Background: Pulmonary vein stenosis (PVS) after radiofrequency ablation for atrial fibrillation remains a challenge despite considerable technological advances. We aimed to evaluate anatomical and functional PVS assessment by cardiovascular magnetic resonance angiography (MRA) and cardiovascular magnetic resonance (CMR) perfusion imaging.

Material and Methods: 57 patients (61 studies) with a known PVS were evaluated. All measurements were done on a 1.5T MR scanner system. All patients received a CMR study including contrast-enhanced three-dimensional pulmonary vein angiography. A high-resolution k-t accelerated CMR lung perfusion was performed in 28 (49%) patients. In 50 (88%) patients previous studies (MRA or CT angiography) were available for comparison. Three dimensional reconstructions of the left atria were performed and pulmonary vein branches were assessed. Pulmonary perfusion deficits were correlated to PV subbranches.

Results: Underlying heart rhythm did not affect CMR image quality. In all patients with a perfusion deficit a PV stenosis of the corresponding subbranch could be identified. In 3 patients without a previous imaging study MRA alone was not sufficient to detect occlusion of a PV subbranch, but when using CMR lung perfusion a perfusion deficit was evident and the corresponding occluded PV subbranch could be identified.

Conclusions:

Anatomical and functional PVS assessment by combined MRA and CMR lung perfusion imaging has the potential to improve diagnosis and evaluation of long term outcome. MRA alone may miss occluded of PV subbranches especially in the absence of pre-interventional PV images and can lead to inaccurate diagnosis. The combined analysis of PV stenosis and its functional consequences is particularly important when aiming at PVS dilatation and the evaluation of therapeutic success during follow-ups.

Figure: A) First dynamic of contrast-enhanced three-dimensional cardiovascular magnetic resonance angiography of the pulmonary veins (p.a.view) showing total occlusion of the left superior PV B) High-resolution k-t accelerated cardiovascular magnetic resonance lung perfusion imaging identified an extensive perfusion deficit of the left upper lobe (coronal orientation).