Clóvis Simão Trad

Magnetic resonance imaging of scrotal diseases: when it makes the difference

OBJECTIVES To investigate the utility of magnetic resonance imaging (MRI) after inconclusive sonography in the evaluation of scrotal disease. METHODS From 1993 to 1999, 622 patients underwent ultrasonography (US) with state-of-the-art equipment to evaluate scrotal diseases. Twenty-six patients, two with bilateral and distinct diseases (age range 1--63 years, mean 33), had an inconclusive sonogram and were sent for MRI. The MRI results were compared with previous US reports and with the final diagnosis. RESULTS MRI yielded additional and correct information (compared with US), coincident with the final diagnosis in 23 cases (82.1%). In regard to lesions suspected of malignancy at US (17 cases), MRI had a great concordance with the final diagnosis and was statistically significant (P <0.002, kappa test). CONCLUSIONS The results of our study indicate that MRI could help elucidate scrotal dilemmas found at US, although the small percentage of inconclusive sonograms confirms this technique as the first choice when imaging is required in scrotal diseases.

Revisão radiológica de 173 casos consecutivos de paracoccidioidomicose

OBJECTIVE: To determine the incidence of most significant radiological findings of paracoccidioidomycosis and to verify its possible variants. MATERIALS AND METHODS: One hundred and seventy-three cases of paracoccidioidomycosis presented between 1970 and 1980 were reviewed, including their radiological workup reanalysis by at least two experienced radiologists. RESULTS: Ninety-four cases were pulmonary only and 38 were pulmonary associated with ganglial, visceral and osseous lesions or in association with tuberculosis. There was no pulmonary involvement in 41 cases, presenting small bowel, viscera, bone lesions, or a combination of these. Most significant radiological findings in cases of pulmonary involvement were bilateral, diffuse reticular and nodular interstitial infiltrate, followed by the diffuse bilateral alveolar form. Visceral and gastrointestinal tract lesions presented predominantly with liver, jejunum and ileum involvement. Lymph nodal involvement was predominantly diffuse, abdominal or peripheral. In bones, osteolytic lesions affected predominantly long bones and clavicle. CONCLUSION: Paracoccidioidomycosis is a granulomatous disease commonly found in Brazil, primarily affecting lungs, caused by inhalation of fungus spores. Other rare or less frequent forms of the disease should be taken into consideration for differential diagnosis.

Optimization of standard patient radiographic images for chest, skull and pelvis exams in conventional x-ray equipment

Optimized radiographic techniques for clinical images of chest, skull and pelvis using conventional single-phase, three-phase and high-frequency x-ray units for a standard patient have been developed. Optimization of image contrast and optical density was obtained by using a homogeneous phantom (PEP) and an Anderson Rando anthropomorphic phantom. Image quality was evaluated by nine radiologists in independent analyses, leading to the choice of the optimized technique. A course of action to implement and validate these techniques in other radiographic systems has also been introduced. A realistic-analytic phantom (RAP) was constructed to certify the validation process. The optimized radiographic technique was implemented in the routine of our home hospital radiodiagnostic routine, enabling a reduction in patient doses around 25, 14 and 72%, respectively, for chest, skull and pelvis exams when compared with the previously used techniques. In addition, a corresponding reduction in the x-ray tube load of 68, 14 and 62% for the respective mentioned exams has been observed. In conclusion, implemented optimal techniques can lead to a reduction in the rate of film rejection, thus contributing to a better risk-benefit relationship for the patient and cost-benefit for the radiodiagnostic facility.

Ressonância magnética do tórax: Aplicações tradicionais e novas, com ênfase em pneumologia

The objective of the present review study was to present the principal applications of magnetic resonance imaging (MRI) of the chest, including the description of new techniques. Over the past decade, this method has evolved considerably because of the development of new equipment, including the simultaneous interconnection of phased-array multiple radiofrequency receiver coils and remote control of the table movement, in addition to faster techniques of image acquisition, such as parallel imaging and partial Fourier acquisitions, as well as the introduction of new contrast agents. All of these advances have allowed MRI to gain ground in the study of various pathologies of the chest, including lung diseases. Currently, MRI is considered the modality of choice for the evaluation of lesions in the mediastinum and in the chest wall, as well as of superior sulcus tumors. However, it can also facilitate the diagnosis of lung, pleural, and cardiac diseases, as well as of those related to the pulmonary vasculature. Pulmonary MRI angiography can be used in order to evaluate various pulmonary vascular diseases, and it has played an ever greater role in the study of thromboembolism. Because cardiac MRI allows morphological and functional assessment in the same test, it has also become part of the clinical routine in the evaluation of various cardiac diseases. Finally, the role of MRI has been extended to the identification and characterization of pulmonary nodules, the evaluation of airway diseases, and the characterization of pleural effusion.

Magnetization transfer ratio as a predictor of malignancy in breast lesions: preliminary results.

MRI is an important tool for investigating breast cancer. Although recognized as the method of choice for screening high‐risk patients, and for other indications the role of MRI for lesion characterization remains controversial. Recently some authors have advocated the use of morphologic and postcontrast features for this purpose. Quantitative breast MRI techniques have not been applied extensively in breast diseases. Magnetization transfer (MT) is a quantitative MR technique commonly used to investigate neurological diseases. In breast diseases the use of MT has been limited to improving visualization of areas of enhancement in postcontrast images. The purpose of this study was to evaluate the feasibility and utility of MT in discriminating benign from malignant breast lesions. Fifty‐two lesions, BIRADS 4 and 5, from 49 patients, were prospectively evaluated using the MT ratio (MTR). Patients were divided into two groups: benign and malignant lesions. The MTR of fat, pectoralis major muscle, fibroglandular tissue, and breast lesions were calculated. A statistically significant difference was found between MTR from benign and malignant lesions (P < 0.001). Preliminary results suggest that MT can be used to evaluate breast lesions. Further studies are necessary to better define the utility and applicability of this technique. Magn Reson Med 59:1030–1034, 2008.

Erros comuns de interpretação de ressonância magnética de joelho: como reconhecê-los e evitá-los

A ressonância magnetica tornou-se o metodo de imagem de escolha para o estudo das articulacoes, devido a sua grande diferenciacao tecidual, resolucao de estruturas, imagens em multiplos planos e estudos dinâmicos (cinematicos). Talvez a articulacao do joelho seja o exame de ressonância magnetica mais solicitado na area osteoarticular. O conhecimento detalhado da anatomia, fisiologia e aspecto de imagenologia da regiao permite uma interpretacao adequada dos exames. No entanto, por vezes, estruturas anatomicas que so aparecem esporadicamente, variantes anatomicas e artefatos podem causar erros de interpretacao desses exames. O presente artigo tem por finalidade discutir as causas mais frequentes de erros de interpretacao, suas causas e como evita-los.

Ressonância magnética na avaliação das reações periosteais

The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods.

Caracterização de lesões intersticiais de pulmão em radiograma de tórax utilizando análise local de textura

OBJECTIVE: To characterize interstitial lesions in anterior-posterior chest X-rays based on the analysis of textural statistical features that allow the detection of abnormalities with diffuse pattern. MATERIALS AND METHODS: Image analysis begins with the semiautomatic segmentation of the lungs, marking the external contour of the lung manually followed by an automatic division of each lung in six regions. The data base of images used in this study consisted of 482 regions obtained from examinations in which lesions were detected and 324 regions from normal examinations. Textural features were automatically extracted from each area and the selection of the best set of features was made based on the Jeffries-Matusita distance. The regions were classified as normal or suspected using the k nearest-neighbor method and half-half, and cross-correlation methodologies were used for training the classifier. RESULTS: Results were assessed based on the value of the area under the ROC (receiver operating characteristic) curve that indicates an ideal response for an area equal to 1. The results showed an area under the ROC curve (AZ) of 0.887, sensitivity of 0.804, and specificity of 0.793. CONCLUSION: These results indicate that the implemented system has a good potential for computer-aided diagnosis of interstitial lung lesions.

Congenital inferior vena cava anomalies: a review of findings at multidetector computed tomography and magnetic resonance imaging

Inferior vena cava anomalies are rare, occurring in up to 8.7% of the population, as left renal vein anomalies are considered. The inferior vena cava develops from the sixth to the eighth gestational weeks, originating from three paired embryonic veins, namely the subcardinal, supracardinal and postcardinal veins. This complex ontogenesis of the inferior vena cava, with multiple anastomoses between the pairs of embryonic veins, leads to a number of anatomic variations in the venous return from the abdomen and lower limbs. Some of such variations have significant clinical and surgical implications related to other cardiovascular anomalies and in some cases associated with venous thrombosis of lower limbs, particularly in young adults. The authors reviewed images of ten patients with inferior vena cava anomalies, three of them with deep venous thrombosis. The authors highlight the major findings of inferior vena cava anomalies at multidetector computed tomography and magnetic resonance imaging, correlating them the embryonic development and demonstrating the main alternative pathways for venous drainage. The knowledge on the inferior vena cava anomalies is critical in the assessment of abdominal images to avoid misdiagnosis and to indicate the possibility of associated anomalies, besides clinical and surgical implications.

Atypical presentation of Prader-Willi syndrome with Klinefelter (XXY karytype) and craniosynostosis

Prader-Willi syndrome is a mental retardation genetic disorder also characterized by hypogonadism, hyperphagia and obesity. We report on a four-years-old boy, born to consanguineous parents, with uncommon co-occurrence of Prader-Willi syndrome, 47,XXY karyotype (Klinefelter syndrome) and coronal craniosynostosis. These are different unrelated conditions and it was not described before in the same patient to the best of our knowledge.