CT rads, what is your CTPA protocol?

Our department has a bit of an outdated protocol and I’m looking to improve it, but in order to convince the managers/radiologists the change would be good, I was hoping to get examples of what other departments around the country do!
The protocol is currently inject 80 at 4 mls a sec with a post threshold delay of 4 seconds. We scan the whole chest.
We have no dedicated protocol for pregnancy, heart failure/tricuspid regurg or obesity.

Thank you in advance! I’m looking forward to hearing what you do!