Successful visualization of pulmonary embolism using fluoroscopic video analysis in a patient with iodine contrast allergy: a case report

BACKGROUND: Contrast-enhanced computed tomography (CT) is commonly used to diagnose pulmonary embolism (PE). However, a history of iodine contrast allergy presents a dilemma in the management of patients with PE. As an alternative approach, X-ray fluoroscopic video analysis has been recently reported to be useful in diagnosing PE. CASE SUMMARY: A 78-year-old man with dyspnoea of 1-month duration visited our hospital. His oxygen saturation was 89%, and echocardiography demonstrated right heart strain. We could not perform contrast-enhanced CT because the patient had a history of contrast allergy and refused to undergo premedicated contrast CT with anti-histamine and/or corticosteroid. Therefore, a video analysis of pulmonary circulation using dynamic chest X-ray (DCR) was performed. The reconstructed pseudo-colour video showed defects of pulmonary circulation in both lung areas. We diagnosed PE and started anticoagulant therapy. Multiple segmental defects were also observed in pulmonary perfusion scintigraphy on Day 3, which confirmed the diagnosis of PE. He was discharged on Day 9, and an improvement of the pulmonary circulation as assessed with DCR was observed. He had no symptoms at the last follow-up visit at 1 year after discharge. DISCUSSION: We describe the successful visualization of PE using DCR in a patient with iodine contrast allergy.