CAMRT Radiography Practice Exam

Which of the following statements is true regarding needle gauges?

1. The smaller the gauge number, the larger the diameter

2. All gauge sizes are standard across manufacturers

3. A larger gauge is always preferred for injections

4. Gauge size has no relation to the needle’s purpose

The correct answer is: The smaller the gauge number, the larger the diameter

The statement about needle gauges that is true is that the smaller the gauge number, the larger the diameter. This is a fundamental principle in the understanding of needle gauges, which are used to measure the thickness of needles. The gauge system is somewhat counterintuitive because as the gauge number increases, the diameter of the needle decreases. For example, a 18-gauge needle has a larger diameter than a 25-gauge needle. This knowledge is crucial in clinical practice, as different procedures may require needles of varying sizes to ensure proper delivery of medication or drawing of blood. The other statements do not hold true across the board. Gauge sizes do not have standardized dimensions that are universal across all manufacturers; variations can exist. Additionally, a larger gauge (which has a smaller diameter) is not always preferred for injections, as different medications and patient conditions may necessitate specific needle sizes. Lastly, gauge size does have a relation to a needle’s purpose; certain procedures require specific gauges based on the fluid being administered or drawn, which directly pertains to the thickness of the needle.