Question: I have documentation for an encounter with a 37-year-old female patient where the radiologist performed an “SIS” procedure. The op note indicates the radiologist introduced saline via a sonohysterographic catheter and the procedure was ordered to evaluate the patient’s abnormal uterine bleeding. What code should I assign for this procedure? Pennsylvania Subscriber Answer: Based on the information you’ve provided in your question, the radiologist performed a saline infusion sonohysterography (SIS). An SIS is an ultrasound of the uterus where sterile saline is introduced into the uterus through the cervix. You’ll assign 76831 (Saline infusion sonohysterography (SIS), including color flow Doppler, when performed) for the procedure as well as 58340 (Catheterization and introduction of saline or contrast material for saline infusion sonohysterography (SIS) or hysterosalpingography) for the saline introduction.