February 26, 2026 Magnetic resonance imaging exams are based on magnetic fields and radio waves and analyze the behavior of hydrogen atoms in body tissues to obtain high‑quality, high‑resolution images. They are painless, non‑invasive imaging tests with a well‑established safety profile. They do not use ionizing radiation, unlike X‑rays or computed tomography. Cardiac MRI and its indications Cardiac MRI allows the heart to be studied in great detail. It evaluates the heart’s anatomy, function and perfusion, and analyses the myocardium (heart muscle), identifying changes such as fibrosis, inflammation and necrosis. It is a fundamental exam for diagnosis, treatment planning and follow‑up of various cardiac diseases , including: Heart failure; Cardiomyopathies; Valvular heart disease; Congenital heart disease; Myocardial ischemia; Post‑infarction sequelae; It is also indicated in the investigation of chest pain, arrhythmias or other cardiac symptoms whose cause requires clarification. How a cardiac MRI is performed and how long it takes Cardiac MRI is performed with the patient lying on their back on a table that slides into the scanner. In most cases, a gadolinium‑based contrast agent is required. This contrast, which helps to better distinguish different structures and tissues, is administered intravenously and is generally safe and well tolerated. Depending on the objectives or findings during the exam, stress induction may also be needed with administration of a specific medication to assess the heart functional response under increased workload. Remaining still during the exam is essential to obtain images of adequate quality. At times, the patient may be asked to briefly hold your breath. A cardiac MRI usually takes between 30 and 90 minutes . Throughout the procedure, continuous monitoring of the patient’s hemodynamic and respiratory parameters is ensured by the clinical team, which includes physicians, nurses and image technicians, guaranteeing the safety of the exam. The analysis of the images and preparation of the final report is usually carried out by radiologists and cardiologists with specialized training in cardiac imaging, who work together to ensure optimal correlation between clinical and imaging data. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
