA, we take refection image, calculate the difference image, and then apply the active contour on the difference image to segment the tumor. To avoid unimportant segmented regions, we improve the results by proposing an enhancement in the form of the second technique, EHASA. In EHASA, we also take reflection of the original image, calculate the difference image, and then change this image into a binary image. This binary image is mapped onto the original image followed by the application of active contouring to segment the tumor region