Pulmonary embolism is a sudden blockage in a lung artery. Blockage usually is caused by a blood clot that travels to the lung from a vein in the leg. Because pulmonary embolism almost always occurs in conjunction with deep vein thrombosis, most doctors refer to the two conditions together as venous thromboembolism. Pulmonary embolism can be life-threatening, but prompt treatment can greatly reduce the risk of death. The most common cause of diagnostic difficulty was breathing motion artifact, followed by beam-hardening artifact.
In Ireland the statistical analysis of pulmonary embolism got the result as a total of 937 pulmonary CTA studies were performed over the study period. PE was diagnosed in the initial report in 174 of these cases (18.6%). There was discordance between the chest radiologists and the original radiologist in 45 of 174 (25.9%) cases. Discordance occurred more often where the original reported PE was solitary (46.2% of reported solitary PEs were considered negative on retrospective review) and located in a segmental or subsegmental pulmonary artery (26.8% of segmental.