title: The accuracy of MRI in diagnosis of suspected deep vein thrombosis: systematic review and meta-analysis.
abstract: Magnetic resonance imaging (MRI) may be used to diagnose deep vein thrombosis (DVT) in patients for whom ultrasound examination is inappropriate or unfeasible. We undertook a systematic review of the literature and meta-analysis to estimate the diagnostic accuracy of MRI for DVT. We searched databases of medical literature and citation lists of retrieved articles. We selected studies that compared MRI with a reference standard in patients with suspected DVT or suspected pulmonary embolus, or high-risk asymptomatic patients. Data were analysed by random effects meta-analysis. We included 14 articles in the meta-analysis. Most compared MRI with venography in patients with clinically suspected DVT. The pooled estimate of sensitivity was 91.5% (95% CI: 87.5-94.5%) and the pooled estimate of specificity was 94.8% (95% CI: 92.6-96.5%). Sensitivity for proximal DVT was higher than sensitivity for distal DVT (93.9% versus 62.1%). However, pooled estimates should be interpreted with caution as estimates of both sensitivity and specificity were subject to significant heterogeneity (P<0.001). Individual studies reported sensitivity ranging from zero to 100%, while specificity ranged from 43 to 100%. MRI has equivalent sensitivity and specificity to ultrasound for diagnosis of DVT, but has been evaluated in many fewer studies, using a variety of different techniques.
authors.affiliation: Health Services Research Section, ScHARR, University of Sheffield, 30 Regent Street, Sheffield, S1 4DA, UK. f.c.sampson@sheffield.ac.uk
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Sampson
authors.forename: Steve W
authors.initials: SW
authors.lastname: Goodacre
authors.forename: Steven M
authors.initials: SM
authors.lastname: Thomas
authors.forename: Edwin J R
authors.initials: EJ
authors.lastname: van Beek
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging; D010690:Phlebography / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*