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Amaç: Bu çalışmada 3 boyutlu yazıcıyla farklı sıcaklıklarda, akış oranlarında ve dolgu oranlarında elde edilen örnek baskıların radyolojik özellik bakımından doku eşdeğerliklerinin değerlendirilmesi amaçlanmmıştır.Gereç ve Yöntem: Çalışma kapsamında Ultimaker 3 Extended marka 3 boyutlu yazıcı ve LW-PLA filament kullanılmıştır. 195oC, 200oC ve 205oC olmak üzere 3 farklı baskı sıcaklığı, %60, %80 ve %100 olmak üzere 3 farklı akış oranı ve %90 ile %100 olmak üzere 2 farklı dolgu oranı kullanılarak toplamda 18 silindir baskı elde edilmiştir. Her bir baskı 1 cm çapında ve 3 cm boyundadır. Elde edilen baskıların yoğunlukları hesaplandıktan sonra Philips Brilliance marka 128 kesitli bilgisayarlı tomografi cihazında görüntüleri alınmıştır. Görüntülerde her bir baskıya ait 5 farklı kesitte ortalama Hounsfield Unit değerleri ve bu değerlerin standart sapmaları kaydedilmiştir. 5 kesit üzerinden alınan ortalama HU ve standart sapma değerleri baskı parametrelerine göre değerlendirilmiştir.Bulgular: Elde edilen baskılara ait yoğunluk değerleri 0.63 g/cm3 ile 1.19 g/cm3 arasındadır. Yoğunluk değerlerinin akış oranı ve dolgu oranıyla doğrudan ilişkili olduğu gözlenmiştir. Baskılara ait ortalama Hounsfield Unit değerlerinin ise -450 ile +73 arasında değiştiği gözlenmiştir. Buna karşılık standart sapma değerleri ise ±6 ile ±25 arasında kaydedilmiştir. Ortalama Hounsfield Unit değerlerinin artan sıcaklık, akış oranı ve dolgu oranıyla arttığı gözlenmiştir. Standart sapma değerlerinin ise artan baskı sıcaklıklarında azaldığı gözlenmiştir.Sonuç: Rutin bilgisayarlı tomografi incelemelerde görüntülenen farklı dokulara ait ortalama Hounsfield Unit değerleri düşünüldüğünde, LW-PLA filamenti kullanılarak farklı baskı parametrelerinde elde edilen örneklerin birçok farklı yumuşak dokuyu temsil edebilecek radyolojik özelliklere sahip olabileceği sonucuna ulaşılmıştır., Purpose: In this study, it is aimed to evaluate the radiological tissue equivalency of different 3D printed samples obtained at different printing temperatures, flow rates and infill rates.Materials and Methods: Ultimaker 3 Extended 3D printer and LW-PLA filament were used witin the scope of this study. A total of 18 cylinders were printed by using 3 different printing temperatures of 195°C, 200oC and 205oC, 3 different flow rates of 60%, 80% and 100%, and 2 different infilling rates of 90% and 100%. Each sample is obtained 1 cm in diameter and 3 cm in height. After calculating the densities of the samples, they were imaged by a Philips Brilliance 128-slice computed tomography scanner. In the images, the average Hounsfield Unit values and the standard deviations of these values were recorded at 5 different axial positions for each sample. The mean HU and standard deviation values recorded over 5 slices were evaluated according to the printing parameters.Results: Density of the samples are obtained between 0.63 g/cm3 and 1.19 g/cm3. It was observed that the density of the samples were directly proportional to the flow rate and the infill rate. In addition, the average Hounsfield Unit values of the samples varied between -450 and +73. On the other hand, the standard deviation values were recorded between ±6 and ±25. It was observed that the mean Hounsfield Unit values increased with increasing temperature, flow rate and infill rate. The standard deviation values decreased with increasing printing temperatures.Conclusion: Considering the mean Hounsfield Unit values of different tissues imaged in routine computed tomography examinations, it is concluded that the samples obtained at different printing parameters using LW-PLA filament may have radiological properties that can represent many soft tissues.

Purpose The main acute and late effects of ionizing radiation on living organisms are the formation of reactive oxygen species (ROS), apoptosis and DNA damage. Since the Rac1 molecule is a subunit of the NADPH oxidase enzyme, it is known to participate in the generation of ROS. The aim of this study was to investigate the role of Rac1 molecule in testicular damage induced by low (0.02 Gy), medium (0.1 Gy) and high (5 Gy) dose irradiation. Material and method In this study, Wistar rats (except the control group) were received whole body X-ray irradiation. Testicular tissues were removed 2 hours, 24 hours and 7 days after radiation exposure. Testicular damage was examined by hematoxylin-eosin staining and Johnsen's score. Immunohistochemical staining and G-LISA method were used to determine Rac1 expression and activation. To evaluate the generation of ROS in the testicular tissues, intracellular ROS, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured. Results Increases in testicular damage were detected in all radiation exposed groups in a dose- and time-dependent manner. Compared to the control group, Rac1 expression decreased in all irradiated groups, while Rac1 activation increased. In addition, intracellular ROS and MDA levels were increased and SOD activity levels decreased in the irradiated groups compared to the control group. Conclusion Our findings suggest that Rac1 has a role in the increase of intracellular ROS and lipid peroxidation which led to an increase in radiation- induced testicular damage.

Objectives: Dentists use dental imaging methods frequently in the diagnosis and treatment of dental diseases. This study aimed to determine dentists' knowledge, attitudes, and behaviors about radiation protection during dental imaging procedures. Methods: Dentists from two major dental health centres in İzmir province were asked to participate in this study. The participants replied to a questionnaire that consisted of questions on the use of radiographic devices, knowledge on the radiation protection of patients and staff, and attitudes and behaviors regarding radiation protection. The questionnaire also included questions about the socio-demographic characteristics of the participants. Descriptive statistics of data were performed using the SPSS software program. Results: Sixty-six dentists participated in the survey. The mean knowledge score of dentists on dental imaging, radiation, and radiation protection was 8.3 ± 2.6 out of 17, while the mean attitude and behavior score was 8.3 ± 2.1 out of 27.97% of the participants stated that medical imaging technicians should carry out imaging procedures. The use of rectangular collimators was 9.1%, and using E/F film was 56.3% among dentists. 23.3% of participants stated that they applied the bisecting angle technique during dental imaging, 23.8% stated that they wear a lead apron during imaging, and 37.8% stated that they always used thyroid shields on the patients. In addition, 37.2% of the dentists stated that the patient holds the film during preapical radiography, and 81.5% used the same imaging parameters for adult and pediatric patients. 62% of dentists stated that they question the pregnancy of female patients before imaging. Conclusion: Findings of the study suggest that the knowledge of dentists about dental imaging procedures and radiation protection needs to be improved. The implementation and the follow-up of quality training programs in accordance with the standards set by the national authority will be of great importance.

Background The aim of the study was to assess anterior cingulate cortex (ACC) neurochemical profile of patients with unipolar major depressive disorder (MDD) before and after electroconvulsive therapy (ECT) by using H-1 magnetic resonance spectroscopy (H-1-MRS). Method Using H-1-MRS, the metabolite levels of choline, glutamate + glutamine (Glx), myo-inositol, N-acetylaspartate, and total creatine were measured in ACC before and after 4-week ECT. The Montgomery-angstrom sberg Depression Rating Scale (MADRS) was implemented by blind raters to evaluate the efficacy of the treatment. Electroconvulsive therapy-remitter (ER) and nonremitter groups were compared using the 1-way repeated measures analysis of variance. Results Thirty patients with unipolar MDD (aged 41.3 +/- 10.0 years, 66.7% female) were included in the study. The ER group (n = 16, 53.3%) and NR group did not differ regarding baseline Global Assessment of Functioning and MADRS scores. At the end of 4-week ECT treatment, results did not suggest any significant difference for metabolite levels in ACC. When compared with the NR group, the ER group had higher baseline levels of Glx (8.8 +/- 1.8 vs 6.3 +/- 2.0, P = 0.005) and total creatine (5.3 +/- 0.6 vs 4.7 +/- 0.5, P = 0.010). In addition, elevated baseline Glx (r = -0.68, P = 0.002) was associated with lower MADRS scores at the end treatment. Finally, the change in Glx levels was correlated with change in MADRS scores after ECT (r = 0.47, P = 0.049). Limitations Modest sample size and H-1-MRS at 1.5 Tesla are limitations of the study. Conclusions Results suggested that Glx levels could be a predictor of remission. Studies with larger samples should explore neurochemical correlates of ECT in unipolar MDD.

Purpose This study aims to develop local diagnostic reference levels (DRLs) for the most common computed tomography (CT) examinations carried out around Izmir, Turkey. Methods Five common CT examinations (head, neck, chest, abdomen–pelvis (AP), chest–abdomen–pelvis (CAP)) from four different radiology centres have been included in the study. CT dose index-volume (CTDIvol) and dose length product (DLP) values were recorded for 50 patients per exam in each centre. Third quartiles of CTDIvol and DLP values were determined as DRLs and compared with international findings. Results 51.3% of the patients were male and 48.7% were female, with a mean age of 57 (between 18 and 93). DRLs for CTDIvol were recorded as 70, 16, 15, 23 and 16 for head, neck, chest, AP and CAP examinations, respectively, while the corresponding DLPs were 1385, 604, 567, 998 and 1180 mGy.cm. Conclusion Results are mostly comparable to the latest international data, except for the head examinations, which were observed to slightly exceed the DRLs established by other countries.

Giriş: Bilgisayarlı tomografi (BT) cihazları teknolojik gelişmeleri ile birlikte hastalıkların tanısında her geçen gün daha fazla kullanılmakta ve bunun sonucu olarak hasta dozlarında büyük bir artışa neden olmaktadır. Klinik olarak BT çekimleri çok yararlı olmasına rağmen, radyasyon dozu ve bunun meydana getirebileceği olası kanser riski geleceğin en büyük problemi olarak değerlendirilmektedir. Bu nedenle BT taramalarında, görüntü kalitesinden ödün vermeden görüntüleme parametrelerini kontrol ederek hasta dozlarının düşürülmesi temel ilke olmalıdır. Amaç: Bu çalışmanın amacı, baş-boyun BT anjiyografi çekimlerinde otomatik tüp akım modülasyon (OTAM) sisteminin kullanılmasının hasta dozlarının azaltılması ve görüntü kalitesi üzerindeki etkilerini araştırmaktır. Yöntemler: Serebrovasküler hastalık nedeniyle izlenen 23 hasta bu çalışmaya dahil edilmiştir. Sabit tüp akımı (mAs) kullanılarak yapılmış rutin baş boyun BT anjiyografi taramasının takibi için gelen hastaya tüm görüntüleme parametreleri sabit kalmak kaydıyla sadece otomatik tüp akımı modülasyonu tekniği kullanılarak tetkik gerçekleştirildi. Her iki yöntemle elde edilen veriler, hem hastaya verilen doz hem de görüntü kalitesi açısından değerlendirildi ve karşılaştırıldı. Bulgular: Akım modülasyonu sistemi kullanıldığında etkin doz değerinde %35’lik bir azalma gözlendi. Objektif değerlendirme için baş-boyun kısmında belirlenen 3 farklı anatomik bölgede sinyal-gürültü oranı (SNR) değerleri için beyin sapında %49, omuz bölgesinde %25, serebellumda ise %42 lik bir azalma olduğu bulundu. Subjektif değerlendirmede ise akım modülasyon sistemi kullanılarak elde edilen görüntüler 2 radyolog tarafından incelendi ve 0-4 arasındaki puanlama sonucunda bu görüntülerin ortalama puanı 2,2 olarak bulundu. Sonuç: Baş-boyun anjiyo BT incelmelerinde otomatik akım modülasyonu ile radyasyon dozlarında belirgin azalma elde edilmiş, SNR nin azalmasına rağmen klinik açıdan tanısal kayıp olmadığı görülmüştür. Hasta dozlarının azaltılması ve tanısal açıdan dezavantaj oluşturmaması için uygun kriterlerde kullanılacak OTAM tekniğinin nöroanjiyo çekimlerinde rutin uygulamaya girmesi kesinlikle önerilmektedir.

The frequency of abdominal computed tomography examinations is increasing, leading to a significant level of patient dose. This study aims to quantify and evaluate the effects of automatic tube current modulation (ATCM) technique on patient dose and image quality in contrast-enhanced biphasic abdominal examinations.Two different scan protocols, based on constant tube current and ATCM technique, were used on 64 patients who visited our radiology department periodically. For three patient groups with different patient size, results from two protocols were compared with respect to patient dose and image quality. Dosimetric evaluations were based on the Computed Tomography Dose Index, dose length product, and effective dose. For the comparison of image qualities between two protocols, Noise Index (NI) and Contrast to Noise Ratio (CNR) values were determined for each image. Additionally, the quality of each image was evaluated subjectively by an experienced radiologist, and the results were compared between the two protocols.Dose reductions of 31% and 21% were achieved by the ATCM protocol in the arterial and portal phases, respectively. On the other hand, NI exhibited an increase between 9% and 46% for liver, fat and aorta. CNR values were observed to decrease between 5% and 19%. All images were evaluated by a radiologist, and no obstacle limiting a reliable diagnostic evaluation was found in any image obtained by either technique.These results showed that the ATCM technique reduces patient dose significantly while maintaining a certain level of image quality.Abdominal bilgisayarlı tomografi incelemelerinin sıklığı artmakta ve önemli miktarda hasta dozuna yol açmaktadır. Bu çalışma, kontrastlı, çift fazlı abdomen incelemelerinde otomatik tüp akım modülasyon tekniğinin hasta dozu ve görüntü kalitesi üzerine etkilerini ölçmeyi ve değerlendirmeyi amaçlamaktadır.Radyoloji anabilim dalını periyodik olarak ziyaret eden 64 hastaya sabit tüp akımı ve otomatik tüp akımı modülasyonu tekniğine dayanan iki farklı tarama protokolü uygulandı. Farklı hasta boyutlarına sahip üç hasta grubu için, iki protokolden elde edilen sonuçlar hasta dozu ve görüntü kalitesi açısından karşılaştırıldı. Dozimetrik değerlendirmeler, Bilgisayarlı Tomografi Doz İndeksi, doz uzunluk çarpımı ve etkin doza dayandırıldı. İki protokol arasındaki görüntü kalitesinin karşılaştırılması amacıyla her görüntü için Gürültü İndeksi (NI) ve Kontrast Gürültü Oranı (CNR) değerleri belirlendi. Ek olarak, her görüntü deneyimli bir radyolog tarafından öznel olarak değerlendirildi ve sonuçlar iki protokol arasında karşılaştırıldı.Otomatik tüp akım modülasyon protokolü ile arteriyel ve portal fazlarda sırasıyla %31 ve %21 doz düşüşleri sağlandı. Öte yandan, NI karaciğer, yağ ve aort için %9 ile %46 arasında bir artış gösterdi. CNR değerlerinin ise %5 ile %19 arasında azaldığı gözlendi. Tüm görüntüler bir radyolog tarafından değerlendirildi ve herhangi bir teknikle elde edilen görüntülerde güvenilir bir tanısal değerlendirmeyi sınırlayan bir engel bulunmadı.Bu sonuçlar, otomatik tüp akım modülasyon tekniğinin, belirli bir görüntü kalitesi seviyesini korurken hastanın dozunu önemli ölçüde azalttığını göstermiştir.

Amac: Radyasyondan korunmada, kisisel korunma icin kursun koruyucu giysiler siklikla kullanilmaktadir. Bu koruyucular, kullanim ve depolama sartlari gibi nedenlerle zamanla hasar gorebilmektedir. Bundan dolayi kursun koruyucu giysilerin yilda bir kez kalite kontrollerinin yapilarak hasarli ve riskli olanlarin belirlenmesi, radyasyon calisanlarinin kisisel korunmasinda buyuk onem tasimaktadir. Bu calismanin amaci, radyasyonla calisan birimlerde kullanilan kursun koruyucu giysilerin hasarli olanlari belirlemek ve onlar icin atik kriterlerini belirlemektir. Gerec ve Yontem : Bu calismada, hastanemizde kullanilan 167 kursun koruyucu giysinin floroskopi esliginde yapilan kalite kontrol calismasinda; delik/yirtik sayilari, bu deliklerin toplam alanlari, x isinlarini % gecirme oranlari ve delik/yirtik altindaki esdeger ve ek doz degerleri belirlendi. Elde edilen bu verilerle, hasarli ve riskli kursun koruyucu giysiler belirlendi. Bunun yanisira radyasyondan korunma amaciyla literatur destekli hasarli kursun giysilerin atik kriterleri tanimlandi. Bulgular: Literature gore atik kriterleri, delik/yirtik alaninin 10 cm 2 ve fazlasi, % gecirme oranlari icin normal alandaki gecirme miktarinin %5 fazlasi ve etkin doz degeri 0.4 mSv olarak belirlendi. Bu atik kriterlerine gore kalite kontrol calismasi yapilan ve hasarli olarak degerlendirilen kursun koruyucularin %7.8’i atik ve %12.8’i ise riskli olarak tespit edildi. Sonuc: Kursun koruyucu giysiler icin hem kisisel radyasyondan korunmadaki guvenlik hem de maliyetleri acisindan bu kriterlere gore hasarli ve atik kararinin verilmesi onemlidir. Hasarli kursun koruyucu giysilerin atik kriterlerine bagli olarak kullanimdan cikarilmasi, gereksiz kursun onluk atiginin olmasini da onler.

© 2016 Society of Biological Psychiatry.Background The antimanic efficacy of a protein kinase C inhibitor, tamoxifen, has been tested in several clinical trials, all reporting positive results. However, mechanisms underlying the observed clinical effects require further confirmation through studies of biological markers. Methods We investigated the effect of tamoxifen versus placebo on brain metabolites via a proton magnetic resonance spectroscopy study. Scanning was performed in 48 adult manic patients with bipolar disorder type I (mean Young Mania Rating Scale score of 37.8 ± 5.8) at baseline and after 3 weeks of double-blind treatment. We hypothesized that alleviation of manic symptoms would improve the levels of markers associated with brain energy metabolism (creatine plus phosphocreatine [total creatine (tCr)]) and neuronal viability (N-acetylaspartate). Results The Young Mania Rating Scale scores decreased from 38.6 ± 4.5 to 20.0 ± 11.1 in the tamoxifen group and increased from 37.0 ± 6.8 to 43.1 ± 7.8 in the placebo group (p

Hastalıkların erken tanı ve tedavisinde, iyonize radyasyon içeren görüntüleme yöntemleri önemli rol oynarlar. Tanı ve tedavide, hastaya uygulanacak radyasyon dozunun mümkün olduğunca az tutulması ve radyasyondan koruyucu önlemler alınmasına rağmen hastada radyasyon hasarı oluşma olasılığı bulunmaktadır. Bu nedenle düşük ve/veya yüksek doz radyasyon uygulamaları, hücrede biyokimyasal ve moleküler sinyal yolaklarını aktive ederek, hücresel düzeyde etkiler oluşturmaktadır. Günümüzde radyasyon içeren uygulamaların sıklığı ve teknik parametrelerin yüksek değerlerde kullanılmasıyla hasta dozları ve buna bağlı doku hasarları görülme olasılığı giderek artmaktadır. Radyasyon hasarı ile ilgili çalışmalarda rapor edilen hücresel mekanizmaların başında, apoptozis ve hücre içi reaktif oksijen türleri (Reactive Oxygen Species, ROS) oluşumu gelmektedir. Apoptozis, radyoterapi uygulamalarında tümörü yok etmede hedeflenen bir sonuç iken tanısal amaçlı düşük doz uygulamalarda doku hasarını arttırıcı istenmeyen bir sonuçtur. Tanı ve tedavi amacıyla kullanılan radyasyonun, farklı dokular üzerinde erken ve geç etkileri bulunmaktadır. Düşük doz iyonize radyasyonun hücresel düzeyde etkileri, hangi moleküller ve/veya sinyal ileti yolakları üzerinden oluştuğu konusunda çok sayıda araştırma olmasına rağmen henüz tam olarak açıklanamamıştır. Radyasyon hasarlarına ait moleküler düzeyde yapılan çalışmalar, oluşabilecek hasarların erken düzeyde belirlenmesi ve sonrasında önleyici tedavilerin planlanabilmesi açısından çok önemlidir. Bu derleme, radyasyonun hücrede farklı sinyal ileti yolakları ve moleküller üzerinden yaptığı etkileri güncel literatüre bağlı olarak değerlendirmeyi amaçlamıştır.

Amaç: Ağız ve diş sağlığı (ADS) problemleri dünyadayaygın olarak görülen önemli bir halk sağlığı sorunudur. Bu çalışmada, DokuzEylül Üniversitesi (DEU) Sağlık Hizmetleri Meslek Yüksek Okulu (SHMYO)öğrencilerinin ağız ve diş sağlığı konusunda bilgilerinin değerlendirilmesiamaçlanmıştır.Gereç ve Yöntem: Kesitsel tipte bir araştırma olup,10.03.2018-31.03.2018 tarihleri arasında DEU SHMYO öğrencileri arasında yapılmıştır. Katılan öğrencileresosyo-demografik özellikler, ağız hijyen alışkanlıkları ve ağız diş sağlığıkonusunda bilgi düzeylerinin sorgulandığı bir anket uygulandı. Veriler, anketformu yardımıyla gözlem altında toplandı. Tanımlayıcı veriler, yüzdedağılımları olarak verildi. Çözümlemede; parametrik test koşullarını sağlayanverilerde ortalamaların karşılaştırılmasında t testi, parametrik testkoşullarını sağlayamayan verilerde ortalamaların karşılaştırılmasındaMann-Whitney U testi kullanıldı. İstatistikselanlamlılık için p

Objective: In this study, we evaluated the knowledge and perception and mitigation of hazards involved in radiological examinations, focusing on healthcare personnel who are not in radiation-related occupations, but who use ionising radiation as a part of their work. Methods: A questionnaire was applied to physicians, nurses, technicians and other staff working in different clinics that use radiation in their work, in order to evaluate their knowledge levels about ionizing radiation and their awareness about radiation doses resulting from radiological examinations. The statistical comparisons between the groups were analyzed with the Kruskal Wallis test using the SPSS program. Results: Ninety two participants took part in the study. Their level of knowledge about ionizing radiation and doses in radiological examinations were found to be very weak. The number of correct answers of physicians, nurses, medical technicians and other personnel groups were 15.7±3.7, 13.0±4.0, 10.1±2.9 and 11.8±4.0, respectively. In the statistical comparison between the groups, the level of knowledge of physicians was found to be significantly higher than the level of the other groups (p=0.005). Conclusion: The present study demonstrated that general knowledge in relation to radiation, radiation protection, health risks and doses used for radiological applications are insufficient among health professions using with ionizing radiation in their work.

Purpose To know breast doses for 2D digital mammography and 3D tomosynthesis equipment ensure that determining risks for breast which organ is radiosensitive. In this study, main objective is to construct a mathematical model, using multiple linear regression analysis method, which takes into account the exam specific parameters such as patient age, breast thickness, breast surface area, force, tube voltage and effective tube current and provides an estimation of the actual breast dose during 2D digital mammography and 3D tomosynthesis exams. Methods A dosimetric quality control test has been carried out to determine the reliabilities of Entrance Skin Dose (ESD) and Average Glandular Dose (AGD) values given by the digital mammography device following each exam. Patient data have been derived from the Picture Archiving and Communication System (PACS) for a retrospective evaluation. Radiologists have separated patients into 4 groups represented as A, B, C and D based on the BI-RADS criteria which account for breast composition. Each group included 50 patients to yield statistically meaningful results. A database has been constructed that contains dose information and the exposure parameters specific to mammography exams. Breast surface area determined by manually drawn regions of interest (ROI) has also been included in the database. AGD and ESD values have separately been analyzed with respect to each exposure parameter. It has been investigated whether there were significant differences between the data sets by applying Kruskal–Wallis analysis. Mathematical model has been constructed on the base of multiple regression analysis to determine the effects of independent variables on AGD and ESD. Results The dosimetric quality control of the digital mammography device was performed and it was found that the device was operating under optimum conditions. Kruskal Wallis tests carried out between AGD, ESD and independent variables have resulted in p values lower than 0.05. In the model based on multiple regression, AGD and ESD corresponded to the 95.4% and 93.9% of variance, respectively. Conclusion The constructed model provides a practical method to calculate AGD and ESD by using the exposure parameters without need to any conversion factors.

Purpose Diagnostic Reference Levels (DRLs) are important databases which help to optimize the radiation exposure to patients undergoing similar radiological examinations at different centers operating regionwide, countrywide or worldwide. This study aims to develop regional DRLs for the most common computed tomography (CT) examinations carried out around Izmir, Turkey, and to compare the results with national and international studies present in the literature. Methods Survey data were based on 5 most common adult CT examinations (Head, Neck, Thorax, Abdomen-Pelvis and Thorax-Abdomen-Pelvis) carried out in 4 different radiology departments located in Izmir (n = 50 per protocol for each department; i.e. n = 1000 in total). Collected data included the examination accession number, patient sex, age, effective tube current, tube voltage, Computed Tomography Dose Index-Volume ( CTDI vol ) and Dose Length Product (DLP) for each examination. Among all the exposure parameters, only CTDI vol and DLP values were statistically analyzed, since they account for the overall dosimetric information regarding the examination. CTDI vol information were based on body phantoms for all examinations except head examinations which were based on head phantoms for all departments. Third quartiles of CTDI vol and DLP datasets have been recognized as DRLs parallel to the literature. Statistical analysis has been performed by using IBM SPSS 23 Statistics software program. Results 51.3% of patients were male and 48.7% was female, with a mean age of 57 (between 18 and 93). DRLs for CTDI vol were recorded as 70 mGy, 16 mGy, 15 mGy, 23 mGy and 16 mGy for head, neck, thorax, abdomen-pelvis and thorax-abdomen-pelvis examinations respectively, while DLP results were 1385 mGy.cm, 605 mGy.cm, 567 mGy.cm, 998 mGy.cm and 1180 mGy.cm with respect to the same order. Conclusions This study was carried out on a wide range of patient age and size. Results agree well with national and international data, except for the head examinations which were observed to slightly exceed the DRLs established by other countries. Consequently, it is planned to bring this study to a furtherly comprehensive point based on data collected countrywide.

Background Neurochemical changes are responsible for bipolar disorder (BD) pathophysiology. Despite current progress in BD research, mood- and trait-related alterations in BD continue to elicit further investigation. Methods In this study, we report a longitudinal proton magnetic resonance spectroscopy study evaluating dorsomedial prefrontal cortex (DMPFC) metabolites N-acetylaspartate (NAA), creatine plus phosphocreatine (total creatine [tCr]), phosphorylcholine plus glycerophosphocholine, myo-inositol, and glutamate plus glutamine levels of manic and euthymic adult BD type I patients (n=48) treated with standard antimanic medicines, compared to matching healthy controls (n=44). Results DMPFC NAA values and NAA/tCr ratio were significantly lower in euthymic BD patients when compared with healthy controls with similar levels of other metabolites in all groups, indicating a trait-related NAA abnormality in euthymic BD patients. Limitations of our study include a relatively low (1.5 T) magnetic resonance field strength and variable drugs administered to achieve euthymia despite the best efforts to standardize the open fashion treatment. Conclusions Our study contributes to the integrating models of trait-related metabolite alterations observed in euthymia since NAA is considered as a marker of neuronal viability and mitochondrial energy metabolism. In light of supporting and conflicting results reported previously, future studies with longitudinal designs and larger patient groups are warranted to better define both state- and trait-related cerebral metabolic alterations associated with BD pathophysiology.

In an examination of the effect of benzodiazepines on brain chemistry, 44 healthy controls underwent a short echo-time proton magnetic resonance spectroscopy (H-1 MRS) session after induced sedation with intravenous midazolam (0.03 mg/kg) plus fentanyl (2 mu g/kg). The regions of interest were the anterior cingulate cortex, right basal ganglia, right frontal lobe, and right hippocampus. Twenty-five of these subjects underwent the second H-1 MRS session while awake. The measured H-1 MRS metabolites included N-acetylaspartate, creatine-containing compounds (PCr+Cr), choline-containing compounds, myo-inositol, and glutamate plus glutamine, which were quantified both as absolute values and metabolite/PCr+Cr ratios. The results were analyzed using independent group t tests and repeated measures analysis of variance (ANOVA, with alpha values set at 0.025 to minimize the risk of false-positive findings arising from multiple comparisons. No significant difference between subjects under midazolam plus fentanyl induced sedation and awake could be detected with unpaired analyses. Paired comparisons by ANOVA with repeated measures found that neither drug (midazolam plus fentanyl) nor the drug by time (interval between two scan times) interaction had a significant effect on the quantified metabolites. These findings encourage utilization of benzodiazepine-induced brief sedation during in vivo H-1 MRS experiments of the brain, and may help with elucidation of state-dependent neurochemical alterations during the course of bipolar and schizoaffective disorders. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

In this study, the relaxivities of various ferri–ferro and superparamagnetic particles in human serum and deionized water were determined by using MRI system operating at 1.5 T. For this purpose, the spin–lattice (1/ T 1 ) and spin–spin (1/ T 2 ) relaxation rates in serum and deionized water were measured versus increasing concentrations of the DyPO 4 , 5Fe 2 O 3 3Gd 2 O 3 + dextran, 5Fe 2 O 3 3Gd 2 O 3 + CMC, 5Fe 2 O 3 3Gd 2 O 3 . The longitudinal relaxivity ( r 1 ) and transverse relaxivity ( r 2 ) of proton were determined from the slopes of fits between the relaxation rates and concentrations. T 1 and T 2 times in serum were decreased due to increased concentrations of the ions added to samples. The r 2 / r 1 values for ions added to serum ranged from 1 to 4, whereas the r 2 / r 1 for the ions added to water changed between 0.57 and 1 except that for 5Fe 2 O 3 3Gd 2 O 3 . PRRE (proton relaxation rate enhancement) data reveals that, the ions added to serum are not bound to the proteins. The present results suggest that chemical compounds of iron oxide studied may have a potential that can be used as an alternative superparamagnetic MRI contrast agent.

IntroductionVolumecomputed tomography dose index(CTDIvol) does not contain any dose information regarding the patient size. Size specific dose estimates (SSDE) give more reliable results accounting for the patient size as well. This parameter uses CTDIvol and size dependent conversion factors (fDw) which are calculated by means of water equivalent diameter (Dw) of the patient cross section in every slice of image.PurposeTo develop software to automatically calculate SSDE and to assess the impact of variations in Dw along the z axis on SSDE for CT examinations of the torso in pediatric patients.Materials and methods55 consecutive CT exams of the combined chest, abdomen and pelvis (CAP) have been examined. SSDE has been calculated for 6 hypothetical scan ranges: chest alone, abdomen alone, pelvis alone, chest and abdomen, abdomen and pelvis, and CAP. Two methods were used in mean SSDE approach: (1) mean SSDE over each scan range; (2) SSDE value at the middle of the scan range.ResultsFor scan ranges 1 to 6, the average of the difference in maximal and minimal Dw accross patients was 3.7, 3.8, 2.6, 4.1, 4.4 and 4.5 cm. The mean SSDE values calculated using methods (1) and (2) were highly compatible, with root mean square differences of 0.4, 0.5, 0.3, 1.0, 1.5 and 0.7mGy or 3%, 4%, 2%, 7%, 10%, 5%.ConclusionUsing the mean CTDIvol and the water equivalent diameter at the middle of the scan range provides a reasonable estimation of patient dose in pediatric exams.

In this study, the absorption capability and the weight of various radiation-shielding materials were evaluated, for applications asalternatives to lead garments. Toxicity, atomic number, density, K-edge absorption energy and availability of elements that canserve as an alternative to lead, including tin, antimony, bismuth and tungsten, were considered. The attenuation coefficients ofthese elements were determined using the XCOM software package, and these metals were mixed with polymers at 50, 70, 80and 85 % mass ratios. It can be concluded that all of the new shielding materials used in the study can be used for a diagnosticrange of X-rays. However, they were compared with the commercial lead garments in terms of weight and attenuation coefficient;the 85 % samples were lighter than a 0.5-mm lead garment and provided superior radiation protection, which demonstrates itspotential for commercial applications.

Lead material is usually used to protect from X-ray for medical or other purposes. The aim of this project is the development of a new material to protect from X-rays. For this purpose, composite samples from four different groups were prepared as a film tablet. In the first group chitosan, the second one Sr (strontium), the third one chitin, the fourth one Mg (magnesium) were used in the same percentages. 66 kV–81 kV–102 kV–150 kV X-ray was performed on composite samples for 15.5 ms–15.2 ms–15.0 ms–17.6 ms and for 4 mA s–3.2 mA s−2.5 mA s−2 mA s, respectively. The distance of the materials and anode was 1.10 m in this test. Each sample was placed on bone and muscle tissue for the simulation of the real situation in the body. After performing X-ray on the samples, the biomechanical tests were performed by using the axial compression testing machine (AG-I 10 kN, Shimadzu, Japan). The axial compression was applied to all specimens with the loading speed of 5 mm/min (max. 100 N). The compression tests were performed at room temperature. It was found that Sr (strontium) has the best X-ray protection and mechanical resistance among these groups. In conclusion, Sr and Sr composites materials can be used for medical protection and other purposes in the future instead of lead.

Purpose: Polymer gel materials are used as dosimeters to provide three dimensional radiation dose distribution. An ideal gel dosimeter should offer radiological properties equivalent to water. This study aims to determine and compare the water equivalencies of various new polymer gel mixtures using Geant4-based Architecture for Medicine-Oriented Simulations GAMOS software program. Methods: To do this, percentage depth dose curves of the simulated polymer gel mixtures were compared with water curves. Different combinations of materials from 2 main classes were used in the mixtures: 1 Sodium Carboxymethyl Cellulose SODIUM CMC , Polyvinyl Alcohol PVA and Polyethylene Glycol PEG as gel matrix, 2 2-Hydroxyethyl Methacrylate HEMA , 1-Vinyl-2-Pyrrolidinone VP and Diethylene Glycol Dimethacrylate DEGDMA as monomer. Each mixture also contained ultra-pure water and an antioxidant material called Tetrakis Hydroxymethyl Phosphonium Chloride THPC . Results: Percentage depth doses of gel mixtures and water was calculated for 6, 18 MV and 50, 70, 100, 150 kVp X rays. The mixture sample showing radiological behavior nearest to water over all energies was observed to be 31a Water, PEG, HEMA, THPC , while the largest difference is observed in 11a Water, SODIUM CMC, HEMA, THPC .Conclusion: As a result, simulated gel formulations were found to be radiologically water equivalent.

Objective: This study aimed to determine the accuracy of the average tumor location in CT-simulator images and PTV margins in radiotherapy treatment planning by detecting lung tumor mobility in dynamic MRI scans of patients presenting with lung cancer.Materials and Method: Dynamic MRI examination was performed in 12 lung cancer patients scheduled for 3-dimensional conformal RT 3D-CRT using CT-simulator. In this study, maximum tumor displacement CC-MRI, ML-MRI, AP-MRI was measured that occurred in CC, AP and ML axes in expiratory and inspiratory phases of dynamic MRI. The distance from the upper limit of GTV to the reference line CC-CT was measured in CT-simulator images. CC-CT and CCmean-MRI values were compared with the Wilcoxon signed-rank test. Furthermore, correlation of these values was evaluated with Spearman’s correlation test.Results: In comparison of CC-CT and CCmean-MRI values, no statistically significant difference was detected between CT-simulator and dynamic MRI modalities p=0.172 . In addition, a high level of correlation was found between these two imaging methods p