title: Use of D-dimer and lower extremity Doppler ultrasound results to obviate the need for computerised tomographic pulmonary angiography.
abstract: We hypothesise that correct interpretation of other diagnostic tests could reduce the use of computerised tomographic pulmonary angiogram (CTPA) examinations in patients with suspected pulmonary embolism (PE).
  
  
  METHODS
  We carried out a retrospective analysis of 158 patients in a 928-bed university hospital. These consecutive patients were investigated for suspected PE from May 2001 to February 2002 using CTPA.
  
  
  RESULTS
  There were 74 men and 84 women with a mean (+/-SD) age of 57 (+/-19) years. Overall, 56% of patients (89/158) showed clinically significant abnormalities on the CTPA examination. The overall prevalence of PE was 15% (24/158). The D-dimers were assayed in 40% (63/158) and lower limbs were scanned with Doppler ultrasound (US) in 22% (35/158) of patients. None of the 19 patients with negative D-dimer assays had PE. Of the patients who were positively tested on Doppler US, 4 were positive and 1 was negative for PE on the CTPA. None of the patients with positive Doppler US had negative D-dimer test. In retrospect, patient management based on negative D-dimer assays and positive lower extremity Doppler US studies could have reduced the need for further investigation with CTPA by 15% (24/158).
  
  
  CONCLUSIONS
  In patients with suspected PE, correct interpretation of D-dimer and leg Doppler US tests may reduce the demand for CTPAs.
authors.affiliation: Departments of Medicine, National University Hospital, Singapore.
authors.forename: Amartya
authors.initials: A
authors.lastname: Mukhopadhyay
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Venkatesh
authors.forename: Poh Sun
authors.initials: PS
authors.lastname: Goh
authors.forename: Tow Keang
authors.initials: TK
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007866:Leg / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D