Author: Prof. Hein Heidbüchel; Joris Ector, M.D.; Stijn De Buck, Sc. Ph. D.

University Hospital Gasthuisberg, Leuven, Belgium

Patient History

A 66-year-old male with symptomatic atrial fibrillation.

Diagnosis

Paroxysmal atrial fibrillation, refractory to medical treatment.

Treatment

Radiofrequency catheter ablation to obtain electrical isolation of the pulmonary veins. A 6 French pigtail catheter was positioned in the left atrium for contrast injection during syngo DynaCT Cardiac acquisition (Fig. 1). The resulting rotational projection images were automatically transferred to the Siemens syngo X Workplace and reconstructed into two-dimensional CT-like images, which were used for further processing into a 3D model of the left atrium (Fig. 2, Fig.3)

Protocol

2D projection at a rate of 60 f/s during a single 5s C-arm rotation over 200°. Contrast agent (60 ml) diluted with saline to 140 cc (approximately 1:2 dilution) and injected at 20 cc/s during ventricular asystole.

Comments

A significant advantage of syngo DynaCT Cardiac is the automatic integration of 3D and fluoroscopic images during the procedure. Patient position is identical during syngo DynaCT Cardiac acquisition and fluoroscopic imaging. With syngo iPilot the location of the reconstructed 3D model relative to the fluoroscopic imaging geometry is identical, and allows for a fully automatic calibration and registration of the acquired 3D model to the fluoroscopy images (Fig. 5) in the primary plane. 

Fig. 1: Injection of diluted contrast agent in the left atrium during adenosine-induced ventricular asystole allows a homogeneous contrast opacification of the left atrium and pulmonary veins (RSPV: right superior pulmonary vein, RIPV: right inferior pulmonary vein, LSPV: left superior pulmonary vein, LA: left atrium, LAA: left atrial appendage) 

Fig. 2 a+b: syngo DynaCT Cardiac allows reconstruction of rotational projection images into a detailed 3D volumetric dataset demonstrating the 3D anatomy of the left atrium and pulmonary veins. 

Fig. 3: Posterior view of the left atrium visualized using the syngo InSpace 3D direct volume rendering. Ungated syngo DynaCT Cardiac during ventricular asystole resulted (in a diagnostic) 3D image of the left atrium, which was used for guiding the ablation procedure. (LA: left atrium, LSPV: left superior pulmonary vein, LIPV: left inferior pulmonary vein, RSPV: right superior pulmonary vein, RIPV: right inferior pulmonary vein) 

Fig. 4a+b: Integration of syngo DynaCT Cardiac-based 3D model of the left atrium with fluoroscopy using syngo iPilot. 
Fig. 4a: Fluoroscopic image in the right anterior oblique view showing the ablation catheter (Abl) and circumferential mapping catheter (Lasso). 
Fig. 4b: After syngo iPilot image integration with the syngo DynaCT Cardiac-based 3D model, the position of the ablation and mapping catheters at the ostium of the left superior pulmonary vein can be accurately determined. (Abl: ablation catheter, Lasso: circumferential mapping catheter, LA: left atrium, RSPV: right superior pulmonary vein, RIPV: right inferior pulmonary vein, LSPV: left superior pulmonary vein, LAA: left atrial appendage) 

Fig. 5: Selective angiographic injection in the right superior pulmonary vein, confirming accurate automatic syngo iPilot integration of the left atrial 3D model acquired with syngo DynaCT Cardiac. (RSPV: right superior pulmonary vein, LSPV: left superior pulmonary vein)

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