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Öğe Acoustic radiation force impulse (ARFI) elastography for detection of renal damage in children(Springer, 2015) Goya, Cemil; Hamidi, Cihad; Ece, Aydin; Okur, Mehmet Hanifi; Tasdemir, Bekir; Cetincakmak, Mehmet Guli; Hattapoglu, SalihAcoustic radiation force impulse (ARFI) imaging is a promising method for noninvasive evaluation of the renal parenchyma. To investigate the contribution of ARFI quantitative US elastography for the detection of renal damage in kidneys with and without vesicoureteral reflux (VUR). One hundred seventy-six kidneys of 88 children (46 male, 42 female) who had been referred for voiding cystourethrography and 20 healthy controls were prospectively investigated. Patients were assessed according to severity of renal damage on dimercaptosuccinic acid (DMSA) scintigraphy. Ninety-eight age- and gender-matched healthy children constituted the control group. Quantitative shear wave velocity (SWV) measurements were performed in the upper and lower poles and in the interpolar region of each kidney. DMSA scintigraphy was performed in 62 children (124 kidneys). Comparisons of SWV values of kidneys with and without renal damage and/or VUR were done. Significantly higher SWV values were found in non-damaged kidneys. Severely damaged kidneys had the lowest SWV values (P < 0.001). High-grade (grade V-IV) refluxing kidneys had the lowest SWV values, while non-refluxing kidneys had the highest values (P < 0.05). Significant negative correlations were found between the mean quantitative US elastography values and DMSA scarring score (r = -0.788, P < 0.001) and VUR grade (r = -0.634, P < 0.001). SWV values of the control kidneys were significantly higher than those of damaged kidneys (P < 0.05). Our findings suggest decreasing SWV of renal units with increasing grades of vesicoureteric reflux, increasing DMSA-assessed renal damage and decreasing DMSA-assessed differential function.Öğe Assessment of Technetium-99m Labeled Macroaggregated Albumin Rhinoscintigraphy for the Measurement of Nasal Mucociliary Transport Rate: Intratest, Interobserver, and Intraobserver Reproducibility(Hindawi Ltd, 2014) Dostbil, Zeki; Dag, Yusuf; Cetinkaya, Ozlem; Akdag, Mehmet; Tasdemir, BekirObjectives. The measurement of mucociliary transport velocity by rhinoscintigraphy with Tc-99m-macroaggregated albumin (Tc-99m-MAA) is reliable measure of mucociliary clearance. The aim of this study is to assess the intratest, interobserver, and intraobserver reproducibility of nasal mucociliary transport rate (NMTR) measurement. Materials and Methods. Twenty-two subjects were evaluated to determine intratest reproducibility and a group of 35 subjects was examined to determine inter and intraobserver reproducibility. Rhinoscintigraphy with Tc-99m-MAA was used to measure NMTR in all study subjects. Paired NMTR measurements were compared using a range of statistical methodologies. Intraclass correlation coefficients (ICC) and repeatability coefficients and Bland-Altman plots were applied to assess the degree of intratest, interobserver, and intraobserver variation. Results. Statistical analysis of test and retest experiments demonstrated the statistical equivalence of intratest NMTR measurements, interobserver NMTR measurements, and intraobserver NMTR measurements. The intratest ICC, interobserver ICC, and intraobserver ICC were 0.96, 0.83, and 0.91, respectively, indicating that intratest and intraobserver reproducibility are excellent and interobserver reproducibility is good. Conclusions. Rhinoscintigraphy using Tc-99m-MAAresults in highly reproducible measurement of NMTR. The use of radionuclide imaging in measuring NMTR results in excellent intratest and intraobserver reproducibility and good interobserver reliability.Öğe Comparison of 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT in patients with non-small cell lung cancer(Lippincott Williams & Wilkins, 2022) Can, Canan; Kepenek, Ferat; Komek, Halil; Gundogan, Cihan; Kaplan, Ihsan; Tasdemir, Bekir; Guzel, YunusAim In this study, we aimed to compare the diagnostic accuracy of F-18-fluorodeoxyglucose (F-18-FDG) and Gallium-68 labeled fibroblast activator protein inhibitor (Ga-68-FAPI)-04 PET/CT in the tumor-node-metastasis (TNM) staging of patients with nonsmall cell lung cancer (NSCLC) and investigate whether adenocarcinoma (ADC) and squamous cell cancer (SCC) exhibit different uptake patterns on Ga-68-FAPI-04 PET/CT. Materials and method Twenty-nine patients with a histopathologically-confirmed diagnosis of NSCLC, who had no history of previous radiation therapy or chemotherapy and underwent F-18-FDG PET/CT and Ga-68-FAPI-04 PET/CT imaging between January 2021 and December 2021 were included in this retrospective study. Staging was performed using the 8th edition of the TNM staging system on both F-18-FDG PET/CT and Ga-68-FAPI-04 PET/CT images. Standardized uptake value (SUV)(max) and tumor-to-background ratios (TBR) were calculated on primary lesions and metastases. Results There was no statistically significant difference in primary lesions in terms of SUVmax and TBR values. However, Ga-68-FAPI-04 PET/CT was significantly superior to F-18-FDG PET/CT in terms of the number of lymph nodes and bone metastases revealed. The SUVmax and TBR values of lymph nodes, hepatic lesions and bone lesions were significantly higher on Ga-68-FAPI-04 PET/CT than on F-18-FDG PET/CT. Ga-68-FAPI-04 PET/CT changed the disease stage of three patients (10.9%). The diagnostic accuracy of Ga-68-FAPI-04 PET/CT was 100%, whereas the diagnostic accuracy of F-18-FDG PET/CT was 89.6% (P = 0.250). Conclusion Although Ga-68-FAPI-04 PET/CT detected more lesions and higher diagnostic accuracy than F-18-FDG PET/CT in NSCLC, neither method was statistically superior to each other in terms of diagnostic accuracy in TNM staging.Öğe A comparison of acoustic radiation force impulse imaging and scintigraphy in the functional evaluation of the major salivary glands(Lippincott Williams & Wilkins, 2015) Tasdemir, Bekir; Goya, Cemil; Dostbil, Zeki; Sengul, Engin; Sezgin, Ilhan; Hattapoglu, SalihPurpose This study aimed to determine the efficacy of acoustic radiation force impulse (ARFI) imaging for the functional assessment of salivary glands by comparing ARFI with salivary gland scintigraphy. Materials and methods We prospectively evaluated 60 parotid (P) glands and 60 submandibular (SM) glands of 30 patients using salivary gland scintigraphy and ARFI elastography. The average pixel uptake and the excretion fraction (EF) in the P and SM glands were determined scintigraphically. The degree of stiffness in the P and SM glands at prelemon and postlemon stimulation periods were measured elastographically with ARFI. Changes in the degree of stiffness of the P and SM glands were also calculated with lemon stimulation. The scintigraphic and elastographic parameters were then compared statistically. Results We found a moderate linear correlation between the excretion function and the changes in the degree of stiffness of the P and SM glands induced by lemon stimulation (P<0.001, r=0.661; P<0.001, r=0.530, respectively). We also found a weak positive correlation between the EF and the degree of stiffness of the P and SM glands in the prelemon stimulation period (P=0.001, r=0.405; P<0.001, r=0.480, respectively). However, we did not find any significant correlation between other scintigraphic and elastographic parameters. Conclusion ARFI imaging may play a role in the determination of the EF of P and SM glands by measuring tissue elasticity changes with lemon stimulation. However, ARFI does not seem to be a suitable substitute for scintigraphy in the evaluation of the parenchymal function of P and SM glands. Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.Öğe Effect of R-CHOP chemotherapy on liver and mediastinal blood pool 18F-FDG standardized uptake values in patients with non-Hodgkin's lymphoma(Elsevier Science Inc, 2015) Kaya, Bugra; Dostbil, Zeki; Ismailoglu, Murat; Tasdemir, Bekir; Sahin, OzlemAim: We aimed to investigate the impact of chemotherapy on F-18-FDG uptake in the liver and mediastinal blood pool (MBP) among patients with non-Hodgkin's lymphoma. Methods: Twenty-three patients with NHL underwent baseline, interim, and postchemotherapy F-18-FDG PET/CT. SUVmax and SUVmean values of the liver and MBP at imaging time were compared statistically. Results: We did not find any significant differences between the liver and mediastinum SUVmean and SUVmax values (P>.05). Conclusions: Our study demonstrates that the F-18-FOG uptake in the liver and MBP are not significantly affected by R-CHOP chemotherapy in patients with NHL. (C) 2015 Elsevier Inc. All rights reserved.Öğe Effectiveness of the addition of the brain region to the FDG-PET/CT imaging area in patients with suspected or diagnosed lung cancer(Springer-Verlag Italia Srl, 2016) Tasdemir, Bekir; Urakci, Zuhat; Dostbil, Zeki; Unal, Kemal; Simsek, F. Selcuk; Teke, Fatma; Goya, CemilPurpose We aimed to evaluate the effectiveness of the brain region imaging in FDG-PET/CT scanning of patients with suspected or diagnosed lung cancer. Materials and methods We performed the study retrospectively on the medical charts of 427 patients. We divided the FDG-PET/CT field of view (FOV) into four major imaging regions: brain, head-neck, abdomen and pelvis. Metastatic findings on these regions were checked and determined the potential of these findings to affect the chemotherapy or radiotherapy protocol or surgical management. If metastatic findings had a potential to modify these parameters, we named this situation as clinical contribution. Considering the number of bed positions of these regions, we calculated the clinical contribution of each region and named as effective clinical contribution. Then, we calculated the metastatic findings, clinical contribution, and effective clinical contribution ratios. Results We found different brain metastasis ratios for lung cancer, solitary pulmonary mass (SPM), and solitary pulmonary nodule (SPN) groups (8.7, 2.8 and 0.9 %, respectively). In addition, the clinical contribution and effective clinical contribution ratios in the brain region for these three groups were 6.4, 2.8, 0.0 and 6.4, 2.8, 0.0 %, respectively. The highest metastatic findings (30.6 %) and clinical contribution (9.8 %) ratios were found in the abdomen region of the lung cancer group. However, the highest effective clinical contribution ratio (6.8 %) was found in the brain region within the same group. Conclusions The addition of the brain region to the limited whole-body FOV in FDG-PET/CT scanning seems to be effective in the lung cancer and SPM groups, but not in the SPN group.Öğe Evaluation of Clinical Contributions Provided by Addition of the Brain, Calvarium, and Scalp to the Limited Whole Body Imaging Area in FDG-PET/CT Tumor Imaging(Hindawi Ltd, 2014) Tasdemir, Bekir; Dostbil, Zeki; Inal, Ali; Unal, Kemal; Yildirim, Sule; Simsek, F. SelcukPurpose. The aim of this study was to detect additional findings in whole body FDG-PET/CT scan including the brain, calvarium, and scalp (compared to starting from the base of the skull) in cancer patients and to determine contributions of these results to tumor staging and treatment protocols. Materials and Methods. We noted whether the findings related to the brain, calvarium, and scalp in 1359 patients had a potential to modify staging of the disease, chemotherapy protocol, radiotherapy protocol, and surgical management. We identified rates of metastatic findings on the brain, calvarium, and scalp according to the tumor types on FDG-PET/CT scanning. Results. We found FDG-PET/CT findings for malignancy above the base of the skull in 42 patients (3.1%), one of whom was a patient with an unknown primary tumor. Twenty-two of the metastatic findings were in the brain, 16 were in the calvarium, and two were in the scalp. Conclusion. This study has demonstrated that addition of the brain to the limited whole body FDG-PET/CT scanning may provide important contributions to the patient's clinical management especially in patients with lung cancer, bladder cancer, malignant melanoma, breast cancer, stomach cancer, and unknown primary tumor.Öğe Evaluation of dual time-point fluorodeoxyglucose PET/computed tomography imaging in gastric cancer(Lippincott Williams & Wilkins, 2020) Tasdemir, Bekir; Guzel, Yunus; Komek, Halil; Can, CananBackground We aimed to evaluate the efficiency of dual time-point fluorodeoxyglucose (FDG) PET/computed tomography (CT) imaging in detecting primary and metastatic lesions in gastric cancer. Methods Between May 2019 and January 2020, 52 patients with gastric carcinoma were prospectively involved in our study. And dual time-point FDG PET/CT imaging performed to the patients. Of detected primary and metastatic lesions, the ones that are better visualized or only appear in delayed imaging were visually identified. Also, maximum standardized uptake value (SUVmax) of the primary and metastatic lesions and the intact liver tissue were measured in early and delayed imaging. Acquired SUVmax values and SUVmax ratios were compared statistically. Results In delayed images, lesions were better visualized in 32 patients (61.5%) and extra lesions were detected in 4 patients (7.7%). SUVmax of primary tumor, SUVmax of liver metastases, SUVmax of lymph node metastases, primary tumor SUVmax/liver SUVmax ratio and lymph node metastasis SUVmax/liver SUVmax ratio were significantly higher in delayed images (P < 0.001, P = 0.022, P < 0.001, P < 0.001, P < 0.001, respectively). However, SUVmax of liver parenchyma was significantly lower in delayed images (P < 0.001). Conclusions There is a visually and statistically significant increase in the number and detectability of lesions seen in delayed images and dual time-point FDG PET/CT imaging seems useful in detecting primary and metastatic lesions in gastric cancer.Öğe Evaluation of Parathyroid Lesions With Point Shear Wave Elastography(Amer Inst Ultrasound Medicine, 2016) Hattapoglu, Salih; Goya, Cemil; Hamidi, Cihad; Tasdemir, Bekir; Alan, Bircan; Durmaz, Mehmet Sedat; Teke, MemikObjectives-The aim of our study was to evaluate the shear wave velocity (SWV) of parathyroid lesions by point shear wave elastography (SWE) and to compare their stiffness with that of thyroid nodules and normal thyroid parenchyma quantitatively. Methods-Thirty-six patients considered to have parathyroid disorders by clinical and laboratory tests and scintigraphy were enrolled in the study between January 2012 and February 2015. Conventional sonography, Doppler sonography, and the Virtual Touch tissue quantification (VTQ) method of point SWE (Siemens Medical Solutions, Mountain View, CA) were conducted with a linear transducer (4-9 MHz) while the patients were in the supine position. Then we compared our VTQ measurements with pathologic results. Results-The 36 patients included 31 female and 5 male patients with a mean age +/- SD of 49 +/- 15.7 years (range, 15-79 years). The mean SWV of parathyroid hyperplasia lesions (n = 4) was 1.46 +/- 0.23 m/s, whereas the mean SWV of parathyroid adenomas (n = 32) was 2.28 +/- 0.50 m/s. The mean SWV of normal thyroid parenchyma (n = 36) was 1.62 +/- 0.20 m/s, and the mean SWV of benign thyroid nodules (n = 21) was 2.25 +/- 0.51 m/s. A significant difference was found between SWV values of normal thyroid parenchyma and parathyroid adenoma (P<.001). A cutoff value of 1.73 m/s for adenomas led to 90.0% sensitivity and 80.6% specificity. Conclusions-The VTQ method of point SWE may contribute to the discrimination of parathyroid adenomas from the thyroid gland. However, more comprehensive studies are needed.Öğe Exploring 18 F-FDG uptake patterns in liver, spleen, and bone marrow: Implications for inflammatory and infectious conditions(Hellenic Soc Nuclear Medicine, 2024) Tuzcu, Sadiye Altun; Cetinkaya, Erdal; Guzel, Fatih; Cetin, lbey Erkin; Mete, Umit; Argin, Esref; Tasdemir, BekirObjective: This study aimed to explore the relationship between fluorine-18-fluorodeoxyglucose (F-18-FDG) uptake in the liver, spleen, and bone marrow and inflammatory markers such as c-reactive protein (CRP), albumin, and erythrocyte sedimentation rate (ESR) in patients undergoing positron emission tomography/computed tomography (PET/CT) imaging for cancer diagnosis. Subjects and methods: This retrospective cross-sectional study included a total of 708 patients with a diagnosis of malignancy. Fluorine-18-FDG PET/CT images acquired between January 2021 and December 2022. Exclusion criteria comprised prior chemotherapy, radiotherapy, hematological malignancies, or liver/spleen tumors. Statistical analysis included correlation analysis, univariate, and multivariate regression analysis. Results: C-reactive protein levels demonstrated a significant positive correlation with F-18-FDG uptake in the spleen (r=0.104, P=0.006) and bone marrow (r=0.112, P=0.003). Albumin showed a negative correlation with liver F-18-FDG uptake (r=-0.220, P<0.001). Regression analysis revealed ESR's impact on spleen-to-liver (P=0.023) and bone marrow-to-liver (P=0.012) F-18-FDG uptake. Conclusion: This study demonstrates the association between inflammatory markers and F-18-FDG uptake in liver, spleen and bone marrow. C-reactive protein and ESR showing significant correlations with spleen and bone marrow F-18-FDG uptake, and albumin correlated with liver F-18-FDG uptake negatively. Erythrocyte sedimentation rate had significant impact on spleen and bone marrow F-18-FDG uptakes. These findings suggest the potential of F-18-FDG PET/CT in diagnosing inflammatory conditions, warranting further investigation into its clinical implications.Öğe Improvement of minimally invasive parathyroidectomy outcomes by real time ultrasonography performed by a surgeon and radiologist team(Soc Romana Ultrasonografe Medicina Biologie-Srumb, 2015) Uslukaya, Omer; Gumus, Metehan; Tasdemir, Bekir; Goya, Cemil; Kilinc, Faruk; Oguz, Abdullah; Turkoglu, AhmetAims: Minimally invasive parathyroidectomy (MIP) has become the first line of treatment for primary hyperparathyroidism caused by solitary parathyroid adenoma. In order to increase the sensitivity of high-resolution ultrasonography (hUS), surgeon performed ultrasonography (SUS) has been increasingly used preoperatively. However, a radiologist and surgeon performing ultrasonography (RSUS) has not been a usual practice. In this study, we aimed to evaluate the clinical contribution of RSUS on MIP. Material and methods: From 2012 to 2014, a total of 30 consecutive patients (4 male, 26 female, mean age 48.87 +/- 14.52 years) with solitary parathyroid adenoma, were included in the study. All patients underwent preoperative hUS and Technetium-99m sestamibi scintigraphy. In patients, demographic characteristics, diagnostic tools used, levels of biochemical parameters, duration of operation, and length of hospital stay were recorded. Results: Adenomas were successfully localized by US in all patients and the surgical approach was determined according to this localization. Parathyroidectomy with MIP was successfully performed under local anesthesia in all patients. Mean operation time was 19.87 +/- 3.35 min. Postoperative PTH and calcium values were significantly decreased. All patients were discharged from the hospital in the same day. None of the patients had complications such as recurrent laryngeal nerve injury, hematoma, or injury to nearby organs. None of the patients had drains placed. Conclusions: Adenoma is well localized by US and thus, MIP can be completed under local anesthesia. US provides a very important clinical contribution to the success of MIP. In addition to these, RSUS helps in determining the location of the incision and the shortest way to achieve the lesion; therefore, it provides a small incision and shortens duration of the operation with a minimal dissection.Öğe Local imaging to interpret tumor size in F18 fluorodeoxyglucose positron emission tomography/CT in lung cancers(Assoc Medica Brasileira, 2024) Tuzcu, Sadiye Altun; Kaplan, Ihsan; Ibiloglu, Ibrahim; Uyar, Ali; Guzel, Fatih; Guzel, Yunus; Tasdemir, BekirOBJECTIVE: This study aimed to determine the thoracic and extra-thoracic extension of the disease in patients diagnosed with lung cancer and who had whole-body F18-fluorodeoxyglucose positron emission tomography/CT imaging and to investigate whether there is a relationship between tumor size and extrathoracic spread. METHODS: A total of 308 patients diagnosed with lung cancer were included in this study. These 308 patients were first classified as group 1 (SPN 30 mm>longest lesion diameter >= 10 mm) and group 2 (lung mass (longest lesion diameter >= 30 mm), and then the same patients were classified as group 3 (nodular diameter of <= 20 mm) and group 4 (nodular size of >20 mm). Group 1 was compared with group 2 in terms of extrathoracic metastases. Similarly, group 3 was compared with group 4 in terms of frequency of extrathoracic metastases. F18 fluorodeoxyglucose positron emission tomography/CT examination was used to detect liver, adrenal, bone, and supraclavicular lymph node metastasis, besides extrathoracic metastasis. RESULTS: Liver, bone, and extrathoracic metastasis in group 1 was statistically lower than in group 2 (p<0.001, p<0.01, and p=0.03, respectively). Liver, extrathoracic, adrenal, and bone metastasis in group 3 was statistically lower than that in group 4 (p<0.001, p=0.01, and p=0.04, p<0.01, respectively). The extrathoracic extension was observed in only one patient in group 3. In addition, liver, adrenal, and bone metastases were not observed in group 3 patients. CONCLUSION: Positron emission tomography/CT may be more appropriate for cases with a nodule diameter of <= 20 mm. Performing local imaging in patients with a nodule diameter of <= 20 mm could reduce radiation exposure and save radiopharmaceuticals used in positron emission tomography/CT imaging.Öğe What approach should we take for the incidental finding of increased 18F-FDG uptake foci in the colon on PET/CT?(Lippincott Williams & Wilkins, 2015) Simsek, Fikri S.; Ispiroglu, Murat; Tasdemir, Bekir; Koroglu, Reyhan; Unal, Kemal; Ozercan, Ibrahim H.; Entok, EmreIntroduction F-18-Fluorodeoxyglucose (F-18-FDG) PET/CT represents an imaging modality that is gaining increasingly more prominence in screening, staging, and therapeutic monitoring of malignant diseases. An incidental focus of uptake in different regions of the body is not an uncommon finding during PET/CT imaging. Patients with incidental gastrointestinal tract findings comprise approximate to 3% of the overall patient group. The aim of the current study was to provide contributory information in relation to the answer on the most appropriate approach in cases with incidental colonic F-18-FDG uptake. Patients and methods A retrospective examination was performed on PET/CT results of 5258 patients. Of these, 152 were recommended to undergo colonoscopy because of the presence of suspicious foci and 31 underwent colonoscopy within 60 days with biopsy from all visible lesions. These dates were also examined. Results Of the 24 patients undergoing colonoscopy with a suspicion of malignancy, five (20.83%) had no pathological findings. Of the 19 (79.17%) cases with a pathological finding in endoscopy, histopathology showed a benign lesion in five (20.83%), premalignant lesion in seven (29.17%), and a malignant lesion in seven (29.17%). Among seven patients undergoing colonoscopy because of a suspicion of inflammatory bowel disease, five were free of pathological signs and two patients with pathological endoscopy findings had nonspecific inflammation as documented by histopathological examination. Conclusion Colonoscopic and histopathological examination of the increased foci of colonic F-18-FDG uptake incidentally detected at PET/CT seems to be a plausible approach. Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.
