This page will quickly go over some basic measurements and conversions that are relevant to the field of interventional radiology (and help better appreciate various types of equipment that are used in interventional radiology).
NEEDLE DIAMETERS: MEASUREED IN GAUGES
The gauge of a needle refers to its diameter. The lower the gauge the larger the needle diameter (i.e an 18 gauge needle will be larger then a 25 gauge needle). Some important things to remember are:
- A 22 gauge needle is the smallest that can be used for a 0.018 inch diameter wire
- A 18 gauge needle is the smallest that can be used for a 0.035 inch diameter wire
It is important to note that needles are color coordinated to indicate their size.
WIRE DIAMETER: MEASURED IN INCHES
There are two sizes of wires that are used in interventional radiology:
- 0.018 wires (0.018 inches in diameter)
- 0.035 wires (0.035 inches in diameter)
CATHETER AND SHEATH DIAMETERS: MEASURED IN FRENCH (F)
The diameter of both catheters and sheaths used in interventional radiology are measured in French (F). Important conversions include:
- 1 F = 1/3 mm
- 1F = 0.013 inch
Page Updated: 02.21.2019