Computer system for acquiring, storing, retrieving and processing images obtained by gamma camera

Gama scintilaciona kamera (GSK) je medicinski uređaj koji prikazuje raspodelu g-fotona emitovanih iz radiofarmaka unetog u organizam intravenski, oralno ili inhalacijom. Razvoj tehnologije integrisanih kola je imao uticaja na konstrukciju glave GSK i na fleksibilnost, brzinu, cenu i povećanu funkcionalnost kompjuterskih sistema za akviziciju, arhiviranje i analizu slike sa GSK. Iako je era digitalnih kamera počela još 80-tih godina 20. veka, mnogi nuklearno-medicinski centri u svetu (posebno u zemljama u razvoju) i dalje imaju analogne ili polu-analogne GSK u kojima i mehanika i scintilacioni kristal, tj. “srce” glave GSK, pravilno funkcionišu. Optimalno rešenje je digitalizacija GSK i integracija sa modernim računarskim sistemima. Digitalizacija analognih i polu-analognih GSK obezbeđuje: 1) produžetak korišćenja starih GSK i odlaganje finansijskih ulaganja u novu instrumentaciju; 2) primenu najboljih postojećih metoda analize nuklearno-medicinskih studija (u skladu sa aktuelnim principima medicine zasnovane na dokazima, MZD); 3) ispitivanje i razvoj novih metoda analize radi poboljšanja tretmana pacijenata, pod uslovom da je arhitektura sistema “otvorena”. Cilj istraživanja koje je prikazano u ovoj doktorskoj tezi je razvoj računarskog sistema (GammaKey sistem) koji daje funkcionalnost (akvizicija, arhiviranje i analiza slika) polu-analognim GSK, kompatibilan je i može se koristiti i sa savremenim digitalnim GSK, a koji svojom otvorenom arhitekturom omogućava razvoj i kliničku primenu novih dijagnostičkih tehnika. GammaKey sistem zadovoljava sledeće zahteve: 1) jednostavnu zamenu originalnog računarskog sistema (npr. MicroDELTA, Siemens Gammasonics Inc., Ilinois, SAD) novim sistemom - jednostavno priključenje na GSK pri čemu obuka korisnika minimalno traje zahvaljujući intuitivnom Windows grafičkom interfejsu; 2) pouzdanost sistema - zadovoljava standarde kvaliteta nuklearno medicinske instrumentacije definisanih od strane udruženja National Electrical Manufacturers Association (NEMA) i testiran je u paraleli sa pređašnjim računarskim sistemom (MicroDELTA, Siemens Gammasonics Inc., Ilinois, SAD); 3) kompatibilnost vi sa drugim (ne)medicinskim sistemima korišćenjem standardnih formata podataka (JPEG, BITMAP, ASCII, DICOM), i sinhronizacija podataka između dve radne stanice (jedna radna stanica je za akviziciju, arhiviranje i obradu studija dobijenih sa GSK, a druga je samo za obradu podataka); 4) brza, jednostavna i jeftina nadgradnja za nove generacije računara i analogno-digitalnih konvertora (ADK) – omogućena izborom LabVIEW softverskog okruženja (National Instruments, Teksas, SAD) i komercijalnog National Instruments ADK; 5) razvoj i dodavanje novih nestandardnih akvizicionih protokola i alatki za obradu studija. U osnovnoj konfiguraciji GammaKey sistema uključene su: 1) standardne funkcije za obradu slika (resemplovanje na dimenziju 1024x1024 piksela bilinearnom interpolacijom, nine-point smoothing, Batervortov i Vinerov filter); 2) alatke za manipulaciju slikom (zumiranje, podešavanje kontrasta, brisanje dela slike koji nije od interesa); 3) standardne funkcije za obradu scintigrafskih studija (crtanje do 10 regiona od interesa (ROI), generisanje dinamskih krivih nad ROI, aritmetičke operacije nad slikama i dinamskim krivama, N-point median i cubic spline filtriranje dinamskih krivih, automatska segmentacija ROI na statičkim studijama, korekcija radioaktivnosti ROI). U proširenoj varijanti, GammaKey sistem uključuje i tri nestandardne analize: 1) EffSpleen akvizicija i analiza za predviđanje efikasnosti splenektomije u bolesnika sa hroničnom trombocitopenijskom purpurom; 2) Submarine analiza za lokalizaciju paratiroidnih tumora; 3) SalivaryScan analiza za kompletnu kvantifikaciju funkcije pljuvačnih žlezda. EffSpleen rutina omogućava kompletnu akviziciju i analizu in vivo ispitivanja kinetike trombocita radi procene efikasnosti splenektomije u bolesnika sa hroničnom imunom trombocitopenijskom purpurom prema metodi razvijenoj u Centru za nuklearnu medicinu Kliničkog centra u Beogradu. Razvijena rutina je omogućila automatizaciju u procesu zahtevne obrade serije statičkih studija i proračuna indeksa sekvestracije trombocita. Submarine rutina predstavlja implementaciju originalne metode za lokalizaciju paratiroidnih tumora na osnovu dinamskih paratiroidnih scintigrama i razvijena je u saradnji sa lekarima iz Instituta za onkologiju i radiologiju Srbije u Beogradu. U tezi je prikazana evaluacija Submarine metode na grupi pacijenata sa histopatološki dokazanim paratiroidnim tumorima i ukazano je na njenu efikasnost pri lokalizaciji hiperplazija i paratiroidnih lezija zaklonjenih tiroidnim nodusima, vii rešavajući time tipične promašaje standardnog subtrakcionog protokola. Predloženi su i algoritmi za vizuelizaciju i automatsko izdvajanje regije paratiroidnih lezija. SalivaryScan rutina omogućava automatski proračun 11 kvantitativnih indeksa koji opisuju funkciju pljuvačnih žlezda, za razliku od komercijalnih softvera koji obično daju samo jedan parameter (ejekcionu frakciju). Uvedena je i značajna modifikacija indeksa koji opisuje brzinu sekrecije. Razvijena alatka je bazični instrument za dalja multidisciplinarna istraživanja u domenu scintigrafije pljuvačnih žlezda...Gamma scintillation cameras (GSC) are medical devices for the analysis of the distribution intravenously injected, inhaled or ingested radiopharmaceuticals. The development of integrated circuit technology had influence on construction of GSC’s head and on flexibility, speed, cost and expandability of GSC’s supported systems for image acquisition, storage and analysis. Although the era of digital GSCs began long ago (1980s), many nuclear medical centres still have analogue or semi-analogue GSCs with fully operational mechanics and scintillation crystals, which are the core of nuclear imaging. Optimal solution is digitizing GSC and integration with modern computer systems. Digitizing of analogue and semi-analogue GSCs ensures: 1) continuity of using old GSCs and the postponement of buying new instrumentation; 2) application of best available analysis of nuclear-medical studies (in accordance with the principles of Evidence Based Medicine, EBM); 3) testing and development of new analysis techniques to improve the treatment of patients, if the system architecture is “opened”. The aim of the research presented in this doctoral thesis is the development of a computer system (GammaKey system) that gives the functionality (acquisition, storage and image processing) to semi-analogue GSCs, compatible and also can be used with modern digital systems, has an open architecture enabling the development and clinical application of new diagnostic techniques. GammaKey system meets the following requirements: 1) simple replacement of the original computer system (e.g. MicroDELTA, Siemens Gammasonics Inc., Ilinois, USA) to the new configuration – a simple connection to GSC and minimal training thanks to the intuitive Windows graphical interface; 2) reliability – meets the quality standards of nuclear medical instrumentation defined by National Electrical Manufacturers Association (NEMA), no loss of information about patients and studies, accurate and precise production of results; 3) compatibility with other (non)medical systems by using standard data formats (JPEG, BITMAP, ASCII, DICOM) and data synchronization between two workstations ix (the first one for acquisition, storage and processing, the second one only for image processing); 4) fast, simple and cheap upgrade to new generations of computers and analog-to-digital convertors (ADC) – enabled by using LabVIEW software environment (National Instruments, Teksas, SAD) and commercial National Instruments ADC; 5) development and implementing novel non-standard acquisition protocols and tools for study processing. Basic configuration of GammaKey system includes: 1) standard functions for image processing (resampling to the matrix 1024x1024 pixels by bilinear interpolation, nine-point smoothing, Butterworth and Winer filter); 2) tools for image manipulation (zoom, contrast adjustment, deleting parts of the image that are not of interest); 3) standard functions for scintigraphic study processing (up to 10 regions of interest (ROI), calculating time-activity-curves (TAC), frame and TAC arithmetic opearations, N-point median and cubic spline TAC filtering, automatic ROI segmentation of static studies, ROI radioactivity correction). Advanced configuration of GammaKey system includes three non-standard features: 1) EffSpleen acquisition and analysis for efficacy of the splenectomy prediction in patients with chronic immune thrombocytopenic purpura; 2) Submarine analysis for localization of parathyroid tumors; 3) SalivaryScan analysis for complete quantitative investigation of salivary glands function. EffSpleen routine enables complete acquisition and analysis of in vivo examination of platelet kinetics in order to estimate splenectomy efficacy according to the method developed in the Center for Nuclear Medicine, Clinical Center of Serbia, Belgrade. Developed routine allows the automation of timeconsuming processing of sequential static studies and calculation of platelet sequestration index. Submarine routine is the implementation of the original method for the localization of parathyroid tumors based on dynamic parathyroid scintigrams, developed in collaboration with physicians from the National Cancer Research Center of Serbia, Belgrade. Evaluation of Submarine method is presented in the group of patients with histopathologically proven parathyroid tumors and its efficacy has been demonstrated for localization of hyperplasia and parathyroid lesions covered by thyroid nodules, solving typical pitfalls of standard subtraction protocol. Algorithms for visualization and automatic extraction of regions with parathyroid lesions are suggested. SalivaryScan routine enables automatic calculation of 11 quantitative indices that describe the function of salivary glands, unlike commercial software that usually gives only one parameter (ejection fraction). A significant modification of secretion velocity index is introduced. Developed tool is a basic instrument for further multidisciplinary research in the field of salivary scintigraphy..

Calibration of HPGe Detectors for Environmental Samples Using GEANT4 Simulation

Determination of full energy peak efficiency is one of the most important tasks that have to be performed before gamma spectrometry. Calibration of the measurement system for measuring environmental samples poses a special challenge to the laboratory. Many different approaches to this task have been developed and examined. One of the most detailed is GEANT4, a Monte Carlo simulation toolkit developed for wide variety of applications. The aim of this paper is to apply GEANT4 simulation for calibration of three HPGe detectors, for measurement of aerosol, plant and coal-like environmental samples. The detectors were modeled using the certificate provided by the manufacturer. The samples chosen for the simulation were secondary reference materials produced in the Laboratory for the purpose of experimental calibration. The efficiencies obtained using a simulation were compared with experimental results, in order to evaluate the trueness of the results. Measurement uncertainties for both simulation and experimental values were estimated in order to see whether the results of the realistic measurement fall within acceptable limits.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Calibration of HPGe Detectors for Environmental Samples Using GEANT4 Simulation

Determination of full energy peak efficiency is one of the most important tasks that have to be performed before gamma spectrometry. Calibration of the measurement system for measuring environmental samples poses a special challenge to the laboratory. Many different approaches to this task have been developed and examined. One of the most detailed is GEANT4, a Monte Carlo simulation toolkit developed for wide variety of applications. The aim of this paper is to apply GEANT4 simulation for calibration of three HPGe detectors, for measurement of aerosol, plant and coal-like environmental samples. The detectors were modeled using the certificate provided by the manufacturer. The samples chosen for the simulation were secondary reference materials produced in the Laboratory for the purpose of experimental calibration. The efficiencies obtained using a simulation were compared with experimental results, in order to evaluate the trueness of the results. Measurement uncertainties for both simulation and experimental values were estimated in order to see whether the results of the realistic measurement fall within acceptable limits.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Natural radioactivity in imported ceramic tiles used in Serbia

Ceramic tiles are one of the commonly used decorative building materials. Body of ceramic tiles is a mixture of different raw materials including clays, quartz materials and feldspat, and may be glazed or left unglazed. Due to the presence of zircon in the glaze, ceramic tiles can show natural radioactivity concentration significantly higher than the average values for building materials. This study presents a summary of results obtained by a survey which was consisted of measurements of activity concentrations of natural radionuclides in imported ceramic tile samples used in Serbia using a gamma spectrometer with HPGe detector. Based on the obtained concentrations, gamma index, radium equivalent activity, the indoor absorbed dose rate and the corresponding annual effective dose were evaluated to assess the potential radiological hazard associated with these building materials

Correlation Between Beryllium-7 in Atmospheric Deposit and Ground Level Air in Serbia for 2014 Year

Activity density of beryllium-7 in atmospheric deposit and in ground level air at five monitoring stations (MS Nis, Vranje, Zajecar, Zlatibor, Palic) in Serbia were determined during the period January-December 2014. Activity of cosmogenic radionuclide beryllium-7 was determined on HPG detectors (Canberra, relative efficienty 20%.) by gama spectrometry method. Activity density of beryllium-7 in aerosols were in range 0.5 - 9.8 mBq/m(3) and in deposits were in range 1.8 - 233 Bg/m(2). Based on the obtained results correlation coefficient between aerosols and deposits was calculated and its value ranged from 0.15 to 0.59.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

The effect of colour on reading performance in children, measured by a sensor hub: From the perspective of gender

In recent decades reported findings regarding gender differences in reading achievement, cognitive abilities and maturation process in boys and girls are conflicting. As reading is one of the most important processes in the maturation of an individual, the aim of the study was to better understand gender differences between primary school students. The study evaluates differences in Heart Rate Variability (HRV), Electroencephalography (EEG), Electrodermal Activities (EDA) and eye movement of participants during the reading task. Taking into account that colour may affect reading skills, in that it affects the emotional and physiological state of the body, the research attempts to provide a better understanding of gender differences in reading through examining the effect of colour, as applied to reading content. The physiological responses of 50 children (25 boys and 25 girls) to 12 different background and overlay colours of reading content were measured and summarised during the reading process. Our findings show that boys have shorter reading duration scores and a longer Saccade Count, Saccade Duration Total, and Saccade Duration Average when reading on a coloured background, especially purple, which could be caused by their motivation and by the type of reading task. Also, the boys had higher values for the Delta band and the Whole Range of EEG measurements in comparison to the girls when reading on coloured backgrounds, which could reflect the faster maturation of the girls. Regarding EDA measurements we did not find systematic differences between groups either on white or on coloured/overlay background. We found the most significant differences arose in the HRV parameters, namely (SDNN (ms), STD HR (beats/min), RMSSD (ms), NN50 (beats), pNN50 (%), CVRR) when children read the text on coloured/overlay backgrounds, where the girls showed systematically higher values on HRV measurements in comparison to the boys, mostly with yellow, red, and orange overlay colours

Results from Radionuclide Interlaboratory Comparison in Sediment and Fish

The results of an intercomparison exercise, designed for the determination of anthropogenic and natural radionuclides in sediment and fish samples from the Danube River, are reported. The methods of gross beta and gamma spectrometry measurements were compared. Considering the uncertainties of measurements, a good agreement between the results obtained by two laboratories has been ascertained.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

ALGORITHM FOR UPTAKE ASSESSMENT IN SMALL LESIONS BASED ON DYNAMIC SCINTIGRAPHY SCANS

The aim of our research was to develop an algorithm for estimation and visualisation of radiopharmaceutical uptake based on time-activity-curve (TAC) analysis in small regions of interest (ROI) in scintigraphic studies. The algorithm is implemented in Labview environment (National Instruments, Texas, Austin) and comprises the following steps: 1) delineation of grid of small ROIs over the examined tissue and corresponding TAC processing; 2) background vs tissue separation; 3) the extraction of all “suspected“ ROIs where TACs are not exponentially descendent; 4) correlation analysis between a TAC corresponding to the suspicious lesion ROI and TACs of neghboring ROIs; 5) the extraction of representative TAC for “suspected“ area by Principal Component Analysis technique; and 6) visual interpretation of radiopharmaceutical distribution in the “suspected“ area. The application of algorithm is presented in data recorded in case of histopathologically proven parathyroid tumors

Assessment of natural radioactivity levels and radon exhalation rate potential from various building materials

Various imported building materials commonly used in construction and industry in Serbia were analyzed using gamma spectrometry. Based on the activity concentrations of 226Ra, 232Th, and 40K in the investigated samples, radium equivalent activity, Raeq, absorbed dose rate, D, annual effective dose, DE, and the external hazard index, Hex, were calculated to assess the radiation hazard for people. The Raeq for most of the analyzed samples (416 in total) was lower than the maximum admissible value of 370 Bqkg-1 set in the UNSCEAR report. The absorbed gamma dose rate in air was found to vary from 0.030 mGyh-1 to 1.328 mGyh-1 which in some cases exceeded indoor dose rates in Europe. The obtained values for annual effective dose exceed the limits of 0.41 mSv given in literature for about 5 % of measured samples, while values of Hex were higher than unity for three samples of cement, eight samples of granite, and one sand sample. As a possible source of elevated effective dose, the radon exhalation from building materials was estimated using the parameters given in literature. The internal dose due to 222Rn exhaled from the building material was found to be up to nine times higher than external dose due to 226Ra content in some cases

The role of a pharmacist in prevention and detection of OTC drug interactions: Nominal group technique

Introduction: Nowadays number of newly approved OTC medicines continuously increases, which can make certain difficulties in drug dispensing process. This fact particularly relates to drug-drug interactions-problems due to lack of data and insufficient of knowledge about the interactions. Aim: To identify the problems pharmacists face when dispensing OTC drugs and to recommend concrete ideas and methods for improving system for detecting OTC drugs interactions. Participants and method: The study was carried out in accordance with methodological principles of nominal group technique. Two meetings of nominal group were conducted, enrolling pharmacists employed in public pharmacies. During the meetings, moderator imposed aset of questions to participants, who gave answers in the form of individual statements. In order to examine agreement of the participants about the individual statements, at the end of both sessions the statements were rated on a Likert's scale. Meetings were recorded and audio recordings later used for qualitative analysis. Results: Nine pharmacists of both sex (7/2 females/males) participated in this study. Average age of the participants was 25.0±1.0 years. During nominal group meetings, participants presented 30 statements on 7 research questions, and after the second meeting agreement was reached about 29 of them. Qualitative analysis of data indicated three categories of statements: (1) pharmacists' knowledge of OTC drugs interactions, (2) problems pharmacists face when dispensing OTC drugs and (3) options of improving system for prevention and detection of OTC drugs interactions. Conclusion: For adequate prevention of potential OTC drugs interactions it is necessary to make guidelines with recommendations referring to proper dispensing procedure and to use regularly available online interaction checkers