title: Diagnosing venous thromboembolism in pregnancy.
abstract: OBJECTIVE
  We report the imaging outcomes of all pregnant patients referred for suspected thromboembolism over a 43-month period.
  
  
  METHODS
  We identified 168 patients who underwent ventilation/perfusion (VQ) single-photon emission CT (SPECT), CT pulmonary angiography (CTPA) or a Doppler ultrasound scan of the lower legs, as well as a control group of 89 non-pregnant age- and sex-matched patients who underwent VQ SPECT during the same period. Imaging outcomes were recorded, and radiation doses were calculated for individual patients.
  
  
  RESULTS
  VQ SPECT and CTPA were equally likely to diagnose pulmonary embolism (PE) in about one patient out of every seven patients investigated. One in three CTPA scans was of suboptimal quality. A Doppler ultrasound examination of the legs will find deep venous thrombosis much less often, in about 1 patient out of every 15 patients investigated. The prevalence of PE in pregnant patients (as diagnosed by VQ SPECT) was similar to that in the non-pregnant, age- and sex-matched control group. The effective dose and the absorbed radiation dose to the maternal breast were lower with VQ SPECT. The foetal dose is comparable for both VQ SPECT and CTPA.
  
  
  CONCLUSIONS
  VQ SPECT and CTPA provide a similar diagnostic yield for diagnosing PE during pregnancy, but VQ SPECT does so with a lower radiation dose to the mother (effective dose and breast dose).
  
  
  CONCLUSIONS
  Ours is the first report of the diagnostic performance of VQ SPECT, rather than planar VQ scans, in pregnancy in a routine clinical setting.
authors.affiliation: 1 Department of Nuclear Medicine, Derriford Hospital, Plymouth, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: Grüning
authors.affiliation: 1 Department of Nuclear Medicine, Derriford Hospital, Plymouth, UK.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Mingo
authors.affiliation: 2 Department of Clinical and Radiation Physics, Derriford Hospital, Plymouth, UK.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Gosling
authors.affiliation: 1 Department of Nuclear Medicine, Derriford Hospital, Plymouth, UK.
authors.forename: Sally L
authors.initials: SL
authors.lastname: Farrell
authors.affiliation: 1 Department of Nuclear Medicine, Derriford Hospital, Plymouth, UK.
authors.forename: Brent E
authors.initials: BE
authors.lastname: Drake
authors.affiliation: 2 Department of Clinical and Radiation Physics, Derriford Hospital, Plymouth, UK.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Loader
authors.affiliation: 3 Department of Imaging, Derriford Hospital, Plymouth, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Riordan
mesh_terms: D000293:Adolescent; D000328:Adult; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010690:Phlebography / Q000379:methods; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000000981:diagnostic imaging*; D011296:Prenatal Diagnosis / Q000379:methods; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018608:Ultrasonography, Doppler / Q000379:methods*; D054556:Venous Thromboembolism / Q000000981:diagnostic imaging*; D014692:Ventilation-Perfusion Ratio; D055815:Young Adult