Besma MNASSRI

Title: How contrast enhancement methods can help in early multiple sclerosis diagnosis

Abstract

Multiple sclerosis (MS) is the leading cause of non-traumatic disability among young adults. MS lesions cause several disorders. Indeed, early detection of lesions provides an accurate MS diagnosis. Thus, with the adequate treatment, clinicians will be able to deal effectively with the disease and reduce the number of relapses. Magnetic resonance imaging (MRI) is the gold standard imaging tool for early diagnosis of MS patients. However, low contrast MRI images can hide important objects in the image such lesions. In this context, we have proposed new automated contrast enhancement (CE) methods to ameliorate the low contrast of MRI images for a better enhancement and visibility of MS lesions. The first developed method BDS is based on Brightness Preserving Dynamic Fuzzy Histogram Equalization (BPDFHE) and Singular Value Decomposition with Discrete Wavelet Transform (SVD-DWT) techniques. BDS is dedicated to improve the low quality of MRI images. The second method MBDS is an improved version of BDS, wherein, we have proposed a new technique for computing the correction factor. MBDS is dedicated for enhancement of very low contrast MRI images.

Experimental results proved the effectiveness of both proposed methods in improving low contrast of MRI images with preservation of brightness level and edge information from degradation. These features are essential in CE approaches for a better lesion recognition. Moreover, performances of both proposed BDS and MBDS algorithms exceeded conventional CE methods. They increase the overall contrast of the image with preservation of edge details, leading to a natural looking of the image with sharper structures and no added artifacts. In addition, the optimized technique MBDS improves considerably the contrast of very low-contrast images and provides better visualization of small details including MS lesions. When applied to various multiple sclerosis MRI images (T1-w, T2-w, and T2-Flair of the brain and the spinal cord), MS lesions present in both the brain and the spinal cord in enhanced images had become sharper than those in the original image with well-defined edges. Proposed methods BDS and MBDS provide a better visualization and delineation of MS lesions. Therefore, they would be a proficient diagnostic tool for early MS diagnosis.

What will the audience take away from your presentation?

• Be aware of possible causes and risk factors of Multiple Sclerosis and symptoms.


• Understand how using medical processing tools can help in the early diagnosis of the disease.


• Insight into the practical steps for implementing automatic methods for contrast enhancement of MRI images with low and very low contrast and their role to assist clinicians to provide a more accurate diagnostic.