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Öğe 1H magnetic resonance spectroscopy of the normal testis(Elsevier Science Inc, 2008) Firat, Ahmet Kemal; Ugras, Murat; Karakas, Hakk M.; Erdem, Gulnur; Kurus, Meltem; Ugras, Meltem; Celik, TayfunPurpose: The purpose of this study was to determine the pre- and postpubertal H-1 magnetic resonance spectroscopic characteristics of the normal testis to establish baseline values for further clinical studies. Materials and Methods: The subjects consisted of male volunteers, of whom 19 were prepubertal with ages between 7 and 13 years and 24 were postpubertal with ages between 19 and 39 years. Their testes were evaluated at 1.5 T with magnetic resonance spectroscopy; in addition, testis volumes were measured. Major metabolite peaks were identified and their ratios were calculated. Metabolite differences of testis between pre- and postpubertal age were analyzed. Results: Major constituents of spectra were 3.21 ppm choline and 0.9-1.3 ppm lipid peaks. At the echo time (TE) spectrum of 31 ms, choline/lipid ratios ranged from 0.35 to 8.30 (mean=1.87) in postpubertal males and from 0.06 to 5.45 (mean=0.88) in prepubertal males (P<.013). At the TE spectrum of 136 ms, choline/lipid ratios ranged from 0.66 to 15.42 (mean=4.09) in postpubertal males and from 0.05 to 4.91 (mean=0.9) in prepubertal males (P<.016). Conclusions: Choline/lipid ratio was higher in the postpubertal period. The existence of higher choline peak in that age group should be due to the initiation of spermatogenesis. The decrease in the lipid peak may represent the effect of testosterone on testicular tissue or may be due to histochemical changes initiated by puberty. The significant decrease in choline/lipid ratio noted after puberty could represent the presence of spermatogenesis. This hypothesis should be evaluated by further studies on postpubertal. subjects with impaired spermatogenesis. (C) 2008 Published by Elsevier Inc.Öğe Advanced MRI findings in patients with breast hamartomas(Turkish Soc Radiology, 2011) Erdem, Gulnur; Karakas, Hakki Muammer; Isik, Burak; Firat, Ahmet KemalPURPOSE Although it has been stated that breast hamartomas are rare tumors, radiologists frequently encounter them in their daily practices. Fat, glandular and fibrous tissues all produce a mass of disorganized but mature specialized cells. Because hamartomas do not have specific diagnostic histological features, the clinical and radiological findings are important in their diagnosis. The aim of this study is to present the advanced magnetic resonance imaging (MRI) findings of breast hamartomas. MATERIALS AND METHODS Eight patients with breast hamartomas were examined using MRI techniques in addition to ultrasonographic and/or mammographic findings. RESULTS Each of the lesions examined showed a gradual enhancement pattern in its time-signal intensity curve on dynamic contrast-enhanced MRI. On MR spectroscopy, water and lipid peaks were detected that resembled normal breast tissue. The diffusion features of the lesions were variable due to the different ratios of the tissue elements constituting them on diffusion-weighted imaging (DWI). CONCLUSION Advanced MRI findings may clarify diagnoses by providing additional information following sonography, especially in lactating or pregnant women, in whom mammographic examination is not preferred.Öğe Bilateral Anterior Inferior Iliac Spine Avulsion in an Adolescent Soccer Player: A Typical Imitator of Malignant Bone Lesions(Lippincott Williams & Wilkins, 2009) Karakas, Hakki Muammer; Alicioglu, Banu; Erdem, GulnurAvulsion fractures are usually diagnosed easily in acutely presented cases. The diagnosis becomes definite if clinical and radiological follow up reflect the fracture's healing phase. A 13-year-old soccer player with bilateral anterior inferior iliac spine (AIIS) avulsion, who had been examined in other institutions with a pre-diagnosis of malignancy, is reported. Clinically, such cases display the importance of medical management of athletic injuries by specially trained physicians. From the perspective of preventive medicine, the high incidence of AIIS injuries-during soccer games, and the bilateral nature of the damage mandate a review of the training programs and shooting techniques for adolescent players.Öğe Bilateral Giant Benign Cystic Mesothelioma (Peritoneal Inclusion Cysts): Ultrasonography and Magnetic Resonance Imaging Findings(Galenos Yayincilik, 2007) Erdem, Gulnur; Celik, Onder; Hascalik, Seyma; Karakas, Hakki Muammer; Firat, Ahmet KemalPeritoneal inclusion cysts are most common in women of reproductive period and involve the abdomen, pelvis, and retroperitoneum. Generally these cases with a history of previous abdominal surgery present with chronic abdominal and pelvic pain. Peritoneal inclusion cysts are lined with mesothelial cells; this condition has also been referred to as benign cystic mesothelioma. In this study, we present the ultrasonographic and magnetic resonanse imaging (MRI) findings of giant benign cystic mesothelioma in 30-year-old infertil woman and the approaches of the treatment mentioned in literature. On ultrasonography and MRI, peritoneal inclusion cysts are seen as abdominopelvic multiloculated cystic masses. In that case, peritoneal inclusion cysts should be added into the differential diagnosis list in the cases with a history of previous abdominal surgery.Öğe Cystic Adrenal Lymphangioma - Report of two cases and review of the literature(Pakistan Medical Assoc, 2012) Cakir, Ebru; Aydin, N. Engin; Samdanci, Emine; Ates, Mustafa; Elmali, Candan; Sayin, Sadegul; Erdem, GulnurCystic adrenal lymphangiomas are very rare, benign vascular lesions. They are usually found during a work up for abdominal pain or incidentally during imaging studies for an unrelated cause. We report two cases of cystic adrenal lymphangiomas. They presented with flank discomfort, hypertension and flushing. Their laboratory findings were in normal limits. Radio logic imagings showed adrenal cystic neoplasm and the patients underwent adrenelectomy. Histopathologic examination and immunohistochemical findings were consistent with lymphangioma. Cystic lymphangiomas may imitate other adrenal neoplasms and must be kept in mind in the clinical and radiologic differential diagnosis of cystic adrenal lesions.Öğe Diffusion-Weighted Images Differentiate Benign From Malignant Thyroid Nodules(Wiley, 2010) Erdem, Gulnur; Erdem, Tamer; Karakas, Hakki Muammer; Mutlu, Deniz Yakar; Firat, Ahmet Kemal; Sahin, Ibrahim; Alkan, AlpayPurpose: To reveal the possible role of diffusion-weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine-needle aspiration cytology (FNAC). Materials and Methods: In an 18-month period (December 2005 to May 2007), 27 cases with benign thyroid nodules with a total of 52 benign nodules, nine cases with thyroid gland malignancy and 24 healthy control cases were included in the study. Cases that were indicated to undergo to FNAC examination and sent by a clinician for biopsy to the radiology unit were included in the study to assess the cytopathologic confirmation of the clime, ultrasonographic, and magnetic resonance imaging (MRI) findings. Results: The mean apparent diffusion coefficient (ADC) values of thyroid nodules were 2745.3 +/- 601.1 x 10(-6) mm(2)/s (1605-3899 x 10(-6)mm(2)/s) in the benign group and 695.2 +/- 312.5 x 10(-6)mm(2)/s (165-1330 x 10(-6)mm(2)/s) in the malignant group. Normal thyroid tissues had mean ADC values of 1344.1 +/- 276.4 x 10(-6) mm(2)/s (1015-1764 x 10(-6)mm(2)/s). The ADC values of three subgroups were significantly different (P = 0.0001). A reduced ADC was observed in most. types of malignant tumors due to the consequent decrease of the extracellular extravascular space. Conclusion: Our preliminary results showed that ADC values of nodules may provide useful data about the nature of a thyroid nodule.Öğe Diffusion-weighted imaging evaluation of subtle cerebral micro structural changes in intrauterine fetal hydrocephalus(Elsevier Science Inc, 2007) Erdem, Gulnur; Celik, Onder; Hascalik, Seyma; Karakas, Hakki Muammer; Alkan, Alpay; Firat, Ahmet KemalObjective: Hydrocephalus is an important etiological factor in neurological decline. With the advent of fetal ultrasound, fetal hydrocephalus is now more frequently detected than in the past. Ultrasonography (USG) provides information on general morphology, but microstructural changes that may play a prognostic role are beyond the resolution of that technique. These changes may theoretically be revealed by diffusion-weighted magnetic resonance imaging (DW-MRI). In this study, our preliminary findings of DW-MRI on the hydrocephalic fetuses are presented. Materials and Methods: Twelve fetuses with fetal USG diagnosis of hydrocephalus were investigated using a 1.5-T MR scanner. In addition to conventional techniques, DWI was performed. It was obtained using a single-shot echo-planar imaging sequence (TR/TE: 4393/81 ms; slice thickness: 5 mm; interslice gap: 1 mm; FOV: 230 mm; matrix size: 128x256; b values: 0 and 1000 s/mm(2)). Apparent diffusion coefficient (ADC) values were measured in the white matter of the periventricular frontal and occipital lobes, basal ganglia, thalamus, centrum semiovale and cerebrospinal fluid in the lateral ventricle. These values were compared with the normal prenatal ADC values from a radiological study published in the literature. bilateral supratentorial ventricular dilatation that was compatible with hydrocephalus. On conventional T1- and T2-weighted imaging, cerebral parenchyma had normal signal pattern and ADC values were significantly lower than those reported for fetuses with normal brain. These values were lower in hydrocephalic fetuses with statistical significance (P<.05-.01). Conclusion: DWI is a sensitive technique to investigate cerebral microstructure. The reduction in cerebral blood flow and alterations in cerebral energy metabolism in cases with hydrocephalus have been shown before. Changes in cerebral blood flow and energy metabolism, as a consequence of cerebral compression, may occur in hydrocephalus. Elevated ventricular pressure may cause cerebral ischemia. The anaerobic glycolysis seen in the hydrocephalic brain tissue by increasing the lactate concentration and intracellular fluid flux may be the reason for the reduced ADC values in hydrocephalic fetuses. However, long-term prospective trials on the correlation of ADC values and neurological outcome are necessary to exploit the full benefit of that novel technique. (c) 2007 Elsevier Inc. All rights reserved.Öğe Diffusion-weighted imaging features of brain in obesity(Elsevier Science Inc, 2008) Alkan, Alpay; Sahin, Ibrahim; Keskin, Lezan; Cikim, Ayse Sertkaya; Karakas, Hakki Muammer; Sigirci, Ahmet; Erdem, GulnurPurpose: Obesity is characterized by an altered distribution of body fluid. However, distribution of fluid (extracellular/intracellular) in brain tissues has not been studied in obese subjects yet. The purpose of this study was to detect possible brain diffusion changes especially in satiety and hunger related centers in obese subjects by diffusion weighted imaging (DWI). Methods: Conventional MRI and DWI of the brain was obtained from 81 obese patients (obese=68, morbid obese= 13) and 29 age-matched, nonobese. The apparent diffusion coefficient (ADC) values were calculated in hypothalamus; amygdala; hippocampal gyrus-1 thalamus; insula; cingulate gyrus; orbitofrontal, dorsomedial and dorsolateral frontal, middle temporal and occipital cortex; cerebellum; midbrain and corpus striatum. Results: The ADC values of hypothalamus, hippocampal gyrus, amygdala, insula, cerebellum and midbrain were significantly increased in patients (n:81) when compared to nonobese subjects. The ADC values of thalamus, hippocampal gyrus, amygdala, orbitofrontal, occipital, dorsolateral and middle temporal cortex, insula and midbrain were significantly increased in morbid obese when compared to nonobese subjects. The ADC values of orbitofrontal and occipital cortex were significantly higher in morbid obese than the values in the obese. The body mass index positively correlated with ADC values of amygdala, insula, orbitofrontal and middle temporal cortex. Conclusion: We observed increased ADC values of distinct locations related to satiety and hunger that suggest altered fluid distribution and/or vasogenic edema in obese subjects. Awareness of this abnormalities in brain tissue composition/function in obesity may contribute to better understanding of the underlying mechanisms. (0 2008 Elsevier Inc. All rights reserved.Öğe Diffusion-Weighted Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy Features of Abdominal Viscera in a Patient with Gaucher's Disease(Univ Sains Malaysia, Sch Medical Sciences, 2014) Kalayci, Tugce Ozlem; Erdem, Gulnur; Kutlu, Ramazan; Kahraman, Aysegul; Alkan, AlpayA 46-year-old woman with Gaucher's disease (GD) consulted our clinic for abdominopelvic magnetic resonance imaging (MRI), as physical examination had revealed hepatosplenomegaly. Upper abdominal MRI showed massive hepatosplenomegaly and innumerable hypointense splenic nodules on T1-weighted images. Diffusion-weighted MRI (DW-MRI) and magnetic resonance spectroscopy (MRS) were performed to liver parenchyma and splenic nodules. MRS revealed lactate, lipid, acetate, and alanine peaks in splenic nodules, and choline, creatine, lipid, myo-inositolglycine, and lactate peaks in the liver parenchyma. The DW-MRI showed diffusion restriction in splenic nodules. It was concluded that MRI is a reliable method for the diagnosis and follow up of GD. Coupling DW-MRI and MRS allows quantitative evaluation, thereby increasing the efficacy of the method. This is the first report in the literature presenting advanced abdominal MRI findings in GD.Öğe Microstructural Changes in Uterine Leiomyomas and Myometrium: A Diffusion-Weighted Magnetic Resonance Imaging Study(Karger, 2009) Erdem, Gulnur; Celik, Onder; Karakas, Hakki Muammer; Hascalik, Seyma; Firat, Ahmet KemalAlthough morphological and histopathological changes in uterine leiomyomas have been investigated in detail, the microstructural disruptions could not be studied in the living organism. Diffusion-weighted magnetic resonance imaging (DWI) is a novel tool to assess microstructural changes in vivo. The aim of this study was to investigate and characterize the diffusional property of leiomyomatous tissues with DWI. Sixteen females with a total of 21 leiomyomas were imaged with a 1.5-tesla clinical MR scanner. DWI images of leiomyomas, adjacent myometrial and myometrial tissues of healthy controls were obtained and quantified using apparent diffusion coefficient (ADC) maps. Mean ADC values of these groups were 1,201, 1,684, 1,661 mm(2)/s x 10(-6), respectively. ADC values in leiomyomas were significantly lower than those observed in the myometrium (p < 0.001). Cut-off values produced 91% sensitivity and 100% specificity. As ADC values implied the presence of cytotoxic edema in leiomyomas, the technique was found to be promising in observing temporal variations in leiomyomas and to monitor even the most subtle effects of therapeutic interventions. Copyright (C) 2009 S. Karger AG, BaselÖğe Pulmonary Alveolar Microlithiasis and Preterm Delivery: A Case Report(Bilimsel Tip Publishing House, 2014) Erdem, Gulnur; Goktan, Asli; Erbay, Fatih; Baysal, TamerPulmonary alveolar microlithiasis (PAM) is a rare, chronic lung disease characterised by extensive intra-alveolar calcium and phosphorus deposition throughout the parenchyma of both lungs. The etiology and pathogenesis of the disease is unclear. In our case, PAM with pregnancy was presented; respiratory distress had been observed during the first and second trimesters. In the following weeks, premature activity developed and the foetus was not able to stay alive. This is the third case of PAM in pregnancy described in the literature. A 36 year-old female was referred to our emergency department complaining that she had suffered from dyspnoea on a couple of occasions since the first trimestry of her last pregnancy. On suspecting a pulmonary embolism, dynamic thorax multidetector computed tomography (MDCT) was performed after the delivery. MDCT revealed typical PAM findings. In PAM, radiological signs are not compatible with clinical symptoms; thus, the clinical symptoms are not as dramatic as imaging findings. However, it should be taken into consideration that this disease, with no effective treatment, may rarely progress into end stage pulmonary disease due to conditions which alter pulmonary functions, such as pregnancy.Öğe Radiological findings of the primary female urethral malignant melanoma: a rare case report(European journal of therapeutıcs, 2018) Oner, Serkan; Erdem, Gulnur; Özdemir, Zeynep Maraş; Gunes, Ali; Unlu, SerkanPrimary malignant melanomas of the female urethra are rare tumors with poor prognosis. Biopsy of the detected urethral mass was performed in a 71-year-old woman who presented with hematuria and voiding dysfunction. No other localized lesions were detected. The patient was diagnosed with primary malignant melanoma of the urethra according to the histopathologic and immunohistochemical findings. Immunohistochemical staining revealed that the tumor cells were immunoreactive for vimentin, HMB-45, S-100, and Melan-A. The present study aimed to present radiological findings of very rare primary urethral malign melanoma with histopathologic correlation and to review the relevant literature.Öğe Radiological Findings of the Primary Female Urethral Malignant Melanoma: A Rare Case Report(Aves, 2019) Oner, Serkan; Erdem, Gulnur; Ozdemir, Zeynep Maras; Gunes, Ali; Unlu, SerkanPrimary malignant melanomas of the female urethra are rare tumors with poor prognosis. Biopsy of the detected urethral mass was performed in a 71-year-old woman who presented with hematuria and voiding dysfunction. No other localized lesions were detected. The patient was diagnosed with primary malignant melanoma of the urethra according to the histopathologic and immunohistochemical findings. Immunohistochemical staining revealed that the tumor cells were immunoreactive for vimentin, HMB-45, S-100, and Melan-A. The present study aimed to present radiological findings of very rare primary urethral malign melanoma with histopathologic correlation and to review the relevant literature.Öğe SUBAREOLAR BREAST ABSCESS: ADVANCED MAGNETIC RESONANCE IMAGING FINDINGS(Aves, 2008) Erdem, Gulnur; Isik, Burak; Karakas, Hakki Muammer; Firat, Ahmet KemalBreast abscesses are generally seen in women in lactation period and located in the retroareolar and periareolar areas. Occasionally, subareolar abscesses may occur in young and middle aged women in non-lactation. Advanced imaging techniques may be needed to discriminate inflammatory breast carcinomas from subareolar abscesses with high risk of recurrence. We detected multipl breast abscesses in 26 year-old woman in non-lactation period and presented the findings of dynamic magnetic resonance imaging, diffusion-weighted imaging and magnetic resonance spectroscopy in addition to the findings of ultrasonography and conventional magnetic resonance imaging. Although the diagnosis of breast lesions depends basically on clinical findings, mammography and sonography findings, the usefulness of advanced magnetic resonance imaging techniques has been reported increasingly in differential diagnosis. This imaging techniques provide additional information to mammography and ultrasonography by bringing about non-invasive approaches.Öğe The utility of diffusion-weighted imaging to assess acute renal parenchymal changes due to unilateral ureteral stone obstruction(Springer, 2017) Duzenli, Kursat; Ozturk, Mehmet; Yildirim, Ismail Okan; Erdem, GulnurOur aim in this study was to evaluate the use of diffusion-weighted imaging (DWI) for acute renal parenchymal changes occurring as a result of unilateral ureteral obstruction due to stones. Twenty four patients with obstructed and opposite unobstructed kidney were enrolled in this prospective study. DWI was used at two different b values (b = 0 s/mm(2) and b = 1000 s/mm(2)). Apparent diffusion coefficient (ADC) measurements were completed on the upper pole, central section and lower pole parenchyma of both kidneys. ADC values were calculated. The unpaired t test was used to assess differences between the groups. The results of measurements identified a reduction in ADC values in obstructed renal parenchyma compared to unobstructed opposite renal parenchyma. The reduction in ADC values was greater in the upper and lower pole parenchyma and was statistically significant (p < 0.001, for both). Diffusion changes in renal parenchyma due to acute unilateral ureteral obstruction linked to stone may be quantitatively shown with DWI. The reduction in ADC values was more pronounced in the upper and lower pole parenchyma.
