Browsing by Author "Duşak, Abdürrahim"

Now showing 1 - 6 of 6

Correlation between hippocampal volume and excessive daytime sleepiness in obstructive sleep apnea syndrome
(Verduci Publisher, 2013-05) Duşak, Abdürrahim; Ursavaş, Ahmet; Hakyemez, Bahattin; Gökalp, Gökhan; Taşkapılıoğlu, Özlem; Parlak, Müfit; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Nöroloji Anabilim Dalı.; 0000-0002-3425-0740; AAG-8521-2021; AAI-3169-2021; AAI-2336-2021; AAI-2318-2021; A-7826-2019; 6507393726; 8329319900; 6602527239; 8312505100; 23037226400; 7003589220
BACKGROUND/AIM: The limbic system, specifically the hippocampus, plays a key role in controlling the sleep-wake cycle. Changes in these particular structures of the central nervous system have been suggested to be related to obstructive sleep apnea syndrome (OSAS). We hypothesized that reduced hippocampal volume is a risk factor for excessive daytime sleepiness (EDS) in OSAS. PATIENTS AND METHODS: Twenty-two patients with newly diagnosed OSAS and 20 healthy controls were included in the present study. Polysomnography was performed for each participant to determine the presence of OSAS. EDS was defined based on the Epworth sleepiness scale (ESS) score, and patients were grouped as sleepy or non-sleepy according to this score. The hippocampal volume was calculated by MR volumetry using a manual tracing technique. RESULTS: There was no significant difference between groups in demographic variables. The hippocampus was markedly smaller in the OSAS groups than in controls (p < 0.001 Hippocampal volume was negatively correlated with the ESS score (r = - 0.631, p = 0.002). CONCLUSIONS: Our findings suggest that EDS is associated with reduced hippocampal volume in OSAS.
Cystadenoma originating from the gallbladder
(Wiley, 2010-04) Duşak, Abdürrahim; Topal, Naile Bolca; Gökalp, Gökhan; Aker, Sibel; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; Uludağ Üniversitesi/Tıp Fakültesi/Tıbbi Patoloji Anabilim Dalı.; AAI-2336-2021; 8312505100; 12795285000
Biliary cystadenomas are very uncommon benign tumors. They are very rare occurrences in the gallbladder, and there are only a few case reports in the literature.(1-3) Cystadenomas are more frequently seen among middle-aged women. The clinical presentation varies and depends on the size and location of the cyst. They are unilocular or multilocular cystic tumors that contain septations. Although biliary cystadenomas are of a benign nature, they may recur after excision, nd there is a risk of development of cystadenosarcomas.(4-6) Hepatobiliary cystadenomas are most commonly seen in the liver (83%) followed by the extrahepatic biliary system (13%) and gallbladder (0.02%).(7) In this report, we present the sonographic results of a rare case of cystadenoma originating in the gallbladder.
Efficacy of ultrasonography-guided shoulder MR arthrography using a posterior approach
(Springer, 2010-06) Gökalp, Gökhan; Duşak, Abdürrahim; Yazıcı, Zeynep; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; A-7826-2019; AAI-2336-2021; AAI-2303-2021; 8312505100; 6507393726; 6701668723
Shoulder MR arthrography has an important role in the assessment of rotator cuff lesions, labral tears, glenohumeral ligaments, rotator interval lesions, and postoperative shoulder status. Injection in direct MR arthrography can be performed with palpation, fluoroscopy, ultrasonography (US), or MRI. Recently, the posterior approach is the preferred method due to the presence of fewer stabilizers, absence of important articular structures and less extravasation, has been advocated. Our aim was to assess the efficacy of US-guided MR arthrography via a posterior approach on the glenohumeral joint. Thirty MR arthrographies were performed on 29 patients. Ultrasonography (Xario, Toshiba) examinations were conducted by a wide-band 5-12 Mhz linear array transducer set to muscle-skeleton. Diluted contrast medium (1 ml gadolinium chelate and 100 ml saline, approximately 15 ml) was delivered into the glenohumeral joint space from between the humeral head and posterior labrum with a 20-gauge spinal needle. MRI examination was conducted by a 1.5 T scanner. Fat-saturated T1-weighted spin echo was applied on coronal, axial, and sagittal planes within the first 30 min after contrast material injection. One (3.3%) arthrography was not successful due to technical reasons associated with obesity. Contrast extravasation around the infraspinatus and teres minor muscles was depicted in twelve examinations. One (3.3%) patient developed vasovagal collapse. Ultrasonography-guided posterior approach is an easy, reliable, fast, and comfortable method in experienced hands. It may be an alternative for fluoroscopy-guided shoulder MR arthrography.
Impaired aortic distensibility in hypothyroid patients with negative coronary angiograms: Simultaneous evaluation with 128-slice multiple row detector computed tomography
(Sage Publications, 2013-03-01) Duşak, Abdürrahim; Gökalp, Gökhan; Erdoǧan, Cüneyt; Parlak, Müfit; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; AAG-8521-2021; A-7826-2019; AAI-2336-2021; 6507393726; 8312505100; 8293835700; 7003589220
Objective To determine the relationship between arterial distensibility and hypothyroidism by simultaneous assessment of coronary angiography and aortic distensibility, measured using 128-slice retrospective electrocardiogram-gated multiple row detector computed tomography (MDCT). Methods Untreated hypothyroid patients and age-matched euthyroid patients, who underwent 128-slice retrospective electrocardiogram-gated MDCT to evaluate the coronary arteries, were assessed. Intraluminal aortic areas in systolic and diastolic phases of the cardiac cycle were measured with multiphase reformation at predefined locations including the ascending aorta, proximal descending aorta and distal descending aorta in the widest axial plane. Results The study included 21 hypothyroid and 21 euthyroid patients. Patients with hypothyroidism exhibited decreased aortic distensibility between each location in the thoracic aorta (ascending aorta, proximal descending aorta and distal descending aorta) compared with euthryoid patients. Conclusions Hypothyroidism was associated with preclinical vascular alteration, characterized by impaired aortic distensibility at each location of the thoracic aorta, which has been shown to be related to increased cardiovascular risk. Monitoring of aortic distensibility is relevant for evaluating coronary artery disease progression and treatment choices.
Solitary metastases and high-grade gliomas: Radiological differentiation by morphometric analysis and perfusion-weighted MRI
(WB Saunders, 2010-01) Hakyemez, Bahattin; Erdoğan, Cüneyt; Gökalp, Gökhan; Duşak, Abdürrahim; Parlak, Müfit; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Anabilim Dalı.; 0000-0002-3425-0740; AAI-2336-2021; AAI-2318-2021; A-7826-2019; 6602527239; 8293835700; 8312505100; 6507393726; 7003589220
AIM: To evaluate the value of morphometric analysis and perfusion-weighted magnetic resonance imaging (MRI) in differentiating solitary metastases from high-grade gliomas. MATERIALS AND METHODS: Forty-eight tumours (22 high-grade gliomas and 26 solitary hemispheric metastases) were evaluated using conventional and perfusion-weighted MRI. T2-weighted, gradient-echo, echo-planar sequences were used for perfusion-weighted MRI. Relative cerebral blood volume (rCBV) ratios were calculated by dividing the rCBV of the intratumoural and peritumoural areas with the average CBV value of the normal white matter areas. Morphometric analysis was carried out by proportioning the area of peritumoural oedema to the mass area. Mann-Whitney U test and ROC Curve analysis were applied for statistical analysis. P < 0.05 was accepted as statistically significant. RESULTS: Mean rCBV ratios of intratumoural areas of high-grade gliomas and metastases were 5.02 +/- 2.47 and 4.62 +/- 2.46, respectively. No statistically significant difference was found (p = 0.515). rCBV ratios of peritumoural oedema were 0.89 +/- 0.51 in high-grade gliomas and 0.31 +/- 0.12 in metastases. The difference was statistically significant (p < 0.001). According to the results of morphometric analysis, a statistically significant difference was present between the two tumour types (p < 0.001). CONCLUSION: Measuring the oedema: mass and rCBV ratios of the oedema surrounding the tumour prior to operation in solitary masses proved to be useful for differentiating metastases from high-grade gliomas.
Ultrasound biomicroscopic evaluation of anterior segment cysts as a risk factor for ocular hypertension and closure angle glaucoma
(IJO Press, 2013-07) Duşak, Abdürrahim; Baykara, Mehmet; Özkaya, Güven; Erdoǧan, Cüneyt; Özçetin, Hikmet; Tuncel, Ercan; Uludağ Üniversitesi/Tıp Fakültesi/Radyoloji Bölümü.; Uludağ Üniversitesi/Tıp Fakültesi/Oftalmoloji Bölümü.; Uludağ Üniversitesi/Tıp Fakültesi/İstatistik Bölümü.; 0000-0003-0297-846X; A-7826-2019; ABI-7051-2020; A-4421-2016; 6507393726; 23093006700; 16316866500; 8293835700; 6603402155; 7006929833
AIM: To investigate the relationship between the ultrasound biomicroscopic (UBM) features of anterior - segment cysts (ASCs) and increased intraocular pressure (IOP) as a risk factor for closed-angle glaucoma (CAG). METHODS: Totally 24 eyes with recently diagnosed ASCs were divided into two groups. First group with ASC and ocular normotension(n=13), second group with ASC and ocular hypertension (n=11). An ophthalmologic examination, including tonometry, slit -lamp biomicroscopy (SLBM), gonioscopy, fundoscopy, pentacam, and UBM, was performed. The features of the ASCs were compared with the IOP. RESULTS: ASCs were accurately diagnosed and delineated in 24 eyes using UBM. IOP was elevated in those ASCs with a secondary aetiology (P=0.027), iridociliary location(P=0.006), deformed shape (P=0.013), increased size (P =0.001) and elongated pupillary aperture (P=0.009). However, the count (P=0.343) of ASCs, anterior chamber depth (ACD; P=0.22) and axial lenght (AL; P =0.31) were not associated with ocular hypertension. Correlations were found between the IOP and ASC size (r =-0.712; P=0.003), anterior chamber angle (ACA; r =-0.985; P<0.001), angle opening area (AOA; r=0.885; P<0.001), angulation of iris (r=-0.776, P<0.001), and affected iris quadrant (r=-0.655, P=0.002). CONCLUSION: Ocular hypertension in some eyes with ASC might be associated with various mechanisms, including secondary aetiology, iridociliary location, deformed shape, increased size and elongated pupill, which can be determined by UBM.