OBJECTIVE: To evaluate dose-area product, skin entrance dose and doses from fluoroscopy and radiography in voiding cystourethrography studies of pediatric patients. MATERIALS AND METHODS: Procedures performed in 37 patients by four physicians of the institution were evaluated. Measurements were performed with an equipment including an ionization chamber directly coupled to the x-ray tube window and an electrometer (Diamentor) connected to a computer for data collection. RESULTS: Some procedures heterogeneity was observed and guidelines for good radiographic techniques were not followed. On average, 11 radiographies are performed for each study, with extended fluoroscopy time delivering a higher average final dose than those reported in the literature. CONCLUSION: The adoption of radiography with high kilovoltage technique and restricted utilization of fluoroscopy can result in a significant reduction of doses during this procedure, considering that the major contribution to the final dose comes from fluoroscopy.

Keywords: X-rays, Dosimetry, Cystourethrography, Fluoroscopy, Pediatric radiology

OBJECTIVE: The present study was aimed at: a) evaluating radiographic procedures and estimating entrance surface air kerma in preterm neonates submitted to chest and abdominal radiography at the unit of neonatology in a public hospital of Belo Horizonte, MG, Brazil; b) estimating the dose to organs and respective risks for cancer as a result from radiation exposure. MATERIALS AND METHODS: Records of patients admitted to the unit of neonatology of this hospital in the period between May and September 2004 were reviewed. Anthropometric data, admission/discharge dates and radiographic studies performed were recorded for each of the patients. The calculation of the entrance surface air kerma was based on the x-ray tube output and irradiation parameters adopted for examinations. Dose to organs was calculated with the aid of the software PCXMC, and the lifetime risk for cancer, with the software IREP. RESULTS: Mean entrance surface air kerma per examination was below the diagnostic reference levels recommended by the European Community. In the most severely irradiated patients, liver, breast and stomach were the organs at highest risk for cancer, with maximum excess relative risk of respectively 3.4%, 2.3%, and 1.7%. CONCLUSION: The present study demonstrated the need for optimization of radiographic procedures in order to reduce the risks for neonates that, in spite of being considered to be low as compared with the benefits, should be reduced to values as low as reasonably achievable.

Keywords: Patient dosimetry, Radiological protection, Pediatric radiology, Cancer risk

OBJECTIVE: The present study was aimed at evaluating the frequency of radiographic assessment of paranasal sinuses in pediatric patients in hospitals of Belo Horizonte, MG, Brazil. Additionally, aspects regarding radiation protection conditions and radiographic parameters were evaluated, and entrance air kerma and organ doses were estimated. MATERIALS AND METHODS: Patients' data and parameters of radiographic technique employed in the assessment of children in the age range between 1 and 16 years were collected in five examination rooms of four hospitals in Belo Horizonte, also taking into consideration the radiation protection aspects. Entrance air kerma calculation was based on the x-ray tubes output, and organ doses were estimated with the PCXMC software. RESULTS: Mean entrance air kerma values found in the five rooms were, respectively, 1398 µGy, 829 µGy, 877 µGy, 1168 µGy and 3886 µGy for patients with ages between 1 and 5 years. CONCLUSION: Most frequently, mento-naso and fronto-naso views are requested in conjunction in the majority of hospitals, which increases the radiation dose to the patients. It may be concluded that the risks for patients can be reduced by means of the utilization of an appropriate x-ray field, non-utilization of antiscattering grids, selection of high voltages and lower exposure times.

Keywords: Pediatric radiology, Patient dose, Organ dose

A wide spectrum of congenital anomalies may affect the gastrointestinal tract at any level from the esophagus to the anus. Atresia is an important cause of gastrointestinal obstruction with high morbidity rate in neonates. Different pathogenetic mechanisms could cause this malformation and the two classical explanations are: a defect of recanalization of the intestinal tube or an interruption of blood supply during intrauterine life. The authors present a literature review with an iconographic essay of imaging findings in children with gastrointestinal atresia.

Keywords: Atresia, Children, Pediatrics, Imaging

We present the preliminary results of testing and acceptance of a method for displaying medical images that employs simple computer freewares that can be run in unsophisticated computational platforms, which are commonly underutilized. This method allows easy and accessible visualization, printing, documenting, archiving, consulting and electronic transmission of a wide range of medical images without the need of expensive, complex and difficult to learn softwares.

Keywords: Medical images, Freeware, Ultrasound

OBJECTIVE: To distinguish healthy from pathological tissues in pediatric patients with posterior cranial fossa tumors using calculated textural parameters from magnetic resonance images. MATERIALS AND METHODS: We evaluated 14 pediatric patients with posterior cranial fossa tumors using the software MaZda to define the texture parameters in selected regions of interest representing healthy and pathological tissues based on T2-weighted magnetic resonance images. RESULTS: There was a statistically significant difference between normal and tumoral tissues as well as between supposedly normal tissues adjacent and distant from the tumoral lesion. CONCLUSION: Magnetic resonance textural evaluation is an useful tool for determining differences among various tissues, including tissues that appear apparently normal on visual analysis.

Keywords: Magnetic resonance imaging, Textural evaluation, Posterior cranial fossa tumors, Pediatric patients, MaZda software

The dose area product was evaluated and the entrance skin dose was subsequently estimated by means of suitable calculations for pediatric examinations. Results showed values around 100% above the reference levels (0.070 mGy). The technical parameters of the X-ray tubes were periodically checked since a routine quality assurance program is implemented in the hospital. Results showed a good performance of the equipment complying with recommended limits according to Brazilian legislation. Therefore, the high doses can be attributed to the low kV techniques and the lack of appropriate training of the radiographers to perform pediatric examinations. Measurements of scattered radiation were performed in the gonads with the use of thermoluminescent dosimeters which proved to be inadequate for these measurements. Therefore an ionization chamber was used instead and the values obtained showed that the doses were far below the values that can cause permanent or transient sterility.

Keywords: Radiation doses, Pediatric radiology, Image quality

OBJECTIVE: To present the process of implementation of toolkits for visualization of medical images using DICOM and to review the basis and characteristics of this protocol. In this paper we present a VDTApplication for visualization of local and remote images, and a VDTApplet that allows the visualization of images on a web browser. MATERIALS AND METHODS: The toolkits were implemented using Java programming language. For the development of this toolkit we considered the different version of the DICOM protocol, creating a generic system capable of reading and opening images generated by different modalities of different manufacturers. The tools were evaluated qualitatively by doctors taking into account the system's interface, image quality and image adjustment. RESULTS: The evaluation score ranged from 1 (very poor ) to 5 (very good) for each item, with the following results: 5 for system interface, 4 for image quality and 3 for the image adjustment. Based on the scores obtained we concluded that the tools can be considered good. CONCLUSION: These results allowed us to conclude that these tools are practical, user friendly and should be added to the PACS (picture archiving and communication system) of "Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo", Ribeirão Preto, SP, Brazil.

Keywords: Medical images, DICOM, Filmless radiology, Medical images visualization

Bronchial atresia is a rare congenital abnormality that usually shows a juxta-hilar mass with distal radiolucency on conventional x-ray films. Most patients are young and have no symptoms. Computed tomography usually confirms the diagnosis, allowing conservative management of the asymptomatic cases. The authors report three cases of bronchial obstruction. One of the patients was of particular importance and interest, a 45-year-old female patient with symptoms of respiratory infection, due to the association with a bulky bronchocele. The diagnosis was made by analyzing the findings of conventional x-ray films and computed tomography, and the comparison with previous conventional x-ray films and linear tomography, which had already demonstrated abnormalities. A literature review on the clinical and radiological findings of this pulmonary malformation is presented.

Keywords: Bronchial atresia, Bronchocele, Bronchial mucocele

OBJECTIVE: The aim of this work is to discuss the effects of the main parameters that influence image quality and the entrance skin dose. MATERIALS AND METHODS: The pediatric chest radiographs of three different Institutions were evaluated. Tests on all x-ray equipment were performed. The skin entrance dose was assessed using thermoluminescent dosimeters. RESULTS: Only one of all x-ray equipments tested was in good operation condition. The average skin entrance dose was: (0.222 ± 0.088) mGy for children under 1 year, (0.28 ± 0.11) mGy for 1.1 to 4 years, (0.26 ± 0.13) mGy for 4.1 to 6 years, (0.23 ± 0.13) mGy for 6.1 to 10 years and (0.26 ± 0.25) mGy for older than 10 years. CONCLUSION: The results showed that the average skin entrance doses are higher than the European Community Commission reference levels and other values reported in the literature. We recommend the implantation of quality assurance programs to reduce skin entrance doses and for obtaining good quality images.

Keywords: Pediatric radiology, Skin dose, Reference levels

Objetivo: Avaliar a percepção de médicos residentes em radiologia de 4º ano sobre as melhores modalidades de imagem na investigação de neoplasias e trauma. Materiais e Métodos: Vinte e sete médicos residentes de 4º ano de quatro programas de residência em radiologia americanos participaram do estudo. Aos participantes foi perguntado sobre a melhor modalidade de imagem para se avaliar o cérebro e a coluna vertebral, pulmões, abdome e o sistema musculoesquelético. As modalidades de imagem disponíveis foram: RM, TC, ultrassonografia, PET e radiografia simples. Todos os achados foram comparados com os Critérios de Adequação de Exames de Imagem e Radioterapia do ACR. Resultados: A RM foi escolhida como melhor modalidade de imagem para se avaliar neoplasias encefálicas, espinhais, abdominais e musculoesqueléticas por 96,3%, 100%, 70,4% e 63% dos residentes, respectivamente. A TC foi escolhida por 88,9% dos residentes para avaliar neoplasias pulmonares. A modalidade de imagem ótima para se avaliar trauma foi a TC para lesões encefálicas (100%), espinhais (92,6%), pulmonares (96,3%), abdominais (92,6%) e grandes lesões traumáticas musculoesqueléticas (74,1%); a RM foi escolhida para lesões esportivas (96,3%). Observou-se concordância com os critérios de adequação do ACR. Conclusão: Houve concordância entre a percepção dos residentes sobre as melhores modalidades de imagem para avaliação de neoplasias e trauma e os critérios de adequação do ACR.

Keywords: Formação de residentes; Educação médica; Modalidades de imagem.

Objective: Study of the cerebral ventricular system by ultrasonography with the objective of establishing parameters for the diagnosis of mild ventricular dilatation. Materials and Methods: Prospective study of 105 healthy, full term infants aged 1–6 months, submitted to monthly scans for morphological data evaluation and measurements of ventricle/hemisphere ratio, and anteroposterior diameter of frontal horn and fourth ventricle. Results: Normality mean, standard deviation and percentile were obtained for each age range. Negative results were observed in the search for anechoic halo surrounding the posterior two thirds of the choroid plexus on coronal section VI for evaluation of temporal/posterior horns, and the third ventricle was seen as an anechoic cleft < 1 mm on coronal section V in all of the evaluated infants. Conclusion: Sonographic findings related to temporal/posterior horns and third ventricle associated with the 95th percentile as upper limit of normality can be utilized as parameters for a simplified diagnosis of mild ventricular dilatation.

Keywords: Cerebral ventricles; Transfontanelle ultrasonography; Brain ultrasonography; Pediatric sonographic measurements.

Unilateral pulmonary vein atresia is a rare congenital condition. In addition to cardiac malformations or pulmonary hypertension, patients may present with recurrent pulmonary infections or hemoptysis in childhood or adolescence. The authors report a case where the typical findings of such condition were observed at computed tomography in an adult patient.

Keywords: Pulmonary veins; Unilateral pulmonary veins atresia; Computed tomography.

OBJECTIVE: To evaluate the percutaneous transhepatic approach to the treatment of biliary strictures in pediatric patients undergoing liver transplantation. MATERIALS AND METHODS: This was a retrospective study of data obtained from the medical records, laboratory reports, and imaging examination reports of pediatric liver transplant recipients who underwent percutaneous transhepatic cholangiography, because of clinical suspicion of biliary strictures, between 1st September 2012 and 31 May 2015. Data were collected for 12 patients, 7 of whom were found to have biliary strictures. RESULTS: In the 7 patients with biliary strictures, a total of 21 procedures were carried out: 2 patients (28.6%) underwent the procedure twice; 3 (42.8%) underwent the procedure three times; and 2 (28.6%) underwent the procedure four times. Therefore, the mean number of procedures per patient was 3 (range, 2–4), and the average interval between them was 2.9 months (range, 0.8–9.1 months). The drainage tube remained in place for a mean of 5.8 months (range, 3.1–12.6 months). One patient presented with a major complication, hemobilia, which was treated with endovascular embolization. Clinical success was achieved in all 7 patients, and the mean follow-up after drain removal was 15.4 months (range, 5.3–26.7 months). CONCLUSION: The percutaneous transhepatic approach to treating biliary strictures in pediatric liver transplant recipients proved safe, with high rates of technical and clinical success, as well as a low rate of complications.

Keywords: Liver transplantation; Biliary atresia; Constriction, pathologic/therapy; Cholangiography; Drainage.

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.