Pulmonary embolism: MR angiography could help diagnose it

Clinical bottom line (level 1b)

  1. 30% of patients with a suspected pulmonary embolism and abnormal perfusion lung scintigraphy had one.
  2. An abnormal MR angiogram made a pulmonary embolism more likely (LR + 32) , but a normal one could not safely rule one out (LR - 0.23) .
Oudkerk et al: Lancet 2002; 359 : 1643-1647
Expires June 2004

The study

Setting: acute hospital, the Netherlands

141 patients (aged 16 to 87; median 53, 57% female) with clinically suspected pulmonary embolism and an abnormal perfusion lung scintigraphy

Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:
  • pulmonary angiography
Diagnostic test: gadolinium-enhanced MR angiography

The evidence

pre-test probability of pulmonary embolism: 30%, (95% CI: 21% to 38%)

diagnostic test pulmonary embolism no PE LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
gadolinium-enhanced MR angiography 27 2 32
(8.0 to 130) 		93% 0.23
(0.13 to 0.43) 		9%
total 35 83

K interobserver : 0.75

Comments

  1. 14% of patients either did not have MR angiography or pulmonary angiography due to technical reasons.

Citation

  1. Oudkerk M, van Beek EJ, Wielopolski P, et al: comparison of contrast-enhanced magnetic resonance angiography and conventional pulmonary angiography for the diagnosis of pulmonary embolism: a prospective study. Lancet 2002; 359 : 1643-1647
Search Terms: from ACP Journal Club other articles noted
Contributor: Chris Ball, June 2002
Reviewer:

Clinical Question.
Patient pulmonary embolism
Intervention or Exposure MR angiography
Comparison pulmonary angiography
Outcome pulmonary embolism