Comparison of standardized uptake values obtained from two- and three-dimensional modes of fluorine-18 fluorodeoxyglucose PET-CT in oncological cases

PURPOSEWe investigated the usability of standardized uptake values (SUV) obtained from both two- and three-dimensional (2D and 3D) positron-emission tomography and computed tomography (PET-CT) imaging, and compared the images obtained from these techniques in terms of image quality, lesion detectability, and the presence of artifacts. MATERIALS AND METHODSImage data from 100 patients, who had undergone two PET imagings obtained in 2D and 3D mode after a low dose CT, were evaluated prospectively. Subjective analysis of 2D and 3D images was performed by two readers evaluating the following criteria: overall image quality, detectability of each identified lesion, and the presence of artifacts. The lesions recognized by the readers were also analyzed quantitatively by measuring SUV values. RESULTSThere was a significant difference between the SUVs obtained in 2D and 3D modes. Regardless if the first scan was performed in 2D or 3D mode, the values obtained from 3D imaging were significantly lower than those obtained from 2D imaging (mean SUVmax was 10.48±7.57 for 2D, and 9.66±6.93 for 3D, P < 0.001). Visual analysis did not reveal significant differences regarding lesion detectability between two modes. CONCLUSIONIn oncological PET-CT applications, SUV values are significantly lower in 3D compared with 2D mode. Thus when serial scanning is needed to evaluate response to therapy in the same patient, the imaging modality should be taken into account and performed with the same method to avoid misinterpretation. Additionally, 3D PET-CT imaging can be used instead of 2D PET-CT due to its shorter scanning time without loss of lesion detectability

The water quality modelling of Eğirdir lake

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1993Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1993Bu çalışma ile Eğirdir Gölünün korunması; mevcut kirliliğin önlenmesi ve zamanla ortaya çıkabilecek farklı kirlenme durumlarında alınması gereken uygulamaya yönelik tedbirlerin belirlenmesi hedeflenmiş, potansiyel kirliliğin izlenmesi ve gelecek yıllardaki gelişiminin tahmini için bir matematik model geliştirilmesi öngörülmüştür. Çalışma bu yönüyle gölün trofik statülerindeki değişimlerin belirlenebilmesi için oluşturulan matematiksel model (GMODEL) vasıtasıyla gölün su toplama havzası bazında su yönetimi planının çıkarılma­sına da olanak tanımaktadır. Söz konusu modelin oluşturulması ve geçerlili­ğinin ispat edilmesi aşamasında gerekli olan parametreler var olan veya yürütülmekte olan çalışmalardan sağlanarak, eksik parametreler sahada yapılan analiz çalışmaları ile temin edilmiştir. Göl hakkında elde edilen tüm analiz sonuçları PC tipi bilgisayarlarda çalışabilen DBASE III PLUS paket programı kullanılarak bir "veri tabanı" programı içinde arşivlenmiştir. Çalışmada ilk olarak bölge hakkında genel bilgiler verilmiş, gölün jeolojik yapısı, hidrolojisi ve iklimi ele alınarak su bilanço değerleri ve "su derinliği (kot)-alan-hacinrT eğrileri oluşturulmuştur. Daha sonra göl havzasındaki yerleşimlerin gelecek yıllara göre nüfus tahminleri yapılarak, kirlilik miktarları belirtilmiş, tarımsal alanlar ve bunlardan gelebilecek kirlilik değerleri ve kirletici kaynaklardan ileri gelen yıllık kirlilik yükleri hesaplanmıştır.Su kalite modellerinin kalibrasyonu 1983-1984 yıllarındaki veriler, doğrulaması ise 1991-1992 yıllarında Eğirdir Su Ürünleri Yüksek Okulu ile Çevre Bakanlığı Göller Bölgesi Projesi kapsamında MİMKO A.Ş. organizesi altında bizzat gölde ölçülen su kalite parametreleri kullanılarak yapılmıştır. Değişik su kalite parametrelerine göre halen temiz durumda olan Eğirdir gölünden içmesuyu, sulama, su ürünleri-balıkçılık, rekreasyon maksatları için yararlanılmakta ve göl "Oligotrofik" bir yapı göstermektedir.The aim of this study is to predict the water quality of Eğirdir Lake by applying a relatively simple model. in this study, informations as regard to morphological, geological characteristics, pollutant resources and water quality data of Eğirdir Lake, were collected and evaluated on the basis of a project, that has been initiated for the Ministery of Environment of Turkey. The project aimed water quality modelling studies of nine lakes located in " Lake' s Region " of Turkey, in Mid-West Anatolia. Eğirdir Lake vvas selected out of total nine lakes studied because Eğirdir Lake is öne of the unpolluted lakes of the region and is used for recreation, aquatic products, irrigation and also for drinking purposes. There are plans to supply the drinking water demand of İsparta city located about 25 km from Eğirdir Lake. The future vvater withdrawal is estimated to be about 86.400 m3/day. Local authorithies want to inquire whether an additional water withdrawal will upset the ecological balance and wi!l reduce the water potential and recreational value of the lake. General informations and background about the region were presented. Also by calculating the water inputs and outputs of the lake basin, rainy and drought periods were determined. Then geological and hydrological characteristics of the lake area vvas investigated and amount of vvater taken from lake vvas determined, depth of vvater - area - volume curves were dravvn by using input (precipitation, surface runoff, ete.), and output flovvrates (evaporation, artificial discharge, ete.) of the lake. Also an input - output equation of the lake vvas developed. The variation range of the lake volume and surface area within the period of 1958-1991 are as follovvs: xix Elevation of vvater surface, m : 915.33 - 919.11 Surface area, m2 : 453 x106 - 481.5 x106 Volume, m3 : 2740 x106 - 4440 x106 Mean depth, m : 5.7 - 9.8 Eğirdir Lake has an alongated shape divided into two parts with a throat section of 3 km wide. The length of the lake in the North-South direction is about 50 km. The maximum vvater depth is 15 m. Temperature and precipitation values measured at Eğirdir station are given in Table -1. Table -1 : Range and Mean Values of the Monthy Average Temperature and Precipitation Readings at Eğirdir Station (Period: 1930-1988) Parameter Range Mean Temperature, °C 2.8- 24.0 13.1 Precipitation, mm/month | 7.4-131.8 | 62.8 Annual precipitation is 753.6 mm. The total drainage area of the Eğirdir lake is 3321 km2. Eğirdir lake receives the surface runoff from agricultural fields and municipal wastewater discharge. The total pollution loads including the nutrient loads of direct precipitation are estimated (Table - 2). Table - 2 : Pollution Loads of Eğirdir Lake Pollutant Period (ton/year) 1983 -1984 l 1991 -1992 BOD5 258.9 31.2 SS 317.5 34.7 TN 1047.9 751.0 TP l 51.3 | 46.2 Approximately 90 percent of the town of Eğirdir is served with a new sanitary sewer system. Therefore pollutant loads have been reduced in the years of 1991-1992. XX Considerable data has also been collected for Eğirdir Lake by different research groups. Water quality measurements required to run the quality model were conducted in the field. A mathematical model that can simulate the nitrogen, phosphorus and algae concentrations using the available data was improved. Pollutant resources and pollutant loads were investigated, pollution levels were determined, agricultural areas and loads caused by agricultural areas were presented. Annual pollution loads due to pollutant resources were determined. in order to evaluate the strategies and altematives of vvater quality management of the lake and to help to the manager ör responsible persons on their decisions, a water quality model of the lake was developed. Using this model its possible to make the future estimates ör scenarios that predict the effect of pollutant loads on vvater quality of the lake. The trophic level that indicates the nutrient level of the lake was investigated. Present vvater guality of Eğirdir Lake can be classified as oligotrophic. The lake water can be used for drinking, irrigation, fishing vvater products and recreation purposes. While deciding on the trophic level of Eğirdir Lake, many parameters including nitrogen and phosphorus loads, chlorophyl-a concentrations, Secchi dişe depths, and dissolved oxygen prof i leş were considered. A dBASE III Plus program was written to organise & classify the collected data. The dBASE III Plus program can be used to organise past and future data. Scenarios were made to illustrate the implication of the model and results were discussed by using the computer outputs, profiles graphics, ete. The purpose of developing a new model was to be able to obtain predictions using the available data. The data on lake vvater quality and the loads is very restricted and does not go beyond few years. xxi Initially use of complicated EPA models such as WASP ( Water Analysis Simulation Program) was tried but such programs require detailed and extensive data. In order to calibrate the eutrophication model (GMODEL) the data collected during the period of 1983 -1984 within the TÜBİTAK Turkish Technical Research Council) research projects (ÇA?-45, ÇA?-47 and ÇA?-46/G) were used. Verification of the model was achieved using Eğirdir Aquatic Products Department measurements in 1991, and MİMKO A.Ş. measurements in 1992. The models constants were chosen to minimize the difference between the measured and calculated values of the water quality parameters such as nitrogen, phosphorus and chlorophyl-a concentrations. The range of the values reported in the literature was also kept in mind before deciding on the value of a constant in the model. Apparently great differences between the calculated and the measured values in the graphs are due to the large scale used in the drawings. Different scenarious included changing the loads on the lake. When the nitrogen load was increased from 87.32 tons / month to 187.32 tons / month in the second year, a sharp increase of the algae concentration was also observed in the second year. In the same way, by running the GMODEL program for five years, when the third year daylight is dropped to 1 hour from 10-13 hour, a sharp decrease in algae concentration is observed. And this drop causes a concentration increase in nitrogen and phosphorus concentrations especially in the third year. In forth and fifth years, increase of algal concentration results in small flactuation ranges of total nitrogen and phosphorus concentrations. Smaller fluctuations indicate that the steady-state conditions are being approached. Another scenario included changes on the lake volume and changes of the water withdrawals for the followings five years. XXll Four times decrease of lake volume in second year was assumed and the water withdrawal was increased to 500 x 106 m3/ month from 20 - 50 x106 m3/tnonth. Such volume and flowrate withdrawals the algae production. And this caused sharp decrease in total organic nitrogen and phosphorus concentrations in second year, tendency to the steady - state condition has started in fourth year. A similar study using different volume and water withdrawals for seven years was done. A tendency towards to the steady - state condition was observed similar to the simulations done for a period of five years.Yüksek LisansM.Sc

The Microbiological and Physico-Chemical Parameters with Trace Metal Pollution of Coastal Bathing Water in Dardanelles and Thracian Sea

The present study was undertaken to determine the microbiological (total coliforms, fecal coliforms, fecal streptococci and Salmonella sp.) and physico-chemical parameters (pH, conductivity, nitrate and phosphate) with trace metal concentration (arsenic, chromium) and cyanide of 74 coastal bathing water samples obtained from Dardanelles (Site 1) and Thracian Sea (Site 2). About 5 of 74 (6.75%) water samples were of unacceptable quality based on recommended criteria of microbiological (3 of 74, 4.05%) and physico-chemical with trace metal concentration (2 of 74, 2.70%) by Turkish Bathing Water, Turkish Water Pollution and European Community Bathing Water Directives. The results indicated that the value of total coliforms and fecal coliforms provided an adequate indicator of Salmonella sp. presence. Among the trace metals, only arsenic was detected at the below acceptable limits. Therefore, it is necessary cleaning of waste waters by purification plants, infiltration of effluent from sewage treatment plants, control industrial factors and maintaining water quality controls

Experimental Study of Flexural Performance of Reinforced Concrete Beams and Hybrid Beams

This study compared the flexural performance of hybrid beams produced by using concrete in glass fiber reinforced plastic box profiles with concrete beams of the same dimension and concrete properties. Hybrid beams were evaluated in two groups, including standard beams and hybrid beams whose certain properties are improved. Five samples were collected from each test group. Flexure tests were performed on 1500 x 100x100 mm hybrid, improved hybrid and reinforced concrete beams, and flexural strength and fracture toughness values were compared. The flexural behavior of hybrid materials, which provide a higher performance increase due to their components than concrete beams, was analyzed. Analyses showed that hybrid materials provided the users with various advantages due to their components; the improved hybrid design had high flexural strength and fracture toughness, while reinforced concrete beams had a higher rigidity than hybrid beams

Effect of carnosine treatment on oxidative stress in serum, apoB-containing lipoproteins fraction and erythrocytes of aged rats

One of the mechanisms underlying the aging process is proposed to be oxidative damage by free radicals. Carnosine (beta-alanyl-L-histidine) is a dipeptide with antioxidant properties. In this study, we investigated the effect of carnosine supplementation on oxidative stress in serum, apoB-containing lipoproteins (LDL + VLDL) and erythrocytes of young and aged rats. At the initiation of the study, young and aged rats were 5 and 22 months old, respectively. Carnosine (250 mg/kg, daily, ip) was administered for 1 month to young and aged rats. We found that serum malondialdehyde (MDA) and diene conjugate (DC) levels and endogenous DC and copper-induced MDA levels in the LDL + VLDL fraction increased in aged rats, but there was no change in plasma antioxidant activity. Endogenous DC and H(2)O(2)-induced MDA. levels were also higher, but glutathione (GSH) levels were lower in erythrocytes of aged rats. Administration of carnosine for 1 month to aged rats resulted in decreased levels of MDA and DC in serum, the LDL + VLDL fraction and erythrocytes and increased levels of GSH in erythrocytes. Our findings indicate that in vivo carnosine treatment may be useful for the decrease in aged-induced oxidative stress in serum, the LDL + VLDL fraction and erythrocytes

Stabil anjina pektoris’li hastaların değerlendirilmesinde dobutamin stres doku Doppler görüntüleme ve miyokardiyal perfüzyon SPECT

To evaluate longitudinal function of ischemic and nonischemic myocardial tissue detected by Tc-99m MIBI single photon emission computed tomography (SPECT) prior to coronary revascularization in patients with stable angina pectoris. Methods: We studied 24 consecutive patients (mean age 62&plusmn;9 years; 5 women) with stable angina pectoris. All patients underwent myocardial perfusion SPECT. Tissue Doppler imaging (TDI) was performed to detect myocardial systolic velocities of anterior, inferior, septum and lateral walls at rest and peak dobutamine stress. Results: A total of 96 segments were visualized with SPECT study. Maximum mean septal, lateral, anterior and inferior TDI systolic velocities were similar in ischemic and nonischemic segments (6.73&plusmn;1.04 cm/sec, 6.93&plusmn;1.34 cm/sec, respectively) at rest. At peak stress, maximum mean TDI systolic velocities were lower in the 37 ischemic segments (11.00&plusmn;2.03 cm/sec) than 59 nonischemic segments (13.76&plusmn;1.97cm/sec, p &lt; 0.001). Because we detected ischemia in whole group using both diagnostic tests, coronary angiography was decided. Critical coronary artery stenosis related to ischemic segments was detected and coronary revascularization decided. Conclusion: TDI with dobutamine stress can be used in patients with stable angina pectoris. In this study, we observed that quantitative data by TDI associated with SPECT showed an agreement for coronary revascularization.Koroner revaskülarizasyon öncesi stabil anjina pektorisli hastalarda Tc-99m MIBI SPECT ile saptanan iskemik ve normal miyokardiyal dokunun longitüdinal fonksiyonunu değerlendirmektir. Yöntemler: Stabil anjina pektoris’li 24 ardışık hasta çalışmaya dahil edildi (ortalama yaş 62±9 yıl; 5 kadın). Tüm hastalara miyokardiyal perfüzyon SPECT sintigrafisi yapıldı. İstirahatta ve zirve dobutamin streste ön, alt, septum ve yan duvarların doku Doppler görüntüleme (DDG) ile miyokardiyal sistolik hızları tespit edildi. Bulgular: SPECT çalışmasında toplam 96 segment görüntülendi. İstirahatta ortalama en yüksek septal, yan, ön ve aşağı duvar DDG sistolik hızları iskemik olan ve iskemik olmayan segmentlerde benzerdi (sırasıyla 6.73±1.04 cm/sn, 6.93±1.34 cm/sn). Zirve streste, ortalama en yüksek DDG sistolik hızları 37 iskemik segmentte (11.00±2.03 cm/sn), 59 iskemik olmayan segmente (13.76±1.97cm/sn, p < 0.001) göre daha düşüktü. Her iki tanı testi ile tüm hasta grubunda iskemi tespit etmemiz nedeniyle tüm vakalara koroner anjiografi uygulandı ve iskemik segmentlerle ilişkili kritik koroner arter darlıkları saptandı. Sonuç: Anlamlı koroner arter darlıkların saptanmasında DDG yöntemi SPECT ile uyumlu olarak ek bilgi sağlayabilir