Iodine Perfusion Maps in Computed Tomographic Pulmonary Angiography: What Radiologists Need to Know?

Computed tomographic pulmonary angiography is the gold standard in diagnosing pulmonary embolism (PE). There is increasing use of dual energy CT (DECT) scanners in producing iodine perfusion maps. These maps assist in diagnosing a PE. However, many conditions can mimic perfusion defects on iodine maps including artefacts, pleural effusion, pulmonary artery compression, emphysema, vasculitis, pulmonary collapse, interstitial lung disease, MacLeod syndrome, mosaic perfusion and lung masses. It is important for the radiologist to familiarize themselves with these conditions to avoid misinterpreting iodine perfusion maps.