Gonad shielding in paediatric pelvic radiography: disadvantages prevail over benefit

Objective To re-evaluate gonad shielding in paediatric pelvic radiography in terms of attainable radiation risk reduction and associated loss of diagnostic information. Methods A study on patient dose and the quality of gonad shielding was performed retrospectively using 500 pelvic radiographs of children from 0 to 15 years old. In a subsequent study, 195 radiographs without gonad shielding were included. Patient doses and detriment adjusted risks for heritable disease and cancer were calculated with and without gonad shielding. Results For girls, gonad shields were placed incorrectly in 91% of the radiographs; for boys, in 66%. Without gonad shielding, the hereditary detriment adjusted risk for girls ranged between 0.1?×?10?6 and 1.3?×?10?6 and for boys between 0.3?×?10?6 and 3.9?×?10?6, dependent on age. With shielding, the reduction in hereditary risk for girls was on average 6?±?3% of the total risk of the radiograph, for boys 24?±?6%. Without gonad shielding, the effective dose ranged from 0.008 to 0.098 mSv. Conclusions With modern optimised X-ray systems, the reduction of the detriment adjusted risk by gonad shielding is negligibly small. Given the potential consequences of loss of diagnostic information, of retakes, and of shielding of automatic exposure-control chambers, gonad shielding might better be discontinued.Support TNWApplied Science

Unintended and accidental medical radiation exposures in radiology: guidelines on investigation and prevention

This paper sets out guidelines for managing radiation exposure incidents involving patients in diagnostic and interventional radiology. The work is based on collation of experiences from representatives of international and national organizations for radiologists, medical physicists, radiographers, regulators, and equipment manufacturers, derived from an International Atomic Energy Agency Technical Meeting. More serious overexposures can result in skin doses high enough to produce tissue reactions, in interventional procedures and computed tomography, most notably from perfusion studies. A major factor involved has been deficiencies in training of staff in operation of equipment and optimization techniques. The use of checklists and time outs before procedures commence, and dose alerts when critical levels are reached during procedures can provide safeguards to reduce risks of these effects occurring. However, unintended and accidental overexposures resulting in relatively small additional doses can take place in any diagnostic or interventional X-ray procedure and it is important to learn from errors that occur, as these may lead to increased risks of stochastic effects. Such events may involve the wrong examinations, procedural errors, or equipment faults. Guidance is given on prevention, investigation and dose calculation for radiology exposure incidents within healthcare facilities. Responsibilities should be clearly set out in formal policies, and procedures should be in place to ensure that root causes are identified and deficiencies addressed. When an overexposure of a patient or an unintended exposure of a foetus occurs, the foetal, organ, skin and/or effective dose may be estimated from exposure data. When doses are very low, generic values for the examination may be sufficient, but a full assessment of doses to all exposed organs and tissues may sometimes be required. The use of general terminology to describe risks from stochastic effects is recommended rather than calculation of numerical values, as these are misleading when applied to individuals

Hukkakuva-analyysi HUS-Röntgenissä

Opinnäytetyön tarkoituksena oli selvittää HUS-Röntgenin röntgentoimipisteiden käytäntöjä natiivikuvantamisessa tehtävään hukkakuva-analyysiin. HUS-Röntgenillä ei ollut yhtenäistä ohjeistusta hukkakuva-analyysin suorittamiseksi, ja haluttiin kartoittaa yksiköiden hyviksi havaitsemia toimintatapoja sekä tavoitella koko organisaation laajuista käytäntöä. Opinnäytetyön teoriataustaa kerättiin röntgenkuvantamisen laadunvarmistuksesta ja tarkemmin hukkakuva-analyysista, niin kansainvälisistä kuin kotimaisista lähteistä. Tietoja hukkakuva-analyysin toteutustavoista pyydettiin HUS-Röntgenin toimipisteiltä kyselyn avulla. Kyselyn vastauksista eriteltiin hukkakuva-analyysin tekotapoihin sekä sen tuloksien hyödynnettävyyteen liittyviä asioita. Toimipisteiltä saatuja vastauksia verrattiin kansainvälisiin julkaisuihin aineistoa ja teoriaa yhdistävän abduktiivisen päättelytavan avulla. 20 eri toimipisteestä saadusta vastauksesta kävi ilmi hukkakuva-analyysin erilaiset menetelmät HUS-Röntgenissä. Yksiköistä saatiin tiedot viimeisimmästä sen suorittamasta hukkakuva-analyysista sekä siitä, miten hukkakuva-analyysin tuloksia on hyödynnetty yksikössä. Suurimmassa osassa yksiköitä tuloksia käytiin läpi henkilökunnan kanssa ja jos systemaattisia virheitä havaittiin, asiaan puututtiin. HUS-Röntgenin laajan röntgenlaitekannan ja niihin liittyvien ohjelmistojen yhteensovittaminen asettaa haasteita yhtenäisen ohjeistuksen luomiselle hukkakuva-analyysin tekoon. Jotta röntgenyksiköiden hukkakuva-analyysin tuloksia voidaan verrata, olisi käytäntöjen kuitenkin hyvä olla samankaltaiset koko organisaatiossa. Kuvien hylkäyssyiden tulisi olla yhtenäiset. Hukkakuvien sekä hukkakuva-analyysin tulosten läpikäyminen henkilökunnan kanssa olisi suotavaa. Käytäntöjä voidaan myös yhtenäistää esimerkiksi analyysin hyödynnettävyyden osalta.The objective of this study was to find out methods and customs for carrying out reject analysis in computed radiography in the organization of HUS-Röntgen, the leading medical imaging provider in Finland, which produces medical imaging services for the Hospital District of Helsinki and Uusimaa. Furthermore the study aimed to create a guideline for reject analysis for the entire organization. Information about quality assurance and reject analysis in computed radiography was collected from studies and journals in the field of radiography. Data from the departments of HUS-Röntgen were gathered by sending a small questionnaire on the latest reject analysis performed in the unit. The responses received from the units were analyzed and compared with the data from previous studies. In total 18 responses were received from the departments of HUS-Röntgen. The data included information on the latest reject analysis and the benefits of the results of the reject analysis. Most of the departments went through the results with personnel and if systematic errors occurred they were processed. The different devices and software of computed radiography in the organization makes it challenging to make a general guideline or instructions for carrying out reject analysis. It would be important to create common instructions among HUS-Röntgen, to enable the comparison of the results of reject analysis between different units. Finally, it would be recommended to study some of the rejected images and to analyze the results of the reject analysis with the staff in purpose of training. Practices can be integrated for instance in the utilization of the results of the reject analysis

Pre and post computerized radiography film reject analysis in a private hospital in Kenya

The production of good quality radiographs is a complex process, given the high level of image quality required (Sniureviciute & Adliene, 2005: 260). Exposure of patients to x-rays, a factor in the production of quality radiographs also entails a risk of radiation injury. In 2006, computerized radiography (CR) was introduced at The Nairobi Hospital to try and reduce the film reject rate, decrease repeats, reduce financial costs of consumables like x-ray films and processing chemicals. However, to date, no formal film reject analysis has been conducted at The Nairobi Hospital. Four years after the incorporation of CR, there is apparently, still a significant number of film rejects, implying operational costs may still be high. The cause of film rejects and overall reject cost is not known. This has led to the research question: “Has the film reject rate in the A & E x-ray unit at The Nairobi Hospital reduced following incorporation of CR?” A quantitative, retrospective, descriptive study involving a reject film analysis of rejected radiographs in the Accident and Emergency (A&E) x-ray unit in the Nairobi Hospital, Kenya was conducted. The researcher collected data for a period of 6 months between 2/12/07 and 28/05/08 using a purpose-designed data collection form. All rejected x-ray films during the study period were included. Capture and analysis of the collected data was completed by the researcher using SPSS 10 and EPINFO computer packages. Permission to conduct the study was obtained from The Nairobi Hospital Education Committee and due consideration to patient and radiographer confidentiality was maintained throughout the study. A total of 851(2.5 percent) x-ray films were collected during the study period. Four hundred and fourteen (2.6 percent) radiographs and 437 (2.5 percent) radiographs were rejected prior to and after the incorporation of CR respectively. Chest radiographs were the most frequently rejected accounting for 277(66.9 percent) and 123 (28.1 percent) prior to and after the incorporation of CR respectively. The most frequently rejected film size was 35x35cm prior to the incorporation of CR (61.6 percent) and 26x35cm film size after the incorporation of CR (91.3 percent). The most frequent cause of film rejects was radiographer causes both prior to and after the incorporation of CR accounting for 496 (58.3 percent). The film reject rate did not significantly reduce after the incorporation of CR, suggesting that there are other factors which contribute to reject rate, other than CR. The study also shows that higher film consumption does not necessarily lead to high reject rates. The percentage value on annual rejects did not change after the incorporation of CR and a demonstrated increase in the annual cost of purchasing x-ray films was attributed to an increase in annual consumption after the incorporation of CR, and also to the higher cost of digital x-ray films. Despite some identified limitations to this study, some recommendations, which included conduction of regular reject analyses and regular continuing professional development with respect to radiographic technique amongst others, were suggested

Resultados en la caracterización de la tasa de repetición de imágenes radiográficas convencionales en un hospital pediátrico

Talking about conventional radiology refers to diagnostic images obtained by ionizing radiation,, which can be visualized on radiographic films or high resolution consoles. These images must comply with high radiographic quality standards so that the radiologist can make a timely and accurate diagnosis. In pediatric patients, when acquiring images, it is essential to observe greater rigor in order to avoid repeating any study. Since children are very young, they have a greater number of immature and proliferating cells, which makes them more sensitive to ionizing radiation and more likely to present late side effects throughout their lives. For this reason, radiological protection is important in this population and the repetition of radiographic images should be carefully reviewed to avoid irreparable damage. The purpose of this research was to characterize the causes of recurrence of radiographic images taken in pediatric patients in a Health Care Institution in Bogotá, through a detailed analysis of the causes of recurrence. In a radiology service that seeks to provide health services with quality assurance, it is necessary to consider that its purpose is to produce radiographic images of optimum quality without unnecessarily affecting the patient and keeping them at the lowest possible cost. Therefore, it is important to mention that, in the implementation of the quality assurance program in radiodiagnostic, it is essential to begin with the evaluation of radiographic images that are repeated because they do not have the necessary quality for diagnosis, establishing in detail their causes and percentages.   The purpose of this research was to characterize the causes of recurrence of radiographic images taken in pediatric patients in a Health Care Institution in Bogotá, through a detailed analysis of the causes of recurrence. In a radiology service that seeks to provide health services with quality assurance, it is necessary to take into account that its purpose is to produce radiographic images of optimum quality without unnecessarily affecting the patient and at the lowest possible cost. Therefore, it is important to mention that, in the implementation of the quality assurance program in radiodiagnostic, it is essential to begin with the evaluation of radiographic images that are repeated because they do not have the necessary quality for diagnosis, establishing in detail their causes and percentages.Hablar de radiología convencional es referirse a imágenes diagnósticas obtenidas mediante radiación ionizante que pueden visualizarse en películas radiográficas o en pantallas de alta resolución.  Estas deben cumplir con altos estándares de calidad radiográfica para que el médico radiólogo haga un diagnóstico oportuno y certero. En pacientes pediátricos, al adquirir imágenes, es indispensable observar mayor rigurosidad con el propósito de evitar repetir algún estudio, ya que dicha población es más sensible a la radiación ionizante por tener mayor cantidad de células inmaduras y proliferantes, además por su edad tienen posibilidad de presentar efectos tardíos a lo largo de su vida. Por eso la protección radiológica es importante en esta población y la repetición de imágenes radiográficas debe ser revisada cuidadosamente para evitar daños irreparables.  El propósito de esta investigación fue caracterizar las causales de repetición de imágenes radiográficas tomadas a pacientes pediátricos en una Institución Prestadora de Salud en Bogotá, por medio de un análisis pormenorizado de las causas que originan repetición. En un servicio de radiología que procura prestar servicios de salud con garantía de calidad es necesario tener en cuenta que su finalidad es producir imágenes radiográficas de óptima calidad sin afectar innecesariamente al paciente y al menor costo posible. Por lo anterior, es importante mencionar que, en la implementación del programa de garantía de calidad en radiodiagnóstico, es imprescindible comenzar con la evaluación de imágenes radiográficas que se repiten por no contar con calidad necesaria para el diagnóstico, estableciendo pormenorizadamente sus causas y porcentajes de estas

Keuhkokuvaus CareMe-oppimispelin avulla : suunnitelma pelin sisällöstä

Opinnäytetyön tarkoituksena oli tuottaa CareMe-simulaatiopeliin osio röntgenhoitajaopiskelijoille keuhkokuvauksesta. Opinnäytetyön lopputuloksena syntyi suunnitelma, kuinka keuhkokuvausprosessi tulisi etenemään CareMe-simulaatiopelissä. Röntgenhoitajaopiskelijoille ei ole vielä suunniteltu yhtään oppimispeliä CareMe-pelipohjaan. CareMe-oppimispeli sijoittuu terveydenhuollon ympäristöön, jossa opetellaan erilaisten potilastapausten avulla potilaan kohtaamista ja hoitoa erilaisilla toimenpiteillä. Suunnittelimme potilastapauksen röntgenosastolle, jossa röntgenhoitajaopiskelijan tulee suorittaa keuhkokuvaus. Keuhkokuvaus on yleisin röntgenkuvauskohde. Peli alkaa lähetteen lukemisella, käsittää kuvanlaatuun liittyviä tekijöitä, potilaan ohjeistuksen ja loppuu kuvien arkistoimiseen. Peli sisältää erilaisia monivalintatilanteita ja ajastettuja kohtauksia. Lisäksi pelissä on kokeneempi röntgenhoitaja antamassa jatkuvaa palautetta pelaajalle hänen suorituksestaan. Opinnäytetyön teoriapohja perustuu keuhkokuvantamisprosessin eri vaiheisiin, kuvien laatuun ja yleisimpiin virheisiin keuhkokuvissa. Näistä tekijöistä muodostuvat pelin kysymykset. Lisäksi perehdyimme oppimistapoihin ja pelien tapaan opettaa ihmistä, jotta peli tulisi olemaan rakenteeltaan opetusta tukeva. Aloittelevakin röntgenhoitajaopiskelija pystyy opinnäytetyön luettuaan vastaamaan suunnitellun CareMe-pelin kysymyksiin. Jotta suunnittelemamme peli vastaisi kohderyhmämme tarpeita, suoritimme kyselyn ensimmäiselle röntgenharjoittelujaksolle meneville opiskelijoille. Kysely sisälsi peliin suunnittelemamme kysymykset sekä kysymyksiä liittyen opiskelijoiden kokemuksiin pelin sisällöstä ja mielenkiintoisuudesta. Palaute oli positiivista ja osa vastanneista innostui pelistä ideana. Tulevat opinnäytetyöt voisivat koskea muita kuvauskohteita tai -laitteita ja keskittyä enemmän röntgenhoitajan rooliin potilashoitajana tai konehoitajana. Muiden alojen opiskelijat, kuten mediatekniikan opiskelijat, voisivat toteuttaa suunnittelemamme pelin konkreettiseksi tuotteeksi.The purpose of our thesis was to develop a part to the CareMe-learning game about thorax imaging for radiographer students. The outcome of the thesis was an outline on how thorax examination process will progress in the CareMe-learning game. So far, thorax imaging has not been included in the CareMe-learning game for radiographer students. CareMe-learning game is situated in a healthcare environment, where the students play through patient cases on how to face patients and perform various procedures. We developed a patient case for an x-ray department in which a radiographer student performs thorax imaging procedures, since thorax is the most common x-ray examination. The game begins with reading of the referral, and includes questionnaires related to the quality of the images, giving instructions for the patient, and ends with archiving the images. The game includes different multiple-choice situations, and exercises with time limits. In addition, there is a more experienced radiographer character in the game, who gives continuous feedback to the player of her/his performance. The theoretical basis of our thesis is based on the different phases of the thorax imaging process, quality of the images, and the most common mistakes made in thorax imaging. The questions in the game came from these topics. Also, we studied different learning styles, and how games can facilitate the learning process, so that the structure of the game complements teaching. After reading this thesis, even first semester radiographer student is able to answer the questions of our CareMe-learning game. We gave a questionnaire to students, who were about to start their first practical x-ray training period to make sure that the game we developed would meet the needs of the target audience. The questionnaire included the questions we had planned for the game, and questions on how the students perceived the content of the game and whether it was interesting or not. The feedback was positive, and some participants got interested in the game. Future research could include studies on imaging other parts of the body, imaging with different modalities, or focus more on the radiographer’s role in working with patients or machines. Students with different majors, such as media engineering students, could make our plans a reality

Indicadores de desempenho imagiológico baseados em meta-informação

Doutoramento em Ciências e Tecnologias da SaúdeA qualidade da prestação de cuidados de saúde é uma das principais preocupações da sociedade atual. Esta preocupação surge evidente na literatura académica mas também em documentos e iniciativas patrocinadas por entidades internacionais como a Organização Mundial de Saúde ou pela Organização para a Cooperação e o Desenvolvimento Económico. Muitas destas iniciativas têm por base a análise da qualidade da prestação de cuidados de saúde nas suas diferentes dimensões, nomeadamente no âmbito da segurança, eficácia e eficiência e utilização de recursos. Uma forma de caraterizar a qualidade da prestação de cuidados de saúde é recorrendo à informação proveniente do mundo real e da evidência que resulta da prestação de cuidados, nomeadamente a meta-informação. No âmbito da Imagiologia, a meta-informação que faz parte da imagem médica no formato da norma Digital Imaging and Communication in Medicine (DICOM), mais especificamente a suportada por metadados DICOM disponibilizados de forma pública, torna possível a sua utilização para a caraterização do exercício profissional no âmbito de diferentes iniciativas, como as que tenham por objetivo a melhoria contínua da prestação de cuidados em Imagiologia. No entanto, assistimos a uma utilização pouco normalizada desta informação por parte de diferentes fabricantes, nomeadamente com recurso a sistemas de informação e metadados DICOM privados. As principais contribuições desta tese são a definição de uma metodologia de aquisição de Metadados DICOM independente das modalidades de imagem médica e fabricantes dos sistemas de informação e equipamentos de imagem, a definição e integração de Indicadores de Desempenho Imagiológicos baseados em Metadados DICOM (IDI-DICOM) e a definição de um modelo de informação que suporta a gestão destes indicadores de uma forma adaptativa à realidade profissional que pretendem caracterizar. A utilização do IDI-DICOM para a caraterização do exercício profissional pode promover a identificação de situações que requerem iniciativas para alcançar uma melhoria da prestação de cuidados de Imagiologia, nomeadamente em termos de uma melhor gestão de recursos humanos e materiais. Estas podem ocorrer no âmbito da framework de Melhoria Contínua de Qualidade em Imagiologia suportada em IDI-DICOM apresentada nesta Tese.The quality of the health care delivery is a major concern in today's society. This concern arises in academic literature but also in documents and initiatives sponsored by international organizations like the World Health Organization or the Organization for Economic Cooperation and Development. Many of these initiatives are based on the analysis of the quality of health care in its different dimensions, particularly in safety, effectiveness, efficiency and resource utilization contexts. One way to characterize the quality of health relies on using the meta-information that embodies the healthcare delivery processes. In the imaging context, the metadata that is part of a medical image object according to the Digital Imaging and Communication in Medicine (DICOM) standard. As we shall show in this thesis data-mining over some meta-data elements provides objective and large scale views that may be used for the characterization of professional practice under initiatives that aim to continuously improve the delivery of imaging based care. The main contributions of this thesis are the definition of a methodology for the acquisition of DICOM metadata that is independent of the imaging modalities and manufacturers of medical information systems and imaging equipment, the definition and integration of imaging performance indicators based on DICOM metadata (IDI-DICOM) and the definition of an information model that supports the management of these indicators in an adaptive way, related to the professional reality they intend to characterize. The use of the IDI-DICOM as an adjunct means for the characterization of professional practice may lead to uncover situations that require initiatives to achieve improved Imaging care, particularly in terms of better human and material resources management. These may occur within the framework of Continuous Quality Improvement in Medical Imaging supported by IDI-DICOM presented in this thesis

OPTICAL GEOMETRY CALIBRATION METHOD FOR COMPUTED TOMOGRAPHY AND APPLICATIONS OF COMPACT MICROBEAM RADIATION THERAPY

Digital tomosynthesis is a type of limited angle tomography that allows for 3D information reconstructed from a set of X-ray projection images taken at various angles using an X-ray tube, a mechanical arm to rotate the tube, and a digital detector. Tomosynthesis reconstruction requires the knowledge of the precise location of the detector with respect to each X-ray source. Current clinical tomosynthesis methods use a physically coupled source and detector so the geometry is always known and is always the same. This makes it impractical for mobile or field operations. We demonstrated a free form tomosynthesis and free form computed tomography (CT) with a decoupled source and detector setup that uses a novel optical method for accurate and real-time geometry calibration. We accomplish this by using a camera to track the motion of the source relative to the detector. A checkerboard pattern is positioned on or next to the detector using an extension arm in such a way that the pattern will not move relative to the detector. A camera is mounted on the source in a way that the pattern is visible during imaging and will not move relative to the source. The image of the pattern captured by the camera is then used to determine the relative camera/pattern position and orientation by analyzing the pattern distortion. This allows for accurate, real time geometry calibration of the X-ray source relative to the detector. This method opens the doors for inexpensive upgrades to existing 2D imaging systems and an even more exciting application of a mobile, hand-held CT imaging system.Doctor of Philosoph

Mammography machine compression paddle movement andobserver performance analysis

Full field digital mammography (FFDM) was introduced into the United Kingdom (UK) as a replacement for screen-film mammography (SFM) in 2005. Since then, individual breast screening centres have begun to report blurred images through local audits. Blurring was probably present in SFM as well, however the improvement in contrast resolution in FFDM may have made it more apparent. The sources of blurring include improper imaging techniques, patient movement caused by breathing and heart motion,the viscoelastic motion of the breast, and paddle motion. This thesis aims to test the hypothesis that paddle motion might cause image blur. It investigates whether blurring can be detected visually on technical review monitors and reporting grade monitors.The thesis presents a method to minimise paddle motion during X-ray exposure. Six papers have been published. Two of these (papers 1 and 2) investigated paddle displacement using linear potentiometers. Three investigated the influence of paddle motion on image quality. Paper 3 investigated whether paddle motion can cause image blur; paper 4 determined the minimum amount of simulated motion required for the visual detection of blurring; and paper 5 evaluated the practitioner’s ability to identify blurring on monitors with different resolutions (2.3 MP and 5 MP). The final research paper (paper 6) investigated a way to reduce paddle displacement settling time; this involved the use of a closed-loop control system.Results: In papers 1 and 2 paddle displacement followed a bi-exponential function with a settling time of approximately 40 s. The use of average paddle displacement to estimate the amount of paddle motion would underestimate the worst case of the threedifferent runs of the experiment. The estimated paddle motion would be greatly reduced if the time of exposure is delayed from 5 to 10 s. In paper 3 all metal ball bearings shown increased in diameters and the range of magnification varied from 1.04 to 1.21. T-test results shown that there was a significant difference (p < 0.05) in the ball bearing diameters between the intensity thresholding and the edge detection methods for all paddle/ compression force combinations. The ball bearing diameters calculated by the intensity thresholding method had higher variability than the edge detection method.In paper 4 the soft-edged mask method best represented the physical process that caused the blurring effect and was chosen as the standard simulation approach for motion blurring. The ratio between the vertical paddle motion and the horizontal breast motion estimated by the mathematical model is approximately 1:0.3.In paper 5 the angular size calculation shown that for a viewing distance of 75 cm the screen resolution for 5 MP and 12 MP monitors was better than the observer eyes' resolution. For a viewing distance of 30 cm the observer eyes' resolution was betterthan the screen resolution for 2.3 MP, 5 MP and 12 MP monitors. Among all three monitors, image displayed on the 12 MP monitor has the lowest loss in image quality after interpolation. In paper 6 the simulation results shown that force overshoot is possible for position control system. Force overshoot occurred almost instantaneously for step input and its magnitude is about 10 times larger than the ramp input. Force overshoot and steadystateerror can be eliminated by the use of force control system.Conclusion: The magnitude of calculated paddle motion is much lower than the minimum amount of simulated motion required for the visual detection of blurring. Mathematical models have shown that vertical paddle motion caused a smaller horizontal breast displacement when compressed. Therefore, there is no sufficientevidence to support the hypothesis that paddle motion is a cause of image blurring in FFDM