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Öğe Magnetic resonance spectral analysis of ovarian teratomas(Elsevier Ireland Ltd, 2005) Hascalik, S; Celik, O; Erdem, G[Abstract Not Available]Öğe Magnetic resonance spectroscopic comparison of the effects of resveratrol (3,4',5-trihydroxy stilbene) to conjugated equine estrogen, tibolone and raloxifene on ovariectomized rat brains(Elsevier Science Bv, 2005) Celik, O; Erdem, G; Hascalik, S; Karakas, HM; Tamser, MObjective: To investigate the effects of resveratrol on basic cerebral metabolites of in the brains of ovariectomized rats. Materials and methods: Twenty-four bilaterally ovariectomized rats were randomly assigned into six groups With four rats in each group. The groups consisted of sham-operated (control), ovariectomized, resveratrol, conjugated equine estrogen (CEE), tibolone and raloxifene treated rats. Drug administration started at the 5th day following ovariectomy and continued for 35 days. At the end of the entire Course, in vivo single vowel magnetic resonance spectroscopy was performed on whole brains to determine choline, creatine and N-acetyl aspartate (NAA) concentrations. Results: Compared to sham-operated group, ovariectomized group had significantly lower NAA (P < 0.008) but significantly higher choline levels (P < 0.031). Administration of CEE and resveratrol resulted in NAA levels that were similar to those in the sham-operated group, showing that the NAA decrease due to ovariectomy was prevented. Treatment with tibolone and raloxifene resulted in a smaller increase in NAA and the effect failed to reach significance. Administration of resveratrol, CEE, tibolone and raloxifene resulted in choline levels similar to those in sham-operated group, showing that the increase in the ovariectomy group was prevented. Conclusion: Resveratrol causes levels of cerebral metabolites that is similar to conventional hormone replacement agents. This finding may suggest that neuronal function in the postmenopausal state was preserved. More detailed investigation of this issue should be the task of future research. (c) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Maxillary sinus hypoplasia(Int Rhinologic Soc, 2002) Erdem, T; Aktas, D; Erdem, G; Miman, MC; Ozturan, OMaxillary sinus hypoplasia (MSH) is an uncommonly, encountered condition by otolaryngologists. Pie computerized tomography (CT) scans provide valuable data about the anatomic details of the paranasal sinuses. MSH may, be misdiagnosed as an infection or a neoplasm of the maxillary, sinuses. Variations of the other paranasal structures, especially the uncinate process associated with MSH were defined. MSH shows three distinct hypoplasia patterns. Type I MSH characteristics are mild hypoplasia of the maxillary sinus, normal uncinate process and a well-developed infundibular passage. Significant hypoplasia of the maxillary, sinus, hypoplastic or absent uncinate process and absent or pathologic infundibular passage are seen in Type II MSH. Type III MSH is characterized by the absence of an uncinate process and cleft-like maxillary, sinus hypoplasia. In this study a series of 18 patients with MSH were presented. Twelve cases of unilateral and 6 cases of bilateral maxillary, antrum hypoplasia were evaluated and 13 MSH hype 1, 7 MSH type II and 4 MSH type III were detected. Three ethmomaxillary sinuses, an overpneumatized posterior ethmoid cell into the orbit and the maxillary sinus were determined. Our series showed that the uncinate process anomalies related to MSH malY lead to inadvertent orbital complications and therefore should be kept in mind.Öğe Nasal pyriform aperture stenosis in adults(Ocean Side Publications Inc, 2004) Erdem, T; Ozturan, O; Erdem, G; Akarcay, M; Miman, MCBackground: Congenital nasal pyriform aperture stenosis (CNPAS) leading to respiratory insufficiency in infants has been well documented. Nevertheless, the nasal pyriform aperture stenosis (NPAS) entity in adulthood has not been discussed at all. The normative data of the width of the pyriform aperture, which has not been revealed before, is necessary for evaluation of the adult subjects with nasal bony inlet stenosis. The aim of this study was to define the normative data about the pyriform aperture width measured in 80 adult subjects with paranasal sinus symptoms without nasal obstruction. and, additionally, to report the surgical results of two representative cases with NPAS. Methods: The nasal bony inlet width measurements have been achieved in axial computerized tomographic sections to establish normative data. The maximal distance between the nasal processes of the opposite maxillary bones was measured. Two adult males complaining of nasal obstruction with overt pyriform aperture stenosis were treated surgically via a sublabial approach. Results: The mean widest dimension of the nasal pyriform aperture was 21.6 +/- 2.2 mm (range, 17-27 mm) in 80 adult subjects. This width was 21.9 +/- 2.1 mm (range 18-27 mm) in men and 21 +/- 2.2 mm (range, 17-26 mm) in women. Stenotic pyriform apertures in two patients were widened surgically by drilling via a sublabial approach from 12 and 10 mm to 24 and 21 mm, respectively. Conclusion: NPAS should be included in the list of differential diagnosis for nasal obstruction. Surgical enlargement using a sublabial approach was found an effective and adequate treatment in pyriform aperture stenosis.Öğe Neurofibromatosis type 1: Diffusion weighted imaging findings of brain(Elsevier Ireland Ltd, 2005) Alkan, A; Sigirci, A; Kutlu, R; Ozcan, H; Erdem, G; Aslan, M; Ates, OPurpose: The purposes of this study were to evaluate the differences in apparent diffusion coefficient (ADC) values between infra and supratentorial unidentified bright objects (UBOs), between UBOs and normal appearing side (NAS, contralateral regions of the UBOs and/or normal appearing region without UBOs) in the neurofibromatosis type 1 patients (NF1) and control group and also to investigate correlation between age and ADC values. Methods: A total of 30 patients and 26 healthy controls were included. The MRI examination consisted of routine imaging and diffusion weighted imaging (DWI). Seven distinct locations (frontal, parieto-occipital and cerebellar white matter, globus pallidum, thalamus, hippocampus, and midbrain) were selected for the analysis. The ADC values were calculated directly from these automatically generated ADC maps with ROI. Results: The ADC values of UBOs were significantly increased in cerebellar white matter, hippocampus, globus pallidum, midbrain, and thalamus when compared with NAS and control group. There were statistically significant differences between NAS and control group in the ADC values obtained from hippocampus and thalamus. There were statistically significant differences between supra and infratentorial UBOs in ADC values. There was a negative correlation between age and the ADC values obtained from normal appearing midbrain, hippocampus, thalamus, and globus pallidum. Conclusion: ADC values both in UBOs and in the normal appearing locations as hippocampus and thalamus were detected to be higher in the patients with NF1. The detection of lesions might be independent of MRI appearance in NF1, i.e. although the brain is affected, MRI appearance may be normal. Therefore, DWI and ADC values should also be utilized in the delineation of brain involvement of NF1 patients. (C) 2005 Elsevier Ireland Ltd. All rights reserved.Öğe Proton magnetic resonance spectroscopy findings of a sacrococcygeal schwannoma(Lippincott Williams & Wilkins, 2006) Hascalik, S; Celik, O; Erdem, G; Ara, C; Kirimlioglu, HSchwannoma is tumor of peripheral nerves, originating from Schwann cells. It is a rare nerve sheath tumor, which frequently occurs in the intracranial acoustic nerve and spinal nerves. We report on a 28-year-old woman who suffered from a large pelvic mass that was diagnosed to be sacrococcygeal schwannoma. The features of proton magnetic resonance spectroscopy (MRS) study are discussed. The magnetic resonance imaging instrument was a 1.5T, Gyroscan Intera with a body coil as a radiofrequency transmitter and a signal receiver. T2-weighted images were obtained under the following conditions-turbo spin echo (TSE) T2: turbo spin echo repeat time (TR) = 4500 msec, echo time (TE) = 96 msec. Single voxel MRS was performed by the point-resolved spectroscopy technique with a long TE (136 msec). MRS measurement was performed on two different parts of the tumor. As well as strongly elevated choline and lipid signals, the tumor spectrum showed increased N-acetylaspartate resonances. MRS can be used effectively in the preoperative diagnosis of retroperitoneal and pelvic masses, which demonstrate unusual clinical features.Öğe A radiological anatomic study of the cribriform plate compared with constant structures(Int Rhinologic Soc, 2004) Erdem, G; Erdem, T; Miman, MC; Ozturan, OBackground: Understanding of the anterior skull base anatomy is crucial to avoid intracranial violations during endoscopic surgery. The aims of this study were to define the normative data about cribriform plate depth and the relationship between this dimension and the measurements of the adjacent anatomical structures such as middle turbinate length, maximal vertical orbital height and distance between the ethmoid roof and the nasal floor. Patients and Methods: Paranasal computerized tomographic scans of 136 healthy adults were included into the study. The cribriform plate depth compared to the ethmoid roof and the adjacent anatomical structures mentioned above were measured bilaterally. Results: The maximal vertical orbital height was detected as the most constant anatomic measurement. We found the mean level dfference between the ethmoid roof and the cribriform plate as 6.1 +/- 2.3 (range 1-12 mm) on the left side and 6.1 +/- 2.2 (1-15 mm) of the right side. The middle turbinate was significantly longer in the Keros Type I group than in the other groups (p<0,05). Furthermore, the distance between the ethmoid roof and the nasal floor was lowest in the Keros Type I group (p<0,01). The distance between the ethmoid roof and the nasal floor was statistically higher in Keros group 3 among all groups (p<0,01). The deeper the cribriform plate, the higher the nasal cavity. Conclusion: To the best of our knowledge, our study has a unique feature by including the data of the constant anatomical structures comparing with the cribriform plate depth. Since in the group with excessive cribriform plate depth, the middle turbinate was short, care should be taken especially during middle turbinate resections.Öğe Subacute sclerosing panencephalitis: Relationship between clinical stage and diffusion-weighted imaging findings(Wiley, 2006) Alkan, A; Korkmaz, L; Sigirci, A; Kutlu, R; Yakinci, C; Erdem, G; Yologlu, SPurpose: To investigate the relationship between clinical stages and apparent diffusion coefficient (ADC) changes in the brain of patients with subacute sclerosing panencephalitis (SSPE). Materials and Methods: A total of 18 patients with stage II (N = 11) and III (N = 7) SSPE and 11 age-matched controls underwent routine MRI and diffusion-weighted imaging (DWI). The ADC values were automatically calculated. Seven distinct neuroanatomic structures (frontal, parieto-occipital, and cerebellar white matter: deep white matter; thalamus: basal ganglia; and brainstem) were selected for analysis In the patient and control groups. Results: Hyperintensities in the periventricular and subcortical white matters on T2-weighted images and ADC maps were detected in 63.6% of patients with stage II and in all patients with stage III. There were significant differences between stage II and III patients and also between patients and control group in ADC values that obtained from all locations. The highest mean ADC values were calculated in stage III patients. Although MRI and DWI findings were normal in four patients with stage II disease, ADC values were significantly increased when compared with controls. Conclusion: The stage of disorder may be independent of DWI appearance during the early stage (stages I and II), even though the brain is affected. Therefore. DWI and ADC values supplemental to routine MRI should also be utilized for lesion detection and definition to enhance diagnostic accuracy in patients with SSPE.Öğe Synchronous endometrial and cervical tumors in a 26-year-old nullipara: Diagnostic modalities updated(Karger, 2005) Hascalik, S; Celik, O; Erdem, G; Usta, U; Alkan, A; Karakas, HM; Mizrak, BProton magnetic resonance spectroscopy (MRS), performed on conventional magnetic resonance imaging (MRI) scanners, provides useful information at the biochemical level. MRS has been used to measure tissue concentrations of proton-containing compounds such as organic and amino acids, and sugars in living tissues. We have used MRS in a 26-year-old female with suspected cervical and endometrial carcinomas. With the use of the above mentioned technique, biochemical differences in the endometrium and the cervix tissues were detected. The presented case is the first virgin patient in the relevant literature in whom endometrial and cervical carcinoma was detected. Choline (Cho), creatine (Cr), N-acetylaspartate (NAA), lipid and lactate region of the MRS spectrum suggested that the technique could be used as an indicator of metabolic alterations in the cervical and endometrial tumor cells. Copyright (C) 2005 S. Karger AG, Basel.
