This is the description of 76998:
Ultrasonography is used during a procedure to guide the physician in successfully accomplishing the surgery. Ultrasonic guidance may be used by the physician intraoperatively during many different types of operations on various areas of the body. Examples of intraoperative ultrasonic guidance include evaluating tissue removal in anatomical structures such as the breast, brain, abdominal organs, etc. This procedure may also be used to determine the location and depth of incisions to be made. This code is not to be used for ultrasound guidance for open or laparoscopic radiofrequency tissue ablation.
Generally, 76942 is most appropriate with 76937 being used for line placement.
Here is the description for this code:
Ultrasonic guidance is used for guiding needle placement required for procedures such as breast biopsies, needle aspirations, injections, or placing localizing devices. Ultrasound is the process of bouncing sound waves far above the level of human perception through interior body structures. The sound waves pass through different densities of tissue and reflect back to a receiving unit at varying speeds. The unit converts the waves to electrical pulses that are immediately displayed in picture form on screen. Once the exact needle entry site is determined along with the depth of the lesion, the optimal route from the skin to the lesion is decided. The needle is inserted and advanced to the lesion under ultrasonic guidance. This code reports the imaging supervision and interpretation only for this procedure.