Influence of flat-panel fluoroscopic equipment variables on cardiac radiation doses.
OBJECTIVE
To assess the influence of physician-selectable equipment variables on the potential radiation dose reductions during cardiac catheterization examinations using modern imaging equipment.


METHODS
A modern bi-plane angiography unit with flat-panel image receptors was used. Patients were simulated with 15-30 cm of acrylic plastic. The variables studied were: patient thickness, fluoroscopy pulse rates, record mode frame rates, image receptor field-of-view (FoV), automatic dose control (ADC) mode, SID/SSD geometry setting, automatic collimation, automatic positioning, and others.


RESULTS
Patient radiation doses double for every additional 3.5-4.5 cm of soft tissue. The dose is directly related to the imaging frame rate; a decrease from 30 pps to 15 pps reduces the dose by about 50%. The dose is related to [(FoV)(-N )] where 2.0 < N < 3.0. Suboptimal positioning of the patient can nearly double the dose. The ADC system provides three selections that can vary the radiation level by 50%. For pediatric studies (2-5 years old), the selection of equipment variables can result in entrance radiation doses that range between 6 and 60 cGy for diagnostic cases and between 15 and 140 cGy for interventional cases. For adult studies, the equipment variables can produce entrance radiation doses that range between 13 and 130 cGy for diagnostic cases and between 30 and 400 cGy for interventional cases.


CONCLUSIONS
Overall dose reductions of 70-90% can be achieved with pediatric patients and about 90% with adult patients solely through optimal selection of equipment variables.
Nickoloff
Edward L
EL
Department of Radiology, College of Physicians and Surgeons, Columbia University and New York-Presbyterian Hospital, MHB 3-265, 177 Fort Washington Avenue, New York, NY 10032, USA. eln1@columbia.edu
Lu
Zheng Feng
ZF
Dutta
Ajoy
A
So
James
J
Balter
Stephen
S
Moses
Jeffrey
J
D000180:Acrylic Resins; D000328:Adult; D006328:Cardiac Catheterization / Q000379:methods; D017115:Catheter Ablation; D002675:Child, Preschool; D017023:Coronary Angiography; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005471:Fluoroscopy / Q000295:instrumentation / Q000379:methods*; D006321:Heart / Q000528:radiation effects*; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D019047:Phantoms, Imaging; D015641:Radiography, Interventional; D016896:Treatment Outcome
D000180:Acrylic Resins