Person: GÜLTEKİN, MEHMET ALİ
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Publication Metadata only 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, ÖMERPurpose: 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.Publication Metadata only 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, ŞEYMAAim: 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.Publication Metadata only 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, ALPAYPublication Metadata only 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 ALİIt 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.Publication Metadata only 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, ALPAYPublication Metadata only 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 BAŞAKBackground: 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.Publication Metadata only Ovarian Granulosa Cell Tumor: A Clinicoradiologic Series with Litera- ture Review(2021-01-01T00:00:00Z) Kilinc, Yagmur Basak; Sari, Lutfullah; Toprak, Huseyin; Karabulut, Ummuhan Ebru; ŞAHİN, NURHAN; GÜLTEKİN, MEHMET ALİ; ŞAHİN, NURHANBackground: Ovarian granulosa cell tumors that originate from the sex cord-stromal cells represent 2% to 5% of all ovarian cancers. These tumors constitute two subgroups according to their clinical and histopathological features: juvenile granulosa cell tumors (JGCT) and adult granulosa cell tumors (AGCT). Granulosa cell tumor (GCT) is considered to be a low-grade malignancy with a favorable prognosis. Methods: This case series includes four patients who were admitted to our university hospital and had an MRI examination within 5 years. Results: The histopathological subtype of granulosa tumor was the adult type in 3 patients and juvenile type in 1 patient. Even though it is extremely rare, bone metastases were present in one of our patients. Liver metastases were also detected in one patient. The MRI examination of tumors revealed a heterogeneous solid mass that contained cystic components in 3 patients. In one of our patients, the tumor had a multiseptated cystic feature, and all of the tumors were ovoid or round with smooth margins. T1 signal hyperintensity, not suppressed on fat saturation sequences, was observed in 3 patients, which represents its hemorrhagic content. Conclusion: Even though granulosa cell tumor shows a wide spectrum in terms of tumor appearance, some common findings have been shown and especially a hemorrhagic content could be a clue for us. The tumor is known to have a good prognosis, but it may have an unpredictable clinical course, so close follow-up is greatly important.Publication Metadata only Relationship with programmed cell death ligand 1 (PD-L1) and DTI features in brain metastases of non-small cell lung cancer; Preliminary study.(2021-02-17T00:00:00Z) Yurtsever, İsmail; Yilmaz, Temel Fatih; Turk, Hacı Mehmet; Gultekin, Mehmet Ali; Besiroglu, Mehmet; Cesme, DİLEK HACER; Shbair, Abdallah T M; Alkan, ALPAY; YILMAZ, TEMEL FATİH; YURTSEVER, İSMAİL; TÜRK, HACI MEHMET; GÜLTEKİN, MEHMET ALİ; ÇEŞME, DİLEK HACER; ALKAN, ALPAYPublication Metadata only Brain Diffusion Tensor Imaging Findings in Hashimoto-s Thyroiditis.(2020-11-06T00:00:00Z) Gultekin, MA; Yurtsever, I; Cesme, DİLEK HACER; Karaman, O; Yilmaz, TF; Alkan, ALPAY; GÜLTEKİN, MEHMET ALİ; ÇEŞME, DİLEK HACER; KARAMAN, ÖZCAN; YURTSEVER, İSMAİL; YILMAZ, TEMEL FATİH; ALKAN, ALPAYPublication Metadata only Relationship between KRAS mutation and diffusion tensor imaging features in brain metastases due to colorectal cancer; preliminary study(2021-05-01T00:00:00Z) Yılmaz, Temel Fatih; GÜLTEKİN, MEHMET ALİ; TÜRK, HACI MEHMET; YILMAZ, TEMEL FATİH; TOPÇU, ATAKAN; ÇOBAN, GANİMEIdentifying Kirsten rat sarcoma (KRAS) mutation status is important for metastatic colorectal cancer treatment. Validating KRAS mutation profile on neuroimaging without histopathologic analysis would be beneficial. We aimed to differentiate Kirsten rat sarcoma (KRAS) gene mutation profile according to diffusion tensor imaging (DTI) metrics obtained from colorectal brain metastases (CRBM). Total of 8 patients with 17 CRBM included with known KRAS gene mutation status. All patients were categorized into two groups according to the KRAS mutation status as positive (+) (n: 5, 11 lesions) and negative (-) (wild type) (n: 3, 6 lesions). DTI values of the BMs were evaluated by consensus of two radiologists. Apparent diffusion coefficient (ADC), normalized apparent diffusion coefficient (nADC) and fractional anisotropy (FA) values of the two groups were compared. For comparison the Mann-Whitney U test was used. KRAS mutation (+) group showed significantly lower ADC and nADC values on CRBM rather than the wild-type. Comparison of the FA values of the two groups did not reveal any statistical significance. In conclusion, decreased ADC and nADC values of CRBM are correlated with presence of KRAS mutation. Lower ADC and nADC values obtained from CRBM can be utilized to insight KRAS mutation profile.