Profile Picture
Google ScholarScopusORCIDPublons
Organizational Units
Organizational Unit
Job Title
First Name
Last Name
Email Address
Birth Date

Search Results

Now showing 1 - 10 of 133
  • PublicationOpen Access
    MRI and MR Spectroscopy Features of Heat Stroke: A Case Report
    (2018-07-01) Yilmaz, TEMEL FATİH; Aralasmak, AYŞE; Toprak, HÜSEYİN; GULER, Serhat; Tüzün, Umit; Alkan, ALPAY; YILMAZ, TEMEL FATİH; ARALAŞMAK, AYŞE; TOPRAK, HÜSEYİN; ALKAN, ALPAY
    Heat stroke is the outcome of over heat stress that results in multiorgan dysfunction with a tendency for central nervous system damage. Brain is very sensitive to hyperthermia, especially the cerebellum that has selective vulnerability to heat stroke. There is complex interaction between heat cytotoxicity, coagulation disorder, cytotoxine - mediated systemic inflammatory response causing multiorgan failure, metabolic derangement, and circulatory insufficiency. We reviewed the literature and discussed brain MRI and MR spectroscopy findings of heat stroke, detailed the pathophysiology underlying brain involvement and proposed excitotoxic injury as an alternative mechanism of brain damage in heat stroke.
  • PublicationUnknown
    Effects of contrast material on the metabolite ratios in single-voxel MR Spectroscopy of intraaxial brain tumors
    (2012-08-01) Alkan, ALPAY; Burulday, Veysel; Oztanir, Namik; Dogan, Metin; ERBAY, MEHMET FATİH; Kocak, Ayhan; Aralasmak, AYŞE; ALKAN, ALPAY; ÖZTANIR, MUSTAFA NAMIK; ARALAŞMAK, AYŞE
    Aim: The purpose of our study was to determine whether the administration of contrast material affects the results of MR Spectroscopy (MRS) in different intraaxial brain tumors.
  • PublicationUnknown
    The Effect of Obesity on Brain Diffusion Alteration in Patients with Obstructive Sleep Apnea
    Purpose: We investigated diffusion alterations in specific regions of the brain in morbid obese, obese, and nonobese OSA patients and searched whether there is a correlation between BMI and ADC values. Materials and methods: DWIs of 65 patients with OSA were evaluated. The patients were classified according to BMI as morbid obese (n = 16), obese (n = 27), and nonobese (control, n = 22) groups. ADC measurements were performed from 24 different regions of the brain in each patient. The relationship of BMI with ADC values was searched. Results: The ADC values in hypothalamus, insular cortex, parietal cortex, caudate nucleus, frontal white matter, and posterior limb of internal capsule were all increased in obese patients (n = 43) compared to control group. The ADC values of midbrain, hypothalamus, orbitofrontal cortex, and parietal cortex were significantly increased in morbid obese compared to obese patients. In obese patients, the degree of BMI was positively correlated with ADC values of orbitofrontal cortex, parietal cortex, and hypothalamus. Conclusion: We observed increasing brain vasogenic edema with increasing BMI, suggesting that the main reason of brain diffusion alteration in patients with OSA could be obesity related.
  • PublicationUnknown
    Cerebral venous Sinus thrombosis after spinal anesthesia: Case report Spinal Anestezi Sonrasi{dotless} Gelişen Serebral Ven Sinüs Trombozu: Olgu Sunumu
    (2011-12-01T00:00:00Z) YÜCEL, NESLİHAN; Akgün, Feride Sinem; Tekin, Yusuf Kenan; ALTINAYAR, SİBEL; Alkan, ALPAY; ALKAN, ALPAY
  • PublicationUnknown
    Neuroimaging depression and anxiety in essential tremor: A diffusion tensor imaging study.
    (2019-06-27) Sengul, Y; Otcu, H; Ustun, I; Sengul, HS; Cersonsky, T; Alkan, ALPAY; Louis, ED; ALKAN, ALPAY
  • PublicationUnknown
    Hydrocephalus due to Galen vein aneurysm associated with arteriovenous malformation in an adult patient
  • PublicationUnknown
    Sleep Disturbances in Essential Tremor: A pilot investigation of the related brain microstructural changes using diffusion tensor imaging
    (2019-12-01T00:00:00Z) Alkan, Alpay; ALKAN, ALPAY
    Sengul Y., Otcu H., Ustun I., Sengul H., Alkan A., -Sleep Disturbances in Essential Tremor: A pilot investigation of the related brain microstructural changes using diffusion tensor imaging-, MOVEMENT DISORDERS, vol.34, pp.S829, 2019
  • PublicationUnknown
    Diagnostic performance of apparent diffusion coefficient values for the differentiation of intrahepatic cholangiocarcinoma from gastrointestinal adenocarcinoma liver metastases
    (2021-12-22T00:00:00Z) Yilmaz, TEMEL FATİH; Gultekin, Mehmet Ali; Turk, Hacı Mehmet; Cesme, Dilek Hacer; Besiroglu, Mehmet; Simsek, Melih; Toprak, Huseyin; Alkan, ALPAY; YILMAZ, TEMEL FATİH; TÜRK, HACI MEHMET; ÇEŞME, DİLEK HACER; ŞİMŞEK, MELİH; ALKAN, ALPAY; TOPRAK, HÜSEYİN
    Background: We aimed to investigate whether there is a difference between intrahepatic cholangiocarcinoma (IHCC) and liver metastases of gastrointestinal system (GIS) adenocarcinoma in terms of apparent diffusion coefficient (ADC) values. Patients and methods: From January 2018 to January 2020, we retrospectively examined 64 consecutive patients with liver metastases due to gastrointestinal system adenocarcinomas and 13 consecutive IHCC in our hospital's medical records. After exclusions, fifty-three patients with 53 liver metastases and 10 IHCC were included in our study. We divided the patients into two groups as IHCC and liver metastases of GIS adenocarcinoma. For mean apparent diffusion coefficient (ADCmean) values, the region of interests (ROI) was placed in solid portions of the lesions. ADCmean values of groups were compared. Results: The mean age of IHCC group was 62.50 ± 13.49 and mean age of metastases group was 61.15 ± 9.18. ADCmean values were significantly higher in the IHCC group compared to the metastatic group (p < 0.001). ROC curves method showed high diagnostic accuracy (AUC = 0.879) with cut-off value of < 1178 x 10-6 mm2/s for ADCmean (Sensitivity = 90.57, Specificity = 70.0, positive predictive value [PPV] = 94.1, negative predictive value [NPV] = 58.3) in differentiating adenocarcinoma metastases from IHCC. Conclusions: The present study results suggest that ADC values have a potential role for differentiation between IHCC and GIS adenocarcinoma liver metastases which may be valuable for patient management.
  • PublicationUnknown
    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.
  • PublicationUnknown
    Detecting the Shape Differences of the Corpus Callosum in Behçet-s Disease by Statistical Shape Analysis
    (2011-05-01T00:00:00Z) ÇOLAK, CEMİL; Ercan, Ilker; Dogan, Metin; Ozdemir, Senem Turan; ŞENER, SERPİL; Alkan, ALPAY; ALKAN, ALPAY