title: Prospective evaluation of unsuspected pulmonary embolism on coronary computed tomographic angiography.
abstract: OBJECTIVE
  This study aimed to analyze patients with unsuspected pulmonary embolism (PE) in coronary computed tomographic angiography (CCTA) and to draw some conclusions regarding their characteristics.
  
  
  METHODS
  All patients suspected of coronary heart disease undergoing CCTA between May 2006 and December 2010 were prospectively analyzed. Patients with previous or suspected current PE were excluded. The CCTA images were reviewed, and the degree of contrast enhancement and the presence or absence of PE were recorded. Where PE was found, the level of the most proximal thrombus was identified. Patients' demographics were recorded.
  
  
  RESULTS
  Of 7287 patients, 65 had unsuspected PE--an overall incidence of 0.9% (1.3% among inpatients and 0.3% among outpatients). Unsuspected PE was more common with increasing age, occurring in 0.4% of all patients younger than 60 years and 1.2% (52/4203) of those older than 60 years (P < 0.05). Of the 65 scans positive for disease, 43 (66.2%) were at the segmental or the subsegmental level. Patients with paroxysmal atrial fibrillation (AF) or AF history and cardiac insufficiency (3.2% and 4.1%) were more likely to have an unsuspected PE compared with those without (0.7%), and this was supported by the statistics. Deep vein thrombosis of the lower extremity was found in 8 (13.1%) of 61 patients with PE and in 12 (19.4%) of 62 patients with a D-dimer level of 500 ng/mL or higher.
  
  
  CONCLUSIONS
  Unsuspected PE was found in 0.9% of all patients undergoing CCTA, and this kind of PE has its own characteristics compared with the typical PE from the literature. Radiologists should routinely analyze the pulmonary arteries in all patients undergoing CCTA, especially for older patients and the patients with AF or AF history and cardiac insufficiency.
authors.affiliation: Department of Cardiovascular Radiology, the First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Chong-Fu
authors.initials: CF
authors.lastname: Jia
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Li
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Yang
authors.forename: Zhong-He
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Xi-Xia
authors.initials: XX
authors.lastname: Sun
authors.forename: Zhao-Qian
authors.initials: ZQ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D015994:Incidence; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011857:Radiographic Image Interpretation, Computer-Assisted; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D007472:Iohexol; C038192:iopromide