Signal processing

Signal processing describes all the functions that can be applied to the echo signal (the Rf signal) after it is produced at the transducer.

Signal processing can be broken down into two main categories:

• Preprocessing

• Postprocessing

Preprocessing is any processing applied to the echo signal BEFORE it is placed in memory.  Postprocessing is any processing that is applied AFTER the signal is placed in memory.  The major difference between the two is that preprocessing can only be applied to a LIVE image.  It cannot be applied to a frozen image. Whereas postprocessing can be applied to either a live image or a frozen image.   Both types of processing can significantly enhance the image quality.

The following two videos explain all the key signal processing functions used by diagnostic medical sonographers.