Ultrasonography

• FSN: Ultrasonography of X (procedure)
• PT: Ultrasonography of X
• SYN: Ultrasound scan of X
• SYN: Ultrasound of X

For example, 

• • 
    • FSN: Ultrasonography of perineum (procedure)
    • PT: Ultrasonography of perineum
    • SYN: Ultrasound scan of perineum
    • SYN: Ultrasound of perineum

Doppler ultrasonography

• FSN: Doppler ultrasonography of X (procedure)
• PT: Doppler ultrasonography of X
• SYN: Doppler ultrasound scan of X

For example, 

• • 
    • FSN: Doppler ultrasonography of venous structure (procedure)
    • PT: Doppler ultrasonography of vein
    • SYN: Doppler ultrasound scan of vein

Obstetric ultrasonography

An obstetric ultrasound may require a complex description. However, the same rules apply, as follows:

• FSN: Obstetric ultrasonography of X (procedure)
• PT: Obstetric ultrasonography of X
• SYN: Obstetric ultrasound scan of X
• SYN: Obstetric ultrasound of X

For example, 

• • 
    • FSN: Antenatal ultrasound scan at 17-22 weeks (procedure)
    • PT: Antenatal ultrasound scan at 17-22 weeks