A ressonância magnética e seu papel na avaliação das principais patologias fetais extra-cranianas / Magnetic resonance and its role in the evaluation of the main extra-cranial fetal patologies

A ressonância magnética (RM) é um exame não invasivo que, através de interações magnéticas com núcleos de átomos de hidrogênio, produz imagens de segmentos do corpo humano com grande acurácia diagnóstica. Seu potencial de delineamento anatômico, associado com ausência de efeitos deletérios, o torna peça importante para avaliação de mal formações fetais.

Magnetic resonance imaging (MRI) is a non-invasive test that produces images of body parts through interactions with hydrogen atoms core, which present high diagnostic accuray. Its potential capability of anatomical delineation and the lack of biological proven effects turns MRI an option of great potential for the fetal assessment.

Ressonância nuclear magnética cardíaca / Cardiac mri

A Ressonância Nuclear Magnética Cardíaca (RMC) estabeleceu-se como um importante método não invasivo de uma grande quantidade de doenças cardiovasculares. Através de estudos, foi comprovada sua real capacidade como método diagnóstico, sendo hoje padrão ouro para diversas patologias cardíacas. Nessa revisão avaliamos as mais importantes aplicações da RMC assim como suas vantagens e desvantagens.

Intraplaque hemorrhage assessed by high-resolution magnetic resonance imaging and C-reactive protein in carotid atherosclerosis.

BACKGROUND: Carotid intraplaque hemorrhage is a marker of atheroma instability. Noninvasive assessment of bleeding can be performed by high-resolution magnetic resonance imaging (MRI), but its association with inflammatory markers has not been clearly demonstrated. METHODS: We evaluated consecutive carotid endarterectomy patients that underwent high-resolution MRI, independent evaluation of neurologic symptoms, C-reactive protein measurement, and histologic analysis. Intraplaque hemorrhage was determined by the presence of a hyperintense MRI signal (T1-weighted sequence). RESULTS: The study included 70 predominantly male (66%) and hypertensive (89%) patients (89%) aged 66 +/- 9 years old. MR angiography identified 15 patients (21.5%) with stenosis between 50% and 69%, 15 (21.5%) with stenosis between 70% and 90%, and 40 (57%) with stenosis >90%. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 45 subjects (64%). All patients who had had transient ischemic attacks >90 days before the surgery showed a hyperintense signal on MRI (P = .007). Age, gender, traditional cardiovascular risk factors, and history of myocardial infarction or peripheral arterial disease were similar in patients with or without signs of intraplaque bleeding on MRI. There was excellent agreement between acute or recent hemorrhage on histologic and MRI findings (kappa coefficient, 0.91; 95% confidence interval, 0.81 to 1.00). Only one of 45 patients (2%) with a hyperintense signal on MRI did not have acute or recent hemorrhage in the histologic analysis (P < .001). High-sensitivity C-reactive protein levels were similar for different degrees of carotid stenosis as assessed by MR angiography, but they were significantly higher in clinically unstable patients (P = .006) and in those with a positive hyperintense MRI signal (P = .01). In an aggregated analysis of neurologic symptoms and MRI findings, we found a progressive increase of high-sensitivity C-reactive protein levels (P = .02). CONCLUSIONS: Intraplaque hemorrhage evaluated by MRI identified neurologically unstable patients with increased levels of high-sensitivity C-reactive protein regardless of the degree of carotid stenosis.

O uso da ressonância nuclear magnética no diagnóstico de fístulas anais / The use of the magnetic nuclear resonance in the diagnosis of fistula-in-ano

O sucesso do manejo das fístulas anais depende da correta identificação do trajeto fistuloso bem como de sua abertura no canal anal. O uso da ressonância nuclear magnética pode colaborar na avaliação de casos complexos, facilitando a abordagem cirúrgica. Desenvolvemos um estudo prospectivo, avaliando a qualidade das imagens obtidas pela ressonância e comparado-as com os achados cirúrgicos. Foram analisados 22 pacientes tratados no Serviço de Coloproctologia do Hospital São Lucas da PUCRS por fístula anal, tendo sido os mesmos submetidos a ressonância nuclear magnética pré-operatória. Observamos uma sensibilidade de 80por cento no diagnóstico de fístulas anais, com especificidade de 100por cento e valor preditivo positivo de 100por cento. Os achados da ressonância e da cirurgia foram coincidentes em 80por cento dos casos. A ressonância se mostrou um método seguro e útil no diagnóstico de fístulas anais.