Aktaş Dinçer, Hayriye
Gökçay, Didem
During healthy aging, the brain undergoes several structural changes which introduce prominent low contrast on the MR images. In this study, the low contrast effects causing segmentation problems were analyzed in the context of image quality ratios such as signal to noise, contrast to noise and gray white intensity: SNR, CNR, GWR. The evaluation of the T-1-weighted MPRAGE and SE scans was conducted across ages. Also by collecting multiple FLASH images with varying flip angles for estimation of T-1, the differences in T-1 value between young and old population are determined. As a result, it's observed that SE images have the best values in SNR metrics. However, it's found that T-1 estimated images are superior in CNR and GWR metrics.
22nd IEEE Signal Processing and Communications Applications Conference (SIU)


Investigation of age dependent contrast and T1 differences in MR images at 3.0 T: a study on MPRAGE, SPIN ECHO and FLASH protocols
Aktaş, Hayriye; Gökçay, Didem; Doğru, Ewa; Department of Biomedical Engineering (2013)
During healthy aging, the brain undergoes several structural changes such as brain atrophy, decreased volume of GM and WM and increase in CSF volume. These changes introduce prominent low contrast effects to the MRI images of the aging population, causing segmentation problems in the data processing pipeline. Measures of tissue characteristics such as T1, T2 provide unique and complementary information to widely used measures of brain atrophy. In this study, image quality metrics such as contrast, SNR, CNR ...
Transcriptomic network analysis of brain aging and alzheimers disease
Parvizi, Poorya; Somel, Mehmet; Tunçbağ, Nurcan; Department of Biology (2017)
Multiple studies have investigated aging brain transcriptomes to identify for age-dependent expression changes and determine genes that may participate in age-related dysfunction. However, aging is a highly complex and heterogeneous process where multiple genes contribute at different levels depending on individuals’ environments and genotypes. Both this biological heterogeneity of aging, as well as technical biases and weaknesses inherent to transcriptome measurements, limit the information gained from a s...
Meta analysis of alzheimer’s disease at the gene expression level
İzgi, Hamit; Somel, Mehmet; Department of Biology (2017)
In this study, publicly available microarray gene expression datasets are used to investigate common gene expression changes in different postmortem brain regions in Alzheimer’s Disease (AD) patients compared to control subjects, and to find possible functional associations related to these changes. The hypothesis is that pathogenesis of the disease converges into common patterns of dysregulation/alteration or dysfunction in molecular pathways across different brain regions in AD. In total, I studied 13 dat...
Review of MRI-based Brain Tumor Image Segmentation Using Deep Learning Methods
Işın, Ali; Direkoğlu, Cem; Şah, Melike (Elsevier BV; 2016)
Brain tumor segmentation is an important task in medical image processing. Early diagnosis of brain tumors plays an important role in improving treatment possibilities and increases the survival rate of the patients. Manual segmentation of the brain tumors for cancer diagnosis, from large amount of MRI images generated in clinical routine, is a difficult and time consuming task. There is a need for automatic brain tumor image segmentation. The purpose of this paper is to provide a review of MRI-based brain ...
Construction of a patterned hydrogelfibrous mat bilayer structure to mimic choroid and Bruch's membrane layers of retina
Komez, Aylin; Baran, Erkan T.; Erdem, Uzeyir; Hasırcı, Nesrin; Hasırcı, Vasıf Nejat (2016-09-01)
Deterioration of retina and death of the retinal cells due to age, diabetes, or occlusion can cause retinal degeneration which leads to loss of vision. In this study, it is aimed to design a bilayered matrix to mimic the choroid and the Bruch's membrane of the retinal tissue. As choroid, a microchanneled network resembling a fractal tree design was fabricated by photolithography over photo-cross-linkable methacrylated hyaluronic acid hydrogel. Gelatin or collagen was immobilized into the microchannels to en...
Citation Formats
H. Aktaş Dinçer and D. Gökçay, “EVALUATION OF MRIS OF THE BRAIN WITH RESPECT TO SNR, CNR AND GWR IN YOUNG VERSUS OLD SUBJECTS,” presented at the 22nd IEEE Signal Processing and Communications Applications Conference (SIU), Karadeniz Teknik Univ, Trabzon, TURKEY, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/55679.