Yazar "Altinok, T" seçeneğine göre listele
Listeleniyor 1 - 10 / 10
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The cisternal segment of the abducens nerve in man: three-dimensional MR imaging(Elsevier Sci Ireland Ltd, 2004) Alkan, A; Sigirci, A; Ozveren, AF; Kutlu, R; Altinok, T; Onal, C; Sarac, KPurpose: The goal of this study was to identify the abducens nerve in its cisternal segment by using three-dimensional turbo spin echo T2-weighted image (3DT2-TSE). The abducens nerve may arise from the medullopontine sulcus by one singular or two separated rootlets. Material and methods: We studied 285 patients (150 males, 135 females, age range: 9-72 years, mean age: 33.3 +/- 14.4) referred to MR imaging of the inner ear, internal auditory canal and brainstem. All 3D T2-TSE studies were performed with a 1.5 T MR system. Imaging parameters used for 3DT2-TSE sequence were TR:4000, TE:150, and 0.70 mm slice thickness. A field of view of 160 mm and 256 x 256 matrix were used. The double rootlets of the abducens nerve and contralateral abducens nerves and their relationships with anatomical structures were searched in the subarachnoid space. Results: We identified 540 of 570 abducens nerves (94.7%) in its complete cisternal course with certainty. Seventy-two cases (25.2%) in the present study had double rootlets of the abducens nerve. In 59 of these cases (34 on the right side and 25 on the left) presented with unilateral double rootlets of the abducens. Thirteen cases presented with bilateral double rootlets of the abducens (4.5%). Conclusion: An abducens nerve arising by two separate rootlets is not a rare variation. The detection of this anatomical variation by preoperative MR imaging is important to avoid partial damage of the nerve during surgical procedures. The 3DT2-TSE as a noninvasive technique makes it possible to obtain extremely high-quality images of microstructures as cranial nerves and surrounding vessels in the cerebellopontine cistern. Therefore, preoperative MR imaging should be performed to detect anatomical variations of abducens nerve and to reduce the chance of operative injuries. (C) 2003 Elsevier Ireland Ltd. All rights reserved.Öğe Effect of nasal septal deviation on total ethmoid cell volume(Cambridge Univ Press, 2006) Firat, AK; Miman, MC; Firat, Y; Karakas, M; Ozturan, O; Altinok, TBackground: The aim of this study was to evaluate the effect of nasal septal deviation (NSD) on ethmoid cell volume and to determine whether there was any correlation between NSD grade and ethmoid cell volume. Methods: Forty computerized tomography (CT) scans from patients with rhinosinusitis symptoms with NSD were evaluated. Septal deviations were classified into three groups according to the degree of deviation on CT. Ethmoid cell volumes were measured and the relationship between NSD and ethmoid cell volume was investigated. Results: There was a moderate but significant negative correlation between the septal deviation angle and the percentage of the ethmoid cell volumes (p = 0.001, r = -0.5152, r(2) = 0.2654). Total ethmoid cell volume on the ipsilateral side compared with the contralateral side was found to decrease as the degree of NSD increased. Conclusions: Nasal septal deviation affects the total ethmoid cell volume of the nasal cavity. The results of our study underline the role of ethmoid cell volume in the compensation mechanism equalizing the nasal cavity airflow changes due to NSD.Öğe En-plaque tuberculomas of tentorium in a pregnant woman(Springer-Verlag, 2003) Alkan, A; Parlak, M; Baysal, T; Sigirci, A; Kutlu, R; Altinok, TEn-plaque tuberculoma is a rare manifestation of CNS tuberculosis and presents as a solitary, focal, caseous plaque-like lesion. It is difficult to differentiate en-plaque like meningeal tuberculoma from true primary or secondary meningeal neoplasia. Good response to antituberculosis treatment in a patient with tuberculosis history and typical MR findings confirm the diagnosis. We present the follow-up MR imaging findings of a case in which an enplaque tuberculoma on tentorium was diagnosed during pregnancy in a patient with a history of tuberculosis. To the best of our knowledge, enplaque tuberculomas of tentorium during pregnancy have not been reported before.Öğe Giant axonal neuropathy: MRS findings(Sage Publications Inc, 2003) Alkan, A; Kutlu, R; Sigirci, A; Baysal, T; Altinok, T; Yakinci, CGiant axonal neuropathy (GAN) is a rare genetic disease of childhood involving the central and peripheral nervous systems. Axonal loss with several giant axons filled with neurofilaments is the main histopathological feature of peripheral nerve biopsies in this disease. Routine neuroimaging studies reveal diffuse hyperintensities in cerebral and cerebellar white matter. In this case report, the authors present the brain magnetic resonance spectroscopic features (normal N-acetylaspartate/creatine and increased choline/creatine and myoinositol/creatine ratios), which might indicate the absence of neuroaxonal loss and the presence of significant demyelination and glial proliferation in white matter, of an 11-year-old boy diagnosed with GAN.Öğe Increased P-wave duration and P-wave dispersion in patients with aortic stenosis(Blackwell Futura Publishing, Inc, 2003) Turhan, H; Yetkin, E; Atak, R; Altinok, T; Senen, K; Ileri, M; Sasmaz, HBackground: P-wave dispersion (PWD), defined as the difference between the maximum and minimum P-wave duration, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (AF). AF is the most common arrhythmia and an important prognostic indicator for clinical deterioration in patients with aortic stenosis (AS). The,aim of the present study was to evaluate PWD in patients with AS. Methods: The study population consisted of two groups: Group I consisted of 98 patients with AS (76 men, 22 women; aged 63 8 years) and group II consisted of 98 healthy subjects (same age and sex) without any cardiovascular disease. A 12-lead electrocardiogram was recorded for each subject. The P-wave duration was calculated in all leads of the surface electrocardiogram. The difference between the maximum and minimum P-wave duration was calculated and was defined as the PWD. All patients and control subjects were also evaluated by echocardiography to measure the left atrial diameter, left ventricular ejection fraction, left ventricular wall thicknesses, and the maximum and mean aortic gradients. Patients were also evaluated for the presence of paroxysmal AF. Results: Maximum P-wave duration and PWD of group I were found to be significantly higher than those of group II. In addition, patients with paroxysmal AF had significantly higher PWD than those without paroxysmal AF. There was no significant difference between the two groups regarding minimum P-wave duration. In addition, there was no significant correlation between echocardiographic variables and PWD. Conclusion: PWD, indicating increased risk for paroxysmal AF, was found to be significantly higher in patients with AS than in those without it. Further assessment of the clinical utility of PWD for the prediction of paroxysmal AF in patients with severe AS will require longer prospective studies.Öğe Occupational prolonged organic solvent exposure in shoemakers: brain MR spectroscopy findings(Elsevier Science Inc, 2004) Alkan, A; Kutlu, R; Hallac, T; Sigirci, A; Emul, M; Pala, N; Altinok, TOur purpose was to investigate, by magnetic resonance (MR) spectroscopy, the metabolite changes in the brains of subjects in the shoemaking industry who had been chronically exposed to organic solvents. A total of 49 male subjects and 30 age-matched healthy volunteers underwent detailed neurological and psychiatric examinations. All subjects had long-echo [repetition time (TR) 2000 ms, echo time (TE) 136 ms] single-voxel MR spectroscopy. Voxels (15 x 15 x 15 mm(3)) were placed in the parietal white matter, thalamus, and basal ganglia. N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were calculated. There was no significant difference between the study subjects and the control group in NAA/Cr ratios obtained from thalamus, basal ganglia, and parietal white matter. Cho/Cr ratios in thalamus. basal ganglia, and parietal white matter were found to be significantly increased compared to controls. There was a positive correlation between basal ganglia Cho/Cr ratio and duration of exposure (r = 0.63). MR spectroscopy should be performed to reveal metabolite changes and determine the degree of brain involvement in solvent-related industry workers. (C) 2004 Elsevier Inc. All rights reserved.Öğe Temporary and permanent inferior vena cava filter combination in a young patient: To implant or not to implant?(Springer-Verlag, 2003) Kutlu, R; Alkan, A; Sigirci, A; Altinok, T; Yildirim, ZThe decision to implant vena cava filters, either temporary or permanent, is difficult in young patients. We present the case of a young man with pulmonary embolism in whom temporary and permanent inferior vena cava filters were implanted. The decision process is discussed in relation to the current literature.Öğe Ultrasonographic assessment of mild and moderate idiopathic carpal tunnel syndrome(W B Saunders Co Ltd, 2004) Altinok, T; Baysal, O; Karakas, HM; Sigirci, A; Alkan, A; Kayhan, A; Yologlu, SAIM: To investigate the diagnostic value of uttrasonography in mild and moderate idiopathic carpal tunnel syndrome (CTS). MATERIALS AND METHODS: Cross-sectional areas (CSA), flattening ratios at three different levels, swelling ratio, and palmar displacement were analysed in 26 patients (14 with bilateral and 12 with unilateral disease, 40 wrists in total) for the presence and the severity of CTS. Twenty had normal nerve conduction studies (NCS) defined as mild, and 20 of them had abnormal NCS defined as moderate. The control group consisted of 20 healthy participants. RESULTS: All parameters were significantly different between patient and control groups. Palmar displacement, swelling ratio, CSA at all levels and distal flattening ratio had the highest significance (p < 0.0001). The criterion with the highest sensitivity was the swelling ratio greater than or equal to 1.3 (72.5%), followed by the middle CSA >9 mm(2) and the palmar displacement >2.5 mm. All of these criteria had a higher sensitivity in diagnosing moderate cases (85-100%) than diagnosing mild cases (30-55%). There was a significant difference between normal and mild CTS groups regarding palmar displacement, distal flattening ratio, middle CSA and swelling ratio (p < 0.0001 for all) and between normal and moderate groups regarding all parameters (p < 0.01 - 0.0001). When combined middle CSA, palmar displacement and swelling ratio had an overall discriminatory accuracy of 83.8%. CONCLUSION: Additional diagnostic confirmation can be provided by ukrasonography and may be preferred as the initial step instead of etectrophysiotogical. studies. Detection of at least two of the three criteria (median nerve CSA >9 mm(2) at pisiform Level, swelling ratio 1.3, and palmar displacement >2.5 mm) may be helpful for the verification of the diagnosis. (C) 2004 Published by Elsevier Ltd on behalf of The Royal College of Radiologists.Öğe Ultrasonographic evaluation of age-related changes in bowing of the flexor retinaculum(Springer, 2004) Altinok, T; Karakas, HMThe effects of age, gender, and hand dominance on bowing of the flexor retinaculum, used in diagnosing carpal tunnel syndrome, were analyzed. Forty men aged 23-58 years old (39.7 +/- 11.2) and 40 women aged 2057 years old (39.6 +/- 11.3) were the normal subjects. A total of 160 wrists was examined with a linear array transducer. Bowing of the flexor retinaculum was measured as the distance from a line drawn between the trapezium and the hamate to the palmar apex of the outer surface of the flexor retinaculum. It was 0.5-3.7 mm (2.00 +/- 0.64) for all hands, 0.6-3.7 mm (2.06 +/- 0.62) for men, 0.5-3.4 mm (1.96 +/- 0.67) for women, 0.5-3.4 mm (1.00 +/- 0.64) for dominant, and 0.6-3.7 mm (2.03 +/- 0.65) for nondominant hands. There was no difference between genders or dominant vs nondominant hands regarding this parameter. However, it was highly correlated with age (r = 0.59, p < 0.0001). In conclusion, bowing of the flexor retinaculum measurements should be carefully compared with the standardized values when diagnosing carpal tunnel syndrome.Öğe An unusual case of acute disseminated encephalomyelitis confined to brainstem(Elsevier Science Inc, 2004) Firat, AK; Karakas, HM; Yakinci, C; Altinok, T; Alkan, A; Biçak, UAcute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating disorder usually encountered in children or adolescents and characterized by multifocal neurological deficits of rapid onset. Typical target areas of demyelination include the corona radiata, centrum semiovale, periventricular white matter, cerebellar peduncles and brainstem. Involvement of deep gray matter nuclei is also frequent. We report a 6-year-old boy with ADEM who had only brainstem involvement. Serial magnetic resonance images representing the stage of disease and response to steroid treatment are presented. (C) 2004 Elsevier Inc. All rights reserved.
