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 purpose of thys study was to investigate the effect of the addition of aluminum (1 mm) and copper (0.4 mm) filters on effective radiation doses and image quality in videofluoroscopy. MATERIALS AND METHODS: An ionization chamber coupled with an electrometer was added to x-ray tube to measure the kerma area product with 65 kV and 0.7 mA technique, without and with additional filtration. Low contrast, gray scale and spatial resolution were measured utilizing Leeds test objects. Fifteen volunteers underwent pharynx study, ten without and five with aluminum and cooper filters associated, and had the kerma area product/minute compared. RESULTS: The specified filters addition, either separated or associated, allowed an expressive decrease in kerma area product besides an actual improvement in the videofluoroscopic images quality determined by a better gray tones differentiation and increased brightness contrast ratio in the gray curve. CONCLUSION: Additional aluminum and copper filters interposition, especially when associated, results in improved image quality with expressive reduction in the required radiation doses.

Keywords: Videofluoroscopy, Kerma area product, X-ray, Radiological image, Radiation dose

OBJECTIVE: The present study evaluates the dose distribution received by physicians involved in hemodynamic procedures of coronary angiography and coronariography. The influence of some factors such as pulsed or continuous fluoroscopy mode and vein and/or artery access site was investigated. MATERIALS AND METHODS: Measurements have been performed with LiF:Mg,Ti thermoluminescent dosimeters placed on seven different sites of the practitioners' bodies: hands, left knee, neck, forehead and chest, under and over the lead apron. Radiation doses for each procedure were evaluated in physicians who had performed 60 coronariography and 30 angioplasty procedures. The thermoluminescent dosimeters were calibrated in the operational quantity personal dose equivalent, Hp(d), at depths of 0.07, 3 and 10 mm. RESULTS: The results of the present study demonstrate the significant role played by thyroid protectors and lead aprons for reducing radiation doses received by practitioners. Occupational doses in continuous mode fluoroscopy through brachial access were higher than with pulsed mode fluoroscopy through femoral access. CONCLUSION: The present study has demonstrated the necessity of implementing additional protective measures as well as a mechanism of training in radiation protection for physicians involved in interventional cardiological procedures.

Keywords: Interventional radiology, Fluoroscopy, Hemodynamic procedures, Radiation protection, Thermoluminescent dosimetry

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: Entrance skin dose, effective dose, and imaging quality in chest radiographs of adult patients have been evaluated. MATERIALS AND METHODS: The study has been developed in eight institutions - seven public hospitals (two of them philanthropic institutions) and one private - in the cities of Agra dos Reis, Cabo Frio, Campos dos Goytacazes, Itaperuna, Niterói, Recife and Rio de Janeiro. Entrance skin dose and effective dose have been evaluated in 735 chest radiographs obtained in posteroanterior/anteroposterior and lateral projections. As regards imaging criteria, 44 radiographs have been evaluated. RESULTS: Variations of up to nine times in entrance skin dose, and six times in effective dose have been detected for a same type of projection. Also, significant discrepancies have been found in values resulting from radiographic techniques employed. Besides, imaging quality has not been good since the rate of compliance with imaging criteria was only 55%. CONCLUSION: There is a pressing need for improvement/standardization of procedures in conventional radiology; this can be achieved by implementing a quality control and assurance program in the department of radiology, including training of technicians, x-ray equipment calibration, and sensitometric control of films processors.

Keywords: Chest x-ray, Quality control, Dosimetry

OBJECTIVE: This study aims to evaluate the effective ionizing radiation dose received by staff involved in interventional vascular procedures to establish parameters for comparison between the data obtained with an ionization chamber and with the dosimeters used for individual monitoring. MATERIALS AND METHODS: The evaluation was performed in a cardiac catheter laboratory and air kerma rate was measured in a real working environment, in the positions occupied by physicians and nurses, with and without the lead glass shield. The number of tests performed in the laboratory was taken into consideration and most common projections and radiographic parameters were selected. Conversion factors founded in the literature were applied for the effective dose estimation. RESULTS: The values found in the effective dose and in the dosimetry report were rather consistent. Additionally, it was observed that the use of the lead glass shield reduces in up to 97% the doses received by the professional and therefore it must be routinely used. CONCLUSION: The reported values are representative but cannot be assumed as a reproduction of individual monitoring conditions, although they are valid for comparison purposes and as a guidance for dosing optimization.

Keywords: Occupational exposure, Dosimetry, X-rays, Hemodynamics

We conducted a study to assess and compare the findings of computed tomography angiography and digital subtraction angiography in patients with intracranial aneurysms, and to evaluate the possibility of a larger utilization of computed tomography angiography in Brazil. Eight patients were studied, 7 with nontreated and 1 with a treated aneurysm. The results were compared with those from the medical literature. Tests were performed at a private clinic and in two private hospitals in Rio de Janeiro, RJ, Brazil. There was good correlation between the two investigational methods regarding diagnosis, follow-up and pretreatment evaluation of these lesions. Computed tomography angiography showed to be less invasive, less costly and more accessible. We concluded that computed tomography angiography should be used more often in the evaluation of intracranial aneurysms.

Keywords: Intracranial aneurysm, X-ray computed tomography, Cerebral angiography, Radiology

OBJECTIVE: The authors have sought to study the calibration of a clinical P_KA meter (Diamentor E2) and a calibrator for clinical meters (PDC) in the Laboratory of Ionizing Radiation Metrology at Instituto de Energia e Ambiente - Universidade de São Paulo. MATERIALS AND METHODS: Different qualities of both incident and transmitted beams were utilized in conditions similar to a clinical setting, analyzing the influence from the reference dosimeter, from the distance between meters, from the filtration and from the average beam energy. Calibrations were performed directly against a standard 30 cm³ cylindrical chamber or a parallel-plate monitor chamber, and indirectly against the PDC meter. RESULTS: The lowest energy dependence was observed for transmitted beams. The cross calibration between the Diamentor E2 and the PDC meters, and the PDC presented the greatest propagation of uncertainties. CONCLUSION: The calibration coefficient of the PDC meter showed to be more stable with voltage, while the Diamentor E2 calibration coefficient was more variable. On the other hand, the PDC meter presented greater uncertainty in readings (5.0%) than with the use of the monitor chamber (3.5%) as a reference.

Keywords: Kerma; Meters; Calibration; Dosimetry; Radiology; X-rays.

OBJECTIVE: Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). MATERIALS AND METHODS: The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. RESULTS: No significant difference was observed in the values for weighted air kerma index (C_W), but the differences were relevant in values for volumetric air kerma index (C_VOL), air kerma-length product (P_KL,CT) and effective dose. CONCLUSION: Only the C_W values were lower than the DRL, suggesting that dose optimization might not be necessary. However, P_KL,CT and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans.

Keywords: Pediatric computed tomography scans; Dosimetric quantities; Weighted dose index; Volumetric air kerma index; Air kermalength product.

Currently, lung impairment is the leading factor responsible for the morbidity and mortality associated with systemic sclerosis. Therefore, the recognition of the various tomography patterns becomes decisive in the clinical management of these patients. In high-resolution computed tomography studies, the most common pattern is that of nonspecific interstitial pneumonia. However, there are other forms of lung involvement that must also be recognized. The aim of this study was to review the literature on the main changes resulting from pulmonary involvement in systemic sclerosis and the corresponding radiological findings, considering the current classification of interstitial diseases. We searched the Medline (PubMed), Lilacs, and SciELO databases in order to select articles related to pulmonary changes in systemic sclerosis and published in English between 2000 and 2015. The pulmonary changes seen on computed tomography in systemic sclerosis are varied and are divided into three main categories: interstitial, alveolar, and vascular. Interstitial changes constitute the most common type of pulmonary involvement in systemic sclerosis. However, alveolar and vascular manifestations must also be recognized and considered in the presence of atypical clinical presentations and inadequate treatment responses.

Keywords: Sclerosis; Scleroderma, systemic; Radiology; Tomography, X-ray computed; Lung diseases.

OBJECTIVE: To determine the value of anterior displacement of the abdominal aorta, when present at any level or only at the level of the adrenal gland, contralateral to the mass, in diagnosing neuroblastoma on computed tomography or magnetic resonance imaging in children up to 7 years of age. MATERIALS AND METHODS: Imaging examinations of 66 patients were classified by consensus as for the presence of anterior aorta displacement and were compared with the pathology report. RESULTS: We found anterior abdominal aorta displacement in 26 (39.39%) of the 66 patients evaluated. Among those 26 patients, we identified neuroblastoma in 22 (84.62%), nephroblastoma in 3 (11.54%), and Burkitt lymphoma in 1 (3.85%). The positive predictive value was 84.62%, and the specificity was 88.24%. The displacement of the aorta was at the adrenal level, contralateral to the mass, in 14 cases, all of which were attributed to neuroblastoma. CONCLUSION: When the abdominal aorta is displaced at the level of the adrenal gland, contralateral to the mass, it can be said that the diagnosis is neuroblastoma, whereas abdominal aorta displacement occurring at other abdominal levels has a positive predictive value for neuroblastoma of approximately 85%.

Keywords: Tomography, X-ray computed; Magnetic resonance imaging; Neuroblastoma; Aorta, abdominal; Pediatrics.

Gastrostomy is indicated for patients with conditions that do not allow adequate oral nutrition. To reduce the morbidity and costs associated with the procedure, there is a trend toward the use of percutaneous gastrostomy, guided by endoscopy, fluoroscopy, or, most recently, computed tomography. The purpose of this paper was to review the computed tomography-guided gastrostomy procedure, as well as the indications for its use and the potential complications.

Keywords: Gastrostomy; Radiology, interventional; Tomography, X-ray computed.

Interventional radiology has been constantly developing in terms of the techniques, materials, and methods of intervention. It interacts with all areas of medicine, always with the ultimate goal of ensuring the well-being of patients. Advances in imaging techniques, especially in the last two decades, have led to a paradigm shift in the field of urological imaging interventions. Many urologic diseases that were previously treated only surgically can now be effectively managed using minimally invasive image-guided techniques, often with shorter hospital stays and requiring only local anesthesia or conscious sedation.

Keywords: Radiology, interventional; Urology; Fluoroscopy; Tomography, X-ray computed; Ultrasonography; Magnetic resonance imaging.

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.

The image-guided gastrostomy techniques, as transoral and transabdominal, can be performed when there is a failure of the endoscopic procedure or in some specific clinical scenarios. This pictorial essay intends to show the percutaneous gastrostomy techniques, indications, technical approaches, post-procedure care, and complications.

Keywords: Gastrostomy; Radiology, interventional; Fluoroscopy; Tomography, X-ray computed.