Diagnostic accuracy of magnetic resonance imaging for an acute pulmonary embolism: results of the ‘IRM‐EP’ study

Abstract

See also Huisman MV, Klok FA. Magnetic resonance imaging for diagnosis of acute pulmonary embolism: not yet a suitable alternative to CT-PA.This issue, pp 741-2; and Sodhi KS, Saxena AK. Diagnostic accuracy of computed tomography pulmonary angiography and magnetic resonance imaging for an acute pulmonary embolism. This issue, pp 961.Summary. Background: Magnetic resonance imaging (MRI) has not been validated as an alternative diagnostic test to computed tomography angiography (CTA) in patients with suspicion of a pulmonary embolism (PE). Objectives: To evaluate performance of current MRI technology in diagnosing PE, in reference to a 64-detector CTA. Patients/methods: Prospective investigation including 300 patients with a suspected PE, referred for CTA after assessment of clinical probability and D-dimer testing. MRI protocol included unenhanced, perfusion and angiographic sequences. MRI results were interpreted by two independent readers, to evaluate inter-reader agreement. Sensitivity and specificity were evaluated globally and according to PE location and to clinical probability category. Results: Of 300 enrolled patients, 274 were analyzed and 103 (37.5%) had a PE diagnosed by CTA. For patients with conclusive MRI results (72% for reader 1, 70% for reader 2), sensitivity and specificity were 84.5% (95% confidence interval [CI], 74.9-91.4%) and 99.1% (95% CI, 95.1-100.0%), respectively, for reader 1, and 78.7% (95% CI, 68.2-87.1%) and 100% (95% CI, 96.7-100.0%) for reader 2. After exclusion of inconclusive MRI results for both readers, inter-reader agreement was excellent (kappa value: 0.93, 95% CI: 0.88-0.99). Sensitivity was better for proximal (97.7-100%) than for segmental (68.0-91.7%) and sub-segmental (21.4-33.3%) PE (P < 0.0001). Sensitivity was similar for both readers within each clinical probability category. Conclusions: Current MRI technology demonstrates high specificity and high sensitivity for proximal PE, but still limited sensitivity for distal PE and 30% of inconclusive results. Although a positive result can aid in clinical decision making, MRI cannot be used as a stand-alone test to exclude PE.

Diagnostic accuracy of magnetic resonance angiography for acute pulmonary embolism - a systematic review and meta-analysis

“…Among the included studies, the sensitivity was actually higher in the study by Zhang et al (100 %) [16] [14]. We speculated there might be some factors which aff ected the sensitivity of MRA in diagnosing acute PE.…”

“…All these studies satisfi ed ten items in the QUADAS list. The most common missing item was the 12 th item, which was unclear in three included studies [23,14,16] and not reported in the study by Stein et al [15]. In addition, the 13 th item was not reported in the studies by Revel et al [14] and Zhang et al [16].…”

“…The most common missing item was the 12 th item, which was unclear in three included studies [23,14,16] and not reported in the study by Stein et al [15]. In addition, the 13 th item was not reported in the studies by Revel et al [14] and Zhang et al [16]. The 10 th item was not reported in the study by Pleszewski et al [23] and unclear in the study by Zhang et al [16].…”

“…The 10 th item was not reported in the study by Pleszewski et al [23] and unclear in the study by Zhang et al [16]. The 11 th item was not reported in the study by Kluge et al [22] and unclear in the study by Revel et al [14] (ESM 3).…”

“…A total of 643 participants over 18 years old were reanalyzed in this study. These studies were conducted in diff erent countries, including Germany [22], Canada [23], France [14], China [16], and the USA [15]. The magnetic fi eld intensity in these studies was 1.5T and/or 3T.…”