An Approach to Establishing Diagnostic Reference Levels in Interventional Pediatric Cardiology from Different Regions of Brazil.

Diagnostic reference levels (DRLs) are a pivotal strategy to be implemented since pediatric interventional cardiology procedures are increasing. This work aimed to propose an initial set of Brazilian DRLs for pediatric interventional diagnostic and therapeutic (D&T) procedures. A retrospective study was carried out in four Brazilian states, distributed across the three regions of the country. Data were collected from pediatric patients undergoing cardiac interventional procedures (CIPs), including their age and anthropometric characteristics, and at least four parameters (number of images, exposure time, air kerma-area product-PKA, and cumulative air kerma). Data from 279 patients undergoing CIPs were gathered (147 diagnostic and 132 therapeutic procedures). There were no significant differences in exposure time and the number of images between the D&T procedures. A wide range of PKA was observed when the therapeutic procedures were compared to diagnostics for all age groups. There were significant differences between the D&T procedures, whether grouping data by patient weight or age. In terms of cumulative air kerma, it was noted that no value exceeded the level to trigger a monitoring process for patients. This study shows that it is possible to adopt them as the first proposal to establish national DRLs considering pediatric patient groups.

Assessment of image quality in digital radiology using the CDRAD contrast-detail phantom in pediatrics / Evaluación de la calidad de la imagen en radiología digital utilizando el fantoma de detalle de contraste CDRAD en pediatría

ABSTRACT The transition from analog to digital radiology has expanded the capabilities of radiological imaging but has also made it possible to increase the radiation dose received by patients. Image quality in radiology is determined by factors such as radiographic techniques (kVp and mAs), which directly impact the dose and image quality. This study focuses on pediatric radiological exams considering their greater radiosensitivity and longer life expectancy. The study aimed to investigate the correlation between image quality and applied radiographic techniques using the CDRAD contrast-detail phantom. The results showed a direct linear relationship between the increase in kVp and the corresponding increase in image quality. Nonetheless, there was a significant variation in image quality between current-time products ranging from 0.5 to 2.5 mAs, in contrast to the nearly linear relationship observed within the 2.5 and 10 mAs range

RESUMEN La transición de la radiología analógica a la digital ha ampliado las capacidades de las imágenes radiológicas, pero ha también permitió aumentar la dosis de radiación que reciben los pacientes. La calidad de la imagen en radiología está determinada por factores como las técnicas radiográficas (kVp y mAs), que impactan directamente en la dosis y la calidad de la imagen. Este estudio se centra en exámenes radiológicos pediátricos considerando su mayor radiosensibilidad y mayor espe ranza de vida. El estudio está dirigido a investigar la correlación entre la calidad de la imagen y las técnicas radiográficas aplicadas utilizando el detalle de contraste CDRAD fantasma. Los resultados mostraron una relación lineal directa entre el aumento de kVp y el correspondiente aumento de calidad de la imagen. No obstante, hubo una variación significativa en la calidad de la imagen entre los productos actuales que van desde 0,5 a 2,5 mAs, en contraste con la relación casi lineal observada dentro del rango de 2,5 y 10 mAs.

Image evaluation and breast density categories as a function of mammary positioning in full-field digital mammography.

BACKGROUND: Appropriate mammary positioning is an important factor in optimizing image quality in mammography (MMG). PURPOSE: To study the correlation of quality criteria and breast density classification proposed by the American College of Radiology (ACR) and European Guidelines and its influence to achieve a proper positioning, therefore an adequate MMG. MATERIAL AND METHODS: A total of 128 routine MMG examinations were reviewed for the definition of breast composition parenchyma and assessment of several quality criteria proposed by the ACR and European Guidelines to achieve an adequate MMG. Adequate MMG was defined as a difference between the posterior nipple line (PNL), difference of the mediolateral oblique (MLO) and craniocaudal (CC) incidences > 1 cm. The quality criteria were analyzed as a function of correlation coefficient in order to evaluate the individual impact of each factor and analysis of variance (ANOVA) for all criteria. Receiver operating characteristic (ROC) curves were plotted to evaluate the performance of the criteria on each type of parenchyma. RESULTS: Negative correlation of fatty breasts and visibility of the mammary angle, a greater number of skin folds and PNL > 1 cm (r < 0). Dense MMG presented less visibility of the lateral tissue compared with other categories. Area under the curve of ROC analysis revealed values of 53.1% and 54.7% for the right and left breasts, respectively. CONCLUSION: Several factors influenced in the MMG process, but we find that breast parenchyma has a substantial role in affecting these criteria and therefore a correct position for diagnosis, which could compromise MMG diagnostic performance.

Evaluation of high-grade astrocytoma recurrence patterns after radiotherapy in the era of temozolomide: A single institution experience.

AIM: Evaluating the recurrence patterns of high-grade astrocytomas in patients who were treated with radiotherapy (RT) plus temozolomide (TMZ). BACKGROUND: The current literature suggests that reducing the margins added to the CTV does not significantly change the risk of recurrence and overall survival; thus, we decided to analyze our data and to examine the possibility of changing the adopted margins. MATERIALS AND METHODS: From February 2008 till September 2013, 55 patients were treated for high-grade astrocytomas, 20 patients who had been confirmed to have recurrence were selected for the present study. Post-operative MRI was superimposed on the planning CT images in order to correlate the anatomical structures with the treatment targets. Recurrences were defined according to the Response Assessment Criteria for Glioblastoma. The mean margins of the PTVinitial and PTVboost were 1.2 cm and 1.4 cm, respectively. The analysis of the percentage of the recurrence volume (Volrec) within the 100% isodose surface was based on the following criteria: (I) Central: >95% of the Volrec; (II) In-field: 81-95% of the Volrec; (III) Marginal: 20-80% of the Volrec; and (IV) Outside: <20% of the Volrec. RESULTS: Of the 20 patients, 13 presented with central recurrences, 3 with in-field recurrences, 2 with marginal recurrences and 2 with outside recurrences. Therefore, the lower Volrec within 100% of the prescribed dose was considered in the classification. CONCLUSIONS: Of the selected patients, 80% had ≥81-95% of the Volrec within 100% of the prescribed dose and predominantly had central or in-field recurrences. These results are comparable with those from the literature.

Monitoramento da radioatividade alfa relacionada ao radônio-222 em águas de poços da região metropolitana de Curitiba (PR) / Alpha radioactivity monitoring related to radon-222 in water from wells in metropolitan area of Curitiba (PR), Brazil

O objetivo desta pesquisa foi avaliar os níveis de concentração de radônio 222Rn em águas de poços da região metropolitana de Curitiba, Paraná. O trabalho apresenta os resultados das concentrações das medidas feitas em águas de poços da região. As concentrações de 222Rn nas amostras das águas de poços foram medidas por meio do monitor de radônio AlphaGUARD. Os cálculos das concentrações de atividade iniciais de radônio na água foram feitos a partir da curva de decaimento do 222Rn e do equilíbrio secular entre o 222Rn e o 226Ra, observados depois de 30 dias. Os resultados indicaram que cerca de 70% dos valores das concentrações de 222Rn ficaram acima do valor recomendado pela USEPA, de 11,1 Bq.L-1, representando risco radiológico causado por este radionuclídeo. O estudo de caso apresentado mostrou que medidas prévias de radônio são recomendadas para que um projeto de construção seja implementado. No caso em questão, observa-se que as concentrações de radônio diminuem cerca de 56% na primeira caixa d'água e 83% na segunda em relação ao poço. Esse fato mostra que as ações para mitigação de radônio são viáveis e não exigem grandes modificações nos sistemas usuais da construção civil.

This research objective was to assess the level of randon-222 concentration in well water of the metropolitan region of Curitiba, Paraná. Current work presents the results of indoor 222Rn activity ground water samples from artesian wells from aquifers of the region. The studies of radon activity in water were performed using the radon detector AlphaGUARD. The calculations of initial radon activity in water were done considering the 222Rn decay correction as well as equilibrium level of 222Rn and 226Ra observed after 30 days of measurements. Obtained results show that about 70% of measured activity levels of 222Rn are higher than the recommended value of 11.1 Bq.L-1, which represent the risk for the human health associated with this radionuclide. The case study showed that previous measurements of radon are recommended for a construction project is implemented. In this case, it is observed that the radon concentrations decrease about 56% in the first water tank and 83% in the second water tank over the well. This fact shows that the actions for mitigation of radon are viable and do not require major modifications to the usual systems of construction.