Subacute thyroiditis (SAT) is an uncommon, granulomatous, inflammatory thyroid disorder. It usually presents with anterior neck and/or jaw pain, diffusely tender goiter, fever, fatigue, myalgia, and anorexia. Most patients with SAT initially develop symptoms and signs of hyperthyroidism which usually subsides within a few weeks with or without going through a transient phase of hypothyroidism. SAT is usually associated with a viral infection of the upper respiratory tract. We report a case of SAT in a 30-year-old male with a recent COVID-19 infection. The patient presented with a three days history of painful anterior neck mass and palpitations. He was diagnosed with COVID-19 16 days before presentation. His infection was mild and did not need any treatment apart from as-needed paracetamol. The patient was found to have a clinical, laboratory, and imaging findings consistent with SAT. The patient was prescribed ibuprofen, prednisone, and propranolol. The patient showed significant clinical and biochemical improvement on follow-up visits, achieving a euthyroid state within several weeks. Like many other respiratory viral illnesses, COVID-19 also seems to be associated with SAT. Other endocrinological sequelae have also been reported. While reviewing patients suffering from COVID-19 infection, these possibilities should be kept in mind.

Generally, cardiac masses are initially suspected on routine echocardiography. Cardiac magnetic resonance (CMR) imaging is further performed to differentiate tumors from pseudo-tumors and to characterize the cardiac masses based on their appearance on T1/T2-weighted images, detection of perfusion and demonstration of gadolinium-based contrast agent uptake on early and late gadolinium enhancement images. Further evaluation of cardiac masses by CMR is critical because unnecessary surgery can be avoided by better tissue characterization. Different cardiac tissues have different T1 and T2 relaxation times, principally owing to different internal biochemical environments surrounding the protons. In CMR, the signal intensity from a particular tissue depends on its T1 and T2 relaxation times and its proton density. CMR uses this principle to differentiate between various tissue types by weighting images based on their T1 or T2 relaxation times. Generally, tumor cells are larger, edematous, and have associated inflammatory reactions. Higher free water content of the neoplastic cells and other changes in tissue composition lead to prolonged T1/T2 relaxation times and thus an inherent contrast between tumors and normal tissue exists. Overall, these biochemical changes create an environment where different cardiac masses produce different signal intensity on their T1- weighted and T2- weighted images that help to discriminate between them. In this review article, we have provided a detailed description of the core CMR imaging protocol for evaluation of cardiac masses. We have also discussed the basic features of benign cardiac tumors as well as the role of CMR in evaluation and further tissue characterization of these tumors.