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

Intracranial aneurysm rupture is a rare cause of morbidity and mortality in pregnancy, with a few endovascular treatment cases reported in the literature. In this study we report a case of a 37-year-old woman in the eighth gestational month presenting tomographic findings and clinical manifestations compatible with subarachnoid hemorrhage (Hunt Hess III) due to rupture of an ophthalmic segment aneurysm in the internal carotid artery.

Keywords: Cerebral aneurysm, Subarachnoid hemorrhage, Pregnancy, Endovascular embolization

OBJECTIVE: To determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. MATERIALS AND METHODS: Retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. RESULTS: Main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. CONCLUSION: Cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates.

Keywords: Magnetic resonance, Cerebral venous thrombosis, Cerebral infarct, Intracranial hemorrhage

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

Objetivo: A principal utilidade da tomografia por emissão de pósitrons com 18-fluordeoxiglicose (FDG-PET) está no estadiamento do câncer de pulmão. Porém, ela também pode ser utilizada para diferenciar lesões pulmonares indeterminadas, mas seu impacto na ressecção cirúrgica de lesões benignas é desconhecido. O objetivo deste estudo foi comparar a prevalência de lesões benignas em toracotomias feitas por suspeição de câncer de pulmão, antes e após a introdução do FDG-PET, em um centro de referência de cirurgia torácica. Materiais e Métodos: Os autores analisaram, prospectivamente, uma base de dados cirúrgicos de todos os pacientes consecutivos submetidos a toracotomia por câncer de pulmão suspeito ou comprovado e compararam a prevalência de lesões benignas em dois grupos ao longo de dois anos consecutivos, respectivamente antes (grupo I) e depois (grupo II) da introdução da FDG-PET. Resultados: Ressecção cirúrgica foi feita em 1.233 pacientes durante o período do estudo. A prevalência de lesões benignas na cirurgia nos grupos I e II foi similar (44/626 e 41/607, ambas correspondendo a 7%), e também no grupo II, entre aqueles submetidos a FDG-PET e os restantes (21/301 e 20/306 respectivamente, ambos correspondendo a 7%). No grupo II, dos 21 pacientes com lesões benignas submetidos a FDG-PET, 19 tiveram um estudo falso-positivo (valor médio padrão de captação 5.3 [faixa 2.6–12.7]). Desses, respectivamente 13 e 4 pacientes tiveram broncoscopia não diagnóstica e biópsia transtorácica percutânea de pulmão antes da toracotomia. Não houve diferença na proporção de lesões benignas diferentes ressecadas entre o grupo I e aqueles submetidos a FDG-PET no grupo II. Conclusão: A introdução da FDG-PET não alterou a proporção de pacientes submetidos a toracotomia por lesões benignas, principalmente devido à avidez pelo isótopo de algumas lesões não malignas. Tais resultados falsos-positivos devem ser considerados nos casos em que se contempla a possibilidade de ressecção cirúrgica em pacientes com câncer de pulmão não confirmado.

Keywords: Tomografia por emissão de pósitrons; Tomografia computadorizada; Pulmão – lesões benignas ou congênitas; Câncer de pulmão – diagnóstico e estadiamento; Câncer de pulmão – cirurgia.

Neurocysticercosis is a disease characterized by the involvement of the central nervous system by the intermediate larval stage of the parasite Taenia solium. The larva degeneration process and the inflammatory reaction of the body cause clinical symptoms. The authors report a case of clinical and radiological reactivation of nodular calcified neurocysticercosis in a patient who was asymptomatic for more than 20 years. Antiparasitic treatment showed a good response.

Keywords: Neurocysticercosis; Reactivation; Cerebral calcifications.

OBJETIVO: Avaliar a completude das fissuras, resposta radiológica ao tratamento e análise quantitativa por TC (AQTC) em população de pacientes com enfisema grave submetidos ao implante de valvas endobrônquicas (VEB). MATERIAIS E MÉTODOS: Foram estudados exames de TC multidetectores de 29 pacientes, realizados com protocolo de baixo dose, cortes finos, sem contraste. Dois radiologistas revisaram, retrospectivamente, os exames em consenso. A completude das fissuras foi estimada em escala de 5% e a resposta radiológica (atelectasia/perda volumétrica do lobo alvo) foi avaliada. AQTC foi realizada nos exames pré e pós-tratamento utilizando programa completamente automático. RESULTADOS: Resposta radiológica positiva foi vista em 16/29 pacientes. Os 13 pacientes sem resposta à TC apresentavam fissuras incompletas e completude média das fissuras obliquas de 72,8%, contra 88,3% no outro grupo. Os resultados mais significativos da AQTC mostraram redução do volume pulmonar (VP) total (média de 542 ml), VP tratado (700 ml) e volume de enfisema (331,4 ml) no grupo com resposta positiva, que também apresentou melhora nos testes funcionais. CONCLUSÃO: O benefício das VEB é maior em pacientes com fissuras completas e que desenvolvem atelectasia lobar. Nos pacientes sem resposta radiológica encontramos maior prevalência de fissuras incompletas e grau de incompletude das fissuras. Nossa AQTC automática detectou as alterações pós-tratamento, principalmente considerado a análise do pulmão tratado.

Keywords: Enfisema; Terapia de colapso pulmonar; Tomografia computadorizada.

OBJECTIVE: The present study was aimed at estimating the doses received by physicians and patients during cerebral angiography procedures in a public hospital of Recife, PE, Brazil. MATERIALS AND METHODS: The study sample included 158 adult patients, and during the procedures the following parameters were evaluated: exposure parameters (kV, mAs), number of acquired images, reference air kerma value (K_a,r) and air kerma-area product (P_KA). Additionally, the physicians involved in the procedures were evaluated as for absorbed dose in the eyes, thyroid, chest, hands and feet. RESULTS: The results demonstrated that the doses to the patients' eyes region were relatively close to the threshold for cataract occurrence. As regards the physicians, the average effective dose was 2.6 µSv, and the highest effective dose recorded was 16 µSv. CONCLUSION: Depending on the number of procedures, the doses received by the physicians may exceed the annual dose limit for the crystalline lenses (20 mSv) established by national and international standards. It is important to note that the high doses received by the physicians are due to the lack of radiation protection equipment and accessories, such as leaded curtains, screens and protective goggles.

Keywords: Dosimetry; Interventional radiology; Cerebral angiography.

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.

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.

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.

Cerebral venous thrombosis (CVT) is an uncommon condition that is potentially reversible if properly diagnosed and promptly treated. Although CVT can occur at any age, it most commonly affects neonates and young adults. Clinical diagnosis is difficult because the clinical manifestations of CVT are nonspecific, including headache, seizures, decreased level of consciousness, and focal neurologic deficits. Therefore, imaging is crucial for the diagnosis. Radiologists should be able to identify the findings of CVT and to recognize potential imaging pitfalls that may lead to misdiagnosis. Thus, the appropriate treatment (anticoagulation therapy) can be started early, thereby avoiding complications and unfavorable outcomes.

Keywords: Intracranial venous thrombosis/diagnostic imaging; Tomography, X-ray computed; Magnetic resonance imaging.

Moyamoya disease is a chronic occlusive cerebrovascular disease that is non-inflammatory and non-atherosclerotic. It is characterized by endothelial hyperplasia and fibrosis of the intracranial portion of the carotid artery and its proximal branches, leading to progressive stenosis and occlusion, often clinically manifesting as ischemic or hemorrhagic stroke with high rates of morbidity and mortality. On cerebral angiography, the formation of collateral vessels has the appearance of a puff of smoke (moyamoya in Japanese), which became more conspicuous with the refinement of modern imaging techniques. When there is associated disease, it is known as moyamoya syndrome. Treatments are currently limited, although surgical revascularization may prevent ischemic events and preserve quality of life. In this review, we summarize recent advances in moyamoya disease, covering aspects of epidemiology, etiology, presentation, imaging, and treatment strategies.

Keywords: Moyamoya disease; Cerebrovascular disorders; Intracranial arterial diseases; Cerebral arterial diseases; Cerebral revascularization.

OBJETIVO: Avaliar os padrões tomográficos relacionados aos agentes etiológicos da pneumonia em pacientes durante o primeiro ano após transplante renal. MATERIAIS E MÉTODOS: Foram analisados dados de prontuários de 956 pacientes submetidos a transplante renal, no período de 2013 a 2018, em um centro transplantador renal do nordeste do Brasil. Nos pacientes que desenvolveram pneumonia, os agentes etiológicos foram classificados em bactérias piogênicas, micobactérias, fungos, vírus e pneumonia polimicrobiana, enquanto os padrões tomográficos foram classificados em consolidação, broncopneumonia, pneumonia intersticial e nódulos e massas. Para verificar associação estatística entre micro-organismos e padrões tomográficos, foi utilizado o teste exato de Fisher, com p < 0,001. RESULTADOS: Foram encontrados 101 casos de pneumonia, dos quais 60 (59,4%) tiveram agente etiológico identificado, sendo as bactérias piogênicas as mais frequentes, detectadas em 22 (36,7%) dos casos. Entre os pacientes com agente causal identificado, o padrão tomográfico predominante foi o de nódulos e massas, identificado em 25 (41,7%) casos. Foi observada associação entre bactérias piogênicas e o padrão de consolidação, fungos com nódulos e massas, bem como entre agentes virais e padrão intersticial. CONCLUSÃO: Foi demonstrada associação estatística entre micro-organismos causadores de pneumonia e padrões tomográficos, informação que pode contribuir para o planejamento da terapia de pacientes transplantados renais.

Keywords: Pneumonia; Transplante de rim; Tomografia computadorizada.