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Dive into the research topics where Nilüfer Yıldırım Poyraz is active.

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Featured researches published by Nilüfer Yıldırım Poyraz.


Renal Failure | 2004

Gastric Emptying in Patients on Renal Replacement Therapy

Galip Guz; Musa Bali; Nilüfer Yıldırım Poyraz; Oktay Bagdatoglu; Zeynep Arzu Yegin; Ibrahim Dogan; Tamer Atasever; Sevki Sert; Sukru Sindel

In addition to gastrointestinal tract symptoms such as nausea, vomiting, and loss of appetite, impaired gastric emptying time (GET) may be related to nutritional parameters and nutritional status of patients on renal replacement therapy (RRT). Patients on RRT are affected by several factors such as uremic toxins, the presence of dialysate in the peritoneal cavity, and the drugs used against renal allograft rejection. In this study, we investigated the gastric emptying time and its relationship with biochemical and nutritional parameters in patients on RRT: those on hemodialysis and peritoneal dialysis, and renal transplantation patients. Seventy‐five patients, 44 on hemodialysis, 16 on peritoneal dialysis, and 15 renal transplant patients, were included in the study. They were examined for gastric emptying time using a radioisotopic method. The results were compared with the GET of healthy subjects. Each group of patients was evaluated in terms of hemoglobin, hematocrit, blood urea nitrogen (BUN), creatinine, blood glucose, total protein, albumin, serum lipids, parathyroid hormone (PTH) and body mass index and biceps and triceps skinfold. The mean GET of patients on RRT was significantly longer than the mean GET of healthy subjects (87.8 ± 23.4 vs. 55 ± 18 min, p < 0.05). The mean GET of each therapy subgroups was significantly longer than the healthy subjects (the mean GET was 85.1 ± 22.4 min for hemodialysis, 87.7 ± 31.8 min for peritoneal dialysis, and 94.6 ± 16.7 min for renal transplant patients, respectively, p < 0.05). On the other hand, the differences in the mean GET between the three therapy subgroups were not statistically significant (p > 0.05). In addition, time on replacement therapy inversely and blood glucose positively correlated with GET in renal transplant patients. In conclusion, GET was longer in patients on all three RRT modalities than in healthy subjects. GET was not significantly different in dialysis patients and renal transplant patients.


Korean Journal of Radiology | 2014

Hot-Clot Artifacts in the Lung Parenchyma on F-18 Fluorodeoxyglucose Positron Emission Tomography/CT due to Faulty Injection Techniques: Two Case Reports

Elif Özdemir; Nilüfer Yıldırım Poyraz; Mutlay Keskin; Zuhal Kandemir; Seyda Turkolmez

F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.


Molecular Imaging and Radionuclide Therapy | 2014

Predictors and Diagnostic Significance of the Adenosine Related Side Effects on Myocardial Perfusion SPECT/CT Imaging

Nilüfer Yıldırım Poyraz; Elif Özdemir; Barış Mustafa Poyraz; Zuhal Kandemir; Mutlay Keskin; Şeyda Türkölmez

Objective: The aim of this study was to investigate the relationship between patient characteristics and adenosine-related side-effects during stress myocard perfusion imaging (MPI). The effect of presence of adenosine-related side-effects on the diagnostic value of MPI with integrated SPECT/CT system for coronary artery disease (CAD), was also assessed in this study. Methods: Total of 281 patients (109 M, 172 F; mean age:62.6±10) who underwent standard adenosine stress protocol for MPI, were included in this study. All symptoms during adenosine infusion were scored according to the severity and duration. For the estimation of diagnostic value of adenosine MPI with integrated SPECT/CT system, coronary angiography (CAG) or clinical follow-up were used as gold standard. Results: Total of 173 patients (61.6%) experienced adenosine-related side-effects (group 1); flushing, dyspnea, and chest pain were the most common. Other 108 patients completed pharmacologic stress (PS) test without any side-effects (group 2). Test tolerability were similar in the patients with cardiovascular or airway disease to others, however dyspnea were observed significantly more common in patients with mild airway disease. Body mass index (BMI) ≥30 kg/m2 and age ≤45 years were independent predictors of side-effects. The diagnostic value of MPI was similar in both groups. Sensitivity of adenosine MPI SPECT/CT was calculated to be 86%, specificity was 94% and diagnostic accuracy was 92% for diagnosis of CAD. Conclusion: Adenosine MPI is a feasible and well tolerated method in patients who are not suitable for exercise stress test as well as patients with cardiopulmonary disease. However age ≤45 years and BMI ≥30 kg/m2 are the positive predictors of adenosine-related side-effects, the diagnostic value of adenosine MPI SPECT/CT is not affected by the presence of adenosine related side-effects.


Molecular Imaging and Radionuclide Therapy | 2012

Additional Value of SPECT/CT to Tc-99m MAG3 Renal Scintigraphy in the Diagnosis of a Patient with Ureteroileal Fistula

Nilüfer Yıldırım Poyraz; Elif Özdemir; Mutlay Keskin; Şeyda Türkölmez

We performed Tc-99m MAG3 dynamic renal scintigraphy followed by a SPECT/CT imaging to a 38-yr-old woman who had a fistula in the lower urinary tract after a gynecological operation for diagnostic purposes. After scintigraphy, CT and fusion images were evaluated, it was observed that the activity in the right lower quadrant was actually in the ileal lumen. When early and late SPECT/CT images were compared, it was seen that the activity was moving distally with intestinal peristaltism. The reason for diagnostic imaging of the fistulas is not only to show the existence of the fistula but also locate it anatomically before the surgery. SPECT systems integrated with CT scanning provide functional and anatomical imaging at the same session. Dynamic renal scintigraphy and abdominal SPECT/CT, is a safe diagnostic procedure in visualization of urinary tract fistulas with advantages of the low cost, low radiation exposure and easier tolerability compared to double contrast imaging. Conflict of interest:None declared.


Revista Espanola De Medicina Nuclear | 2014

18F-FDG PET/CT findings in a case with HIV (−) Kaposi Sarcoma

Elif Özdemir; Nilüfer Yıldırım Poyraz; Mutlay Keskin; Zuhal Kandemir; Seyda Turkolmez

Although mucocutaneous sites are the most frequently encountered sites of involvement, Kaposi Sarcoma (KS) may also occasionally involve the breast and the skeletal, endocrine, urinary and nervous systems.. Various imaging modalities may be used to delineate the extent of the disease by detecting unexpected sites of involvement. Herein, we report a case of classical type KS, in whom staging with (18)F-FDG PET/CT imaging disclosed widespread disease and unexpected findings of bone and salivary gland involvement.


Bozok Tıp Dergisi | 2014

TANI AMAÇLI UYGULANAN İYOT-131 İLE ABLATE OLAN EKTOPİK TİROİD DOKUSU: OLGU SUNUMU

Celil Alper Usluoğullari; Fevzi Balkan; Elif Özdemir; Nilüfer Yıldırım Poyraz; Fatma Sağlam; Şahin Doğanay; Reyhan Ersoy; Bekir Cakir

The presence of ectopic thyroid tissue has been reported at a rate of 10% in autopsy studies. The significance of ectopic thyroid tissue among asymptomatic individuals is unknown. However, there are reports in literature suggesting an increased risk of thyroid cancer in the presence of ectopic thyroid tissue. Iodine-131 is used for detecting ectopic thyroid tissue. Screening scintigraphy is performed using low doses (2-5 mCi). Iodine-131 given for ablative purposes is approximately 6 MBq (160 μCi) per gram of thyroid gland. In this report 42-year-old woman who underwent bilateral subtotal thyroidectomy 14 years ago, with a diagnosis of diffuse toxic goiter was performed completion thyroidectomy with a diagnosis of recurrent nodular diffuse toxic goiter. At six months after the operation, midline, at the level of the hyoid bone, 12X24 mm in size, ectopic thyroid tissue was present in patient. “Atypia of undetermined significance” was reported in FNA results. The thyroglobulin level was 300 in washing samples drawn up during FNA. In order to evaluate the presence of malignancy and metastasis, wholebody scan with 3 mCi of iodine-131 was performed and only the activity accumulation leads to star artifact was observed in the neck. Ectopic thyroid tissue was not observed in the neck ultrasound performed after three months because of cytologic findings . There was no findings to suggest ectopic thyroid tissue in the thyroid scintigraphy after cessation treatment of L-thyroxine. It was concluded that thyroid tissue was ablated after application of iodine-131 treatment.


Annals of Nuclear Medicine | 2014

Diagnostic value of 18F-FDG PET/CT in patients with TENIS syndrome: correlation with thyroglobulin levels

Elif Özdemir; Nilüfer Yıldırım Poyraz; Sefika Burcak Polat; Seyda Turkolmez; Reyhan Ersoy; Bekir Cakir


Malecular Imaging and Radionuclide Therapy | 2015

18F-FDG PET/CT Findings of a Patient with Wegener’s Granulomatosis Before and After Therapy

Elif Özdemir; Nilüfer Yıldırım Poyraz; Ayşegül Şentürk; Ebru Uz; Mutlay Keskin; Levent Yüksel; Zuhal Kandemir; Şeyda Türkölmez


Gazi Medical Journal | 2015

Kemik Sintigrafisinde Metastazı Taklit Eden İnguinal Mesane Hernisi: Tanıda SPECT/BT’nin Katkısı

Elif Özdemir; Şule Vicdan Kılınç; Nilüfer Yıldırım Poyraz; Sabire Yilmaz Aksoy; Zuhal Kandemir; Mutlay Keskin; Şeyda Türkölmez


Gulhane Medical Journal | 2014

The spinal nerve invasion detected with FDG-PET/CT in an operated patient with penile cancer:A case report

Zuhal Kandemir; Elif Özdemir; Nilüfer Yıldırım Poyraz; Hatice Filiz Erdil; Mutlay Keskin; Şeyda Türkölmez

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Elif Özdemir

Yıldırım Beyazıt University

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Zuhal Kandemir

Yıldırım Beyazıt University

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Seyda Turkolmez

Yıldırım Beyazıt University

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Bekir Cakir

Yıldırım Beyazıt University

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Aylin Kilic Yazgan

Yıldırım Beyazıt University

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Cevdet Aydin

Yıldırım Beyazıt University

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