Mean glandular dose in digital mamography in women with breast implants.

PURPOSE: Mean Glandular Dose (MGD) is the quantity related to the risk of radiation-induced breast cancer. This study aimed to evaluate the MGD in screening mammography for women with breast implants. METHODS: This retrospective study used data of 2680 mammographies of 335 asymptomatic women with mammary implants examined in a digital direct x-ray unit. Each woman had a total of eight images: four in standard views and four with posterior displacement of the implant (ID). Data on kV, mAs, target/filter combination, compressed breast thickness and MGD were obtained from the DICOM header of the stored images. Quantitative variables were presented through descriptive statistics for median (5th-95th percentiles); and the qualitative variables were presented by numbers and percentages. Mean glandular doses of standard views and ID views were compared and statistical analysis was used to assess the influence of implant position, breast glandularity and thickness on mean glandular doses. RESULTS: Median MGD for standard views were 3.30 (2.60-4.00) mGy for CC and 3.31 (2.70-4.20) mGy for MLO. For ID views, median were 1.20 (0.90-2.20) mGy and 1.40 (0.97-3.74) mGy for CC and MLO views, respectively. Median MGD for the whole examination of women with breast implants was 9.60 (7.92-12.07) mGy, ranging from 6.25 to 21.50 mGy. When comparing MGD median for standard and ID views it was found a statistically significant difference (p < 0.05), with higher doses for the standard views due to the greater compressed breast thickness in these views. It was observed that, in the standard views, MGD decreases with increasing breast thickness due to the manual radiographic techniques used to expose the women. It was also observed that implant position does not affect MGD in breast augmentation mammography. CONCLUSION: Mammography of women with mammary implants gives higher radiation doses when compared with those without implants. For more accurate dose assessment in augmented breast mammography, it is necessary that specific conversion factors for the calculation of MGD based on air kerma at entrance of breasts with implants are made available.

Evaluation of radiation protection conditions in intraoral radiology

Abstract Introduction: The dental radiology represents about 20% of human exposure to radiation in radio diagnostic. Although the doses practiced in intraoral dentistry are considered low, they should not be ignored due to the volume of the performed procedures. This study presents the radiation protection conditions for intraoral radiology in Curitiba - PR. Methods Data was collected through a quantitative field research of a descriptive nature during the period between September of 2013 and December of 2014. The survey sample consisted of 97 dentists and 130 intraoral equipments. The data related to the equipments was collected using structured questions and quality control evaluations. The evaluations of the entrance skin dose, the size of the radiation field and the total filtration were performed with dosimetry kits provided and evaluated by IRD/CNEN. The exposure time and voltage were measured using noninvasive detectors. The occupational dose was verified by thermoluminescent dosimeters. The existence of personal protection equipment, the type of image processing and knowledge of dentists about radiation protection were verified through the application of a questionnaire. Results Among the survey's results, it is important to emphasize that 90% of the evaluated equipments do not meet all the requirements of the Brazilian radiation protection standards. Conclusion The lack of knowledge about radiation protection, the poor operating conditions of the equipments, and the image processing through visual method are mainly responsible for the unnecessary exposure of patients to ionizing radiation.

Survey and analysis of optical density of dental films processed manually in portable dark chambers

Introduction Intraoral film processing can be performed manually using chambers manufactured from opaque material to prevent light from entering and consequently blurring images. The aim of this study was to evaluate whether portable darkrooms used in offices, clinics and educational institutions prevent the entry of light during the processing of intraoral films. Methods To this end, tests were carried out and images were analyzed by measuring the optical base-plus-fog densities (ODs) upon imaging. Results Review of the OD measurements revealed that in 70.7% of the evaluated manual portable revelation cameras, the base-plus-veil density of intraoral films was not in accord with that of the protocol reference. Discussion The results of this work can be used to identify chambers that are commonly exposed to light from fluorescent lamps and solar lighting.

Redução das doses na entrada da pele utilizada em exames de radiologia intra-oral no Rio de Janeiro / Reduction of the skin doses used in intra-oral radiology in Rio de Janeiro

Este trabalho apresenta resultados de doses na entrada da pele produzidas por aparelhos de raios X intra-orais em dois períodos. Resultados comparativos entre as doses empregadas antes e após a publicação da Portaria 453 revelam, para 481 aparelhos analisados, que em 54% destes as doses foram reduzidas. Verifica-se ainda que a média ponderada da dose diminuiu cerca de 25% em relação ao período anterior à portaria 453. Os resultados permitem interpretar que em 67% dos aparelhos avaliados as doses estão dentro dos níveis de refêrências estabelecidos pelo Ministério da Saúde, mostrando avanços da radioproteção nesta área.