Contrast-enhanced multidetector-row computed tomography vs. Time-resolved magnetic resonance angiography vs. contrast-enhanced perfusion MRI: Assessment of treatment response by patients with inoperable chronic thromboembolic pulmonary hypertension

Purpose: To compare therapeutic effect assessment capability of multidetector-row computed tomography (MDCT), magnetic resonance angiography (MRA), and dynamic perfusion MRI for chronic thromboembolic pulmonary hypertension (CTEPH) patients. Materials and Methods: Twenty-four consecutive CTEPH patients treated with conventional therapy underwent pre- and posttherapeutic MDCT, MRA, dynamic perfusion MRI, 6-minute walk distance (6-MWD), cardiac ultrasound (US), and right heart catheterization. According to therapeutic results, all patients were divided into response (n = 13) and nonresponse (n = 11) groups. CTEPH indexes for MDCT (CTEPH_CT) and MRA (CTEPH_MRA) were calculated on the basis of embolic burden. Pulmonary perfusion parameter maps were generated from all perfusion MR data, followed by determination of improvements in mean perfusion parameter at regions of interest (ROIs) for each patient. Receiver operating characteristic (ROC)-based positive tests were performed to determine the feasible threshold values for distinguishing two groups. Finally, diagnostic capabilities were compared by means of McNemar's test. Results: When feasible threshold values adapted, specificity (90.9 〈10/11〉%, P < 0.05) and accuracy (95.8 〈23/24〉%, P < 0.05) for improvement in pulmonary blood flow were significantly higher than those for CTEPH_CTA (specificity: 36.4 〈4/11〉%, accuracy: 70.8 〈17/24〉%). Conclusion: Dynamic perfusion MRI has better capability for assessment of therapeutic effect on CTEPH patients than does MDCT. J. Magn. Reson. Imaging 2012;36:612-623.