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GÜLTEKİN, MEHMET ALİ

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MEHMET ALİ
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    Relationship between KRAS mutation and diffusion weighted imaging in colorectal liver metastases; Preliminary study.
    (2020-02-25T00:00:00Z) Türk, HM; Gültekin, MEHMET ALİ; Uysal, Ö; Beşiroğlu, M; Yilmaz, TF; Yurtsever, I; GÜLTEKİN, MEHMET ALİ; TÜRK, HACI MEHMET; TOPRAK, HÜSEYİN; YURTSEVER, İSMAİL; YILMAZ, TEMEL FATİH; SHARIFOV, RASUL; UYSAL, ÖMER
    Purpose: We aimed to investigate whether there are any differences in apparent diffusion coefficient (ADC) values obtained from colorectal liver metastases (CRLM) according to Kirsten rat sarcoma (KRAS) gene mutation status.
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    Papillary Lesions of the Breast: Addition of DWI and TIRM Sequences to Routine Breast MRI Could Help in Differentiation Benign from Malignant
    (2022-01-01T00:00:00Z) GÜLTEKİN, MEHMET ALİ; ÇELİK YABUL, FATMA; OTÇU TEMUR, HAFİZE; SARI, LÜTFULLAH; YILMAZ, TEMEL FATİH; TOPRAK, HÜSEYİN; YILDIZ, ŞEYMA; GÜLTEKİN, MEHMET ALİ; ÇELİK YABUL, FATMA; OTÇU TEMUR, HAFİZE; SARI, LÜTFULLAH; YILMAZ, TEMEL FATİH; TOPRAK, HÜSEYİN; YILDIZ, ŞEYMA
    Aim: We aimed to investigate the magnetic resonance imaging (MRI) features of benign, atypical, or malignant papillary breast lesions and to assess the additional value of diffusion-weighted imaging (DWI) and turbo inversion recovery magnitude (TIRM) sequences to routine breast MRI. Background: Differentiation between benign and malignant papillary breast lesions is essential for patient management. However, morphologic features and enhancement patterns of malignant papillary lesions may overlap with those of benign papilloma. Methods: Seventy-two papillary breast lesions (50 benign, 22 atypical or malignant) were included in the current study, retrospectively. We divided the patients into two groups: benign papillary breast lesions and atypical or malignant papillary breast lesions. Morphologic, dynamic, turbo inversion recovery magnitude (TIRM) values and diffusion features of the papillary lesions were compared between two groups. Results: Benign papillary lesions were smaller in size (p=0.006 and p=0.005, for radiologists 1 and 2 respectively), closer to the areola (p=0.045 and 0.049 for radiologist 1 and 2 respectively), and had higher ADC values (p=0.001 for two radiologists) than the atypical or malignant group. ROC curves showed diagnostic accuracy for ADC (AUC=0.770 and 0.762, p & lt; 0.0001 for two radiologists), and showed a cut-off value of <= 957 x 10-6 mm(2/s) (radiologist 1) and <= 910 x 10-6 mm(2/s) (radiologist 2). Conclusion: MRI is a useful method for differentiation between benign and malignant papillary breast lesions. Centrally located, lesser in size, and higher ADC values should be considered benign, whereas peripherally located, larger in size, and lower ADC values should be considered malignant.
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    PublicationOpen Access
    Comparison of MRI Features of Invasive Pleomorphic and Classical Lobular Carcinoma: Differentiation Is Possible?
    (2022-01-01T00:00:00Z) YILMAZ, TEMEL FATİH; OTÇU TEMUR, HAFİZE; SARI, LÜTFULLAH; GÜCİN, ZÜHAL; GÜLTEKİN, MEHMET ALİ; ÇELİK YABUL, FATMA; TOPRAK, HÜSEYİN; YILDIZ, ŞEYMA; YILMAZ, TEMEL FATİH; OTÇU TEMUR, HAFİZE; SARI, LÜTFULLAH; GÜCİN, ZÜHAL; GÜLTEKİN, MEHMET ALİ; ÇELİK YABUL, FATMA; TOPRAK, HÜSEYİN; YILDIZ, ŞEYMA
    To evaluate breast MRI and DWI and demographic features of pleomorphic invasive lobular carcinoma (pILC) and classic invasive lobular carcinoma (cILC). Invasive lobular (ILC) is the second most common breast malignancy after invasive ductal carcinoma (IDC) and constitutes the 8-14% of all invasive breast cancers. ILC morphologically can be classified into the classic, alveolar, solid, tubulolobular, and pleomorphic subtypes according to WHO. This study was performed retrospectively. The MRI and demographic features of 18 patients with 23 pILC were compared with those 22 consecutive patients with 27 cILC. There was no significant difference in demographic features of patients, MR appearance, kinetics, and ADC values between two groups. pILC, an aggressive subtype of ILC, cannot be differentiated from cILC with breast MRI.
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    PublicationOpen Access
    Diffusion Tensor Imaging Can Discriminate the Primary Cell Type of Intracranial Metastases for Patients with Lung Cancer.
    (2021-03-04T00:00:00Z) Bilgin, Sabriye Sennur; Gultekin, Mehmet Ali; Yurtsever, Ismail; Yilmaz, Temel Fatih; Cesme, Dilek Hacer; Bilgin, Melike; Topcu, Atakan; Besiroglu, Mehmet; Turk, Haci Mehmet; Alkan, ALPAY; Bilgin, Mehmet; GÜLTEKİN, MEHMET ALİ; YURTSEVER, İSMAİL; YILMAZ, TEMEL FATİH; ÇEŞME, DİLEK HACER; TÜRK, HACI MEHMET; ALKAN, ALPAY; BİLGİN, MEHMET
    Purpose: Histopathological differentiation of primary lung cancer is clinically important. We aimed to investigate whether diffusion tensor imaging (DTI) parameters of metastatic brain lesions could predict the histopathological types of the primary lung cancer. Methods: In total, 53 patients with 98 solid metastatic brain lesions of lung cancer were included. Lung tumors were subgrouped as non-small cell carcinoma (NSCLC) (n = 34) and small cell carcinoma (SCLC) (n = 19). Apparent diffusion coefficient (ADC) and Fractional anisotropy (FA) values were calculated from solid enhanced part of the brain metastases. The association between FA and ADC values and histopathological subtype of the primary tumor was investigated. Results: The mean ADC and FA values obtained from the solid part of the brain metastases of SCLC were significantly lower than the NSCLC metastases (P < 0.001 and P = 0.003, respectively). ROC curve analysis showed diagnostic performance for mean ADC values (AUC=0.889, P = < 0.001) and FA values (AUC = 0.677, P = 0.002). Cut-off value of > 0.909 × 10-3 mm2/s for mean ADC (Sensitivity = 80.3, Specificity = 83.8, PPV = 89.1, NPV = 72.1) and > 0.139 for FA values (Sensitivity = 80.3, Specificity = 54.1, PPV = 74.2, NPV= 62.5) revealed in differentiating NSCLC from NSCLC. Conclusion: DTI parameters of brain metastasis can discriminate SCLC and NSCLC. ADC and FA values of metastatic brain lesions due to the lung cancer may be an important tool to differentiate histopathological subgroups. DTI may guide clinicians for the management of intracranial metastatic lesions of lung cancer.
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    Meme kanseri beyin metastazlarının moleküler subgruplarının difüzyon tensor görüntüleme ile değerlendirilmesi
    (2019-04-27T00:00:00Z) Yurtsever, İsmail; Gültekin, Mehmet Ali; Yılmaz, Temel Fatih; Türk, Hacı Mehmet; Alkan, Alpay; YURTSEVER, İSMAİL; GÜLTEKİN, MEHMET ALİ; YILMAZ, TEMEL FATİH; TÜRK, HACI MEHMET; ALKAN, ALPAY
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    PublicationOpen Access
    COVİD-19 infection in a membranous nephropathy patient treated with rituximab.
    (2020-09-04T00:00:00Z) Elcioglu, Omer Celal; Artan, Ayse Serra; Mirioglu, Safak; Gursu, Meltem; Durdu, Bulent; Koc, Meliha Meric; Okyaltirik, Fatmanur; Gultekin, Mehmet Ali; Kazancioglu, Rümeyza; ELÇİOĞLU, ÖMER CELAL; MİRİOĞLU, ŞAFAK; GÜRSU, MELTEM; DURDU, BÜLENT; MERİÇ KOÇ, MELİHA; OKYALTIRIK, FATMANUR; GÜLTEKİN, MEHMET ALİ; KAZANCIOĞLU, RÜMEYZA
    While COVID-19 pandemic continues to afect our country and most countries in the world, we have to make some changes both in our social life and our approach to healthcare. We have to struggle with the pandemic on one hand and also try to follow up and treat our patients with chronic diseases in the most appropriate way. In this period, one of our group of patients who are challenging us for follow-up and treatment are those who should start or continue to use immunosuppressive therapy. In order to contribute to the accumulation of knowledge in this area, we wanted to report a patient who was followed up with the diagnosis of COVID-19 and had been administered rituximab very recently due to a nephrotic syndrome caused by membranous nephropathy.
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    PublicationOpen Access
    Diffusion Tensor Imaging Features of the Auditory Pathways in Patients With Vestibular Schwannoma After Gamma Knife Radiosurgery
    (2021-03-01T00:00:00Z) ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; Alkan, Gokberk; KAYA, AHMET; MAYADAĞLI, Alpaslan; Akdur, Kerime; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZ; ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; KAYA, AHMET; MAYADAĞLI, ALPASLAN; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZ
    Objective In this study, we aimed to investigate whether there is any change in diffusion tensor imaging (DTI) parameters in ipsilateral and contralateral auditory pathways after Gamma Knife radiosurgery (GKR) in patients with vestibular schwannoma (VS) and the relationship between radiosurgery variables. Methods Sixty-six patients were evaluated with MRI and DTI before and after GKR. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured from the bilateral lateral lemniscus (LL), inferior colliculus (IC), medial geniculate body (MGB), and Heschl's gyrus (HG). Results There was no significant difference in ADC and FA values obtained from bilateral LL, IC, and MGB before and after radiosurgery. However, there was a significant difference between pretreatment and post-radiosurgery contralateral HG ADC values. The ADC values obtained from the contralateral HG and IC positively correlated with the duration after radiosurgery. As the duration after radiosurgery increases, the difference between the ADC values obtained from ipsilateral and contralateral HG also increases. Conclusion The high ADC values in the contralateral HG after radiosurgery may indicate microstructural alterations such as demyelination and axonal loss. Radiation exposure doses to the brainstem and cochlea are the most important factors that can cause microstructural damage to the auditory pathways. When planning radiosurgery, extreme care should be taken to prevent the harmful effects of radiation on the auditory pathways.
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    Efficacy of Shear Wave Elastography in the Differentiation of Acute and Subacute Deep Venous Thrombosis
    (2021-06-01T00:00:00Z) Durmaz, Fatma; GÜLTEKİN, MEHMET ALİ; GÜLTEKİN, MEHMET ALİ
    It is important to know the age of clot formation to determine an appropriate treatment for deep vein thrombosis (DVT). The present study aims to differentiate between acute and subacute DVT using the shear wave elastography (SWE) technique. Patients with complaints no longer than 4 weeks and who were found to have early-stage (acute-subacute) thrombus on ultrasound (US) between January 2020 and May 2020 were included in the study. All of the patients underwent SWE using a Philips Healthcare EPIQ 5 Ultrasound System Inc. device with a high-resolution linear US probe (eL18-4, 22-2 MHz). Included in the study were 50 patients, including 23 with acute DVT and 27 with subacute DVT. Of the patients, 22 were women and 28 were men, and the mean age was 46.32 +/- 11.33 years (range: 24-74 years). The mean SWE value was 2.63 +/- 0.16 (2.39-2.96) in patients with acute DVT and 3.34 +/- 0.31 (2.65-3.88) in patients with subacute DVT. The findings were statistically significant in the comparison of the 2 groups using an independent samples t test (P < 0.001). In the receiver operating characteristic analysis, the area under the curve was found to be 97.6%. When the cutoff value was taken as 2.85 according to the area under the curve, sensitivity was found to be 96.3%, and specificity was 91.3%. Thrombus stage plays a critical role in treatment decisions in DVT in the lower extremities. The present study reveals that the shear wave US elastography technique can be used to discriminate between acute and subacute DVT.
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    The Utility and Efficiency of Diffusion Tensor Imaging Values to Determine Epidermal Growth Factor Receptor Gene Mutation Status in Brain Metastasis from Lung Adenocarcinoma; A Preliminary Study
    (2021-02-01T00:00:00Z) Gültekin, Mehmet Ali; Alkan, Alpay; Yılmaz, Temel Fatih; Yurtsever, İsmail; Atasoy, Bahar; Aliyev, Altay; GÜLTEKİN, MEHMET ALİ; TÜRK, HACI MEHMET; YURTSEVER, İSMAİL; YILMAZ, TEMEL FATİH; ALKAN, ALPAY
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    A Case of Intratumoral and Hepatic Portal Venous Gas in Patient with Gastric Cancer Liver Metastases
    (2022-01-01T00:00:00Z) KARABULUT, ÜMMÜHAN EBRU; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; KILINÇ, YAĞMUR BAŞAK; KARABULUT, ÜMMÜHAN EBRU; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; KILINÇ, YAĞMUR BAŞAK
    Background: Hepatic portal venous gas [HPVG] is not a common finding in daily practice. It is usually associated with mesenteric ischemia and bowel necrosis in adults. Combination of intratumoral gas in metastatic liver lesions with HPVG is quite rare and thought to be associated with chemotherapy-induced necrosis and infection of the necrotized metastasis. Objective: Here we present a case of gastric adenocarcinoma with portal venous and intratumoral gas in metastatic liver lesions due to the infected necrosis. Case Presentation: The patient was presented to the emergency room with severe abdominal pain and septic condition after the second round of chemotherapy. Hepatic portal venous and intratumoral gas in metastatic liver lesions due to the infected necrosis of liver metastasis was detected in computed tomography images. There were no findings of mesenteric ischemia both clinically and radiologically. Massive intratumoral infected necrosis in metastatic liver lesions and fistulization to the right portal vein branches were detected on abdominopelvic CT. Secondary infection of the necrotic metastases and fistulization to portal vein branches was believed to cause the air in metastatic liver masses and portal venous gas. Conclusion: Infected necrosis of metastatic liver lesions and fistulizations to the portal venous structures is extremely rare. Clinicians and radiologists should be aware of such a rare complication because early detection is crucial for patient management.