OBJECTIVE: To evaluate the performance and quality of images of a x-ray equipment utilized in interventional radiology, by means of some tests of quality control. MATERIALS AND METHODS: Measurements have been performed on a Philips Integris H3000 x-ray equipment dedicated to interventional procedures in the hemodynamics laboratory of a hospital in Rio de Janeiro, RJ, Brazil. Leeds test objects have been used to evaluate the image quality. Dosimetric measurements have been developed with a Radcal 9015 dosimetric system. RESULTS: In high and normal modes, the air kerma rates have been different from the expected results. In some cases, values have not been affected by the use of different magnification modes. The images quality evaluation has showed different results from those recommended by technical standards. This could lead to the acquisition of poor quality images besides an increase in the radiation exposure levels for both patients and staff. CONCLUSION: The results have shown the importance of a periodical quality control testing, allowing the monitoring of the x-ray equipment performance and evaluation of radiation exposure levels for both patients and staff. The results suggest the need of a revision of the x-ray images acquisition system.

Keywords: Interventional radiology, Hemodynamics, Quality control

OBJECTIVE: To develop an acceptance testing protocol for magnetic resonance imaging systems and to show which and how phantoms could be used to collect data. MATERIALS AND METHODS: The definition, procedure, analysis and the acceptation criteria were created for each of 15 selected tests. RESULTS: These tests allow the evaluation of technical specifications stated on the manufacturer's sales proposal and to establish reference values to be used in subsequent constancy tests. CONCLUSION: Future quality assurance programs in magnetic resonance imaging should consider employing tests similar or equal to the ones described in this paper.

Keywords: Magnetic resonance imaging, Quality control

Quality control tests, according to "Portaria 453/98" of the Brazilian Health Ministry, were applied in seven public hospitals of Rio de Janeiro including 29 X-ray tubes, 30 cassettes and 20 individual protection garments. These tests evaluate mainly the X-ray generator and system geometry. Other tests in the accessories were also performed, such as: cassettes, screens, viewing boxes, darkrooms and clear rooms. In the kVp tests, 55% of the equipments were disapproved in exactitude and 15% in reproducibility. Time exactitude and reproducibility were not approved in 53% and 31% of the equipments, respectively. The percentages of disapprovement were: for the HVL (half-value layer) 30%, for beam alignment 18%, for field coincidence 30%, for exposure linearity 40% and for focal spot 64%. It has also been observed that frequently the lead aprons were not kept in appropriate hangers and this procedure may cause damage to these accessories. The results of the test suggest the need of implementation of quality assurance tests in these services. The cost benefit analysis of the results reinforces the importance of the implementation of the recommendations contained in this paper.

Keywords: Quality assurance, Quality control, Radiodiagnostic

OBJECTIVE: To reduce radiation dose and increase x-ray tube life in computed tomography. MATERIALS AND METHODS: Head, upper abdomen and chest scans were evaluated. We assessed the techniques employed and if these could be changed, suggested new protocols and compared the quality of the images, the radiation dose and the x-ray tube heating. RESULTS: A mAs reduction could be done without interfering with the diagnostic quality, allowing a decrease of up to 20% in the average dose for adults' head exams and up to 45% for 0 to 6 years old children; patients with less than 50 kg had a reduction of 37% on the upper abdomen radiation average dose; for chest routine scans the reduction was 54%. The decrease in the heating of the x-ray tube for head, upper abdomen and chest scans was approximately 13%, 23% and 41%, respectively. CONCLUSION: A change on the described protocols will produce a significant reduction on the radiation dose and an increasing in x-ray tube life without loss of diagnostic quality.

Keywords: X-ray computed tomography, Radiation exposure, Radiation dosage, Radiation protection

In view of the great importance of quality control in radiotherapy services, this paper aimed primarily to evaluate the tests recommended by international protocols TG40 and ARCAL XXX for teletherapic equipments (cobalt, linear accelerator and simulator). A second objective was to evaluate the tests currently used in some radiotherapy services in Brazil and Latin America and to compare these tests with the ones recommended by the international protocols. Our results suggest that ARCAL is more complete than TG40, although the latter includes all the essential basic tests. We concluded that radiotherapy services should implement all basic quality control tests and that all other complementary tests should be implemented according to the need of each service. Finally, suggestions of protocols are presented, elaborated from the official and routine protocols used.

Keywords: Teletherapy, Protocols, Quality control

We present the quality control tests performed on a monophasic X-ray equipment and on two noninvasive monitoring systems. The results were compared with the values obtained using an invasive monitoring system and a hyperpure germanium detector, providing correction factors for utilization of the noninvasive voltage meters in the quality control program of X-ray equipment. We concluded that there is a need for periodic calibration and control.

Keywords: X-radiation, Quality control, Noninvasive systems

We present the results of a study for the development of a computational program for the evaluation and control of medium size medical radiological facilities in agreement with the recent guidelines of radiological protection of the Brazilian Ministry of Health. The routine procedures of the Radiology Department of Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil, were analyzed and a computer program was developed using Windows tools. The program named "Sistema Radiológico" (Radiological System) was implemented and tested with data and measurements. The results proved that the methodology employed allows fulfillment of the requirements of the Directive nº 453 of the Brazilian Ministry of Health, and moreover, increases the efficiency of several other activities in the radiology department.

Keywords: Radiology, Quality control, Software

Technetium-99m labeled radiopharmaceuticals are currently the main diagnostic agents used in nuclear medicine. Radiopharmaceuticals are prepared locally through a reaction between a complexant agent (pharmaceutical) and technetium-99m. These reactions may generate impurities resulting into the production of radiopharmaceuticals with substandard quality or with different characteristics from those considered ideal. In this article we discuss some of the factors that may interfere with the preparation of radiopharmaceuticals and the quality control tests that can be used to ensure the quality of the agents.

Keywords: Radiopharmaceuticals. Generators. Technetium-99m. Quality controls.

Objective: The present study was aimed at determining the acceptability of a national or regional phantoms bank to be deployed in Brazil for shared use in quality control activities by nuclear medicine centers. Materials and Methods: The authors analyzed the answers to a questionnaire applied to medical physicists and radioprotection supervisors in Brazilian nuclear medicine centers. Initially, the questionnaire was validated by professionals in the city of Aracaju, SE, which is located in the Northeast region. The present study sample was geographically distributed as follows: the Northeast region, with answers from 13 professionals of nuclear medicine centers; the North region, with 2 professionals; the South region, with 7 professionals; the Southeast region, with 43 professionals; and the Midwest region, with 2 professionals. Results: According to the data analyzed, 82% of the respondents consider that the implementation of a phantoms bank would be a suitable alternative for improving nuclear medicine quality control. The interest in sharing the bank was reported by 87% of the respondents. Conclusion: The present study demonstrated the motivation for a shared use of a future phantoms bank.

Keywords: Nuclear medicine; Quality control; Phantom.

Objective: To evaluate the intermethod agreement in the measurement of compression force as well as variations in the testing of different mammography systems. Materials and Methods: Ten compression force measurements were performed for each proposed method on each mammography apparatus (Mammomat 3000-Siemens, Mammo Diagnostic UC-Philips and Alpha ST-GE), with an evaluation of the differences among the mammographic equipments as far as the application of such measurement methods is concerned, as well as the differences among the applied methods. Results: Significant differences were observed among the results for the different systems and methods, and the values measured with the aid of a bathroom-scale-type dynamometer resulted in compression force underestimation. Each compression system presented different responses for the proposed methods. Conclusion: Differences were observed among compression systems and among proposed methods. Thus the choice of the way the compression test is performed is critical for the acceptance of the mammography equipment, the technical lead being the most competent to define the most appropriate and realistic testing method. It is suggested that the compression force measurement should be performed with an extension dynamometer, rather than with a compression dynamometer, in cases where the mammography compression system functioning is not known.

Keywords: Mammography; Compression force; Quality control.

Objective: To evaluate the light and radiation fields congruence and radiation beam alignment in medical X-ray equipment in Paraíba state radiology centers by means of two quality control tests. Materials and Methods: A loaded cassette, a measuring tape and a bubble level were utilized in the field size and alignment testing. The evaluation of collimation systems accuracy and X-ray beam alignment was undertaken during health inspections performed in radiology centers between 2008 and 2009. Results: In 2008, 121 X-ray machines were evaluated in the Paraíba state. In 2009, 117 machines were tested. From this universe, 86 machines were selected for comparison, since they were evaluated both in 2008 and 2009, with 18.60% (n = 16) showing test results improvement from one year to another. Conclusion: The percentage of problematic X-ray machines decreased between 2008 and 2009, notwithstanding no quality assurance program has been observed in Paraíba state radiology centers.

Keywords: Equipment; X-rays; Quality control.

Objetivo: A principal utilidade da tomografia por emissão de pósitrons com 18-fluordeoxiglicose (FDG-PET) está no estadiamento do câncer de pulmão. Porém, ela também pode ser utilizada para diferenciar lesões pulmonares indeterminadas, mas seu impacto na ressecção cirúrgica de lesões benignas é desconhecido. O objetivo deste estudo foi comparar a prevalência de lesões benignas em toracotomias feitas por suspeição de câncer de pulmão, antes e após a introdução do FDG-PET, em um centro de referência de cirurgia torácica. Materiais e Métodos: Os autores analisaram, prospectivamente, uma base de dados cirúrgicos de todos os pacientes consecutivos submetidos a toracotomia por câncer de pulmão suspeito ou comprovado e compararam a prevalência de lesões benignas em dois grupos ao longo de dois anos consecutivos, respectivamente antes (grupo I) e depois (grupo II) da introdução da FDG-PET. Resultados: Ressecção cirúrgica foi feita em 1.233 pacientes durante o período do estudo. A prevalência de lesões benignas na cirurgia nos grupos I e II foi similar (44/626 e 41/607, ambas correspondendo a 7%), e também no grupo II, entre aqueles submetidos a FDG-PET e os restantes (21/301 e 20/306 respectivamente, ambos correspondendo a 7%). No grupo II, dos 21 pacientes com lesões benignas submetidos a FDG-PET, 19 tiveram um estudo falso-positivo (valor médio padrão de captação 5.3 [faixa 2.6–12.7]). Desses, respectivamente 13 e 4 pacientes tiveram broncoscopia não diagnóstica e biópsia transtorácica percutânea de pulmão antes da toracotomia. Não houve diferença na proporção de lesões benignas diferentes ressecadas entre o grupo I e aqueles submetidos a FDG-PET no grupo II. Conclusão: A introdução da FDG-PET não alterou a proporção de pacientes submetidos a toracotomia por lesões benignas, principalmente devido à avidez pelo isótopo de algumas lesões não malignas. Tais resultados falsos-positivos devem ser considerados nos casos em que se contempla a possibilidade de ressecção cirúrgica em pacientes com câncer de pulmão não confirmado.

Keywords: Tomografia por emissão de pósitrons; Tomografia computadorizada; Pulmão – lesões benignas ou congênitas; Câncer de pulmão – diagnóstico e estadiamento; Câncer de pulmão – cirurgia.

OBJECTIVE: To evaluate the quality of primary and secondary displays of conventional radiography systems based on luminance measurements. The level of ambient lighting within the rooms was also measured. MATERIALS AND METHODS: Luminance measurements were performed with an Unfors Xi Light Detector in 23 primary and 22 secondary displays (six of them utilized in emergency departments) at five different institutions, and according to the method described on the American Association of Physicists in Medicine (AAPM) TG18 report. The level of ambient lighting was measured with Delta Ohm HD 9221 lux meter. RESULTS: In general, both the primary and secondary the displays were compliant with the AAPM guidelines. As regards ambient lighting, the primary workstation rooms were slightly above the recommended levels. As far as The Royal College of Radiologists (RCR) recommendations are concerned, the number of compliant displays corresponded to a minority, with no significant difference, though. CONCLUSION: Although most of the displays could not meet the strict RCR guidelines, in general, the results were satisfactory. The level of agreement between primary and secondary displays should be as high as possible in order to guarantee the image quality. Considering the key role played by diagnostic imaging systems, medical imaging displays must be regularly evaluated to assure that the quality of the imaging system is maintained.

Keywords: Quality control; Luminance; Illuminance.

OBJECTIVE: To describe the technique of injecting hemostatic matrix, as well as the experience of our interventional radiology department in its application. MATERIALS AND METHODS: We conducted a single-center study with retrospective analysis of the experience of our group in the use of hemostatic gelatin matrix in percutaneous biopsies. RESULTS: In a total of 73 biopsies in different organs, such as the liver, kidney, and spleen, hemostatic gelatin matrix was introduced into the coaxial needle. The only complication observed was migration of the hemostatic matrix to the left kidney collecting system, and that was resolved with clinical treatment. There were no cases of bleeding after the injection of hemostatic matrix. CONCLUSION: The use of hemostatic matrices in the path of percutaneous biopsies is another tool available for consideration in minimally invasive procedures.

Keywords: Hemostatic techniques; Hemostatics/administration & dosage; Biopsy, needle/methods; Hemorrhage/prevention & control.

Os nervos cranianos representam extensões das estruturas funcionais do cérebro que cruzam a cabeça e o pescoço. Eles estão ligados a diferentes estruturas cranianas e se relacionam com diversas doenças. Uma compreensão profunda de sua complexa anatomia e aparência normal de imagem permite ao examinador identificar e caracterizar com mais precisão as anormalidades. A ressonância magnética com contraste é uma importante ferramenta para avaliar essas estruturas, especialmente as sequências tridimensionais de precessão livre de estado estacionário, que proporcionam alta resolução espacial e de partes moles, apesar da fina espessura dos nervos cranianos. Na maioria dos casos, os achados de imagem são inespecíficos, e uma anamnese completa, exame físico dirigido e testes laboratoriais são necessários para estreitar o diagnóstico diferencial. Este ensaio iconográfico ilustra e discute doenças congênitas, traumáticas e vasculares dos nervos cranianos, mostrando imagens em uma abordagem fisiopatológica.

Keywords: Neuroimagem/métodos; Radiologia/métodos; Ressonância magnética/métodos; Nervos cranianos/diagnóstico por imagem.