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

OBJECTIVE: To make a software available for training professionals in the interpretation of mammography images on digital systems. MATERIALS AND METHODS: The software was developed in Delphi and linked to a Interbase database to store mammographic images in association with the BI-RADS® category results. Images were previously qualified and digitized using a Lumiscan 75 laser scanner. Training is done on 18 × 24 cm images displayed on a 17² commercial monitor. The software allows displaying of each breast view individually, medial-lateral oblique and cranial-caudal views, or four images simultaneously. The user selects an exam from the database and makes a diagnosis classifying the image into BI-RADS® categories. At the end of the process, the software compares the user's interpretation with the data stored in the database and than yields scores. RESULTS: The user becomes familiar with digital systems, images interpretation using BI-RADS® categories and with the quality of the image generating process regarding the detection of fibers and microcalcifications. CONCLUSION: The software is available at "Universidade Federal de São Paulo", São Paulo, Brazil, intranet and is a valuable tool for training professionals interested in digital systems.

Keywords: Data base, Mammography, Digital, 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

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

Quality control of automatic processors is an important issue in the implementation of quality assurance programs in diagnostic radiology. A pilot program of quality control for automatic processors using the sensitometric method was implemented in the Radiodiagnosis Service of a University Hospital in Rio de Janeiro, RJ, Brazil. An initial survey of the darkrooms showed that they had high temperature and humidity and several light leaks; fog levels were excessively high requiring an increase in mAs of up to 24% to compensate for contrast loss; dry to dry processing time was out of control with errors of up to 56%; developer temperature was as high as 39°C (4°C higher than the recommended by the manufacturers); replenishment rates presented values as high as 417% above manufacturer's recommendations; and rejection rates of radiographic films were of the order of 21% in the mammography service. Sensitometric measurements performed before the implementation of the quality control showed values of base + fog as high as 0.24 optical density and speed and contrast outside recommended limits. The radiographic films presented several artifacts that resulted in low quality images. The pilot program consisted of the implementation of the quality control in the mammography service. Several initiatives were taken including training of the technicians, improvement of maintenance of the processors and increase in the number of patients/day from 7 to 12. This procedure allowed replenishment rates to be lowered to acceptable levels. The implementation of the quality control maintained chemical products stable keeping the sensitometric parameters under control. However, the most significant result of the program was better image quality, free from artifacts, a significant reduction in costs to the hospital and especially lower doses imparted to the patients due to the reduction in rejection rates to 7.7%.

Keywords: Quality control, Automatic processors, Sensitometric method

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

This paper describes the operational characteristics of the final process of implementation of a quality control program using routine mechanical and radiation tests. The quality control program was performed during 35 months and demonstrated the excellent stability of this accelerator.

Keywords: Linear accelerator, Quality control, Photon radiation

We developed a Tandem system using a pair of ionization chambers (a cylindrical and a parallel-plate type) to perform X-ray measurements in a medical Institution, in substitution of the routine conventional procedure of determination of half-values layers using absorbers. The results obtained indicate the possibility of application of this method in dosimetric procedures of orthovoltage beams (radiotherapy) as a complementary procedure in a quality control program.

Keywords: X-rays, Ionization chambers, Quality control

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.

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.