title: Effective radiation dose of three diagnostic tests in cardiology: single photon emission computed tomography, invasive coronary angiography and cardiac computed tomography angiography.
abstract: BACKGROUND
  Diagnostic tests that use ionizing radiation play a central role in cardiology and their use has grown in recent years, leading to increasing concerns about their potential stochastic effects. The aims of this study were to compare the radiation dose of three diagnostic tests: single photon emission computed tomography (SPECT), invasive coronary angiography (ICA) and cardiac computed tomography (cardiac CT) and their evolution over time, and to assess the influence of body mass index on radiation dose.
  
  
  METHODS
  We assessed consecutive patients included in three prospective registries (SPECT, ICA and cardiac CT) over a period of two years. Radiation dose was converted to mSv and compared between the three registries. Differences over time were evaluated by comparing the first with the fourth semester.
  
  
  RESULTS
  A total of 6196 exams were evaluated: 35% SPECT, 53% ICA and 22% cardiac CT. Mean radiation dose was 10.7±1.2 mSv for SPECT, 8.1±6.4 mSv for ICA, and 5.4±3.8 mSv for cardiac CT (p<0.001 for all). With regard to the radiation dose over time, there was a very small reduction in SPECT (10.7 to 10.5 mSv, p=0.004), a significant increase (25%) in ICA (7.0 to 8.8 mSv; p<0.001), and a significant reduction (29%) in cardiac CT (6.5 to 4.6 mSv, p<0.001). Obesity was associated with a significantly higher radiation dose in all three exams.
  
  
  CONCLUSIONS
  Cardiac CT had a lower mean effective radiation dose than invasive coronary angiography, which in turn had a lower mean effective dose than SPECT. There was a significant increase in radiation doses in the ICA registry and a significant decrease in the cardiac CT registry over time.
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal; CEDOC - Chronic Diseases Research Center - Faculdade de Ciências Médicas-UNL, Lisboa, Portugal; Centro Cardiovascular, Hospital da Luz, Lisboa, Portugal. Electronic address: paraujogoncalves@yahoo.co.uk.
authors.forename: Pedro
authors.initials: P
authors.lastname: de Araújo Gonçalves
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal; Centro Cardiovascular, Hospital da Luz, Lisboa, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Jerónimo Sousa
authors.affiliation: Serviço de Cardiologia, Hospital Garcia de Orta, Almada, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Calé
authors.affiliation: Centro de lmagiologia, Hospital da Luz, Lisboa, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Marques
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Borges dos Santos
authors.affiliation: Serviço de Medicina Nuclear, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Dias
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Hélder
authors.initials: H
authors.lastname: Dores
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Maria Salomé
authors.initials: MS
authors.lastname: Carvalho
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Ventosa
authors.affiliation: Serviço de Medicina Nuclear, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Martins
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Campante Teles
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Almeida
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Mendes
mesh_terms: D000368:Aged; D057791:Cardiac Imaging Techniques / Q000379:methods*; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Cardiac computed tomography; Cintigrafia de perfusão miocárdica; Coronariografia invasiva; Invasive coronary angiography; Ionizing radiation; Obesidade; Obesity; Radiação; Single photon emission computed tomography; Tomografia computorizada cardíaca