How is TE selected as long or short?

[Ian Martin]

Hi

Apparently a long TE gives a good T2 image yet how is TE length selected?

If I stand in a cave and shout I don’t control the time that the echo gets back to me, right?

Cheers

Ian

 

[anorlunda]

If you want a good answer, you'll have to do much better writing the question. I don't know what you mean by TE and T2.

If I stand in a cave and shout I don’t control the time that the echo gets back to me, right?

You select where in the cave you stand. But standing in one place, the time for the echo returns depends on the distance to the cave walls.

 

[Dale]

Apparently a long TE gives a good T2 image yet how is TE length selected?

TE is selected by controlling when your gradients are refocused. You can control the gradients so you can control TE. If you move the refocusing time later then the TE will be later

If I stand in a cave and shout I don’t control the time that the echo gets back to me, right?

It isn’t that kind of an echo.

 

[berkeman]

Using Google Translate, TE echo translates to "I miss you". Aww...

http://www.spanishdict.com/translate/te echo de menos

te echo de menos
I miss you

 

[Dale]

Hahaha. So the topic is magnetic resonance imaging. TE and TR are two numbers used to characterize image acquisition techniques and T1 and T2 are two numbers used to characterize tissues. The TE (echo time) alters the sensitivity to T2 (transverse relaxation) and the TR (repetition time) alters the sensitivity to T1 ( longitudinal relaxation).

 

[berkeman]

Oh! I knew that of course...