Semra OZDEMIR

Dr. Semra OZDEMIR


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2022 in Molecular Imaging and Radionuclide Therapy
Verified
Journal Article
Open access
YSYavuz Sami Salihoğlu
Yavuz Sami Salihoğlu
RERabiye Uslu Erdemir
Rabiye Uslu Erdemir
BPBüşra Aydur Püren
Büşra Aydur Püren
SOSemra OZDEMIR
Semra OZDEMIR
CUCaglar Uyulan
Caglar Uyulan
Huseyin Ozan TekinHuseyin Ozan Tekin
Huseyin Ozan Tekin
This study aimed to evaluate the ability of 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomic features combined with machine learning methods to distinguish between benign and malignant solitary pulmonary nodules (SPN). Data of 48 patients with SPN detected on 18F-FDG PET/CT scan were evaluated retrospectively. The texture feature extraction from PET/CT images was performed using an open-source application (LIFEx). Deep learning and classical machine learning algorithms were used to build the models. Final diagnosis was confirmed by pathology and follow-up was accepted as the reference. The performances of the models were assessed by the following metrics: Sensitivity, specificity, accuracy, and area under the receiver operator characteristic curve (AUC). The predictive models provided reasonable performance for the differential diagnosis of SPNs (AUCs ~0.81). The accuracy and AUC of the radiomic models were similar to the visual interpretation. However, when compared to the conventional evaluation, the sensitivity of the deep learning model (88% vs. 83%) and specificity of the classic learning model were higher (86% vs. 79%). Machine learning based on 18F-FDG PET/CT texture features can contribute to the conventional evaluation to distinguish between benign and malignant lung nodules.

1 November 2013 in Nuclear Medicine Communications
Verified
Journal Article
Closed access
SOSemra OZDEMIR
Semra OZDEMIR
YTYusuf Ziya Tan
Yusuf Ziya Tan
YCYücel Colkesen
Yücel Colkesen
ATAhmet Temiz
Ahmet Temiz
FTFatmanur Turker
Fatmanur Turker
SASemra Akgoz
Semra Akgoz
Aim Fragmented QRS (fQRS) complex is an ECG parameter that has recently been introduced and investigated. It is assumed that fQRS occurs because of disruptions in ventricular conduction due to ventricular infarction and ischemia. Therefore, in this article, we aimed to investigate the relationship between the detection of infarction and ischemia on myocardial perfusion-gated single-photon emission computed tomography images and appearance of fQRS on ECG. Materials and methods We retrospectively reviewed the records of patients with a diagnosis of coronary artery disease who were referred to our institution for myocardial perfusion scintigraphy. In total, 261 patients (122 women and 139 men, with a mean age of 61±10.33 years) with and without fQRS (136 and 125, respectively) were included in the present study. The myocardial perfusion scintigraphy results were evaluated for the presence or absence of myocardial ischemia and infarction by visual and quantitative (summed stress score, summed rest, summed difference score, summed motion score, and summed thickening score) assessments. Statistical analysis was performed to determine the relationship between the presence of fQRS and myocardial ischemia and/or infarction. Student’s t-test and the Mann–Whitney U-test were used for comparing the results. Pearson’s χ2-test and Fisher’s exact tests were also used to compare the distribution of variables between the two groups. Results The prevalence of ischemia and infarction were found to be, respectively, 4.38-fold and 5.95-fold higher in patients with fQRS compared with the control group. Moreover, the prevalence of both ischemia and infarction was found to be 10.54-fold higher in patients with fQRS compared with the control group. Conclusion There is a highly statistically significant possibility of detecting ischemia and infarction in perfusion myocardial scintigrams of patients whose ECGs have fQRS.

26 April 2012 in Genetic Testing and Molecular Biomarkers
Verified
Journal Article
Closed access
SOSemra OZDEMIR
Semra OZDEMIR
FSFatma Silan
Fatma Silan
ZHZekiye Hasbek
Zekiye Hasbek
AUAhmet Uludag
Ahmet Uludag
SASinem Atik
Sinem Atik
OOOzturk Ozdemir
Ozturk Ozdemir
Background: Epigenetic alterations in the global DNA methylation status may be associated with an increased risk of some cancer types in humans. The methylenetetrahydrofolate reductase ( MTHFR ) gene is involved in folic acid metabolism and plays an essential role in inherited DNA methylation profiles. The common 677 C>T and 1298 A>C polymorphisms in the MTHFR gene cause the production of a thermolabile enzyme with reduced function and, eventually, genomic DNA hypomethylation. The current preliminary study was designed to determine the association between germ-line polymorphism in the MTHFR gene and differentiated thyroid carcinoma (DTC). Methods: In the current case-control study of 60 thyroid carcinomas (TC); 45 papillary TC, 9 follicular TC, and 6 DTC of an uncertain malignant potential were examined. Genomic DNA was extracted from peripheral blood with EDTA, genotyped by a multiplex real-time polymerase chain reaction. Results: An elevated 2.33-fold risk was observed for DTC in individuals with the 677TT genotype when compared with the control group (odds ratio [OR]: 1.92, 95% confidence interval [CI]: 1.03-3.58). Current DTC patients showed similar results as a control group for the 1298 A>C allele. No significant risk was detected for the homozygous 1298CC genotype (CC vs. AA or AC) (OR: 1.30, 95% CI: 0.73-2.29). Conclusion: The current results are supportive of the hypothesis that the homozygous MTHFR 677TT genotype increases the risk factor of developing thyroid cancer, and further large-scale studies are needed to validate this association.

30 May 2013 in Asian Pacific Journal of Cancer Prevention
Verified
Journal Article
Open access
PDF file
SOSemra OZDEMIR
Semra OZDEMIR
AUAhmet Uludag
Ahmet Uludag
FSFatma Silan
Fatma Silan
SASinem Yalcintepe Atik
Sinem Yalcintepe Atik
BTBulent Turgut
Bulent Turgut
OOOzturk Ozdemir
Ozturk Ozdemir
Possible Roles of the Xenobiotic Transporter P-glycoproteins Encoded by the MDR1 3435 C>T Gene Polymorphism in Differentiated Thyroid Cancers Differentiated thyroid carcinoma;MDR1 gene;increased T allele frequency in codon C3435T; Background: P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter which plays an important role in pharmacokinetics. The current preliminary study was designed to determine associations between a germ-line polymorphism in the MDR1 gene with differentiated thyroid carcinoma (DTC). Materials and Methods: In the current case-control study, 60 differentiated thyroid cancers (DTC)- 45 papillary TC (PTC), 9 follicular TC(FTC) and 6 well-differentiated tumors of uncertain malignant potential (WDT-UMP) were examined. Results were compared to a healthy control group (n=58) from the same population. Genomic DNA was extracted from peripheral blood with EDTA and the target gene was genotyped by real-time PCR. Results: Carriers of the variant allele of MDR1 exon 26 polymorphism were at 2.8-fold higher risk of DTC than the control group (odds ratio [OR]: 0.3805, 95% confidence interval [Cl]: 0.1597-0.9065 (p> 0.046). Conclusions: Presented results suggest that the MDR1 3435TT genotype might influence risk of development of DTC and that the CC genotype might be linked to a poor prognosis. Large-scale studies are now needed to validate this association.

27 November 2014 in Annals of Nuclear Medicine
Verified
Journal Article
Closed access
PDF file
SOSemra OZDEMIR
Semra OZDEMIR
BKBahadır Kırılmaz
Bahadır Kırılmaz
ABAhmet Barutçu
Ahmet Barutçu
YTYusuf Ziya Tan
Yusuf Ziya Tan
FÇFatmanur Çelik
Fatmanur Çelik
SASemra Akgoz
Semra Akgoz

26 August 2020 in Nuclear Medicine Seminars
Verified
Journal Article
Closed access
FTFevziye Canbaz Tosun
Fevziye Canbaz Tosun
SOSemra OZDEMIR
Semra OZDEMIR
FŞFeyza Şen
Feyza Şen
HDHakan Demir
Hakan Demir
EÖELİF ÖZDEMİR
ELİF ÖZDEMİR
GAGülay Durmuş Altun
Gülay Durmuş Altun