Andreas Tausig MD, Presenter: Nothing to Disclose

Martin R. Karch, Abstract Co-Author: Nothing to Disclose

Karin Schreiber MD, Abstract Co-Author: Nothing to Disclose

Jörg Hausleiter MD, Abstract Co-Author: Nothing to Disclose

Stefan Martinoff MD, Abstract Co-Author: Nothing to Disclose

Ernst Josef Rummeny MD, Abstract Co-Author: Nothing to Disclose

Segmental pulmonary vein (PV) radiofrequency ablation is an effective procedure to cure paroxymal atrial fibrillation, but it may lead to PV-stenoses after treatment. Substantial variation of the PV anatomy is well known, therefore exact knowledge of the PV-situation is crucial for successful ablation. Thus the purpose of this study was to evaluate if high-resolution 3D-MRAs and CTAs reveal comparable results.

Forty patients (26M; 57±9.6 yrs) were examined with CTA and MRA (2±6.1 days in between) prior to PV-intervention. Contrast enhanced CTA was acquired in breath-hold at a multislice CT scanner (16-row detector, SIEMENS); min. voxel size: 0.6x0.6x0.75mm. MR imaging was performed at 1.5 T (Sonata, SIEMENS) using a contrast enhanced breath-hold FLASH-3D-MRA pulse sequence (GRAPPA; Voxel size: 1.0x0.8x1.0mm; TA 16 s). MIP and MPR reconstructions were available. A blinded reader reported the number of PV, their position and number of common ostia, early branching, the area of the PV-ostia and PV-caliber changes. The CTA served as a golden standard.

In terms of absolute number (5 PV-ostia in 5 pts, 4 PV-ostia in 29 pts and 3 PV-ostia in 6 pts), number of common ostia (6/40), supernumerary PV (7/40) and early branching of the PV (6/40) both modalities provided identical results. There was no significant difference between the ostial area measured with CTA and MRA (mean area CTA/MRA [cm²]: right upper: 2.8±0.8 / 2.7±0.6, right lower: 2.3±0.5 / 2.2±0.5; left upper: 2.8±1.1 / 2.5±1.2; left lower: 1.7±0.5 / 1.6±0.4). In 8 pts a physiological PV narrowing <30% was observed which can potentially be mistaken as a mild stenosis after treatment.

Contrast-enhanced high-resolution 3D-MRA is an adequate techniques to visualize PV-anatomy. Because substantial physiologic PV-caliber variations exist, serial examinations, prior to and after ablation, are recommended in order to differentiate them from an iatrogenic stenosis.

Tausig, A, Karch, M, Schreiber, K, Hausleiter, J, Martinoff, S, Rummeny, E, Depiction of Pulmonary Vein Anatomy before Ablation for Atrial Fibrillation: Value of High-Resolution 3D-MRA in Comparison to CTA.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4416026.html