Table 2:

Properties of radiopaque materials used in market-approved FDs

Radiopaque Materials
Alloy	Radiopacity (Density)^a	Market-Approved FD Examples	Radiopaque Element Type
Platinum-tungsten	∼19.75 g/cm³	PED, PED Flex, PED Shield, Surpass Streamline, Surpass Evolve	12 Platinum-tungsten wires incorporated into the overall braid²
Tantalum	16.65 g/cm³	FRED, FRED Jr, FRED X	Interwoven tantalum strands between braided layers and 4 markers on flared ends of device²
Platinum	21.45 g/cm³	Silk, Silk+, p64, Tubridge	Silk features 4 platinum wire strands with flared ends. Silk+ features 8 platinum wires and 4 platinum coils at device ends.² The p64 features 2 platinum wires wrapped along the length of the device and 8 markers at the device end.³⁶ Tubridge features 2 platinum strands²
Nitinol outer, platinum inner DFT	∼6 g/cm³ for nitinol; 21.45 g/cm³ for platinum	Silk Vista, Silk Vista Baby, p48MW (phenox), p48_HPC, DERIVO	48 Braided DFT wires. DERIVO features 3 additional markers on the device end²
Cobalt-nickel-chromium outer, platinum inner DFT	∼8.5 g/cm³ for cobalt-nickel-chromium; 21.45 g/cm³ for platinum	Pipeline Vantage	48 or 64 Braided DFT wires¹⁴

a Density is given as a rough proxy for radiopacity in lieu of the lack of corroborative data for these materials and geometries by a consistent approach. Future studies, outside the present scope, may focus on quantitative radiopacity comparison as a function of material, geometry, filtering materials, and imaging parameters. Such a study could be used to aid in the design of future devices.