özkan ünal - Academia.edu (original) (raw)

Papers by özkan ünal

Cureus, Jul 16, 2023

Purpose: This study evaluated the differences between arachnoid and epidermoid cysts in computeri... more Purpose: This study evaluated the differences between arachnoid and epidermoid cysts in computerized tomography (CT) texture analysis (TA). Material and methods: The study included 12 patients with intracranial epidermoid cysts and 26 patients with intracranial arachnoid cysts who were diagnosed with diffusion-weighted magnetic resonance imaging (DW-MRI) and who had undergone an unenhanced CT examination before treatment. The LIFEx application software was used to obtain texture features. Eighty-two texture features from 38 lesions were automatically calculated for each lesion. The Shapiro-Wilk test was used to test the normality of the scores, and the Mann-Whitney U Test was used to test the difference between the groups. Receiver operating characteristic (ROC) curves and multivariate logistic regression modeling examined the parameters' diagnostic performances. Results: The median age of the patients was 53 years (range: 19-88 years). Eighty-two texture parameters were evaluated in the first order: gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), neighbor gray-tone difference matrix (NGTDM), and gray-level size zone matrix (GLSZM) groups. There was a statistically significant difference between the arachnoid cyst and the epidermoid cyst in the variables of compacity, compactness 1, compactness 2, sphericity, asphericity, sum average, coarseness, and low gray-level zone (p<0.05). According to the multiple logistic regression model, it was determined that the sum average in the GLCM group (B=-0.11; p=0.015), coarseness (B= 869.5; p=0.044) in the NGTDM group, and morphological sphericity (B=24.18; p=0.047) were the radiomics variables that increased the probability of epidermoid diagnosis. According to the classification table of the model, the sensitivity rate was found to be 83%, and the specificity rate was found to be 96%. Therefore, the probability of accurate model classification was 92%. Conclusion: CT TA is a method that can be applied with high diagnostic accuracy in the differential diagnosis of intracranial epidermoid and arachnoid cysts, especially in patients who cannot undergo an MRI examination.

Journal of X-ray Science and Technology, Jul 6, 2023

BACKGROUND: The etiology, clinicopathological features, and prognosis of cancer in cases with EGF... more BACKGROUND: The etiology, clinicopathological features, and prognosis of cancer in cases with EGFR mutations are different from those without mutations. OBJECTİVE: This study aims to evaluate the differences in ADC histogram analysis in brain metastases with EGFR mutation status in lung adenocarcinoma cases and the relationship between ADC histogram analysis differences and overall survival. METHODS: In this retrospective case-control study, 30 patients (8 EGFR+/22 EGFR-) and 51 brain metastases (15 EGFR+/36 EGFR-) were included. ROI markings are first performed from each section, including metastasis in ADC mapping using FIREVOXEL software. Next, ADC histogram parameters are calculated. Overall survival analysis after brain metastasis (OSBM) is defined as the time from initial brain metastasis diagnosis to the time of death or last follow-up. Patient-based (by evaluating the largest lesion) and lesion-based (by evaluating all measurable lesions) statistical analyses are then performed. RESULTS: In the lesion-based analysis, skewness values are lower in EGFR+ patients, which is statistically significant (p = 0.012). The two groups have no significant difference regarding other ADC histogram analysis parameters, mortality, and overall survival (p > 0.05). In the ROC analysis, the most appropriate skewness cut-off value is determined as 0.321 to distinguish the EGFR mutation difference, and this value is statistically significant (sensitivity: 66.7%, specificity: 80.6%, AUC: 0.730) (p = 0.006). CONCLUSİON: The findings of this study provide valuable insights into the differences in ADC histogram analysis according to EGFR mutation status in brain metastases due to lung adenocarcinoma. The identified parameters, especially skewness, are potentially non-invasive biomarkers for predicting mutation status. Incorporating these biomarkers into routine clinical practice may aid treatment decision-making and prognostic assessment for patients. Further validation studies and prospective investigations are warranted to confirm the clinical utility of these findings and establish their potential for personalized therapeutic strategies and patient outcomes.

The Neuroradiology Journal

Aim Brain metastases are seen in 15–40% of patients diagnosed with cancer. We aimed to search the... more Aim Brain metastases are seen in 15–40% of patients diagnosed with cancer. We aimed to search the relationship between the T2 hypointensity, diffusion-weighted imaging characteristics, and the presence and amount of vasogenic edema of brain metastasis in magnetic resonance imaging (MRI). Methods A total of 292 patients with brain metastasis were included in the study. T2 signals of metastatic lesions, accompanying diffusion restriction and perilesional vasogenic edema findings, were investigated. In metastases accompanied by vasogenic edema, the largest dimension of the vasogenic edema-mass complex on T2-weighted sequences and the largest dimension of the mass in contrast-enhanced T1-weighted series were measured and the edema-mass ratio (EMR) was calculated by comparing these two values. Results The frequency of vasogenic edema was statistically significantly higher in T2 hypointense metastases (89.1% vs 58.8%, χ2 = 18.949, p = <.001) and metastases accompanied by diffusion rest...

Acta oncologica turcica, 2024

Cholangiocarcinomas are cancers arising from epithelial cells of the intrahepatic and extrahepati... more Cholangiocarcinomas are cancers arising from epithelial cells of the intrahepatic and extrahepatic bile ducts. Most are locally advanced lesions when present. They usually present with jaundice, abdominal pain, and abnormal liver biochemical tests. Proptosis developed in the right eye of a 49-year-old female patient who was diagnosed with carcinoma metastasis in the right femur and we examined for the primary one. Lacrimal gland biopsy of the patient was found to be compatible with cholangiocarcinoma metastasis. Neuroopthalmologic complications in cholangiocarcinoma are very rare and 10 cases have been reported in the literature.

Background The aim of this retrospective study to share our eight years of experiences with prima... more Background The aim of this retrospective study to share our eight years of experiences with primary and metastatic tumors affecting the fornix. Methods Between January 2015 and March 2023, 1087 patients, of both sexes, who applied to the radiology department and whose cranial MRI were obtained due to the preliminary diagnosis of intracranial malignancy, were evaluated retrospectively.The relationship of primary and metastatic tumors with the fornix was performed by two radiologists with 6 and 10 years of experience in MRI examination. Results Fornix involvement diagnosed in 29/1087 (2.66%) patients, fornix was affected by metastatic lesions in 14 patients (48.2%) and by primary tumors in 15 patients (51.7%). Metastatic lesions were localized only to the fornix in seven patients and localized with neighboring structures in eight patients. Lung cancer and breast cancer constituted the majority of metastatic lesions origin, other tumors were osteosarcoma, renal cell carcinoma, pancreat...

Journal of the College of Physicians and Surgeons Pakistan

Objective: To determine the relationship of the presence and amount of vasogenic edema with origi... more Objective: To determine the relationship of the presence and amount of vasogenic edema with origin, type, and grade of primary cancer.

Journal of Pediatric Neurology, 2015

Abstract. In this study, cranial computerized tomography (CT) and/or magnetic resonance imaging (... more Abstract. In this study, cranial computerized tomography (CT) and/or magnetic resonance imaging (MRI) findings were inves-tigated in nine children with acute herpes simplex encephalitis (HSE). HSE was confirmed by polymerase chain reaction. Our purpose was to evaluate ...

Papillary thyroid carcinoma (PTC) is a relatively uncommon malignancy. The prognosis is generally... more Papillary thyroid carcinoma (PTC) is a relatively uncommon malignancy. The prognosis is generally good and the mortality rate is low. PTC is more common in younger patients; incidence is two to three times higher in women and in individuals with radiation exposure to the neck. We report on a 75-year-old woman with PTC admitted to our clinic for a giant mass in the neck dating back ten years. A hyperintense huge cystic lesion and hypo-intense central solid component were seen on T1- and T2-weighted magnetic resonance imaging. No distant metastasis was present. The PTC was treated surgically and radioiodine (131I) treatment was applied postoperatively. No recurrence was observed one year later.

Journal of the Belgian Society of Radiology, 2012

Journal of Ultrasound in Medicine, Jun 1, 2000

onchromaffin paragangliomas are very rare tumors. They arise from chemoreceptor cells at multiple... more onchromaffin paragangliomas are very rare tumors. They arise from chemoreceptor cells at multiple sites throughout the body, specifically the jugular, tympanic, vagal and aortic glomus, and retroperitoneal regions. Carotid body tumors, also known as chemodectomas, are a subtype of extraadrenal paraganglioma. They are slow-growing, usually benign tumors with malignancy occurring in about 6% of tumors. 1,2 They tend to be hypervascular and arise predominantly in intimate contact with vital structures, making their excision a surgical challenge. 3 Sonography is the screening method of choice, followed by angiography, determines the diagnosis. 4 In this study, we attempted to show the power Doppler imaging findings in carotid body tumors. MATERIAL AND METHODS Six patients (three men and three women) between the ages of 25 and 65 years with nontender mass beneath the mandibular angle were referred to the radiology department. The lesions were located on the right side in four cases and on the left in two cases.

Congenital abnormalities of the internal carotid artery (ICA) are extremely rare and aplasia/hypo... more Congenital abnormalities of the internal carotid artery (ICA) are extremely rare and aplasia/hypoplasia of the ICA associated with other congenital malformations is uncommon. An 8-year-old male patient was admitted to our hospital for extreme nervousness, attention problems and hyperactivity. On MR examination, left phytisis bulbi, left frontal lobe atrophy, assymmetric dilataion in the left lateral ventricle and hamartomas in both globus pallidi, right thalamus, and bilateral cerebellar hemispheres posterior to the fourth ventricle were observed. Left ICA was observed as hypoplastic in the cervical and cranial MR-angiography. Left MCA and ACA could not be visualised. Left carotid canal hypoplasia and left sphenoidal bone dysplasia were detected on CT. As far as we know, only 4 cases with concomitancy of ICA hypoplasia-NF Type-1 have been reported up to the present. In our case, in addition, phytisis bulbi is accompanying this coexistence.

Fetal and Pediatric Pathology, 2011

Fetal & Pediatric Pathology, 2011

Enchondromatosis is a congenital nonhereditary condition characterized by multiple symmetrically ... more Enchondromatosis is a congenital nonhereditary condition characterized by multiple symmetrically distributed intraosseous cartillaginous masses in the metaphyses and diaphyses of bones. We report a case of bilateral multiple enchondromas and cerebral hamartomas in an 11-year-old boy in whom x-rays displayed distortion and expansion of bilateral long tubuler bones, hands and feet, scapulas, pelvis, and occipital regions of the calvarium. In addition to osseous abnormalities, bilateral cerebral hamartomas were observed on cranial magnetic resonance imaging (MRI). To the best of our knowledge, this is the first case in the literature with enchondromatosis and cerebral hamartomas.

European Journal of Radiology Extra, 2010

Acute mountain sickness (AMS) is a pathological reaction, occurring as a result of failure to ada... more Acute mountain sickness (AMS) is a pathological reaction, occurring as a result of failure to adapt to altitude. The main symptoms reported are headache, nausea, vomiting and fatigue. However, high altitude cerebral and pulmonary edema, occurring in AMS, cause potentially fatal consequences. In our 31-yearold case, who is the group leader and activity organizer among nine mountaineers, who climbed Mt. Agrı for winter climbing, nausea, vomiting, unconsciousness, lack of appetite and severe headache have occurred in connection with high altitude at 4200 m. Brain MRI of the patient revealed widespread hyperintense lesions at subcortical white matter, corpus callosum, globus pallidi, and bilateral cerebellar peduncles on T2 and FLAIR series. The patient was referred to anesthesia-intensive care unit of our hospital. Since the appearances are demonstrative, MRI findings are presented.

European Journal of Radiology, 2007

Introduction: We evaluated chest X-ray and clinical findings of patients with lower respiratory t... more Introduction: We evaluated chest X-ray and clinical findings of patients with lower respiratory tract infection due to influenza H5N1 and presented the radiological findings and clinical course of the infection. Materials and methods: Between December 2005 and February 2006, eight hospitalized patients (median age 10, 5-15 years) with avian-flu were evaluated in this study. All patients were evaluated with chest X-ray and four of them with CT scan. Post mortem pathological characterization were also available for three of the patients. Results: A rapidly progressive pneumonia with high mortality rate was observed especially for cases with late admission. The major radiologic abnormalities were extensive pneumonic infiltration with segmental and multifocal distribution, mostly located in lower zones of the lung. No pleural effusion and hilar lymphadenopathy was noted. Conclusion: Avian flu may be presented as rapidly progressive pneumonia. The chest radiography has an important role in diagnosis and should be obtained daily because of rapid change of the findings that may necessitate prompt action.

Clinical Imaging, 2000

The aim of this study was to show reduction of the diaphragmatic excursion with MR fluoroscopy in... more The aim of this study was to show reduction of the diaphragmatic excursion with MR fluoroscopy in patients with chronic obstructive pulmonary disease (COPD) and to compare the results with pulmonary function test (PFT). The study included 13 men and 10 women (average age 56.2) with COPD, and 9 men and 6 women (average age 55.8) as a control group. MR fluoroscopy images with Spoiled Gradient-echo pulse sequence was obtained during deep inspiration and expiration. After examination, over cine-loop display, the highest and lowest positions of the diaphragm were identified and the distance of excursion was measured. Differences in the diaphragmatic excursion between patient and healthy subjects were compared. We have also compared MR fluoroscopy results with PFT. In each person of both groups, excursion of the diaphragm was demonstrated clearly in cine-loop display. Differences of excursion between deepest and highest point of diaphragm were on average 26 and 20 mm, respectively, in the right and left side in patients and 69 and 56 mm in healthy group. Significant correlation was found between expiratory volume in 1 s and MR fluoroscopy results. MR fluoroscopy study showed that there were significant statistical differences in diaphragmatic excursion between patients with COPD and healthy subjects. Expiratory volume in 1 s is closely associated with the diaphragmatic excursion. MR fluoroscopy would seem to be a useful method for showing diaphragmatic excursion.

Clinical Imaging, 1999

Twenty-five fetal kidneys of 22 healthy fetuses be-2167519. tween 22 and 40 weeks gestation (mean... more Twenty-five fetal kidneys of 22 healthy fetuses be-2167519. tween 22 and 40 weeks gestation (mean 32.6 weeks)

American Journal of Roentgenology, 1999

Brain metastases are seen in 15–40% of patients diagnosed with cancer. We aimed to search the rel... more Brain metastases are seen in 15–40% of patients diagnosed with cancer. We aimed to search the relationship between the T2 hypointensity, diffusion weighted imaging characteristics and the presence and amount of vasogenic edema of Brain metastasis in Magnetic Resonance Imaging (MRI). 292 patients with brain metastasis were included in the study. T2 signals of metastatic lesions, accompanying diffusion restriction and perilesional vasogenic edema findings were investigated. In metastases accompanied by vasogenic edema, the largest dimension of the vasogenic edema-mass complex on T2-weighted sequences and the largest dimension of the mass in contrast-enhanced T1-weighted series were measured and the edema-mass ratio (EMR) was calculated by comparing these two values.The incidence of vasogenic edema was statistically significantly higher in T2 hypointense metastases(89.1% vs 58.8%, χ2 = 18.949, p = < 0.001) and metastases accompanied by diffusion restriction(81% vs 61.5%, χ2 = 6.971,...

Polish Journal of Radiology

Purpose: The tent shape of the tentorium cerebelli helps preserve brain anatomy by providing cere... more Purpose: The tent shape of the tentorium cerebelli helps preserve brain anatomy by providing cerebellum protection against pressure caused by the brain's gravity effect. In the absence of this support structure of the tentorium, herniation occurs in the brain. Isolated tentorial hypoplasia (TH) is extremely rare. In this study, we aimed to calculate the prevalence of this entity, which is reported to be rare in the literature. Material and methods: Magnetic resonance imaging (MRI) images of 5163 patients who applied to the training and research hospital for various reasons between 1 September 2020, and 31 August 2021, who underwent brain MRI, were reviewed retrospectively. Results: The prevalence of TH among patients screened during a period of one year was calculated as 2.22%. Of these, 76.59% were female (n = 72) and 23.41% were male (n = 22). The rates of presentation of complaints among TH patients were 60.63% headache, 17.02% vertigo, 4.25% seizures, 3.19% tremor, 3.19% syncope, 7.44% forgetfulness, and 2.12% visual impairment. Five patients (11.76%) were admitted for metastasis investigation due to their primary malignancy; they did not have any complaints. Localization of TH: 18.08% (n = 17) were observed on the right side, 28.72% (n = 27) on the left side, and 53.19% (n = 50) on the bilateral tentorium leaf. Conclusions: Being aware of TH during brain MRI evaluation will help prevent possible misdiagnoses. We hope that this study with a large number of patients will increase awareness about TH, because there are no studies other than cadaver studies and a few case reports.