Oh, wow, oh, oh, whoa, oh, wow.

Oh, wow.

Oh, Jane. Hello, you're listening to The Science of Everything podcast, episode 154, Magnetic Resonance Imaging.

I'm your host, James Fodor.

So today we're going to talk about MRI or magnetic resonance imaging.

We're going to cover the physics behind it, including how the excitation, the magnetic excitation occurs in the nucleus, how magnetic gradients are used to encode spatial information about the image.

We're going to talk about how the image is reconstructed, the computational techniques underpinning that, and we're also going to compare how structural versus functional imaging works and explain the differences there. And we'll conclude with

a bit of a discussion about post-processing of functional imaging data. So this is a topic that's been

requested a few times, I think, and is a particularly sort of interesting and tricky area that I don't

think very well understood. So I think it should be an interesting episode. Recommended pre-listening is episode 14 principles of quantum mechanics and episode

61 on magnetism. So without further ado, let's get started and we'll begin by talking about

nuclear magnetic resonance. MRI stands for magnetic resonance imaging. It's a medical imaging technique,

which is also used in science, scientific research, which is able to generate pictures of the

anatomy and physiological processes within the body. What makes MRI unique is that it's able to

generate high-resolution images of soft tissue within the body,

so without needing to cut open any parts of the body. So it's non-invasive. It differs from other

imaging modalities like CT or x-rays, which are primarily only useful for imaging hard tissues of the body like bones, for example.

It also has much higher resolution than other imaging modalities like PET scans or ultrasound.

Because of this, MRI has attracted a lot of interest over the years, both from researchers and the public.

The name of the technique, magnetic resonance imaging,

has actually been changed. Originally it was called nuclear magnetic resonance imaging because

that's the technique that it actually uses, but the nuclear was removed from the name because

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