> they'd quickly replace ultrasound during pregnancy
Since scan time goes up with detail, and babies are really squirmy, it would be interesting to see how a quick-scan (low resolution) MRI compares with ultrasound quality.
But ultrasound destroys MRI in terms of portability, availability, and cost: just wheel in the cart, apply some goo, and there's the baby.
Perhaps more serious situations should use MRI more often instead of diagnostic ultrasound.
I expect that portability is actually a reason why often even visual ultrasound isn't used. Doppler scanning is often all that's needed to monitor heart rhythms
Those are much easier because heartbeats are regular, breathing is regular, and you can image a bunch of breaths and heartbeats and synthesize a nice clean movie.
Random motion is far harder to control for. Irregular heart beats cause a lot of trouble, as do moving babies.
So imagine foetal cardiac MRI.
There are new methods using some pretty mind boggling maths (at least it is tonne) that deal with movement very well. But as with all clever MRI stuff, you can have nice, or you can have quick.
> they'd quickly replace ultrasound during pregnancy
Since scan time goes up with detail, and babies are really squirmy, it would be interesting to see how a quick-scan (low resolution) MRI compares with ultrasound quality.
But ultrasound destroys MRI in terms of portability, availability, and cost: just wheel in the cart, apply some goo, and there's the baby.
Perhaps more serious situations should use MRI more often instead of diagnostic ultrasound.