The vanishing atrial mass.

A 52-year-old woman with atopic asthma and a long smoking habit underwent CT pulmonary angiography (CTPA) for investigation of atypical, pleuritic chest pain. There was no history of heart disease or cardiovascular risk factors. As per usual practice for non-cardiac imaging, CTPA was performed without ECG gating. While there was no pulmonary embolism, CT showed an apparent large left atrial filling defect (arrows), demonstrated in axial ( Panel A …