Sphincteric function is evaluated with which instrument?

• A. Electrodes for EMG
• B. Ultrasound probes
• C. Pressure catheters
• D. Nuclear medicine probe

Answer: (C)

Sphincteric function is about how well the sphincter can generate and maintain pressure to keep urine in. The instrument that directly measures this pressure inside the urethra is a pressure catheter. It has multiple sensors along a thin tube that records intraluminal pressures at different points as the sphincter contracts and relaxes, giving a urethral pressure profile and metrics like maximum urethral closure pressure.

Electrodes for EMG assess electrical activity of muscles, not the actual pressure they generate. Ultrasound probes visualize anatomy and movement but don’t quantify pressure. Nuclear medicine probes image function with tracers, not the continuous pressure measurements needed to evaluate sphincteric competence. Hence, pressure catheters are the appropriate tool for this assessment.