Practice and patient doses in fluoroscopically guided interventional procedures in two departments
- Kostova-Lefterova, I. Dyakov
The use fluoroscopically guided interventional procedures as an important diagnostic imaging and therapeutic modality has grown remarkably over the last decades. The purpose of the current study was to survey the typical patient doses in two different departments in Sofia, Bulgaria, and to compare the results with the published data. A prospective study was performed for four most common procedures: coronary angiography (CA), percutaneous coronary intervention (PCI), lower limb arteriography (LLA) and stent placement in iliac/femoral artery. A total number of 225 procedures were recorded, including: patient data, frame rate, fluoroscopy time (FT), total number of series/images, and total air kerma area product (KAP). Entrance surface air kerma (ESAK) rates in fluoroscopy and acquisition mode were measured with a PMMA phantom. Image quality was assessed by calculation of signalto-noise ratio (SNR) and contrast-to-noise ratio (CNR) from the DICOM images. Large variations were observed in patient dose: KAP ranges were 6-172 Gy.cm2, 31-498 Gy.cm2, 3-78 Gy.cm2 and 12-326 Gy.cm2 for CA, PCI, LLA and iliac/femoral artery stent placement respectively. The mean values of KAP were higher than national DRL (40 Gy.cm2 for CA and 140 Gy.cm2 for PCI) in three of the angiography rooms and lower for only one of them. The mean KAP values of 34 Gy.cm2 for LLA and 65 Gy.cm2 for stent placement were lower compared to published DRLs. Such high values for patient doses were a consequence of the higher number of acquired images during most of the procedures. Image quality was evaluated to be better for the system with higher doses but sufficient for all other systems. Patient dose recording, establishment of typical doses and comparison with published data demonstrated to be good optimization tool.
Key words: FLUOROSCOPICALLY GUIDED INTERVENTIONAL PROCEDURES. PATIENT DOSIMETRY. OPTIMISATION