Wos Kapalı Erişimli Yayınlar

Permanent URI for this collectionhttps://hdl.handle.net/11727/10753

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Author: search.filters.author.Haberal, K. Murat

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    Virtual contrast enhancement for CT scans of abdomen and pelvis
    (2022) Liu, Jingya; Tian, Yingli; Duzgol, Cihan; Akin, Oguz; Agildere, A. Muhtesem; Haberal, K. Murat; Coskun, Mehmet; 0000-0002-8211-4065; 35914340; R-9398-2019
    Contrast agents are commonly used to highlight blood vessels, organs, and other structures in magnetic resonance imaging (MRI) and computed tomography (CT) scans. However, these agents may cause allergic reactions or nephrotoxicity, limiting their use in patients with kidney dysfunctions. In this paper, we propose a generative adversarial network (GAN) based framework to automatically synthesize contrast-enhanced CTs directly from the non-contrast CTs in the abdomen and pelvis region. The respiratory and peristaltic motion can affect the pixel-level mapping of contrast-enhanced learning, which makes this task more challenging than other body parts. A perceptual loss is introduced to compare high-level semantic differences of the enhancement areas between the virtual contrast-enhanced and actual contrast-enhanced CT images. Furthermore, to accurately synthesize the intensity details as well as remain texture structures of CT images, a dual-path training schema is proposed to learn the texture and structure features simultaneously. Experiment results on three contrast phases (i.e. arterial, portal, and delayed phase) show the potential to synthesize virtual contrast-enhanced CTs directly from non-contrast CTs of the abdomen and pelvis for clinical evaluation.
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    Incidence and Immunologic Analysis of Coronavirus Disease (COVID-19) in Hemodialysis Patients: A Single-Center Experience
    (2020) Arslan, Hande; Musabak, Ugur; Soy, Ebru H. Ayvazoglu; Azap, Ozlem Kurt; Sayin, Burak; Akcay, Sule; Haberal, K. Murat; Akdur, Aydincan; Yildirim, Sedat; Haberal, Mehmet; 0000-0001-8287-6572; 0000-0003-1511-7634; 0000-0002-5735-4315; 0000-0002-0993-9917; 0000-0002-8726-3369; 0000-0002-3171-8926; 0000-0002-8360-6459; 0000-0002-3462-7632; 0000-0002-8211-4065; 32519618; J-3707-2015; AAU-1810-2020; AAF-4610-2019; AAC-5566-2019; AAA-3068-2021; AAK-4089-2021; AAB-5175-2021; AAJ-8097-2021; R-9398-2019
    Objectives: COVID-19 is a great threat to the modern world and significant threat to immunocompromised patients, including patients with chronic renal failure. We evaluated COVID-19 incidence among our hemodialysis patients and investigated the most probable immune mechanisms against COVID-19. Materials and Methods: Baskent University has 21 dialysis centers across Turkey, with 2420 patients on hemodialysis and 30 on peritoneal dialysis. Among these, we retrospectively evaluated 602 patients (257 female/345 male) with chronic renal failure receiving hemodialysis as renal replacement therapy; 7 patients (1.1%) were infected with SARS-CoV-2. We retrospectively collected patient demographic characteristics, clinical data, and immunological factors affecting the clinical course of the disease. We divided patients into groups and included 2 control groups ( individuals with normal renal functions): group I included COVID-19-positive patients with normal renal function, group II included COVID-19-positive hemodialysis patients, group III included COVID-19-negative hemodialysis patients, and group IV included COVID-19-negative patients with normal renal function. Lymphocyte subsets in peripheral blood and typing of human leukocyte antigens were analyzed in all groups, with killer cell immunoglobulin-like receptor genes analyzed only in COVID-19-positive patients and healthy controls. Results: No deaths occurred among the 7 COVID-19-positive hemodialysis patients. Group I patients were significantly older than patients in groups II and III ( P = .039, P = .030, respectively) but not significantly different from group IV (P = .060). Absolute counts of natural killer cells in healthy controls were higher than in other groups (but not significantly). Activated T cells were significantly increased in both COVID-19-positive groups versus COVID-19-negative groups. Groups showed significant differences in C and DQ loci with respect to distribution of alleles in both HLA classes. Conclusions: Although immunocompromised patients are at greater risk for COVID-19, we found lower COVID-19 incidence in our hemodialysis patients, which should be further investigated in in vitro and molecular studies.