Copper filters in angiography and secondary radiation: an experimental study

Claudio Cuellar-Fritis, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Martín Abarca-Arredondo, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Vicente Córdova-Jorquera, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Pablo Nilo-Aguilera, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Vicente Lobos-Valladares, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Rocío Valdivia-Vásquez, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Cristobal Guerrero-Lara, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
Camila Cortés-Barrera, Servicio de Imagenología, Hospital de Urgencia Asistencia Pública, Chile
Sebastián Pereira, Servicio de Imagenología, Hospital de Urgencia Asistencia Pública, Chile
Eduardo Espinoza-Parra, Gerencia de Administración, Protección Radiológica Ltda. Santiago, Chile
Marvin Querales, Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile; Centro Interdisciplinario de Investigación Biomédica e Ingeniería para la Salud (MEDING), Universidad de Valparaíso, Valparaíso. Chile

Introduction: In interventional cardiology, copper filters reduce patient radiation dose; however, their impact on occupationally exposed workers remains uncertain. Objective: To evaluate the effect of copper filter utilization on the absolute percentage variations (APVs) of dose rates between the work positions of the interventional cardiologist and the radiologic technologist during interventional cardiology procedures. Material and methods: An experimental study was conducted using a polymethyl methacrylate geometric phantom and calibrated ionization chambers. Dose rates were measured at the physician and technologist positions during fluoroscopy (with filters) and cineangiography (without filters) under various angiographic projections and acquisition frequencies, and APVs were calculated for each condition. Results: Cineangiography showed the highest APVs, with no significant differences between acquisition frequencies. In fluoroscopy, APV decreased significantly with increasing copper filter thickness, whereas no changes were observed when filter thickness remained constant. Conclusions: At the experimental level, the use of copper filters in fluoroscopy is associated with a reduction in APVs between the interventional cardiologist and the radiologic technologist, suggesting a redistribution of scattered radiation. These findings provide preliminary evidence to support the optimization of occupational radiological protection and highlight the need for further validation in real clinical settings.

Keywords: Percutaneous coronary intervention. Radiation dosage. Occupational exposure. Fluoroscopy. Cineradiography. Radiation protection.