Allura fd20

Both groups underwent CB ablation using the same angiocardiography system (Allura FD20, Philips, the Netherlands) by a limited number of operators (REB, MF, SCY). The fluoroscopy frame rate in both groups was set to 7.5 pulses per second. During fluoroscopy, spectral filters containing 0.9 mm copper and 1.0 mm aluminum were used; cine runs were performed with filters containing 0.1 mm copper and 1.0 mm aluminum. In group A (conventional group), the degree of PV occlusion prior to each freeze cycle was filmed (cine run). In group B (intervention group), the following modifications were made: (1) degree of PV occlusion prior to each freeze cycle was only visualized by fluoroscopy and stored with the “store fluoroscopy” function (no cine run); (2) increased radiation awareness (e.g., optimal collimation, minimizing distance between patient and detector, limiting fluoroscopy) (Fig. 1).Fig. 1

Example of stored fluoroscopic image during occlusion of the left superior pulmonary vein demonstrating the amount of collimation

Experimental measurements were used three x-ray angiography systems(one was Philips Allura FD20, the others were Philips Allura FD 10) with similar cardiac catheterization protocols. All protocols followed standard technical characteristics of image acquisition and quality control. Collimation and magnification were used during the procedures according to the clinical requirements. The operational protocols evaluated were fluoroscopy (15 pulses/s and 0.9 mm Cu as additional filtration) and cine acquisition (15 pulses/s without Cu filtration) modes. All staff adhered to standard radiation protection procedures. Each staff wore a lead apron, a thyroid collar, and leaded glasses. Because the thyroid is known to be radiosensitive and makes a significant contribution to the radiation dose [18 (link)–21 (link)], a real-time electronic personal dosimeter (EPD) system (i2, Raysafe) was placed over the left side of staff’s thyroid collar to measure the radiation dose at various locations. EPD system has store instantaneous dose rate and cumulative dose values at the beginning to the end of each procedure. In addition, the system is design to measure the personal dose equivalent at depth of 10 mm (Hp(10)) for x-ray, and is considered to be the dose to the whole body [22 ].