Magnetic resonance pulmonary angiography should be considered in the setting of a pulmonary embolism only at centers that routinely perform it well and only for patients for whom standard tests are contraindicated. MRA has a sensitivity and specificity of a range of 75-100% and 95-100%, respectively.[1]
Sensitive in the detection of clot in the inferior vena cava (IVC) and pelvic veins
Although MR is more expensive than V/Q scanning, when one takes into account the high number of indeterminate findings on V/Q, the effective cost per diagnosis may be cheaper with MR.
Magnetic resonance pulmonary angiography and magnetic resonance venography combined have a higher sensitivity than magnetic resonance pulmonary angiography alone in patients with technically adequate images. [2]
Although the criticism of using CT and MR angiography is that it lacks sensitivity when examining the subsegmental arteries, inter-reader agreement was only 66% with pulmonary angiography in the PIOPED Study. However, the clinical significance of undetected subsegmental PE is uncertain because they rarely cause severe symptoms.[3]
ACC/AHA Guidelines- ACCF/ACR/AHA/NASCI/SCMR 2010 Expert Consensus Document on Cardiovascular Magnetic Resonance (DO NOT EDIT)[4][edit | edit source]
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CE-MRA may be used in patients with a strong suspicion of pulmonary embolism in whom the results of other tests are equivocal or for
whom iodinated contrast material or ionizing radiation are relatively contraindicated. The writing committee agrees that data in the literature are insufficient to recommend where pulmonary CE-MRA should fit into a diagnostic pathway for pulmonary embolism.
↑Hull RD, Raskob GE, Ginsberg JS, Panju AA, Brill-Edwards P, Coates G; et al. (1994). "A noninvasive strategy for the treatment of patients with suspected pulmonary embolism". Arch Intern Med. 154 (3): 289–97. PMID8297195.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)