Diagnostic value of three-dimensional contrast-enhanced MR pulmonary angiography with liver acquisition volume acceleration sequence on a 3-T MR system for acute pulmonary embolism

To assess the value of three-dimensional (3D) contrast-enhanced (CE) magnetic resonance pulmonary angiography (MRPA) with liver acceleration volume acquisition (LAVA) in the detection of acute pulmonary embolism (PE). Thirty-two patients with symptoms indicative of acute PE underwent both CT pulmonary angiography (CTPA) and MRPA within 4 hours. Three of the patients were excluded from the final analysis. The results of MRPA were compared with those of 256-slice CTPA, which served as the reference standard. The pulmonary emboli were independently analyzed on per-patient and per-vascular zone bases by two radiologists in consensus. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PE detection were calculated. Twenty-three patients had PEs which were observed in 3 of the 46 main arteries, 22 of 138 lobar arteries, and 38 of 414 segmental arteries on CTPA, and no PEs were detected in six patients. The readers correctly detected 59 clots in 22 patients using MRPA. The sensitivities, specificities, and NPVs for MRPA were 95.7%, 100% and 85.7% per-patient, respectively, 100%, 100% and 100% for the main PA, respectively, 95.4%, 100% and 99.3% for the lobar PA, respectively, and 86.8%, 100% and 98.9% for the segmental PA, respectively. The PPV was 100%. 3D contrast-enhanced MRPA on a 3-T MR system with a LAVA sequence is a suitable alternative modality to CTPA for the detection of PE on per-patient and per-vascular bases according to this small cohort study.