There are multiple definitions:

1. phase or pulse inversion imaging(English)

   • achieves improved signal to clutter ratio similar to harmonic imaging. Unlike harmonic imaging, it has the advantage of maintaining spatial resolution in B-mode imaging since it is not compromised by the formers narrow band pulse
   • Medical imaging
   • https://doi.org…10116-8.50019-1

2. Personally Identifiable Information(English)

   • details such as name, e-mail address, telephone number, postal address, organizational affiliation, areas of expertise, IP address, and system usage
   • BSN, SSN
   • Data exchange
   • https://www.dol.gov/general/ppii