Dispositivos cardíacos implantables y uso de resonancia magnética / Cardiac implantable devices and use of magnetic resonance / Dispositivos cardíacos implantáveis e utilização da ressonância magnética

El uso de la resonancia magnética (RM) en las distintas áreas de la medicina se ha expandido de manera significativa y de forma diaria se solicitan numerosos estudios. El hecho de que los resonadores pueden interaccionar con algunos objetos ha llevado a que históricamente se les niegue la realización de este estudio a pacientes portadores de dispositivos cardíacos porque se entiende que existen contraindicaciones absolutas. El avance de la tecnología de los dispositivos y la creciente evidencia publicada han cambiado este concepto. Nos proponemos revisar los mecanismos por los cuales un dispositivo implantable puede interactuar con el resonador y las implicancias clínicas que esto podría tener si las hubiera. La mayoría de los pacientes portadores de dispositivos cardíacos de estimulación podrán realizarse una RM, pero para que este procedimiento sea seguro es importante conocer las características y el tipo específico de dispositivo implantado. Proponemos finalmente puntos clave y algoritmos para tener en cuenta para el manejo adecuado de estos pacientes.

The use of magnetic resonance imaging (MRI) in different areas of medicine has expanded significantly and numerous procedures are indicated daily. The fact that resonators could interact with some objects has historically led to patients with cardiac devices being denied an MRI on the understanding that they suppose an absolute contraindication. Advances in device technology and the increasing evidence have changed this concept. We intend to review the mechanisms by which an implantable device could interact with the resonator and the clinical implications that this could have if any. Most patients will be able to undergo these studies, but to determine the safety of performing an MRI it is important to know the characteristics and specific type of implanted device. Finally, we provide key points and algorithms to take into account for these patients.

O uso da ressonância magnética em diferentes áreas da medicina tem se expandido significativamente e inúmeros exames são indicados diariamente. A possibilidade de que os ressonadores interajam com alguns objetos historicamente levou os pacientes com dispositivos cardíacos a terem a ressonância magnética negada por entender que existem contraindicações absolutas. Os avanços na tecnologia de dispositivos e o aumento das evidências publicadas mudaram esse conceito. Pretendemos revisar os mecanismos pelos quais um dispositivo implantável pode interagir com o ressonador e as implicações clínicas que isso pode ter, se houver. A grande maioria dos pacientes poderá se submeter a esses estudos, mas para determinar a segurança de realizar uma ressonância magnética é importante conhecer as características e o tipo específico de dispositivo implantado. Por fim, propomos pontos e algoritmos para a gestão dos pacientes.

The role of the magnetic resonance imaging safety supervisor: what we should know? / El papel del supervisor de seguridad de imágenes de resonancia magnética: ¿qué debemos saber?

The increasing attention that is given to the protection of health professionals and patients has stimulated researchers and organizations to create alternatives to improve safety practices in health services, including in the Magnetic Resonance Imaging (MRI) environment. However, this theme still needs to be further explored in the MRI field. This paper aims to review the current literature, explore the approach to the MRI Safety Supervisor, to describe the role of the MRI Safety Supervisor and how it could serve as an agent to enhance the safety of health professionals and patients in the MRI environment. To achieve this, a narrative literature review was carried out in the electronic databases: ScienceDirect, PubMed, Scielo and Google Scholar, using as inclusion criteria, articles published in Portuguese and English between the years 2008 to 2019. The articles were filtered according to relevant aspects, such as authorship, title, year of publication, objectives, methodology and main results. Lastly, it considered aspects related to adverse events, international and national regulations on security and safety management in the MRI sector. Nevertheless, in the search for actions that effectively mitigate risks on this modality, it was observed that studies on the MRI Safety Supervisor are scarce, which reinforce the need for further studies on this matter.

Localización infrecuente del quiste hidatídico suprarrenal primario / Uncommon location of the primary adrenal hydatid cyst

El quiste hidatídico suprarrenal primario es una patología muy infrecuente por su localización y se encuentra en este órgano en menos del 0,5 por ciento de los casos, incluso en países con presencia endémica del Echinococcus. La mayoría de los quistes hidatídicos suprarrenales son asintomáticos, siendo el diagnóstico un hallazgo incidental. Las pruebas serológicas para el diagnóstico pueden ser negativas en muchos casos y el tratamiento es en su mayoría quirúrgico, con múltiples vías de abordaje. Es una patología poco común; el diagnóstico, manejo, tratamiento y vías de abordaje no se encuentran aún muy establecidos. Con este artículo tratamos de realizar un acercamiento más certero en cuanto a estos aspectos(AU)

The primary adrenal hydatid cyst is a very rare disease for its location and it is found in less than 0.5 percent of the cases, even in countries with endemic presence of Echinococcus. Most adrenal hydatid cysts are asymptomatic, and the diagnosis is an incidental finding, the serological tests for the diagnosis are negative in many cases and the treatment is mostly surgical, with multiple surgical approaches. It is a rare pathology whose diagnosis, management, treatment and surgical approaches are not yet well established. This article was intended to address these aspects in a more accurate way(AU)

Magnetic Field Interactions of Copper-Containing Intrauterine Devices in 3.0-Tesla Magnetic Resonance Imaging: In Vivo Study

OBJECTIVE: An ex vivo study found a copper-containing intrauterine device (IUD) to be safe for women undergoing an MRI examination at a 3.0-T field. No significant artifacts caused by the metallic implant were detected. However, there are still no in vivo data about these concerns. The aim of this study was to evaluate 3.0-T magnetic field interactions of copper-containing IUDs in vivo. MATERIALS AND METHODS: Magnetic field interactions and potential adverse events were evaluated in 33 women using a questionnaire-based telephone survey. Two experienced radiologists performed artifact evaluation on MR images of the pelvis. RESULTS: Eighteen patients were eligible for the survey. One patient reported a dislocation of the IUD after the MR examination. All other patients had no signs of field interactions. No IUD-related artifacts were found. CONCLUSION: MRI at 3.0-T is possible for women with copper-containing IUDs. However, consulting a gynecologist to check the correct position of the IUD and exclude complications after an MR examination is highly recommended. High-quality clinical imaging of the female pelvis can be performed without a loss in image quality.

Early Experience of Pre- and Post-Contrast 7.0T MRI in Brain Tumors

We investigated the safety and clinical applicability of 7.0 Tesla (T) brain magnetic resonance imaging (MRI) in patients with brain tumors. Twenty-four patients with intraaxial or extraaxial brain tumors were enrolled in this study. 7.0T MRIs of T2*-weighted axial and T1-weighted coronal or sagittal images were obtained and compared with 1.5T brain MRIs. The T2*-weighted images from 7.0T brain MRI revealed detailed microvasculature and the internal contents of supratentorial brain tumors better than that of 1.5T brain MRI. For brain tumors located in parasellar areas or areas adjacent to major cerebral vessels, flow-related artifacts were exaggerated in the 7.0T brain MRIs. For brain tumors adjacent to the skull base, susceptibility artifacts in the interfacing areas of the paranasal sinus and skull base hampered the aquisition of detailed images and information on brain tumors in the 7.0T brain MRIs. This study shows that 7.0T brain MRI can provide detailed information on the intratumoral components and margins in supratentorial brain tumors. Further studies are needed to develop refined MRI protocols for better images of brain tumors located in the skull base, parasellar, and adjacent major cerebrovascular structures.

histological study on the effect of repeated exposure to MRI lumber spine protocol on Swiss Albino Rats

The study was carried out to investigate the bio-effects of repeated exposure to high intensity electromagnetic fields [EMFs] used in the medical field. An in vivo study was done by using repeated exposure of Swiss Albino Rats to MRI machine [1.5 Tesla, 64.85MHZ]. The rats were exposed to combination of both magnetic fields and radio frequency electromagnetic fields, daily for 30 minutes, 1 hour, three times per week for 2 weeks. The exposure was under the protocol of lumber spine scanning. A histological study was conducted on some of the rats' vital organs and rats' body weight to detect any cellular effects. A significant reduction in the rats body weights gain was detected. The histological findings were severe hemorrhage, necrosis in cardiac muscles, kidney, liver, dilatation of blood vessels in bone marrow, bone cartilage atrophy. No histological changes were detected in all the organs of the control group, in addition there is no reduction in their body weight. The above results showed that there is a big doubt about the safety of MRI techniques as far as the results and the literature review indicates severe effects on some vital organs. Therefore the safety considerations as repeated exposure to the MRI techniques must be reviewed and needs to be clearer

No association between gadolinium-based contrast agents and development of nephrogenic systemic fibrosis: a case study

Nephrogenic systemic fibrosis [NSF], previously known as nephrogenic fibrosing dermopathy, is an emerging systemic fibrosing disorder that develops in the setting of renal insufficiency. Nephrogenic fibrosing dermopathy [NFD] is a fibrosing condition of the skin which shows an increased number of dendritic cells, fibroblasts and thickened collagen fibers resembling scleromyxedema. It is characterized by indurated plaques mainly on the extremities and the absence of paraproteinemia. Although the exact causes of NSF have not been established, evidence suggests an association between gadoliniumbased contrast agents and development of nephrogenic systemic fibrosis. We report a patient who was under dialysis and developed NSF but she never did MRI

The posterior reversible encephalopathy syndrome.

The posterior/potentially reversible encephalopathy syndrome is a unique syndrome encountered commonly in hypertensive encephalopathy. A 13-year-old boy presented with of intermittent high grade fever, throbbing headache and non-projective vomiting for 5 days. The patient had a blood pressure of 120/80 mmHg but fundoscopy documented grade 3 hypertensive retinopathy. The patient improved symptomatically following conservative management. However, on the 5(th) post-admission day headache reappeared, and blood pressure measured at that time was 240/120 mmHg. Neuroimaging suggested white matter abnormalities. Search for the etiology of secondary hypertension led to the diagnosis of pheochromocytoma. Repeated MRI after successful surgical excision of the tumor patient showed reversal of white matter abnormalities. Reversible leucoencephalopathy due to pheochromocytoma have not been documented in literature previously.

Ressonância magnética em paciente portadora de marcapasso / Magnetic resonance imaging in a patient with pacemaker

Mulher de 24 anos, portadora de marcapasso dupla câmara, com hipertensão intracraniana e perda visual progressiva, e vários exames de tomografia de crânio inconclusivos. Foi submetida à Ressonância Magnética, mesmo sendo este método diagnóstico uma contra-indicação absoluta em portadores de marcapasso.

Magnetic resonance imaging: bioeffects and safety concerns.

Magnetic resonance imaging (MRI) is the state-of-the-art noninvasive imaging modality in clinical diagnosis. During MRI examination, the patient is exposed to three different forms of electromagnetic radiation: (i) a static magnetic field, (ii) gradient magnetic fields, and (iii) radiofrequency (RF) fields. Each of these may cause significant adverse bioeffects if applied at sufficiently high exposure levels. This article describes in some detail the areas of health concern for both the patient and the health practitioner with respect to the use of clinical MRI, in addition to describing the potential bioeffects of electromagnetic radiations used in this sophisticated imaging modality.

Ressonância magnética da sela turca: avaliaçäo de pacientes com galactorréia, amenorréia e hiperprolactinemia / Magnetic ressonance imaging of sella turcica: evalution of patients with galactorthea, amenorhea and hyperprolactinemia

Resumo: Selecionamos 135 casos de pacientes que realizaram exame de ressonância magnética da sala turca, no período de setembro de 1991 a agosto de 1996, e que apresentavam galactorréia (G), amenorréia (A) e hiperprolactemia, (H), isoladamente ou em associaçäo. Esses pacientes foram divididos em sete grupos, com base na presença desses sinais e sintomas. Todos os exames foram feitos em clínica privada na cidade do Rio de Janeiro. Correlacionamos os pacientes com os achados de ressônancia magnética e encontramos57 casos de microadenomas, 31 exames normais, 22 macroadenomas, 11 hiperplasias, 7 selas vazias e 7 casos incluídos em "outros achados". O microadenoma predominou nos grupos 1 (GAH), 2(GH), 3(HA) E 5(H), ou seja em todos os que apresentaram hiperprolactenemia. Nos macroadenomas a presença de hipersinal nas sequencias ponderadas em T1 é indicado de apoplexia hipofisária com sangramento intramural. Concluindo, a ressonância magnética é excelente método na avaliaçäo de pacientes com alteraçöes no eixo hipotálamo-hipofisário.