I get my medical work done at a large complex containing a medical office building - exam room clinics, labs, pharmacy, many specialty offices including eye clinic and optician - and a hospital, the latter of which also contains some clinics including radiology.
They're separate buildings but also connected. There's a ground-level breezeway between the office building and a side entrance to the hospital, and the buildings are directly connected on the second floor.
Restrictions for entering the office building have been relaxed since the earlier days of the pandemic, but the hospital's have been tightened up, and the line in front of the hospital main non-emergency entrance is very long.
The e-mail announcing the rule changes said that you don't have to go through the restrictive procedures if you're just headed for one of the clinics like radiology, but it didn't say how to do so.
I looked at the line at the main entrance. I didn't want to walk past it and earn the irritation of those who'd queued up, even if the folks at the door would let me in. I remembered the side entrance. Surprise, it now says "Employees only," which it didn't the last time I tried this.
But! There's still the second floor corridor. So I turned back from the hospital side entrance, went into the office building, hopped it up the stairs (the elevator is at the other end of the office building) to the second floor, and walked down the corridor, where there was nobody at the hospital end but one guard at a desk. I said I was headed for radiology, and he told me how to take the hospital's elevator back down to the ground floor, not that I didn't already know where to go.
Thing that I'm glad I took with me to radiology: an e-book reader. Thing that I wish I took with me to radiology: shoes that will easily slip on. Thing that I'm glad I only had to do once at radiology: hold my breath for 20 seconds.