Hmmmmmmmmmmmm.

What does running spellsilver through veins do to a person?

Not much with the modern setup if you have healthy kidneys. Probably leaves a little sitting around in your brain forever. You wouldn't want to like, get an MRI tracer injection weekly. They'll only do it if they need a better view on a tumor or inflammation or something.

What does it accomplish? What is the point of putting it in her veins? What is the alternative?

If she has a brain tumor it'll leak into her brain and then they can see the tumor.

— they're sort of confused about what's going on with her, but if it's just that her doctor gave her really weird unconventional drugs then probably the MRI will mostly be ruling out various other possibilities? And if so, probably they won't need the contrast agent. So they can just pull her out of the MRI machine and talk over the cost-benefit analysis if there turns out to be any reason to need it?

Technically iron oxides are an alternative but they wouldn't really be an improvement. Sometimes they use manganese but it isn't a good substitute when checking for brain lesions.

Has this stuff been vetted by... Providence scientists... in long-term experiments with large sample sizes? She's really not a fan of untested drugs.

Well, there aren't like, multigenerational large sample size RCTs, that would be pretty impractical? But they have, what, on the order of billions of doses of observational data. Acutely: 1 in 216 mild reaction — nausea, headache, etc — 1 in 7776 she runs into an issue that needs some sort of treatment, 1 in 279936 severe anaphylactoid reaction. Maybe a dozen nanomorts — there aren't literally zero cases of a death.

Delayed harm is trickier to give a rigorous bound on. There's no reason to believe having a tiny amount of spellsilver in your brain causes any particularly big issues but if it has a small effect size in your 200₆s it's not like they could see it in the data. It's on the order of nanohefts — similar to the amount of iron already in your brain — though it's not like they do brain autopsies to check? Some ends up in your bones too.

(..."Providence scientists"? Maybe Providence retroactively purchased some of the impact...)

"I... guess it's okay?"

...they'll run it by her again if it comes up.

Okay, time to put her in a 3 Tesla* magnetic field that sends iron flying at up to 44 strides a second! She can sit in her hospital bed while they move her over to it.

...well, okay, they're going to put her through a metal detector first. Of course.

Does the metal detector conclude she has any metal?

* 6⁵³ ħ / ((e/6)c²day²). Where (e/6) is the down quark charge, obviously, not a sixth of exp(1).

No metal!

Okay!

Here's the button she can use to signal that they should pull her out. Here's her hearing protection / headphones. Does she have any particular video-show she'd like to watch — they can pull up anything, though if it costs money they'll charge her account — or does she want to see the list of commonly-agreeable defaults? (They have a mirror-projector setup.) 

She'll look at the defaults!

For this sort of thing you want a list of inoffensive, widely-liked media of various different types, so you can maximize the fraction of people which will have at least one option they're happy with while not forcing them to disclose some sort of niche personal favorite to a random doctor they don't trust.

So most hospitals pull from a list maintained by a particular small organization, that carefully decides what sorts of things to put on it. They cycle options in and out on a regular basis, so people who get medical procedures often don't end up needing to do repeats.

MRIs tend to take a particular subset — they're not banning comedy, if you request it, but they don't exactly want to actively encourage people in MRI machines to break down laughing continuously the whole time.

So Berra will be handed a menu including options like:

• Nothing
• Generic calm music and pretty colors
• A video documentary on the logistics of summiting Olympus Mons. No one has done it yet, obviously, but it'll probably happen when they send a serious mountain climber to Mars. The documentary is presented as though it were a vlog performed by a person climbing Olympus Mons — an Eifweni viewer would be expected to understand the genre convention, but this could in theory fly over Berra's head.
• A relatively standard guided meditation — of the sort that doesn't presume you to be in some calm environment that isn't an MRI machine, that is, so more focusing on your breath or somatic sensations than on, say, sounds. Not that you can't try to use the MRI machine sounds as a meditative focus if you want, but most people who are going to try that don't need to be walked through the idea.
• The latest release by one of the more famous mathematics video artists, trying to explain how yet another well-known fundamental theorem is obvious-in-retrospect once you look at it from a particular angle
• A one-button rhythm game, carefully constructed to play nice with the very noisy MRI machine. Lots of people have gotten full clears of the computer version, but everyone agrees it doesn't count unless you do it while actually getting an MRI.
• Because she's in Nemesia, the most popular televised court case currently happening. Right now that's Estate of Verisimilitude v. Cojones, a wax-homicide case. The representatives of Verisimilitude argue that the wax-homicide was not just illicit — as would be much easier to argue — but in fact invalid, and that Verisimilitude should therefore be unexiled. Cojones argues first of all that they can't prove he wasn't framed, and second of all that it was licit anyways. A decent number of people had already been following the trial, but it started standing out when an ostensibly neutral third party started making a surprisingly compelling case that it was invalid yet illicit, despite the fact that conventionally the invalidity would suggest there did not exist any act to be deemed illicit. Viewers keep taking the "licit but invalid" stance for completion but no one has managed to get the court to acknowledge them as having standing to make that case yet.
• Some sort of fast-paced polyform packing game that decidedly is not tetris. It doesn't have a line-clearing mechanic, it's mostly just about trying to pack the board as densely as possible before you run out of room.
• Whatever the most-viewed livestream event worldwide is at the time — right now it's the finals in a lockout tournament for one of the most popular randomized action adventure games. Or, well, it's the official stream for the match, including one of the format's developers and a couple previous champions on commentary — plenty of people are restreaming and commentating the match besides the official commentators. Each game goes to the first to complete 8 of 15 objectives, and the match is best of 5, with the score currently 1-1.
• Some sort of surreal art film that evades descr... actually the nurse is going to lightly disrecommend this one on the basis that Berra doesn't need something crazymaking or unsettling right now. Not that the nurse has even seen this particular one, just on the vibes of the genre.
• A competitive cooking show involving highly unconventional appliances and a kitchen that requires mild acrobatics to navigate. Being weirdly good at improvising chemistry is essential to perform well, because the competitors do not have access to basically any of the things you'd actually want to be convenient in a kitchen.

They're all conveniently MRI-length. Well, except the livestreams.

What does Berra want to be subjected to for most of a period?

Ooh, math... no, she has math at home. Today she wants to learn more about this universe. How about Estate of Verisimilitude v. Cojones? Does the video explain what a wax homicide is and what makes one illicit or invalid?

If someone randomly tuned into a livestream of one of her cases, would there be exposition on exactly what a "universe" is? Or whatever?

Okay, fine, no exposition. What does she learn?