['Pulmonary vein (PV) stenosis is a major complication of PV isolation (PVI) by catheter ablation, so in the present study the optimal position for detecting PV stenosis on enhanced multidetector computed tomography (MDCT) image acquisition was determined.', 'The 64-slice enhanced MDCT was carried out before and after PVI in 116 consecutive patients with atrial fibrillation while they were in the prone position, as well as while supine. The supine position MDCT image showed >50% diameter stenosis of the PV in 11 (9%) patients before PVI (% diameter stenosis: mean 55+/-4%, range 51-65%). Greater than 50% diameter stenosis was seen in the left inferior PV in all 11 patients. The prone position attenuated the PV stenosis findings in the MDCT images in all 11 patients (mean 9+/-6%, range 2-18%). Stenosis visualized on images acquired in the supine position was, therefore, concluded to be pseudostenosis caused by descending aorta compression. At 3 months after PVI, no significant changes in PV diameter were observed in these 11 patients.'] Is prone position essential for detection of pulmonary vein pseudostenosis by enhanced multidetector computed tomography in patients who undergo pulmonary vein isolation?