Which statement is true regarding the visibility of the catheter in the vessel lumen?

• A. The catheter is invisible during ultrasound
• B. The catheter is only visible in thick vessels
• C. The catheter is clearly visible in the vessel lumen
• D. The catheter is visible in arterial structures only

Answer: (C)

The statement indicating that the catheter is clearly visible in the vessel lumen is accurate due to the characteristics of ultrasound imaging. When utilizing ultrasound, the catheter causes a distinct echogenic (bright) signal due to its material composition and the way it interfaces with surrounding tissues and fluid. This echogenicity allows the catheter to be easily identified within the lumen of a vessel, facilitating accurate visualization and assessment during phlebology procedures.

The visibility of the catheter is not limited to specific vessel types or wall thickness. Instead, the ability to visualize the catheter depends on the ultrasound settings and technique used, along with the interface between the catheter and the blood or tissue around it. Consequently, this statement reflects a fundamental aspect of ultrasound usage in the evaluation of catheter placement within vascular structures.