Increasing Source-Object Distance: A Computed Radiographybased Strategy to Reducing Radiation Dose in Occipital-Frontal Skull X-Ray

@#Introduction: Exploring potential optimization strategies and developing evident practices is critical. Previous studies show that radiation dose can be reduced by increasing the source-image distance (SID). Although most studies use digital radiography, many hospitals in underdeveloped countries still use computed radiography (CR). Therefore, research will investigate the relationship between SID and Entrance surface dose (ESD) using the CR. Methods: This study involved the measurement of radiation dose and image quality of a radiological procedure performed at a reference SID; 100cm and the tested SIDs; 110cm, 120cm, and 130cm, using constant technical factors (70kVp, 25mAs, grid). A LiF; Mg Ti thermoluminescence dosimeter (TLD-100) chip was placed in the center of the radiation field of the OF10° skull radiography examination to measure ESD. Image quality was assessed using the European Commission guidelines and graded using relative visual assessment analysis (VGA). Results: Significant ESD reduction from 21% and 45% when SID was increased from 100cm to 130cm (p <0.001), where SID was negatively correlated with ESD (r= - 0.98). The VGA scores showed no statistical difference in the image quality of the OF10° skull radiography examination for the tested and reference images (p=0.21). VGA scores for 120cm images showed the highest image quality among the SIDs tested with a dose reduction of 37%. Conclusion: ESD was statically reduced when SID was increased from 100cm to 130cm, while image quality was diagnostically acceptable. The study suggests that 120cm is the optimal SID when both dose and image quality are considered.

Analysis of radiation dose at the entrance of the medical linear accelerator treatment room / 中国辐射卫生

@#<b>Objective</b> To investigate the radiation dose at the entrance of the accelerator treatment room, and to guide the radiation protection detection at the entrance of the treatment room. <b>Methods</b> The FLUKA program was used to build the model of accelerator head and treatment room. Under the simulation conditions of 10 MV and 600 cGy/min for the accelerator, the radiation dose rate inside the entrance of the treatment room was measured at different gantry angles, irradiation conditions, and labyrinths. <b>Results</b> The entrance dose rate with a water tank was significantly higher than that without a water tank under different inner labyrinth wall thicknesses and gantry angles. The entrance dose rate reached the maximum at the inner labyrinth wall thickness of 1800 mm and the gantry angle of 90°. When the inner labyrinth wall thickness was 1000 mm and the gantry angles were 0° and 180°, the entrance dose rate was significantly higher than that at other conditions. The dose rate at the entrance of the treatment room reached (82.26 ± 48.95) μSv/h to (314.09 ± 96.34) μSv/h under the following conditions: the inner labyrinth wall thickness of 1800 mm, the gantry angle of 90°, with a water tank, and the width of the inner labyrinth entrance of 1400-2200 mm. <b>Conclusion</b> The dose at the entrance of the accelerator treatment room mainly comes from the scattering and leakage radiation of the useful wire harness on the patient’s body surface, and the entrance dose rate increases with the increase in the width of the inner labyrinth entrance. In the entrance protection test, the gantry angle should be determined considering the inner labyrinth wall thickness, and the test should be performed at four angles in the uncertain case to ensure the comprehensiveness and accuracy of test results.

Avaliação psicológica em concursos públicos e porte de arma: histórico e desafios / Psychological assessment in civil service entrance examination and firearms license: history and challenges / Evaluación psicológica en competencias y la portación de armas: historia y desafíos

Resumo Trata-se de um estudo teórico que aborda a avaliação psicológica no contexto de avaliações compulsórias, tanto em concurso público quanto para posse ou porte de arma de fogo. São apresentados os maiores desafios da área, a partir do histórico e da exposição de alguns dos problemas enfrentados na prática, diante das diferentes normativas que regulam este contexto. Na avaliação psicológica em concursos, ressalta-se como um dos maiores desafios a forte influência do poder judiciário nos últimos 60 anos, que inclui a definição ou restrição de procedimentos na atuação do profissional. Quanto à avaliação para porte de arma de fogo, discutem-se as diversas mudanças que ocorreram nos últimos anos e suas implicações. O texto incentiva os profissionais que atuam na área a refletir sobre as consequências sociais que o resultado dessa avaliação pode trazer. No Brasil, as pesquisas realizadas no contexto de avaliação psicológica compulsória ainda são escassas, o que mostra a necessidade de estudos que contribuam para melhoria nesse campo de atuação. É necessário compreender, inclusive, os impactos que a publicação de normativas e a qualidade da atuação dos profissionais podem provocar, bem como seus efeitos sobre a sociedade como um todo.

Abstract This theoretical study addresses psychological assessment in the context of compulsory exams for civil service entrance examination and firearms licenses. By presenting the history and some issues related to regulations, this article presents the greatest challenges in the area of compulsory exams. When it comes to procurement exams, a major challenge accounts for the strong influence of the judiciary over the past 60 years, defining or restricting procedures in professional performance. As for firearms license exams, the article expatiates on several changes that have occurred in recent years, as well as their implications. The text encourages professionals working in the field to reflect upon the social consequences of this assessment results. Studies on compulsory psychological assessment are still scarce in the Brazilian literature, indicating the need for research to improve this field of action. Moreover, one should also consider the impacts of regulations and quality professionals on these assessments and on society as a whole.

Resumen Este estudio teórico aborda la evaluación psicológica en el contexto de las evaluaciones obligatorias tanto en concurso público como por posesión o portación de armas de fuego. Se presentan los mayores desafíos del área a partir de la historia y de algunos de los problemas que se enfrentan en la práctica, dadas las diferentes normativas que regulan este contexto. En el contexto de la evaluación psicológica en los concursos públicos, uno de los mayores desafíos es la fuerte influencia del Poder Judicial en los últimos 60 años, que incluye la definición o restricción de procedimientos en el desempeño del profesional. En cuanto a la evaluación para portación de arma de fuego, se discuten los distintos cambios que se han producido en los últimos años y sus implicaciones. El texto anima a los profesionales que trabajan en el área a reflexionar sobre las consecuencias sociales que puede traer el resultado de esta evaluación. En Brasil, la investigación realizada en el contexto de la evaluación psicológica obligatoria es aún escasa, lo que muestra la necesidad de estudios que contribuyan a la mejora en este campo de acción. Incluso es necesario comprender los impactos que puede causar la publicación de normativas y la calidad del desempeño de los profesionales, así como sus efectos en la sociedad en su conjunto.

El programa de tutorias: canal de acompañamiento a las trayectorias educativas en medicina veterinaria / Tutorship programs: a way of accompanying educational trajectories in Veterinary Medicine

Resumen El propósito del presente trabajo es socializar el impacto del Programa de Tutorías en la trayectoria educativa de los ingresantes a la carrera de medicina veterinaria de la Universidad Nacional del Litoral. El Programa de tutorías data del año 2010 cuando mediante el plan de mejoramiento de la carrera se instaura la necesidad de iniciar una labor de acompañamiento dirigida a los estudiantes ingresantes. Dicho programa se lleva a cabo mediante la labor profesional realizada desde la cátedra de Introducción a la Veterinaria, el Director de carrera y el Servicio de Orientación Educativa (S.O.E) de la Facultad de Ciencias Veterinarias siendo los co-responsables de dicha ejecución. El desafío constante del programa es responder a la construcción continua de alternativas que permitan a los estudiantes apropiarse de las habilidades necesarias para alcanzar el éxito académico. Teniendo en cuenta los resultados se observa que el Programa de Tutorías es recomendado por el 98% de los tutorados, debido a que el mismo es favorecedor de los procesos de afiliación universitaria. La novedad del programa es que se lleva a cabo por estudiantes avanzados, quienes luego de un proceso de selección y capacitación realizan la tarea orientativa.

Abstract The purpose of this work is to socialize the impact of the Mentoring Program in the educational path of the entrants to the veterinary medicine career at the National University of the Coast. The Mentoring Program dates back to 2010 when, through the career improvement plan, the need to start an accompaniment work aimed at incoming students was established. This program is carried out through the professional work carried out by the Chair of Introduction to Veterinary Medicine, the Career Director and the Educational Guidance Service (S.O.E) of the Faculty of Veterinary Sciences, being the co-responsible for said execution. The constant challenge of the program is to respond to the continuous construction of alternatives that allow students to appropriate the necessary skills to achieve academic success. Taking into account the results, it can be seen that the Tutoring Program is recommended by 98% of the tutors, because it is favorable to the university affiliation processes. The novelty of the program is that it is carried out by advanced students, who after a selection and training process carry out the orientation task.

Transtorno de ansiedade generalizada entre estudantes de cursos de pré-vestibular / Generalized anxiety disorder among university-entrance preparation course students

RESUMO Objetivo Medir a prevalência de sintomatologia de transtorno de ansiedade generalizada (TAG) entre estudantes de um curso pré-vestibular do sul do Brasil e sua associação com fatores sociais, demográficos, acadêmicos e psicológicos. Métodos Este estudo teve delineamento transversal, tendo como participantes estudantes com idade igual ou superior a 18 anos de um curso pré-vestibular privado do sul do Brasil. Foi administrado um questionário autoaplicável que avaliava aspectos sociais, demográficos, acadêmicos, de ansiedade relacionada à prova e estresse percebido. O desfecho analisado foi a sintomatologia de TAG, por meio do instrumento General Anxiety Disorder-7 (GAD-7). Para análise multivariável, utilizou-se a regressão de Poisson com ajuste robusto da variância. Resultados Participaram 137 alunos (taxa de resposta de 90,7%) e a prevalência de sintomatologia de TAG foi de 41,4%. Após análise ajustada, ser do sexo feminino, ter estudado em escola privada, ter maiores escores de estresse percebido e de ansiedade relacionada à prova permaneceram como fatores de risco. Estar com 19 anos apresentou-se como fator de proteção. Conclusões A ansiedade relacionada à prova foi o fator mais fortemente associado com a sintomatologia de TAG, o que sugere que as emoções e preocupações específicas do contexto de avaliação podem predispor o indivíduo a maior risco de desenvolver esse transtorno. A partir desses resultados, sugere-se a inclusão de profissionais da saúde mental no contexto do pré-vestibular, assim como intervenções direcionadas ao desenvolvimento de uma relação saudável entre o aluno e suas demandas acadêmicas.

ABSTRACT Objective To measure prevalence of symptomatology of generalized anxiety disorder (GAD) among students from a university-entrance preparation course in southern Brazil and its association with social, demographic, academic and psychological factors. Methods This study had a cross-sectional design and participants were students aged 18 years or older from a private university-entrance preparation course in southern Brazil. A self-administered questionnaire that assessed social, demographic, and academic variables, as well as test-related anxiety and perceived stress was administered. The outcome analyzed was the symptomatology of GAD through the General Anxiety Disorder-7 (GAD-7) instrument. Poisson regression with robust adjustment of variance was used in multivariate analysis. Results 137 students participated (90.7% response rate) and the prevalence of GAD symptomatology was 41.4%. After adjusted analysis, being female, having studied in a private school, having higher perceived stress and test anxiety scores remained as risk factors. Being 19 years old was a protective factor. Conclusions Anxiety regarding the test was the factor most strongly associated with symptomatology of GAD, which suggests that the emotions and concerns specific to the context of evaluations may predispose the individual to a higher risk of developing this disorder. Based on these results, we suggest the inclusion of mental health professionals in the context of university-entrance preparation courses, as well as interventions aiming the development of a healthy relationship between the student and their academic demands.

Investigation on entrance surface doses to patients from medical X-ray diagnosis in Inner Mongolia autonomous region / 中华放射医学与防护杂志

Objective@#To analyze the levels of entrance surface dose (ESD) to patients from diagnostic medical X-ray examinations in Inner Mongolia autonomous region.@*Methods@#The investigation of diagnostic medical X-ray examinations was completed in 30% of the number of hospitals under the requirement of the program plan of the national survey on frequency and dose from medical exposure. The investigation of ESDs to patients from general diagnostic X-ray examinations was carried out in terms of the scale of annual outpatients in different levels of hospital. The difference in ESDs to patients was compared for different equipments, different grade hospitals and different exposure sites, with the comparison result being subjected to rank sum test.@*Results@#In all types of diagnostic medical X-ray equipment, DR photography equipment accounted for the majority. During various routine diagnostic X-ray examinations, the average ESDs was lumbar vertebral 3.39 mGy, pelvic and hip 1.65 mGy, cervical spine 0.90 mGy, extremities 0.38 mGy and thorax 0.37 mGy, respectively. In the diagnostic examinations of chest, lumbar and cervical spine, the ESDs caused by the use of screen film photography equipment were higher than those by DR photography equipment, with statistically significant difference (Z=-3.229, -4.820, -5.265, P<0.05).@*Conclusions@#Screen film photography equipment results in higher ESD than DR photography equipment. The doctor′s operation behavior is an important factor that affects the ESD.

Clinical Characteristics of Intraocular Foreign Bodies According to Entrance Location: Corneal vs. Non-Corneal

PURPOSE: To investigate differences in the clinical features of post-traumatic intraocular foreign bodies (IOFBs) according to their entrance locations, specifically, those penetrating the cornea and those not penetrating the cornea. METHODS: A retrospective chart review was performed of patients with an IOFB from January 2011 to July 2016. The patients were divided into two groups: those in whom the IOFB entered through the cornea (“corneal entrance” group) and those in whom the IOFB did not penetrate the cornea (“non-corneal entrance” group), and compared. Damage to the anterior and posterior capsule, retinal tear, and retinal detachment were analyzed, and differences in surgical techniques including the IOFB extraction route and intraocular lens implantation were recorded. RESULTS: A total of 43 eyes (43 patients) were included, with 33 (76.7%) in the corneal entrance group and 10 (23.3%) in the non-corneal group. The posterior capsule was preserved in 24.2% (eight) of eyes in the corneal group and 80% (eight) of eyes in the non-corneal group. The corneal group had significantly more posterior capsule ruptures but dramatically fewer retinal tears (39.4%) than the non-corneal group (80% retinal tears). CONCLUSIONS: The location of IOFB entrance is a predictable factor of lens capsule and retinal injuries.

Investigation and analysis on entrance surface dose of patients in radiography procedures in China / 中华放射医学与防护杂志

Objective To investigate the entrance surface dose to the examined patients in radiography using digital and screen-film system in hospitals at different levels in 15 provinces and municipalities in China,in order to provide data for developing diagnostic reference level of radiography suitable for our national physical characteristics.Methods According to the requirements of the Technical Study on Medical Radiation Hazard Assessment and Control,the examined patients aged 20-70 years were selected,with body weight ranging from 55 to 80 kg for male and 50 to 70 kg for female.TLDs were used to measure the entrance surface dose to adult patients in radiography.No less than 10 examined patients were required at each body position,with examined locations including head (PA,LAT),chest (PA,LAT),abdomen (AP),pelvis (AP),lumbar (AP,LAT),and thoracic vertebra (AP,LAT).Results A total of 19 975 individuals undergoing radiography and 1 813 radiographic equipment of different types including screen-film radiography,computed radiography (CR) and digital radiography (DR),were investigated in 342 hospitals in 15 provinces and municipalities throughout the country.For these three types of equipment,the average entrance surface dose to the examined were 1.75,1.9,and 1.15 mGy in head (PA),1.69,1.46and 1.03 mGy in head (LAT),0.75,0.65 and 0.36 mGy in chest (PA),1.81,1.26 and 0.88 mGy in chest (LAT),4.37,3.77 and 2.15 mGy in abdomen (AP),3.73,3.56 and 2.75 mGy in pelvis (AP),5.49,5.84 and 4.17 mGy in lumbar (AP),12.01,9.37 and 6.82 mGy in lumbar (LAT),4.53,3.65 and 2.49 mGy in thoracic vertebra (AP),and 6.91,6.43 and 4.15 Gy in thoracic vertebra (LAT).Conclusions Entrance surface dose caused by radiography examination varies dependent on different exposure locations.Entrance surface doses caused by digital radiography are all lower than by screen-film radiography;those caused by digital radiography are lower than by computed radiography,except for thoracic vertebra (AP).In all examinations,no difference of statistical significance is found between CR and screen-film radiography in entrance surface dose.

Investigation on entrance surface doses to patients from medical X-ray diagnosis in Inner Mongolia autonomous region / 中华放射医学与防护杂志

Objective To analyze the levels of entrance surface dose (ESD) to patients from diagnostic medical X-ray examinations in Inner Mongolia autonomous region.Methods The investigation of diagnostic medical X-ray examinations was completed in 30％ of the number of hospitals under the requirement of the program plan of the national survey on frequency and dose from medical exposure.The investigation of ESDs to patients from general diagnostic X-ray examinations was carried out in terms of the scale of annual outpatients in different levels of hospital.The difference in ESDs to patients was compared for different equipments,different grade hospitals and different exposure sites,with the comparison result being subjected to rank sum test.Results In all types of diagnostic medical X-ray equipment,DR photography equipment accounted for the majority.During various routine diagnostic X-ray examinations,the average ESDs was lumbar vertebral 3.39 mGy,pelvic and hip 1.65 mGy,cervical spine 0.90 mGy,extremities 0.38 mGy and thorax 0.37 mGy,respectively.In the diagnostic examinations of chest,lumbar and cervical spine,the ESDs caused by the use of screen film photography equipment were higher than those by DR photography equipment,with statistically significant difference (Z =-3.229,-4.820,-5.265,P＜0.05).Conclusions Screen film photography equipment results in higher ESD than DR photography equipment.The doctor's operation behavior is an important factor that affects the ESD.

Comparison of digital radiography's entrance surface doses computed from DICOM file or directly from TLDs / 中华放射医学与防护杂志

Objective To make comparison of consistency between the ESD's informationcalculated values and TLD readout values based on PHILIPS DigitalDiagnost so as to provide reference for realizing information management of medical exposure radiation dose during DR diagnosis and treatment.Methods TLDs were used to obtain the ESD values on chest,abdomen,vertebral body,pelvis and limbs.The exposure parameters were collected from the DICOM files,and the information value of ESD were calculated through the dose area product (DAP) method and the exposure parameter method.The consistency between information value and TLD readout value was compared by intraclass correlation coefficient and the Bland-Altman method.Results The ESD values obtained from DAP method,exposure parameter method and TLD method are,respectively,(0.730 ± 0.870) mGy,(0.720 ± 0.863) mGy and (0.770 ±0.948) mGy.ICC was 0.988 for ESDDAP-TLD and 0.982 for ESDParameters-TLD,respectively.The Bland-Altman map showed that the D-value of ESD obtained from DAP-TLD and Parameters-TLD beyond the 95％ consistency interval was 6.7％.Conclusions The PHILIPS DR daily diagnosis and treatment process is based on fixed-mode programmed diagnosis and treatment.Under the premise of qualified equipment quality control,the information calculated value based on DICOM files has a good consistency with TLD readout value.

Intervenção para stress e ansiedade em pré-vestibulandos: estudo piloto / Intervention for stress and anxiety in senior high school students: a pilot study / Intervención para el estrés y la ansiedad en preuniversitarios: estudio piloto

O vestibular se tornou um grande fator de comprometimento da saúde mental dos jovens. O objetivo desse artigo é relatar a experiência de aplicação de um programa breve de intervenção para o manejo de stress e ansiedade em vestibulandos e apresentar seus resultados preliminares. Foram utilizados instrumentos de avaliação psicológica para análise da ansiedade, depressão, desesperança, stress e repertório de habilidades sociais, aplicados aos 12 participantes antes e após a intervenção, composta por seis sessões grupais. Os resultados e relato dos participantes registrado durante as sessões foram promissores, indicando melhora nos sintomas de alguns participantes, embora estes dados devam ser analisados com cautela.

The college entrance examination has become a major factor affecting the mental health of young people. The objective of this article is to report the experience of applying a brief intervention program for the management of stress and anxiety in senior high school students and present its preliminary results. Psychological evaluation tools were used to analyze anxiety, depression, hopelessness, stress and repertoire of social skills, applied to the 12 participants before and after the intervention, composed of six group sessions. The results and report of the participants recorded during the sessions were promising, indicating improvement in the symptoms of some participants, although these data should be analyzed with caution.

Las pruebas de ingreso a la educación superior se han convertido en un gran factor de riesgo para la salud mental de los jóvenes. El objetivo de este artículo es relatar la experiencia de aplicación de un breve programa de intervención para el manejo del estrés y la ansiedad en estudiantes preuniversitarios y presentar sus resultados preliminares. Se utilizaron instrumentos de evaluación psicológica para el análisis de la ansiedad, depresión, desesperanza, estrés y repertorio de habilidades sociales, aplicados a los 12 participantes, antes y después de la intervención, que estuvo compuesta por seis sesiones grupales. Los resultados y manifestaciones de los participantes registrados durante las sesiones fueron promisores, indicando mejoría en los síntomas de algunos participantes, aunque estos datos deben ser analizados con cautela.

Optimization of exposure parameters for chest digital radiography in infants and young children / 中华放射医学与防护杂志

Objective To optimize the exposure parameters and reduce the irradiation dose level in infants and young children during digital radiography (DR) chest radiography under the premise of satisfied image quality.Methods The thoracic thickness of 100 patients were measured.Determined the aluminum equivalent of the thoraxes of the infants and young children by comparing the grayscale value and the aluminum step wedge.Another 100 infants and young children of experimental exposure were performed with the aluminum step wedge as a phantom,under AEC control,kV was the only variant to explore the optimal exposure parameters with dose monitor simultaneously.At last,clinical validation was performed.Images quality was compared with x2 test.The radiation dose of two groups was compared with t test.Results The maximum,minimum,average thoracic thickness and their correspondent aluminum equivalent were 13.5 and 2.3 cm,8.0 and 1.4 cm,(10.6 ± 1.3) and 2.0 cm,respectively.The average thoracic thickness of experimental group was (10.1 ± 2.2) cm.The range of entrance surface dose was 0.068-0.056 mGy while the tube voltage range was 55-65 kV.The exposure index range was 0.60-0.74.The visual inspection of aluminum step wedge was from grades 8 to 11 with satisfying image quality at lower radiation.The infant chest X-ray photography exposure parameters formula have been optimized,that was kV =thoracic thickness (cm) × 2 + 38 (constant),mAs (0.8-1.0) with SID =100 cm,without filter grid.Compare to the conventional parameters,the image quality of new method had no significant differences (P ＞ 0.05).The actual average entrance surface dose was (0.048 ± 0.007) mGy,lower than AEC group (0.066 ± 0.008) mGy.The difference was statistically significant (t =16.781,P ＜ 0.001).Conclusions The optimized formula kV =thoracic thickness (cm) ×2 + 38(constant),mAs (0.8-1.0) with SID =100 cm was credible for lowering the radiation exposure with good image quality for clinical diagnosis.

Assessment of radiation dose in dual energy X-ray absorptiometry scanner / 中华放射医学与防护杂志

Objective To evaluate the radiation dose from a dual energy X-ray absorptiometry (DXA) study. Methods A Radcal multifunctional dosimeter (1800 cc ionization chamber, USA) was used, for purpose of comparison, to measure the entrance surface doses (ESD) from Norland XR-800 DXA ( pencil beam scan, 100/46. 8 kVp, 1. 3 mA) and from Hologic Discovery A DXA ( fan beam scan, 140/100 kVp, 5. 0 mA) . Ambient dose equivalent rate at 1 m away from studied phantom center and at 1 m above floor was measured using the US 451P ionizaion chamber survey meter ( Fluke, USA). Results The ESD measured using a Radcal dosimeter for Norland XR-800 DXA was 0. 43 μGy in high speed mode and 0. 73 μGy in standard mode ( AP spine ) , 1. 93 μGy ( hip ) , 0. 40 μGy ( wrist ) and 1. 06 μGy ( mandible) . The ESD measured for Hologic Discovery A DXA was 65. 6 μGy ( AP spine) and 63. 9 μGy ( hip) . The ESD measured for Norland XR-800 at different scan types and scan speeds was <2 μGy while Hologic Discovery A DXA showed a result of <66 μGy ( AP spine and hip scan ) , which were both consistent with the data given in their own respective operational manual. A comparison of DXA scanners with fan beam and pencil beam indicated that ambient equivalent dose rate, measured with 451P survey meter, from fan beam scan was 65 times that from pencil beam scan. Conclusions Compared with other medical X-ray studies, the ESD to the phantom undergoing a DXA study is relatively low. DXA pencil beam scan doses to lumbar spine and hip were about 1/153-1/33 of those from DXA fan beam scan. Pencil beam scan dose to DXA staff was negligible and fan beam scan dose to DXA staff was lower than the personal dose limits of 20 mSv per year.

Imaging measurement of circumferential cortical thickness of anterior entrance and anterior half of lower cervical pedicles and its application analysis / 第二军医大学学报

Objective To measure the circumferential cortical thickness of anterior entrance and anterior half of lower cervical pedicles on computed tomography (CT) images, providing a reference for accurate anterior cervical pedicle screws. Methods CT scanning was performed in 10 normal lower cervical vertebrae from fresh cadavers, and the coronal and sagittal reconstructed images were obtained. The images were then opened in AutoCAD-2007 software to perform quantitative measurement (accuracy was 0. 1 mm) using the “dimaligned function” of dimension menu, and measurement parameters included the thicknesses of superior, medial, inferior and lateral cortex of anterior entrance of pedicle (SAE. MAE. IAE and LAE. respectively), and thicknesses of superior, medial, inferior and lateral cortex of anterior half of pedicle (SPA, MPA, IPA and LPA, respectively). Results Average thicknesses of SAE. MAE. IAE. LAE, SPA, MPA. IPA, and LPA at left and right side from Q to C7 were (1. 9 + 0. 6) and (1. 9 + 0. 5) mm, (1. 9 + 0. 7) and (1.9+0. 4) mm. (2.4 + 0. 6) and (2. 4 + 0. 5) mm, (0. 9 + 0. 5) and (0. 9 + 0. 6) mm, (2. 3 + 0. 9) and (2. 3 +0. 7) mm, (2. 1 + 0. 5) and (2. 1 + 0. 6) mm, (2. 2+0. 8) and (2. 2+0. 7) mm, and (1. 0 + 0. 7) and (1. 0 + 0. 6) mm, respectively. There was no significant difference in same measurement parameter between left and right sides at same cervical level (P>0. 05). Single factor random block analysis of variance found LAE and LPA were significantly thinner than the other 6 parameters of the same side of same cervical vertebra (all P0. 05). Conclusion LAE and LPA are the thinnest among the 8 measurement parameters from C3 to C7, which suggests LAE and LPA have the weakest resistance to exotic force if resistance strength to exotic force is parallel to cortex thickness. We should avoid locating close to LAE when finding anterior entrance or close to LPA when inserting anterior cervical pedicle screws.

The influence of different ceiling-mounted shield positions on operators' radiation dose in percutaneous coronary intervention / 中华放射医学与防护杂志

Objective To discuss the influence of the change in ceiling-mounted shield positions on the radiation doses to the first and second operators during percutaneous coronary intervention.Methods In this study,the entrance surface dose (ESD) rates were measured for the first and second operators at 125 cm and 155 cm height on different ceiling-mounted shield positions separately through transradial approach.Measurements were repeated 20 times for each position and T test was used for statistical analysis of dose rate arithmetic mean values.Results For the first operator,the effective dose values were obtained only on left foot position.The ESD rate values at ceiling-mounted shield position close to patient were higher than that close to operators (t125 =46.9,t155 =4.1,P ＜0.05).For the second operator,the ESD rate values on his foot position,right foot position,left anterior oblique position and right anterior oblique position at ceiling-mounted shield position close to the operator,were higher than that close to the patient separately (t125 =11.9,24.4,11.2,2.7,t155 =16.1,2.8,14.4,28.8,P ＜ 0.05).The ESD rate values on head position,left foot position,left head position at ceiling-mounted shield position close to the operator,were lower than that close to the patient (t125 =-4.3,-2.4,-80.4,t155 =-10.2,-6.7,-152.6,P ＜ 0.05).Conclusions The change in the ceiling-mounted shield positions gave rise to change in radiation dose to the operators.The changes in radiation doses caused by the changes in ceiling-mounted shield positions are different in various angiographic positions.Ceiling-mounted shield should be used in a reasonable way in agreement with different positions in percutaneous coronary intervention so as to effectively reduce operators radiation dose.

Admission To Medical Colleges- Predictive Validity Of Selection Criteria.

Background & objective: Appropriate selection criteria for admission to medical college is a fundamental prerequisite where number of aspirants seeking admission to medical college has increased. The selection criteria used by medical colleges has been changing from time to time and not uniform all over India. Hence it is important to validate the selection criteria by observing performance of students during medical course. The study aims to find predictive value of entrance test & science score obtained at HSC level on the performance of medical students in I MBBS University Examination. Methods: The study included marks obtained in science subjects at HSC level, Entrance and I MBBS University examination for four consecutive batches(2009 to 2012). Correlation between all three variables was found using spearman rank correlation. Results: Performance in I MBBS examination showed no correlation with Entrance score but correlated significantly with science scores at HSC level (p<0.001). Also on Linear Regression Analysis, only HSC score showed strong positive correlation with First MBBS score(p<0.001). Interpretation & conclusion: This study indicates that Entrance test needs revision. Either the test should be modified or several selection tools like giving additional weightage to science score at HSC level should be combined, so as to select the optimum standard students.

Experimental study of correlation between the focus-to-flat panel detector distance and entrance surface dosed in digital radiography of lumbar spine / 中华放射医学与防护杂志

Objective To investigated the correlation between the focus-to-flat panel detector distance and entrance surface dosed in digital radiography of lumbar spine.Methods The spine phantom used for bone mineral density(BMD) calibration was radiographed at different value of FFD (100 ～ 240 cm with the interval 10 cm,totally 15 times) using 70 kV and 90 kV with the automatic exposure control (AEC) mode without anti-scatter grid.The parameters measured by QUART dido 2100K type X-ray dose meter.So record the value parameters of the tube current (mAs) and entrance surface dose (ESD).The relation curve were counted between FFD,ESD,mAs and Exposure index (EI) use excle.Pearson correlation analysis and related coefficient difference analysis were performed using the SPSS 19.0 software (P ＜0.05 for the statistically significant level).The FFD and ESD values of regression equation were obtained with regression analysis.Results (1) When the tube voltage was 70 kV:FFD and ESD were negative correlation (r =-0.922,P ＜ 0.001),FFD and mAs were positive correlation (r =0.991,P ＜0.001),FFD and EI negative correlation (r =-0.938,P ＜ 0.001).(2) When the tube voltage was 90 kV:FFD and ESDwere negative correlation (r=-0.955,P ＜0.001),FFD and mAs were positive correlation (r=0.994,P ＜0.001),FFD and EI showed no significant correlation (r=-0.523,P＞0.05).(3) Different position correlation coefficient analysis of the difference was not statistically significant difference.(4) The regression analysis results:The regression equation of the lumbar anteriorposterior position FFD and the ESD at 70 kV:y=0.805 x + 319.731 (F=74.175,P ＜0.001).The regression equation of the lumbar lateral position FFD and the ESD at 90 kV:y =3.152 x + 457.613 (F =133.524,P ＜ 0.001).Conclusions The FFD and ESD in the lumbar spine X-ray radiography were relevant and highly negative correlation.It can effectively reduce the radiographic ESD of lumbar spine with the increasing of the FFD.

Patient Dose Assessment for Common Digital Diagnostic Radiology Examination in Hamad Medical Corporation Hospitals in the State of Qatar.

The aim of this study was to estimate radiation doses to patients undergoing standard radiographic examinations using Computed Radiography (CR) and Direct Digital Radiography (DDR) in two hospitals within Hamad Medical Corporation (HMC) in Qatar, and compare the results with regional and international Diagnostic Reference Levels (DRLs). Data on 3391 patients were recorded from different X-ray rooms in HMC hospitals. Entrance Skin Dose (ESD) was measured for 1046 patients for the most five common X-ray examinations (a total of 7 projections) namely: Skull, Chest, Abdomen, Lumbar Spine and Pelvis. Exposure factors such as kV, mAs and Focal to Skin Distance (FSD) were recorded for each patient. Tube Output was measured for a range of selected kV values. ESD for each individual patient was calculated using the tube output and the technical exposure factors for each examination. The ESD values were compared with some international DRLs for all types of examinations. HMC patient demographic data evaluated from this study were: average age of 39 years, average weight of 60-80 kg and mean height of 165 cm. The most procedure performed during the time of this study was chest PA (52%), and the least procedure performed was skull AP/LAT (1%) examination. The mean ESD values found to be generally lower than the published values. With exception of abdomen examinations at Hamad General Hospital (HGH), mean ESD values were found to be within the established IAEA (DRL). The mean ESD values at HGH were found to be much higher than that at Al Khor Hospital (AKH) for abdomen, Lumbar spine AP, Lumbar Spine LAT and pelvis, but generally lower than the published values.

Evaluation of Mean Glandular Dose from Digital Mammography Exams at Qatar and Compared with International Guidelines Levels.

The primary objective of this study was to measure the mean glandular dose (MGD) from craniocaudal (CC) and mediolateral oblique (MLO) views from mammography patients in Hamad Medical Corporation (HMC) in the state of Qatar and to compare them with the international guidelines levels as well as to establish Dose Reference Level (DRL) for the country by applying the quality control (QC) protocol for the Digital mammography units and to reduce the patient dose and improve the image quality. All patients data was taken from two Selenia digital mammography units for 18 months period. Quality control was implemented for the two mammography machines and corrective actions have been done for the image quality evaluation with rejected film analysis. The total number of collected patient data was 4085 mammography exams which considered as around 93% of the overall mammography procedures done in Qatar during that period. Based on the IAEA selection criteria of breast thickness between 2-7 cm and kV machine value from 26 to 33 kV, only 3280 mammography procedures satisfies the above criteria and are analysed accordingly, National Centre for Cancer Care & Research (NCCCR) 949 and Hamad General Hospital (HGH) 2331 exposures. The present study revealed that there were significant differences between the MGD values for the CC and MLO views (p <0.006). Referring to the limiting dose values in the European guidelines, the results from the two mammography units showed that 94.5% and 99.7% of the mean glandular doses are acceptable from NCCCR and HGH respectively. Due to compression devise error in the NCCCR mammography machine, the MGD for some patients became more than the acceptable values especially at small breast thickness values (0-3 cm) which it seems 0% in the acceptable range.

Gender Might Be Factor for Student Admission in Two Brazilian Medical Schools / Gênero Pode Ser um Fator na Seleção do Vestibular de Duas Escolas Médicas Brasileiras

This is a secondary data-based study conducted to investigate whether gender is related to acceptance. Two Brazilian Medical Schools, Universities A and B, were studied. Their entrance exams (EE) were analysed and the number of candidates who took the EE was compared to the number of students admitted to the MS according to gender, in the period between 1995 and 2009. The same data from MS in the United States in 2011 was also evaluated. There was an increase in the percentage of female applicants but it did not correspond to the percentage of admitted students of the same gender. There was a trend of selecting men. At A, 39.3% of the applicants and 47% of the admitted students were men (OR = 1.37; CI95% = 1.24 – 1.51). In B, men represented 39.3% of the applicants and 65.4% of the admitted students (OR = 2.93; CI 95% = 2.76 – 3.11). This was not seen in US MS. The analysis of the EE suggests that the greater selection of men could be a product of EE format.

Este é um estudo de dados secundários para investigar se o gênero é um fator determinante na admissão do vestibular de Medicina. O vestibular de duas escolas médicas (EM) brasileiras, universidades A e B, foi analisado, e o número de candidatos de cada vestibular foi comparado ao número de alunos matriculados em cada EM de acordo com o gênero no período de 1995 a 2009. Os mesmos dados disponíveis dos Estados Unidos (EUA) em 2011 foram avaliados. Notou-se um aumento do número de mulheres prestando vestibular de Medicina, mas este aumento não correspondeu à porcentagem de mulheres matriculadas. Houve uma tendência a selecionar mais homens. Em A, 39,3% dos candidatos e 47% dos estudantes admitidos eram homens (OR = 1,37; IC95% = 1,24 – 1,51). Em B, os homens representavam 39,3% dos candidatos e 65,4% dos estudantes admitidos (OR = 2,93; IC95% = 2,76 – 3,11). Estes resultados não foram confirmados nas EM dos EUA. A análise do EE sugere que a maior seleção de homens poderia ser produto do formato dos vestibulares.