h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

CT is Xray - CAT is an older term no longer used as the images are not necessarily axial esp if reformatted

you have mentioned that other species than hydrogen can be used which is the case in some research applications

MRI applications are expanding with improved software and third generation scanners which cut scan times dramatically. Newer uses include coronary MRI using ECG gating and MRCP (magnetic resonance cholangiography). MRI shows up blood as a void

Hello everyone.

Just read the entry again, and it looks good.

But it now refers to deoxy... as being paramagnetic. Not sure if Joe Average will know about paramagnetic/diamagnetic. Is a word of explanation needed (or is this the crucial physics of MRI) ?

In the entry, H2O would be much better with a subscript, as would H2.

Like the idea of an advanced article. One thing not clear from the entry is why zillions of computer power is necessary to get the results, but I'm sure that's a bit technical.

Let us know when you've finished the paragraph on MRI from the patient's point of view.

You should consider putting a few headings into the text. Just put the heading on a line on its own with a blank line before and after it.

Zillioflop computers are required because the signals from the body are encoded using gradient fields. The higher the applied field, the higher the resonant frequency of a proton, so, by applying a gradiated field across a slice of the human body, you can locate *where* a signal is coming from by its resonant frequency. But this means you get back, instead of one clear chiming resonance (rather like a bell note) a cacophony of different proton resonances. The computers are need to deconvolute the mixed-up radio signals in real time.

How about an entry on NMR spectroscopy as well?

A scout has recommended this entry for the Edited Guide. Let me know if it's done and I'll push the Accept button

Your Guide Entry has just been picked from Peer Review by one of our Scouts, and is now heading off into the Editorial Process, which ends with publication in the Edited Guide. We've therefore moved this Review Conversation out of Peer Review and to the entry itself.

If you'd like to know what happens now, check out the page on 'What Happens after your Entry has been Recommended?' at EditedGuide-Process. We hope this explains everything.

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Well done!

... is leo still around in h2g2?

Why thank you. It may not be complete or perfect, but I think it is a good start. I will try to find time to work on an advanced version. Thanks to all for the good advice.

Sorry, infinite_shadow, I mistakenly thought this entry was from leo mackern. Shows my forgetory is working as normal.