Browsing by Author "Hakyemez, Bahattin"
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Publication A rare cause of epilepsy: Ulegyria revisited in a series of 10 patients(Sage Publications, 2021-09-17) Demir, Aylin Bican; Eser, Pınar; Bekar, Ahmet; Hakyemez, Bahattin; Bora, İbrahim; BİCAN DEMİR, AYLİN; Eser, Pınar; BEKAR, AHMET; HAKYEMEZ, BAHATTİN; BORA, İBRAHİM HAKKI; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Nöroloji Anabilim Dalı/Epilepsi Merkezi.; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Beyin Cerrahi Anabilim Dalı.; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0001-6739-8605; 0000-0003-0132-9927; 0000-0002-3425-0740; ABX-9081-2022; AAI-2073-2021; V-7170-2017; AAI-2318-2021; ENI-7759-2022Introduction. Ulegyria results from perinatal hypoxic-ischemic brain injury in term infants. The specific mushroom-shaped configuration of ulegyria results from small atrophic circumvolutions at the bottom of a sulcus underlying an intact gyral apex. Clinically, ulegyria is generally associated with epilepsy. Here, we aimed to delineate the characteristics of patients with ulegyria and the epileptic seizures they experience. Material and methods. Medical records including radiology and pathology reports, video-electroencephalographic (EEG) analysis, operative notes, hospital progress and outpatient clinic notes were reviewed retrospectively in a total of 10 ulegyria patients. Results. Patients ages ranged between 24 and 58 years (mean, 32 +/- 9.8 years). Past medical history was confirmed for neonatal asphyxia in 2 (20%). Neurological examination was remarkable for spastic hemiparesis in 1 (10%) patient with perisylvian ulegyria and for visual field deficits in 2 patients (20%) with occipital ulegyria. Ulegyria most commonly involved the temporoparietal region (n = 5, 50%) followed by the perisylvian area (n = 2, 20%). Except the one with bilateral perisylvian ulegyria, all patients had unilateral lesions (n = 9, 90%). Hippocampal sclerosis accompanied ulegyria in 2 patients (20%). All patients experienced epileptic seizures. Mean age at seizure onset was 8.8 +/- 5.4 years (range, 2-20 years). Interictal scalp EEG and EEG-video monitoring records demonstrated temporoparietal and frontotemporal activities in 5 (50%) and 2 (20%) patients, respectively. The seizures were successfully controlled by antiepileptic medication in 8 patients (n = 8, 80%). The remaining 2 patients (%20) with concomitant hippocampal sclerosis required microsurgical resection of the seizure foci due to medically resistant seizures. Discussion. Ulegyria is easily recognized with its unique magnetic resonance imaging characteristics and clinical presentation in the majority of cases. It is highly associated with either medically resistant or medically controllable epileptic seizures. The treatment strategy depends on the age at onset and extends of the lesion that has a significant impact on the severity of the clinical picture.Publication A rare cause of posterior reversible leukoencephalopathy after kidney transplantation(Frontiers Media Sa, 2019-10-01) Ersoy, Alparslan; Ersoy, Yavuz; Kır, Elif; Kaya, Ahmet; Oruç, Ayşegül; Akgür, Suat; Ünsal, Oktay; Hakyemez, Bahattin; ERSOY, ALPARSLAN; Kır, Elif; KAYA, AHMET TUFAN; ORUÇ, AYŞEGÜL; AKGÜR, SUAT; Ünsal, Oktay; HAKYEMEZ, BAHATTİN; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radiyoloji Anabilim Dalı.; Bursa Uludağ Üniversitesi/Tıp Fakültesi/İç Hastalıkları Anabilim Dalı.; 0000-0001-9094-9735; 0000-0002-0342-9692; AAH-5054-2021; AAI-2318-2021; AAH-4002-2021; CZH-4661-2022; JYF-5512-2024; EJA-1761-2022; JJY-8484-2023Item Akut iskemik uyanma inmesinde mekanik trombektominin etkinliğinin retrospektif olarak değerlendirilmesi(Bursa Uludağ Üniversitesi, 2020) Bilgin, Cem; Hakyemez, Bahattin; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.Akut iskemik inmede tedavi yanıtını belirleyen en önemli parametrelerden biri semptomların süresidir. Semptom süresi uzadıkça geri dönüşümsüz nöron hasarı ve hastalarda fonksiyon kaybı meydana gelme ihtimali artar. Bu nedenle, akut inmede, mekanik trombektomi kararının verilmesinde semptom süresi oldukça önemlidir. Ancak akut iskemik uyanma inmelerinde semptom süresi bilinmemektedir. Bu durum akut iskemik uyanma inmeli olgularının yönetimini zorlaştırmaktadır. DAWN ve DEFUSE-3 çalışmalarında ileri görüntüleme yöntemleri ile seçilen hastalarda mekanik trombektominin bu hastalarda 16-24 saate kadar etkili olabileceği gösterilmiştir. Bu sayede semptomlarının başlangıç zamanı bilinmeyen olgularda mekanik trombektomi günlük pratikte daha çok uygulanmaya başlanmıştır. Biz bu tez çalışmasında akut iskemik uyanma inmesi ile başvuran ve büyük damar tıkanıklığı saptanan olgularda mekanik trombektominin etkinliğini değerlendirmeyi amaçladık. Çalışmamızda Ocak 2012- Şubat 2020 tarihleri arasında Bursa Uludağ Üniversitesi Tıp Fakültesi hastanesinde mekanik trombektomi ile tedavi edilen 22 akut iskemik uyanma inmesi olgusu retrospektif olarak değerlendirildi. Hastaların demografik verileri, komorbid hastalıkları kaydedildi. Mekanik trombektomi sonrası ilgili damarın rekanalizasyonu Thrombolysis in Cerebral Infarction (TICI) skalası ile değerlendirildi. TICI≥2b rekanalizasyon başarılı olarak kabul edildi. Çalışmamızda TICI≥2b rekanalizasyon %86,36 (19/22) oranında sağlandı. Klinik yanıt ise 90. gün modifiye Rankin Skalası (mRS) ile değerlendirildi. Hedeflenen klinik sonuç fonksiyonel bağımsızlık (mRS≤2) olarak belirlendi. Fonksiyonel bağımsızlık ise %36,36 (8/22) oranında sağlandı. İki olguda (%9,09) semptomatik intrakranial hemoraji gözlendi. Tez çalışmamızda elde ettiğimiz sonuçlar doğru hasta seçimi ile akut iskemik uyanma inme olgularında mekanik trombektomi ile yüksek fonksiyonel bağımsızlık oranlarının sağlanabileceğini göstermektedir. Benzer şekilde düşük iv komplikasyon oranları mekanik trombektominin bu hasta grubununda güvenilirliğini desteklemektedir.Item Akut lenfoblastik lösemili bir olguda gelişen nöroaspergillozun başarılı tedavisi: Cerrahi, sistemik antifungal tedavi ve intrakaviter tedavinin rolleri(Ankara Mikrobioloji Derneği, 2009-07) Özçelik, Tülay; Özkalemkaş, Fahir; Kocaeli, Hasan; Altundal, Yıldız; Ener, Beyza; Ali, Rıdvan; Özkocaman, Vildan; Hakyemez, Bahattin; Tunalı, Ahmet Semih; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/İç Hastalıkları Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Beyin Cerrahisi Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Enfeksiyon Hastalıkları ve Klinik Mikrobiyoloji Anabilim Dalı.; 0000-0002-4803-8206; 0000-0002-3425-0740; AAG-8523-2021; X-3647-2018; AAI-2318-2021; AAH-1854-2021; AAG-8495-2021; 7005424333; 6601912387; 6603500567; 15080726300; 15053025300; 7201813027; 6603145040; 6602527239; 6602797853Serebral aspergilloz nadir bir durum olup konvansiyonel antifungal tedavilere genellikle kötü yanıt vermektedir. Bu raporda, 34 yaşında akut lenfoblastik lösemi tanısı olan bir erkek hastada agresif nörocerrahi, intrakaviter amfoterisin B tedavisi ve vorikonazol kombinasyonu ile başarıyla tedavi olan bir serebral aspergilloz olgusu sunulmuş ve nöroaspergillozun tedavisinde cerrahi tedavi, intrakaviter tedavi ve antifungal tedavinin rolleri tartışılmıştır. Amfoterisin B tedavisi altında dizartri ve sağ hemiparazi gelişen olgumuzda beyin manyetik rezonans görüntülemede sol paryeto-oksipital bölgede 7 cm çapında lezyon saptanmıştır. Tanı amaçlı yapılan cerrahi girişim aşırı kanama nedeniyle başarıyla gerçekleştirilememiştir. Lezyondan alınan aspirat örneğinin kültüründe Aspergillus flavus üremesi saptanmıştır. Tedavi kaspofungin ve vorikonazol kombinasyonu olarak değiştirilmiştir. Tedavi altında enfeksiyonun ilerleme göstermesi üzerine hastaya ikinci cerrahi girişim uygulanmış ve lezyonun boyutunda gerileme tespit edilmiştir. Cerrahi tedaviyi takiben vorikonazol ve kaspofungin kombinasyon tedavisine ek olarak intrakaviter amfoterisin B uygulaması yapılmıştır (0.3 mg/gün 15 gün). Kaspofungin tedavisine 42 gün devam edildikten sonra kesilmiştir. Vorikonazol tedavisine ise 100 gün devam edilmiştir. Bu dönemde beyindeki lezyon tama yakın düzelme göstermiştir. Ancak, hastanın takibi sırasında lösemi relapsı görülmüş ve kemoterapi sırasında aplazik dönemde gelişen nötropenik tiflitis tablosu ile hasta kaybedilmiştir. Serebral aspergillozlu olgularda erken dönemde radikal cerrahi uygulanması sonucunda daha iyi sonuçlar elde edildiği belirtilmektedir. Antifungal tedavide kullanılan ilaçların vorikonazolde olduğu gibi kan-beyin bariyerini geçebilme özelliğine sahip olması gerekmektedir. Tüm lezyonlar düzelinceye ve altta yatan predispozan faktörler geri dönünceye kadar tedaviye devam edilmelidir. Sonuç olarak, serebral aspergillozlu olgularda cerrahi girişim ve vorikonazol tedavisinin güvenilir ve etkin tedavi yaklaşımları olduğu düşünülmüştür.Publication Analysis of predictive and preventive factors for access complications associated with vascular closure devices in complicated endovascular procedures(Springer, 2021-06-21) Gönen, Korcan Aysun; Hakyemez, Bahattin; Erdogan, Cuneyt; HAKYEMEZ, BAHATTİN; Erdoğan, Cüneyt; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0002-3425-0740; AAI-2318-2021; COE-1124-2022Purpose The main goal is to evaluate the effectiveness of angioseal and starclose vascular closure devices (VCDs) in high-risk patients under intensive anticoagulation who require therapeutic angiographic procedures and to discuss which factors are important in complications associated with VCDs. Materials and methods Medical records of the patients who underwent therapeutic complex interventional vascular procedures were reviewed retrospectively. One hundred sixty-six patients were divided into two groups regarding VCDs used for access-site closure after the procedure: group 1, (angioseal); group 2, (starclose). Data including patients' demographics and comorbidity information, procedural characteristics, and complications were analyzed. Results The device deployment success rate was 100%. For the procedural characteristics, there was no significant difference between the groups except access site (P = 0.016) and sheath size > 6F (P = 0.0001). No major complications had occurred in none of the patients. Minor complications including hematoma, access-site pain, and access-site infection, except prolonged hemostasis did not differ significantly between groups. The patients' demographic and periprocedural factors were not significantly correlated with the development of complications. Conclusion Contrary to published reports, our study showed that demographic and periprocedural factors may not be responsible for the vascular access-site complications associated with VCDs.Item Anatomical correlation between existence of concha bullosa and maxillary sinus volume(Springer France, 2015-11-01) Demir, Uygar Levent; Akça, Mehmet Ege; Özpar, Rıfat; Albayrak, Canan; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Kulak Burun ve Boğaz Hastalıkları Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0001-6649-9287; 0000-0002-3425-0740; CNQ-7672-2022; AAO-2435-2020; AAH-5062-2021; CBY-9868-2022; AAI-2318-2021; 56868421800; 56549051900; 56548983600; 56548472600; 6602527239The objective of this study was to assess the effects of concha bullosa variation on maxillary sinus volume and uncinate angle. The study group included 169 patients (338 sides) who underwent either surgical or medical treatment with the diagnosis of chronic rhinosinusitis. The paranasal sinus computed tomography of these patients was analyzed to measure maxillary sinus volume, uncinate angle and existence of concha bullosa. Subsequently, these variables were evaluated to find out possible relationship inbetween. Mean maxillary sinus volume and uncinate angle at right and left sides were 15.21 +/- A 0.47 and 15.51 +/- A 0.48 mm(3), 30.57 +/- A 0.62A degrees and 30.20 +/- A 0.68A degrees, respectively. There was no difference between patients with or without concha bullosa in regard to maxillary sinus volume and uncinate angle at both sides. Maxillary sinus volume and degree of uncinate angle did not show any significant correlation at both sides; r = -0.124, p = 0.107 and r = -0.136, p = 0.078. In conclusion, concha bullosa is a common anatomical variation at nasal cavity. The existence of concha bullosa does not have any association with the volume of maxillary sinus and angle of uncinate process.Item Apparent diffusion coefficient measurements in the hippocampus and amygdala of patients with temporal lobe seizures and in healthy volunteers(Academic Press Inc Elsevier Science, 2005-03) Yıldız, Harun; Hakyemez, Bahattin; Erdoğan, Cüneyt; Ercan, İlker; Parlak, Müfit; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Biyoistatistik Anabilim Dalı.; 0000-0002-3425-0740; 0000-0002-2382-290X; AAI-2318-2021Purpose: The goals of this work were to measure the apparent diffusion coefficients (ADCs) for both hippocampus and amygdala of persons diagnosed with temporal lobe epilepsy (TLE) and unilateral hippocampus pathology on magnetic resonance imaging and to evaluate the sensitivity of diffusion-weighted (DW) images in determination of the lateralization of the epileptogenic focus. Methods: Thirteen cases with a TLE diagnosis and 21 healthy subjects were evaluated. Fluid-attenuated inversion recovery and T2W images of TLE cases revealed hippocampal volume loss and signal intensity changes. DW images were obtained by spin-echo echo-planar sequences vertical to the hippocampal axis. Qualitative and quantitative ADCs for left and right hippocampus and the amygdala of the controls and the patients were determined. Hippocampal ADCs were obtained independently at the head, body, and tail levels of the hippocampus. Statistical evaluation was conducted with Kruskal–Wallis and Mann–Whitney U tests. Predictive cutoff levels of hippocampal ADCs for identifying pathologic areas were established through receiver operating characteristic (ROC) curve analysis. Result On conventional images, 5 of 13 cases had right hippocampal pathology, and 8 of 13 cases had left hippocampal pathology. There were no bilateral hippocampal changes in signal intensity and no cases with bilateral atrophy. The amygdala was normal in all patients except one case of hyperintense signals. No statistical differences were found between the hippocampal and amygdaloid ADCs of the control subjects (P > 0.05). However, there was a significant difference between the ADCs for the side with hippocampal pathology and the ADCs for the contralateral side, and the control group (P < 0.001). No statistical difference was detected for the amygdala (P > 0.05). Hippocampal and amygdaloid ADCs of the contralateral lesion and the values of the control group were not statistically significantly different (P > 0.05). ROC curve analysis indicated 136 as the best cutoff level for hippocampal pathology. Conclusion DW trace images are insensitive in lateralization of hippocampal pathology; however, lateralization can be achieved through ADC measurements of the hippocampus. An increase in ADC on the affected side should be considered as indicating pathology. On the other hand, amygdaloid ADC values remain inaccurate.Item Assesment of perfusion in glial tumors with arterial spin labeling; comparison with dynamic susceptibility contrast method(Elsevier Ireland, 2014-10) Öztürk, Esin Işık; Gümüş, Caner; İnecikli, Mehmet Fatih; Cebeci, Hakan; Aydın, Ömer; Bekar, Ahmet; Kocaeli, Hasan; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Beyin ve Sinir Cerrahisi Anabilim Dalı.; 0000-0002-3425-0740; AAI-2318-2021; 56033553000; 55933661900; 6603677218; 6603500567; 6602527239Purpose: Arterial spin labeling perfusion imaging (ASL-PI) is a non-invasive perfusion imaging method that can be used for evaluation and quantification of cerebral blood flow (CBF). Aim of our study was to evaluating the efficiency of ASL in histopathological grade estimation of glial tumors and comparing findings with dynamic susceptibility contrast perfusion imaging (DSC-PI) method. Methods: This study involved 33 patients (20 high-grade and 13 low-grade gliomas). Multiphase multislice pulsed ASL MRI sequence and a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence were acquired for all the patients. For each patient, perfusion relative signal intensity (rSI), CBF and relative CBF (rCBF) on ASL-PI and relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values on DSC-PI were determined. The relative signal intensity of each tumor was determined as the maximal SI within the tumor divided by SI within symetric region in the contralateral hemisphere on ASL-PI. rCBV and rCBF were calculated by deconvolution of an arterial input function. Relative values of the lesions were obtained by dividing the values to the normal appearing symmetric region on the contralateral hemisphere. For statistical analysis, Mann-Whitney ranksum test was carried out. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBF-ASL, rSI-ASL, rCBV and rCBF ratios and grade of gliomas. Their cut-off values permitting best discrimination was calculated. The correlation between rCBV, rCBF, rSI-ASL and rCBF-ASL and glioma grade was assessed using Spearman correlation analysis. Results: There was a statistically significant difference between low and high-grade tumors for all parameters. Correlation analyses revealed significant positive correlations between rCBV and rCBF-ASL (r=0.81, p<0.001). However correlation between rCBF and rCBF-ASL was weaker (r=0.64, p<0.001). Conclusion: Arterial spin labeling is an employable imaging technique for evaluating tumor perfusion non-invasively and may be useful in differentiating high and low grade gliomas.Publication Association of brain volume and cognition in the chronic and episodic migraine patients(Sage Publications, 2013-06-01) Zarifoğlu, Mehmet; Şener, D. K.; Karlı, Nejdet; Hakyemez, Bahattin; Taşkapılıoğlu, Özlem; Özbek, Sevda Erer; Bakar, Mustafa; ZARİFOĞLU, MEHMET; Şener, D. K.; KARLI, HAMDİ NECDET; HAKYEMEZ, BAHATTİN; Taşkapılıoğlu, Özlem; ERER ÖZBEK, ÇİĞDEM SEVDA; BAKAR, HACI MUSTAFA; Uludağ Üniversitesi/Tıp Fakültesi/Nöroloji Bölümü; 0000-0003-4436-3797; AAI-2318-2021; AAK-6623-2020; EHN-5825-2022; IOZ-7564-2023; CXD-7623-2022; DLN-1836-2022; EKN-8251-2022Item Aterosklerotik karotis arter darlığı nedeniyle endovasküler stent tedavisi uygulanmış olgularda erken dönem klinik ve radyolojik sonuçlar(Uludağ Üniversitesi, 2010) Orcan, Gökhan; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.Karotis arter stentleme (KAS), karotid endarterektomiye (KEA) bir alternatiftir. Bu çalışmanın amacı, karotis arter stentleme yapılmış hastalarda klinik ve radyolojik sonuçlarının belirlenmesidir.Bu retrospektif çalışmada, Haziran 2007 ve Nisan 2010 tarihleri arasında karotid arter darlığı nedeniyle tedavi edilen 96 olgu/105 arterin (59 [%61,4] olgu semptomatik ve 37 [%38,6] olgu asemptomatik) verileri analiz edildi. Hastaların demografik özellikleri, darlık yüzdeleri, kullanılan stent ve emboli koruma cihazlarının sayı ve çeşitleri ile perioperatif 30 günlük inme miyokard infarktüsü (Mİ), ve ölüm oranları araştırıldı.30 günlük, minör inme oranı %4,8, ölüm oranı %0,9, toplam inme ve ölüm oranı %5,7 idi. Transient iskemik atak (TİA), majör inme ve Mİ görülmedi.Sonuç olarak, KAS kabul edilebilir 30 günlük komplikasyon oranlarıyla uygulanabilir. Gelişen ve olgunlaşan KAS malzeme ve tekniğiyle, günümüzde KEA'ya iyi bir alternatiftir. Gelecekte, KEA'dan ziyade KAS'tan fayda görecek hastaların belirlenmesi için yeni çalışmalar yapılmalıdır.Item Benign ve malign vertebral çökme fraktürü tanısında multiparametrik spinal MR görüntülemenin etkinliğinin retrospektif değerlendirilmesi(Bursa Uludağ Üniversitesi, 2022) Tanlak, Erdinç; Hakyemez, Bahattin; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.Vertebral çökme fraktürleri özellikle yaşlı hastalarda sık görülen, etyolojisinde travma – osteoporoz benzeri benign veya primer tümör – metastaz – multipl myelom benzeri malign süreçlerin yer alabileceği bir hastalıktır. Manyetik rezonans (MR) incelemesi; benign veya malign çökme ayrımında kullanılabilen bir görüntüleme yöntemidir. Genellikle konvansiyonel sekanslar (T1, T2, yağ baskılı teknikler) tanı açısından kullanılmakla birlikte diffüzyon MR, dinamik kontrastlı perfüzyon MR gibi ileri teknikler de son yıllarda ayrım açısından tercih edilmeye başlanmıştır. Buna karşın, malignite şüphesi giderilmeyen olgularda patolojik verifikasyon gerekebilmektedir. Bu çalışmada difüzyon, perfüzyon MR ve konvansiyonel teknikler kullanılarak yapılan multiparametrik spinal MR'ın vertebral çökme fraktürlerinin benign-malign ayrımındaki etkinliğinin değerlendirilmesi amaçlandı. Çalışmaya, vertebra çökme fraktürü olan, vertebra biyopsisi ve vertebral biyopsi öncesinde multiparametrik MR incelemesi yapılmış 42 hasta dahil edildi. T1-T2 sekanslardaki bulgular, kantitatif diffüzyon ve perfüzyon MR bulguları ve perfüzyon MR eğri tipleri kullanılarak tümöral, multipl myelom, benign ve malign çökme kategorisindeki lezyonların ayrımındaki başarı değerlendirildi. Tümöral, myelom ve benign çökme grupları arasında ve benign – non-benign çökme grupları arasında perfüzyon MR eğri tipi, Ktrans, Kep ve ADC parametrelerinde istatistiksel olarak anlamlı fark saptandı (p=0,000-0,02). ROC analizinde benign ve malign çökme ayrımında en yüksek sensitivite ve spesifisite değerleri Ktrans için %73,9 ve %77,8, Kep için %88 ve %77,8, ADC için %63 ve %87, saptanan ADC, Ktrans ve Kep cut off değerlerine göre yapılan multiparametrik değerlendirmede ise %91,30 ve %96,29 olarak bulundu. Kantitatif ADC, Kep ve Ktrans analizine ait kombine bilgiler multiparametrik spinal MR ile benign – malign çökme ayrımı yüksek tanısal doğruluk ile yapılabilir. İçerisinde yer alan her bir tekniğin birlikte kullanımı ile vertebral çökmelerin etyolojisinde rol oynayabilecek maligniteler daha yüksek doğrulukla saptanabilir ve sadece tanı amaçlı yapılacak invaziv işlemlere gereksinim azalabilir.Item Brain abscess and cystic brain tumor - Discrimination with dynamic susceptibility contrast perfusion-weighted MRI(Lippincott Williams & Wilkins, 2005) Erdoğan, Cüneyt; Hakyemez, Bahattin; Yıldırım, Nalan; Parlak, Mufit; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0002-3425-0740; AAI-2318-2021Differentiating between brain abscesses and cystic brain tumors such as high-grade gliomas and metastases is often difficult with conventional MRI. The goal of this study was to evaluate the diagnostic utility of perfusion MRI to differentiate between these pathologies. MRI was performed in 19 patients with rim-enhancing brain lesions (4 pyogenic abscesses, 8 high-grade gliomas, 7 metastases). In addition to standard MR sequences, trace diffusion-weighted MRI with apparent diffusion coefficient (ADC) maps and perfusion-weighted MRI by using a first-pass gadopentetate dimeglumine T2*-weighted gradient echo single-shot echo-planar sequence were performed. Relative cerebral blood volume (rCBV) ratios were obtained via the values of the capsular portions of the lesions and the normal white matter. All the abscesses had markedly hyperintense signals in trace diffusion images, whereas they had significant hypointense signals in ADC images. In perfusion-weighted images, the capsular portions of the abscesses demonstrated low colored areas compared with the normal white matter and the rCBV ratio calculated was 0.76 +/- 0.12 (mean +/- SD). All but two of the cystic tumors showed low signal intensity on trace diffusion-weighted images and high signal intensity on ADC maps. Hyperintense signal was found in two brain tumors mimicking brain abscesses on trace diffusion images. The rCBV values in high-grade gliomas and metastases were 5.51 +/- 2.08 and 4.58 +/- 2.19, respectively. The difference between abscesses and cystic tumors was statistically significant (P = 0.003). Perfusion MRI may allow the differentiation of pyogenic brain abscess from cystic brain tumors, making it a strong additional imaging modality in the early diagnosis of these two entities.Publication Cadasil in the differential diagnosis of multiple sclerosis: Five case reports(Wiley, 2015-06-01) Taşkapılıoğlu, O.; Görükmez, O.; Uzun, Pınar; Atasay, G.; Hakyemez, Bahattin; Yakut, T.; Bakar, Mustafa; Uzun, Pınar; Atasay, G.; HAKYEMEZ, BAHATTİN; Yakut, T.; BAKAR, HACI MUSTAFA; Uludağ Üniversitesi/Tıp Fakültesi/Nöroloji Bölümü; Uludağ Üniversitesi/Tıp Fakültesi/Radioloji Bölümü; 0000-0002-9241-0896; AAI-2318-2021; GIK-0439-2022; EML-7784-2022; GIS-1493-2022; EKN-8251-2022Item Catheter-directed ultrasound-accelerated thrombolysis may be life-saving in patients with massive pulmonary embolism after failed systemic thrombolysis(Springer, 2016-10) Sağ, Saim; Nas, Ömer Fatih; Kaderli, Aysel Aydın; Özdemir, Bülent; Baran, İbrahim; Erdoğan, Cüneyt; Güllülü, Sümeyye; Hakyemez, Bahattin; Aydınlar, Ali; Uludağ Üniversitesi/Tıp Fakültesi/Kardiyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0001-8404-8252; 0000-0002-3425-0740; 0000-0002-8974-8837; AAW-9185-2020; AAG-8561-2021; AAI-2318-2021; AAI-6632-2021; 12140008100; 51864050100; 7801322152; 7004168959; 35572557400; 8293835700; 57204660708; 6602527239; 6603131517The treatment options for high risk acute pulmonary embolism (PE) patients with failed systemic thrombolytic treatment (STT) is limited. The clinical use of catheter directed thrombolysis with the EkoSonic Endovascular System (EKOS) in this population has not been evaluated before. Catheter directed thrombolysis is an effective treatment modality for high risk PE patients with failed STT. Thirteen consecutive patients with failed STT were included in the study. EKOS catheters were placed and tissue plasminogen activator (t-PA) in combination with unfractionated heparin were given. Clinical and echocardiographic properties of the patients were collected before EKOS, at the end of EKOS and during the follow-up visit 6 months after discharge. The duration of EKOS treatment was 21.8 +/- 3.8 h and the total dose of tPA was 31.2 +/- 15.3 mg. One patient who presented with cardiac arrest died and the clinical status of the remaining subjects improved significantly. Any hemorrhagic complication was not observed. EKOS resulted in significant improvement of right ventricular functions and decrease of systolic pulmonary artery pressure. During a follow-up period of 6 months none of the patients died or suffered recurrent PE. In addition, echocardiographic parameters or right ventricular function significantly got better compared to in-hospital measurements. EKOS is an effective treatment modality for high risk PE patients with failed STT and can be applied with very low hemorrhagic complications.Publication Causes of ischemic stroke in patients with atrial fibrillation(Türk Nöroloji Derneği, 2020-12-01) Dinc, Yasemin; Bakar, Mustafa; Hakyemez, Bahattin; Dinç, Yasemin; DİNÇ, YASEMİN; Bakar, Mustafa; BAKAR, HACI MUSTAFA; Hakyemez, Bahattin; HAKYEMEZ, BAHATTİN; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; AAI-2318-2021; IUQ-6999-2023Objective: Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting 1% of the adult population. However, ischemic strokes in patients with AF can be triggered by alternative mechanisms, especially in high-risk patients with additional vascular risk factors. In some patients, atherothrombotic mechanisms may cause stroke, and AF may be incidental or a symptom of atherosclerotic disease. In this case, it may be difficult to distinguish cardioembolic stroke from stroke due to large artery atherosclerosis. The aim of this study was to determine the causes of non-cardioembolic ischemic stroke in patients with non-valvular AF and to determine the risk factors for craniocervical atherosclerotic stenosis.Materials and Methods: This study identified risk factors for craniocervical atherosclerotic stenosis in patients followed up at the Uludag University Faculty of Medicine Department of Neurology with a diagnosis of ischemic stroke and non-valvular AF. In this study, 180 patients who were followed up with a diagnosis of non-valvular AF and acute ischemic stroke between January 1st, 2019 - March 1st 2020, in Uludag University Faculty of Medicine Department of Neurology, were retrospectively included.Results: In this study, the non-cardiac stroke rate was 20% in patients with non-valvular AF who had acute ischemic stroke. Ischemic stroke due to large vessel atherosclerosis was found in 14.4% of these patients, and 9.5% of all patients with AF were stented. When dermographic features, clinical features, and risk factors were analyzed for craniocervical atherosclerotic stenosis, a significant statistical result was obtained with male sex (p=0.020) and smoking (p<0.001).Conclusion: Stroke is a heterogeneous group of diseases caused by many complex mechanisms. Prevention of stroke recurrence is possible by starting effective treatment early. The presence of critical artery stenosis in a patient with acute ischemic stroke with AF causes stroke recurrence and this relapse cannot be prevented by anticoagulant treatment. Angiographic evidence also revealed ethnic and racial differences in patients with acute ischemic stroke. Therefore, more precise information can be obtained through prospective studies in our population.Item Classification of phosphorus magnetic resonance spectroscopic imaging of brain tumors using support vector machine and logistic regression at 3T(IEEE, 2014) Er, Füsun; Hatay, Gökçe Hale; Yıldırım, Muhammed; Öztürk , Esin Işık; Ökeer, Emre; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0002-3425-0740; AAI-2318-2021; 56529606700; 6602527239This study aims classification of phosphorus magnetic resonance spectroscopic imaging (P-31-MRSI) data of human brain tumors using machine-learning algorithms. The metabolite peak intensities and ratios were estimated for brain tumor and healthy P-31 MR spectra acquired at 3T. The spectra were classified based on metabolite characteristics using logistic regression and support vector machine. This study showed that machine learning could be successfully applied for classification of P-31-MR spectra of brain tumors. Future studies will measure the performance of classification algorithms for P-31-MRSI of brain tumors in a larger patient cohort.Item Clinical importance of the basal cavernous sinuses and cavernous carotid arteries relative to the pituitary gland and macroadenomas: Quantitative analysis of the complete anatomy(Elsevier Science, 2008-08) Yılmazlar, Selçuk; Kocaeli, Hasan; Eyigör, Özhan; Hakyemez, Bahattin; Korfali, Ender; Uludağ ÜniversitesiNöroşirürji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Histoloji ve Embriyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Nöroradyoloji Anabilim Dalı.; 0000-0002-3425-0740; 0000-0003-3633-7919; 0000-0003-3463-7483; AAI-2318-2021; AAH-5070-2021; ABE-5128-2020; 6603059483; 6603500567; 6603109907; 6602527239; 7004641343Background: It is unusual to encounter hemorrhagic complications caused by arterial or venous damage during TSS. Problems with these structures can lead to permanent disability or death. Our aim was to quantitatively analyze anatomical and radiologic relationships among the BCS, the CCA, and the pituitary gland, as these structures are accessed during TSS. Methods: Forty-nine formaldehyde-fixed, sellar-parasellar tissue blocks from adult cadavers were used to simulate accessing the BCSs via TSS. In each specimen, size of the pituitary gland and specific characteristics of each BCS and the horizontal segment of each CCA were recorded. Nine other specimens were used for histologic investigation and microanatomical measurements. To attest correlation between clinical data and cadaveric measurements, coronal MRI scans of 22 healthy adults as well as of 28 patients with macroadenomas were analyzed. Results: In cadaveric specimens, distances between both CCAs in the BCS were 17.1 +/- 4.0 mm anteriorly, 20.3 +/- 4.2 mm medially, and 18.8 +/- 4.6 mm posteriorly. In this study, the anterior medial space of the BCS was dominant in 12 specimens on the right side and in 5 specimens on the left; the posterior medial space of the BCS was dominant in 23 specimens on the right side and in 9 specimens on the left side. The right medial BCS was dominant in 35 specimens. On histologic coronal sections, some part of the carotid artery's (CA's) diameter was located below the line passing from the basal dural layer ranging from 5.3% to 65.4%. In normal-sella images, distances between both CCAs were 15.4 +/- 1.8 mm anteriorly, 16.0 +/- 2.8 mm medially, 16.2 +/- 3.4 mm posteriorly. On coronal normal-sella images, some part of the CA's diameter was located below the line passing from the basal dural layer ranging from 16.4% to 66.7%. In macroadenomas, distances between both CCAs were 22.0 +/- 3.6 mm anteriorly, 21.5 +/- 3.8 mm medially, and 20.7.2 +/- 3.7 mm posteriorly. On coronal images, in only 6 of 28 macroadenomas, some part of the CA's diameter was located below the line passing from the basal dural layer ranging from 12.5% to 100%. Conclusions: Our results indicate that a working area of 15.0 +/- 2.6 x 10.3 +/- 2.1 mm is safe during TSS. The position of the CCA posterior segment was notably more caudal than the anterior segment with respect to the basal dura, which should be taken into account during extended exposure. Also, preoperative recognition of the anatomical variations is beneficial for detection of the boundaries of dissection, which is particularly important in the BCS, where variable course of CCAs may transform the anatomical configuration. Slowly growing pituitary adenomas stretch out both CCAs considerably from medial to lateral directions, and they cause widening of intercarotid distances in all segments. Processing of fixation, decalcification, and paraffin embedding for the cadaveric tissue in contrast to physiologically hydrated tissues may change the accuracy of measurements. These measurements are significantly different than those in the radiologic images when arterial blood under pressure is in the CCA as well as when venous blood fills the cavernous sinus as is the case in vivo. In clinical practice, these facts must be taken into consideration in the cadaveric measurements.Item Closure of the axillary artery puncture site with starclose system after endovascular interventions(Elsevier, 2014-04) Gönen, Korcan Aysun; Erdoğan, Cüneyt; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0002-3425-0740; AAI-2318-2021; 8293835700; 6602527239The use of the StarClose vascular closure device for puncture site hemostasis after therapeutic endovascular interventions performed through the axillary artery under anticoagulant therapy in six patients is reported. Three minor complications, including hematoma, prolonged hemostasis, and pain, occurred in three patients. Based on this limited experience, this method can be used safely for axillary artery puncture site hemostasis after endovascular procedures without significant complications.Publication Comparison of the effects of medical and surgical treatments in giant prolactinoma: A single-center experience(Springer, 2021-07-08) Hakyemez, Bahattin; Cander, Soner; CANDER, SONER; Oz Gul, Ozen; ÖZ GÜL, ÖZEN; Eylemer, Eda; Gunes, Elif; Hakyemez, Bahattin; HAKYEMEZ, BAHATTİN; Gullulu Boz, Elif; GÜLLÜLÜ BOZ, SAİDE ELİF; Yilmazlar, Selcuk; YILMAZLAR, SELÇUK; Ersoy, Canan; ERSOY, CANAN; Bursa Uludağ Üniversitesi/Tıp Fakültesi.; AAA-3274-2019Purpose Giant prolactinomas, which have extremely large sizes and high prolactin (PRL) values, are rarely seen. Although medical therapy is effective, surgical treatment is more frequently applied due to slightly lower response rates and compression symptoms. This study aimed to compare the medical and surgical treatment results in giant prolactinomas. Methods Thirty-nine patients who were followed up in our center for giant prolactinoma were included in the study, and the response rates of the patients were evaluated after the medical and surgical treatments. The treatment responses were compared in terms of tumor volume, PRL level, visual field, and pituitary function. Results The outcomes of the 66 treatment periods (medical n = 42; surgical n = 24) in 39 patients (mean age, 47.2 years; men, 89.7%) were evaluated. The most common presentations were hypogonadism and visual defects. The mean longest tumor diameter at diagnosis was 52.2 +/- 11.8 mm, and the median PRL levels were 5000 ng/mL. PRL level normalization was achieved in 69% with medical therapy, and a curative response was obtained in only two patients with surgery. Tumor volume reduction was 67% (no cure) in the medical and 75% (13% cure) in the surgical groups (p = 0.39). Improvement of visual field was 70.8% in the medical and 84.2% in the surgical group (p = 0.12). Conclusion In our study, it was observed that medical therapy was effective and safe in patients with giant prolactinomas. The use of surgical treatment should be limited to prolactinomas with compression or post-resistance to medical treatment in serious cases.Item Computational fluid dynamics simulations based on time-of-flight magnetic resonance angiography(IEEE, 2014) Topkara, Ahmet; Öztürk-Işık, Esin; Olcay, Ali Bahadır; Ökeer, Emre; Hakyemez, Bahattin; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 56529606700; 6602527239Computation fluid dynamics (CFD) is widely used to simulate blood flow in vascular systems. Most of the studies focus on identification of reasons behind the cardiovascular disorders. In this study, magnetic resonance angiography data belonging to a patient were used to obtain brain vasculature solid model. This model prior to CFD simulations was evaluated in terms of surface quality and critical region was identified to be investigated. After CFD analysis, the regions with low and high velocity vector fields, pressure, contours and wall shear stresses (WSS) were obtained. The effect of shape and orientation of vessels was observed. It was seen that increased blood velocity increases the pressure and WSS especially in narrow regions.