Diagnostic performance of contrast-enhanced and unenhanced combined pulmonary artery MRI and magnetic resonance venography techniques in the diagnosis of venous thromboembolism.

Abstract

We aimed to determine the diagnostic performance of the contrast-enhanced and unenhanced combined pulmonary arterial MRI and magnetic resonance venography techniques in the diagnosis of venous thromboembolism (VTE). 44 patients who underwent CT pulmonary angiography (CTPA) for suspected PE constituted the study population. Patients underwent combined pulmonary and lower extremity MRI, and Doppler ultrasonography within 72 h after CTPA. Combined MRI included two sequences: unenhanced steady-state free precession (SSFP) and contrast-enhanced three-dimensional (3D) gradient echo (GRE). The presence of emboli in pulmonary arteries and thrombi in lower extremity veins on 3D-GRE and SSFP sequences was recorded. CTPA showed a total of 244 emboli in 33 (75%) patients whereas contrast-enhanced 3D-GRE MRI showed deep vein thrombosis (DVT) in 34 (77%) subjects. Sensitivities for SSFP vs 3D-GRE MRI respectively in PE detection were 87.9 vs 100% on a per-patient basis, and 53.7 vs 73% on a per-embolus basis. Of 34 patients with established DVT, 31 (91%) were detected by Doppler ultrasound and 29 (85%) were detected by SSFP technique respectively. Both contrast-enhanced and unenhanced combined MRI of acute PE and DVT are feasible one-stop-shopping techniques in patients with suspected thromboembolism. Pulmonary VTE is a common disease with high mortality. Non-invasive techniques withhigh accuracy are required for the assessment of VTE. CT-related radiation and contrast material risks cause concerns. MRI is a radiation-free technique evaluating the vessels with and without contrast. Combined contrast enhancedor unenhanced pulmonary and lower extremity MRI is feasible in patients with suspected thromboembolism.