3D-rendered computed tomography imaging support the diagnosis and strategic decision-making: a rare case of acute pulmonary thromboembolism presenting with thrombus straddling a patent foramen ovale

A 63-year-old man with hypertrophic cardiomyopathy was transferred to our hospital for investigation of swollen left lower limb and gradual development of dyspnoea in the last few days. Venous echography showed blood clots in the left femoral vein. Transthoracic echocardiography (TTE) showed dilated right heart cavities, pulmonary hypertension estimated at 50 mmHg and snake-shaped thrombus with flipping movement across atrioventricular valves with cardiac cycle in each individual left (Panel A, Supplementary material online, Video S1) and right atrium (Panel B, Supplementary material online, Video S2). As the reason for poor TTE-acoustic window, the spatial relationship and continuity of the both atrial thrombi were not clearly depicted. A spiral computed tomography (CT) scan showed bilateral intra-atrial filling defect (Panel C) as well as intramural filling defect in pulmonary arteries (Panel D). Prompt 3D-rendered imaging reconstruction revealed a long thrombus caught in transit across a patent foramen ovale (PFO; Panel E, Supplementary material online, Video S3). Urgent decision for open-chest surgery was made to prevent additional adverse effect to both pulmonary and systemic circulation. Surgical removal of clots in both atria and pulmonary arteries with direct suturing of a PFO was completed uneventfully (Panel F). This is the first report of informative assessment of a thrombus straddling a PFO by use of 3D-rendered CT imaging.