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ALKAN, ALPAY

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Author: ARALAŞMAK, AYŞE × Author: Alkan, ALPAY × Rights: info:eu-repo/semantics/openAccess ×

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Now showing 1 - 7 of 7
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    PublicationOpen Access
    The Effect of Obesity on Brain Diffusion Alteration in Patients with Obstructive Sleep Apnea
    (2014-01-01) KILICARSLAN, Rukiye; Alkan, ALPAY; Sharifov, RASUL; Akkoyunlu, MUHAMMED EMİN; Aralasmak, AYŞE; KOCER, Abdulkadir; KART, Levent; ALKAN, ALPAY; SHARIFOV, RASUL; AKKOYUNLU, MUHAMMED EMİN; ARALAŞMAK, AYŞE
    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.
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    Comparison of TOF MRA, Contrast-Enhanced MRA and Subtracted CTA from CTP in Residue Evaluation of Treated Intracranial Aneurysms
    (2018-01-01) Dundar, TOLGA TURAN; Kits, Serkan; Ozdemir, HÜSEYİN; Seyithanoglu, MEHMET HAKAN; Uysal, Omer; Toprak, HÜSEYİN; Ozek, ERDİNÇ; Alkan, ALPAY; DÜNDAR, TOLGA TURAN; ARALAŞMAK, AYŞE; ÖZDEMİR, HÜSEYIN; SEYİTHANOĞLU, MEHMET HAKAN; UYSAL, ÖMER; TOPRAK, HÜSEYİN; KİTİŞ, SERKAN; ÖZEK, ERDİNÇ; ALKAN, ALPAY
    AIM: To compare effectiveness of contrast-enhanced magnetic resonance angiography (CE-MRA), 3D-Time-of-flight magnetic resonance angiography (3D-TOF-MRA) and subtracted computed tomography angiography from computed tomography perfusion (sub-CTA) in residue evaluation of intracranial aneurysms treated either with coiling or clipping.
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    PublicationOpen Access
    Brain Diffusion Changes in Obstructive Sleep Apnoea Syndrome
    (2013-01-01) Akkoyunlu, MUHAMMED EMİN; Kart, Levent; KILICARSLAN, Rukiye; Bayram, MEHMET; Aralasmak, AYŞE; Sharifov, RASUL; Alkan, ALPAY; AKKOYUNLU, MUHAMMED EMİN; BAYRAM, MEHMET; ARALAŞMAK, AYŞE; SHARIFOV, RASUL; ALKAN, ALPAY
    Background: Obstructive sleep apnoea syndrome (OSAS) is a disorder characterized by repeated apnoeic episodes during sleep. Neurocognitive changes secondary to OSAS are likely to occur due to hypoxia in certain brain locations. Advances in magnetic resonance imaging technology, such as diffusion-weighted imaging (DWI), enable non-invasive and accurate identification of OSAS-induced changes. Objective: We aimed to use DWI to investigate changes in the brain secondary to hypoxia in OSAS. Methods: Eighty-eight patients underwent polysomnography and were classified as non-OSAS, mild-moderate OSAS and severe OSAS sufferers. DWI was used to evaluate 14 areas of the brain, and apparent diffusion coefficients (ADCs) were calculated. We investigated whether there were differences in the ADC values in specific areas of the brain between the non-OSAS and OSAS patients. Results: We measured the ADC values of the 68 newly diagnosed OSAS patients (21 mild, 15 moderate and 32 severe) and of 20 healthy controls. There were significant increases in the ADC values in the hippocampus, amygdala and putamen in OSAS patients. Compared to thenon-OSAS subjects, the ADC values of the putamen in severe OSAS patients, those of the hippocampus in moderate or severe OSAS patients and those of the amygdala in moderate OSAS patients were significantly increased. A negative correlation between the lowest oxygen saturation during sleep and the ADC values of the hippocampus and amygdala was found. Conclusions: Increased ADC levels in the hippocampus, amygdala and putamen in OSAS patients indicate hypoxia and likely cause vasogenic oedema in specific regions of the brain.
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    PublicationOpen Access
    Severe Posterior Reversible Encephalopathy in Pheochromocytoma: Importance of Susceptibility-Weighted MRI
    (2013-09-01) SERTER, Asli; Alkan, ALPAY; Aralasmak, AYŞE; KOCAKOC, Ercan; ALKAN, ALPAY; ARALAŞMAK, AYŞE
    Pheochromocytoma is a rare cause of hypertension in children. Hypertension is one of the common reasons of posterior reversible encephalopathy. Intracerebral hemorrhage is a serious and unexpected complication of hypertensive encephalopathy due to pheochromocytoma, and very rarely seen in the childhood. Intracerebral hemorrhages should be searched if there are hypertensive reversible signal changes on the brain. Susceptibility weighted imaging (SWI) is a more sensitive method than conventional MRI when demonstrating cerebral microhemorrhagic foci. This is the first report of SWI findings on intracerebral hemorrhages in basal ganglia, brain stem and periventricular white matter due to hypertensive encephalopathy in a child with pheochromocytoma.
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    PublicationOpen Access
    Craniocervical Dissections: Radiologic Findings, Pitfalls, Mimicking Diseases: A Pictorial Review
    (2018-01-01) MEHDI, Elnur; Aralasmak, AYŞE; Toprak, HÜSEYİN; Yildiz, Seyma; Kurtcan, SERPİL; Kolukisa, MEHMET; Asil, TALİP; Alkan, ALPAY; ARALAŞMAK, AYŞE; TOPRAK, HÜSEYİN; YILDIZ, ŞEYMA; KURTCAN, SERPİL; KOLUKISA, MEHMET; ASİL, TALIP; ALKAN, ALPAY
    Background: Craniocervical Dissections (CCD) are a crucial emergency state causing 20% of strokes in patients under the age of 45. Although DSA (digital substraction angiography) is regarded as the gold standard, noninvasive methods of CT, CTA and MRI, MRA are widely used for diagnosis. Aim: Our aim is to illustrate noninvasive imaging findings in CCD. Conclusion: Emphasizing on diagnostic pitfalls, limitations and mimicking diseases.
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    PublicationOpen Access
    Microstructural brain changes in acromegaly: quantitative analysis by diffusion tensor imaging
    (2014-06-01) KILICARSLAN, R.; ILHAN, M. M.; Alkan, ALPAY; ARALASMAK, AYŞE; AKKOYUNLU, M. E.; KART, L.; TASAN, ERTUĞRUL; İLHAN, MAHMUT MUZAFFER; ALKAN, ALPAY; ARALAŞMAK, AYŞE; TAŞAN, ERTUĞRUL
    Objective: We examined brain diffusion changes of patients with acromegaly. We searched whether there are differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values between remission and nonremission patients with acromegaly and investigated any effect of time of hormone exposure on diffusion metrics. Methods: The values of FA and ADC were calculated in a total of 35 patients with acromegaly and 28 control subjects. Patients were subdivided into remission and non-remission groups. We looked at brain FA and ADC differences among the groups and looked for any relation between the diffusion changes and time of hormone exposure among the patients with acromegaly. Results: We found decreased FA and increased ADC values in some of the growth hormone responsive areas. There were no significant brain diffusion changes between remission and non-remission groups. The most affected areas were the hypothalamus, parietal white matter and pre-motor cortex in patients with acromegaly. In terms of hormone exposure time among the patients with acromegaly, there was no effect of disease duration on brain microstructural changes. Conclusion: All patients with acromegaly showed increased brain diffusion with no relation to disease duration and treatment status. We suggested that in patients with acromegaly, brain damage had already occurred in the subclinical period before symptom onset. Advances in knowledge: This study contributes to the understanding of the mechanisms in acromegaly.
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    PublicationOpen Access
    Involvement of the corpus callosum splenium in a case with SSPE: magnetic resonance spectroscopy findings
    (2013-04-01) Alkan, ALPAY; Sharifov, RASUL; GULER, Serhat; Aralasmak, AYŞE; KOCER, Abdulkadir; YUKSEL, Adnan; ALKAN, ALPAY; SHARIFOV, RASUL; ARALAŞMAK, AYŞE