OBJECTIVE: To obtain mean angulation values for renal hila in relation to the horizontal plane traced over the right and left spinal erector muscles, considering the center of the lumbar vertebral spine as a parameter for measuring the renal hila angles. MATERIALS AND METHODS: The authors have analyzed 250 abdominal computed tomography studies of both male and female healthy individuals (128 men with mean age 52.45 ± 17.42 years, and 122 women with mean age 54.39 ± 18.27 years), corresponding to 500 renal hila evaluated. The mean angulation of each hilum in relation to the horizontal plane was obtained taking acute angles into consideration. RESULTS: The comparative study have not found any statistically significant difference in acute angles of renal hila between male and female individuals. The statistical analysis demonstrated limits of 40.40° and 44.54° for mean right hilum angulation and 39.91° and 43.23° for mean left hilum angulation, with a confidence interval of 95%. CONCLUSION: Renal hila present similar angulation independently of sex. Higher angulation values correspond to hyper-rotation or excessive rotation, and lower angulation values, to incomplete or reverse rotation.

Keywords: Congenital anomalies, Renal pelvis, Urinary tract, Helical computed tomography

OBJECTIVE: To propose a model to standardize computed tomography reports on abdominal aortic aneurysms. MATERIALS AND METHODS: Interviews were carried out with members of Vascular Surgery Division of our institution, in the period between April and October 2004, aiming at developing a standardized model of computed tomography reports on abdominal aortic aneurysms. Based on this model, a questionnaire was elaborated and sent to other nine surgeons, all of them experienced in the field of abdominal aortic surgery. The questionnaires response rate was 55.5% (5/9). RESULTS: The most frequently mentioned parameters of interest for evaluation of abdominal aortic aneurysms were: maximum diameter of proximal aortic neck, proximal aortic neck length to lower renal arteries, shape of proximal aortic neck, maximum diameter of the aneurysm and diameter of the common iliac arteries. These data allowed the development of a proposal for a model to standardize computed tomography reports. CONCLUSION: A model for standardized tomographic analysis of abdominal aortic aneurysms has met vascular surgeons' needs for following-up patients and planning their treatment.

Keywords: Aorta, Aneurysm, Computed tomography

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 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

Callosal dysgenesis is a malformation of the corpus callosum with origins in the embryogenesis of the telencephalon. We reviewed the computed tomography and magnetic resonance imaging findings of 11 patients with callosal dysgenesis and one patient with normal corpus callosum associated with a lipoma. The patients were divided into three distinct groups: total agenesis (three patients), partial agenesis (six patients) and hypoplasia (two patients). Associated abnormalities were observed in nine patients, including Chiari II malformation (one patient), schizencephaly (one patient), interhemispheric cyst (two patients), Dandy-Walker cyst (one patient), nodular heterotopy (one patient) and lipoma of the corpus callosum (four patients). This paper presents a review that may contribute to the diagnosis of these disorders.

Keywords: Dysgenesis of the corpus callosum, Brain malformation, Developmental anomalies, Lipoma of the corpus callosum

Aberrant internal carotid artery is an anomaly of the embryogenesis of the vertical portion of the internal carotid artery, characterized by projection of the internal carotid artery into the middle ear, adjacent to the cochlear promontory. The authors report a case of a patient in which contrast-enhanced computed tomography and magnetic resonance angiography examinations were decisive to adequately characterize the anomaly, thus avoiding instrumental or surgical intervention, which could bear fatal consequences.

Keywords: Vascular malformation, Internal carotid artery, Congenital anomalies, Temporal bone

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.

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: To evaluate the accuracy in the detection of abdominal aortic calcification by densitometry as compared with lateral spine radiography. MATERIALS AND METHODS: Study comprising 80 individuals, 50 of them with abdominal aortic calcification and 30 without calcification. Densitometry was performed once for each participant, with the patient in right lateral decubitus position. RESULTS:Both groups were similar in terms of age range and body mass index - mean age of 74.56 ± 10.55 years and 68.40 ± 10.80 years and mean body mass index of 28.94 ± 6.06 kg/m², and 26.84 ± 4.11 kg/m², respectively for the individuals with abdominal aortic calcification and for the individuals without calcification. A statistical comparison between densitometry and radiography demonstrates similar performances of the two methods in the detection of abdominal aortic calcification, with 100% specificity and positive predictive value, 94% sensitivity, 90.9% negative predictive value, and 96.3% accuracy. Qualitative equivalence in diagnosis was demonstrated by kappa correlation index of 0.922. CONCLUSION: The results obtained by radiography and densitometry were statistically equivalent, which endorses the indication of densitometry for investigating abdominal aortic calcification.

Keywords: Atherosclerosis; Abdominal aorta; Densitometry.

The authors report the case of an elderly woman assessed for dyspnea and right costal margin pain, whose chest radiography demonstrated opacity simulating pulmonary lesion, and computed tomography revealed the vascular origin of the condition. Acute aortic syndrome due to ruptured atheromatous plaque penetrating through the elastic lamina in association with aortic hematoma and aneurysm is a relevant differential diagnosis to be considered in these cases.

Keywords: Aorta; Aortic arch; Computed tomography.

Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease.

Keywords: Computed tomography; Thoracic aorta; Aortic diseases; Atherosclerosis; Cardiovascular surgery.

OBJECTIVE: To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. MATERIALS AND METHODS: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. RESULTS: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. CONCLUSION: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

Keywords: Aneurysm; Aorta, abdominal; Endovascular procedures; Ultrasonography; Angiography/methods.

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.

Coronary arteries originating from the contralateral (noncoronary) sinus and having an interarterial course, in which they run from the ascending aorta to the pulmonary trunk, is a potentially fatal anomaly. Computed tomography (CT) angiography facilitates the recognition and therapeutic planning of such anomalies because of its ability to acquire high-resolution images of the entire course of the coronary artery, as well as of the accompanying atherosclerotic involvement. The right coronary artery originating from the left coronary sinus is the most prevalent anomaly of this type and usually implies a better prognosis, the interarterial course being classified as "high" or "low", depending on whether it is above or below the level of the pulmonary valve, with consequent stratification of the risk and the treatment. However, it is known that there is a high risk of sudden death among patients with a left coronary artery of anomalous origin from the right sinus. In such cases, surgical treatment is recommended, regardless of whether there are symptoms or evidence of ischemia. Given the importance of those aspects, which can be identified on CT of the chest or CT angiography of the aorta, this pictorial essay aims to illustrate such anomalies to facilitate their recognition and description by radiologists who are not specialists in cardiac imaging.

Keywords: Coronary vessel anomalies/complications; Coronary vessel anomalies/diagnostic imaging; Aorta, thoracic/abnormalities; Aorta, thoracic/diagnostic 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.