I want to Do Penile Doppler. Or not?

Penile ultrasound is safe ??, bcz I search about it and I found many of post about that, after the penile Doppler test eraction Not reduce In 2 hours this is true ? And this is harmful aur not ?? My eraction is not maintain in 1 second and penis also not fully eract, I have injury is penis and blood leaking the foreskin but not heard any crack or pop sound, I don't know this is injury aur scar but I had s*x in 8 month before and some races showing penis, and than I again go for s*x blood leaking the scar in eract penis and half of condom blood leak,  than penis eraction slowly slowly loss, and now after my penis eraction is only 1 or 2 second, and also facing pain in penis sometime after the eraction, I don't the know the  reason this is injury or truma, but now no any scar of my penis, but it always goes down, and afer the reaction it goes down in 1 second , and my second  question is can I do penile Doppler taking a viagra tablet not injection, its works or not ??