Fakülteler / Faculties
Permanent URI for this communityhttps://hdl.handle.net/11727/1395
Browse
6 results
Search Results
Item Internal Comparison Standard for Abdominal Diffusion-Weighted Imaging(2017) Koc, Zafer; Erbay, Gurcan; Karadeli, Elif; 0000-0002-1706-8680; 0000-0002-0352-8818; 0000-0003-0987-1980; 27956463; AAK-5370-2021; AAK-5399-2021; S-8384-2016Background: Standards for abdominal diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) measurements, and analysis are required for reproducibility. Purpose: To identify optimal internal comparison standards for DWI to normalize the measured ADC for increased accuracy of differentiating malignant and benign abdominal lesions. Material and Methods: We retrospectively studied 97 lesions (89 patients; age, 57 +/- 13 years) with histopathologically confirmed abdominal disease. Seven normal body parts/contents (normal parenchyma, spleen, kidney, gallbladder bile, paraspinal muscle, spinal cord, and cerebrospinal fluid [CSF]) were assessed as internal references for possible use as comparison standards. Three observers performed ADC measurements. Statistical analyses included interclass correlation coefficients (ICCs), Mann-Whitney and Kruskal-Wallis tests, and coefficient of variation (CV). ROC analyses were performed to assess diagnostic accuracy of lesion ADC and normalized ADC for differentiating lesions. Pathology results were the reference standard. Results: Mean and normalized ADCs were significantly lower for malignant lesions than for benign lesions (P< 0.001). ICC was excellent for all internal references. Gallbladder had the lowest CV. Receiver operating characteristic (ROC) analyses showed that normalized ADCs obtained using normal parenchyma were better than lesion ADCs for differentiating malignant and benign abdominal lesions (area under the curve [AUC], 0.808 and 0.756, respectively). The normalized ADCs obtained using CSF shows higher accuracy than lesion ADCs (0.80 and 0.76, respectively) for differentiating between malignant and benign abdominal lesions. Conclusion: The normal parenchyma from a lesion-detected organ can be used as an internal comparison standard for DWI. CSF can be used as a generalizable in plane reference standard.Item Predicting Tumor Recurrence in Patients with Cervical Carcinoma Treated with Definitive Chemoradiotherapy: Value Of Quantitative Histogram Analysis On Diffusion-Weighted MR Images(2017) Erbay, Gurcan; Onal, Cem; Karadeli, Elif; Guler, Ozan C.; Arica, Sami; Koc, Zafer; https://orcid.org/0000-0002-1706-8680; https://orcid.org/0000-0002-0352-8818; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0003-0987-1980; 27445314; AAK-5370-2021; HOC-5611-2023; AAK-5399-2021; AAC-5654-2020; S-8384-2016Background: Further research is required for evaluating the use of ADC histogram analysis in more advanced stages of cervical cancer treated with definitive chemoradiotherapy (CRT). Purpose: To investigate the utility of apparent diffusion coefficient (ADC) histogram derived from diffusion-weighted magnetic resonance images in cervical cancer patients treated with definitive CRT. Material and Methods: The clinical and radiological data of 50 patients with histologically proven cervical squamous cell carcinoma treated with definitive CRT were retrospectively analyzed. The impact of clinicopathological factors and ADC histogram parameters on prognostic factors and treatment outcomes was assessed. Results: The mean and median ADC values for the cohort were 1.043 +/- 0.135 x 10(-3) mm(2)/s and 1.018 x 10(-3) mm(2)/s (range, 0.787-1.443 x 10(-3) mm(2)/s). The mean ADC was significantly lower for patients with advanced stage (>= IIB) or lymph node metastasis compared with patients with stage < IIB or no lymph node metastasis. The mean ADC, 75th percentile ADC (ADC75), 90th percentile ADC (ADC90), and 95th percentile ADC (ADC95) were significantly lower in patients with tumor recurrence compared with patients without recurrence. In multivariate analysis, tumor size, ADC75 and ADC95 were independent prognostic factors for both overall survival and disease-free survival. Conclusion: ADC histogram parameters could be markers for disease recurrence and for predicting survival outcomes. ADC75, ADC90, and ADC95 of the primary tumor were significant predictors of disease recurrence in cervical cancer patients treated with definitive CRT.Item Abdominal CT Findings in Patients with Primary Lymphoma Causing Small Bowel Obstruction(2017) Karadeli, Elif; Erbay, Gurcan; Parlakgumus, Alper; Yabanoglu, Hakan; 0000-0002-0352-8818; 0000-0002-1706-8680; 0000-0002-1161-3369; 29132484; AAK-5399-2021; AAK-5370-2021; AAJ-7865-2021The purpose of this study was to investigate retrospectively CT findings in patients with primary lymphoma causing small bowel obstruction. CT scans of 11 patients with small bowel lymphoma were separately analysed in terms of affected section of the small bowel, focality, wall thickness, pattern and degree of contrast enhancement, lymphadenopathy, organ involvement, perforation, and the presence of intraabdominal fluid. Eight patients had diffuse large B-cell lymphoma, and one patient each had marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT), T-cell lymphoma, and anaplastic T-cell lymphoma. Affected sections of the bowels involved were jejunum (n=5, 45.4%), ileum (n=2, 18.1%), and one case (9%) each of distal ileum, distal jejunum, distal jejunum and ileum, and distal jejunum and colon. Primary gastrointestinal (GI) lymphoma is an uncommon disease, that may lead to small bowel obstruction sometimes.Item Utility of Diffusion Weighted Magnetic Resonance Imaging with Multiple B Values in Evaluation of Pancreatic Malignant and Benign Lesions and Pancreatitis(2018) Karadeli, Elif; Erbay, Gurcan; Parlakgumus, Alper; Koc, Zafer; https://orcid.org/0000-0002-0352-8818; https://orcid.org/0000-0002-1706-8680; https://orcid.org/0000-0003-0987-1980; 29394967; AAK-5399-2021; AAK-5370-2021; S-8384-2016Objective: To determine the feasibility of diffusion-weighted imaging in evaluation of pancreatic lesions and in differentiation of benign from malignant lesions. Study Design: Descriptive study. Place and Duration of Study: Baskent University Adana Teaching and Research Center, Adana, Turkey, between September 2013 and May 2015. Methodology: Forty-three lesions [pancreas adenocarcinoma (n = 25)], pancreatitis (n = 10), benign lesion (n = 8)] were utilized with diffusion-weighted magnetic resonance imaging with multiple b-values. Different ADC maps of diffusion weighted images by using b-values were acquired. Results: The median ADC at all b values for malignant lesions was significantly different from that for benign lesions (p < 0.001). When ADCs at all b values were compared between benign lesions/normal parenchyma and malignant lesions/normal parenchyma, there was a significant statistical difference in all b values between benign and malignant lesions except at b 50 and b 200 (p<0.05). The lesion/normal parenchyma ADC ratio for b 600 value (AUC=0.804) was more effective than the lesion ADC for b 600 value (AUC=0.766) in differentiation of benign and malignant lesions. The specificity and sensitivity of the lesion/normal parenchyma ADC ratio were higher than those of ADC values of lesions. When the ADC was compared between benign lesions and pancreatitis, a significant difference was found at all b values (p<0.001). There was not a statistically significant difference between the ADC for pancreatitis and that for malignant lesions at any b value combinations (p>0.05). Conclusion: Diffusion-weighted magnetic resonance images can be helpful in differentiation of pancreatic carcinoma and benign lesions. Lesion ADC / normal parenchyma ADC ratios are more important than lesion ADC values in assessment of pancreatic lesions.Item A Case of Mediastinal Mesenchymal Tumor Resembling Hemopericardium(2021) Acibuca, Aynur; Yilmaz, Mustafa; Karadeli, Elif; Canpolat, Emine Tuba; Erol, Tansel; 34404995Mediastinal neoplasms are rare in the elderly, and clinical suspicion is the first and most important step of differential diagnosis. Mediastinal tumors can be misdiagnosed because their symptoms or signs can overlap with cardiovascular diseases, which have a higher prevalence among the older population. The diagnostic process should be managed with multimodality imaging and clinical judgement. Here, the case of a 74-year-old male patient, who presented with shortness of breath, is examined. A chest X-ray revealed an increased cardiothoracic ratio, and he was diagnosed with hemopericardium following an emergent chest computed tomography. In the echocardiography, it was suspected that a hyperechogenic area adjacent to the heart might be due to a mass, and further examinations confirmed a mediastinal neoplasm. A surgical biopsy was performed, and it was determined to be a mesenchymal tumor. To conclude, clinicians should keep in mind the possibility of paracardiac neoplasm in the elderly, as well as in other age groups, when encountering mediastinal widening so that the patient can be protected from unnecessary interventions such as pericardiocentesis.Item Prognostic values of ADC(mean) and SUVmax of the primary tumour in cervical cancer patients treated with definitive chemoradiotherapy(2019) Yildirim, Berna Akkus; Onal, Cem; Erbay, Gurcan; Guler, Ozan Cem; Karadeli, Elif; Reyhan, Mehmet; Koc, Zafer; 0000-0002-2742-9021; 0000-0003-0987-1980; 30354907; D-5195-2014; S-8384-2016We analysed the correlation of F-18-fluorodeoxyglucose uptake into primary tumours using the maximum standardised uptake value (SUVmax) and the mean apparent diffusion coefficient (ADC(mean)) values in magnetic resonance imaging (MRI) with the clinical and pathological factors in patients with cervical cancer who were treated with concurrent chemoradiotherapy. The patients were stratified according to the primary tumour pre-treatment ADC(mean) and SUVmax cut-off values. There were significant correlations between the SUVmax of the primary tumour and tumour size, and the treatment response. The correlation between the ADC(mean) and FIGO stage, tumour size, and the lymph node metastasis was significant. The SUVmax was significantly and inversely correlated with the ADC(mean) for cervical cancer (r = -0.44, p <.001). In the multivariate analysis, the primary tumour ADC(mean), treatment response and the lymph node metastasis emerged as significant independent predictors of both OS and DFS, and of the primary tumour SUVmax for DFS. Tumour size has a borderline significance for OS. High SUVmax and low ADC(mean) of the primary tumour are important predictive factors for identifying high-risk patients with cervical cancer who are treated with definitive chemoradiotherapy. These results point to a future role for the diffusion-weighted MRI and for F-18-fluorodeoxyglucose positron emission tomography, not only in the staging of cervical cancer but as an aid in the selection of an adjuvant treatment regimen after chemoradiotherapy for individual patients.