How is TE selected as long or short?

  • I
  • Thread starter Ian Martin
  • Start date
  • Tags
    Short
In summary, the conversation discusses the selection of TE length in magnetic resonance imaging and its relation to T2 image quality. The participant also brings up the concept of controlling the time for an echo to return in a cave, which is unrelated to magnetic resonance imaging.
  • #1
Ian Martin
1
0
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
 
Physics news on Phys.org
  • #2
:welcome:

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.

Ian Martin said:
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.
 
  • Like
Likes sophiecentaur
  • #3
Ian Martin said:
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

Ian Martin said:
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.
 
  • #5
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).
 
  • Like
Likes berkeman
  • #6
Oh! I knew that of course...:sorry:
 

1. How is the length of a TE determined?

The length of a TE (transposable element) is determined by the size of its DNA sequence, which can vary greatly depending on the type of TE. Some TEs may be as small as 100 base pairs, while others can be thousands of base pairs long.

2. What factors influence whether a TE is selected as long or short?

The length of a TE can be influenced by several factors, including the number of copies of the TE present in the genome, the location of the TE within the genome, and the activity of genes near the TE.

3. Are there any advantages to having a long TE?

Long TEs may provide certain advantages, such as increasing genetic diversity and allowing for the evolution of new gene functions. They may also play a role in the regulation of gene expression.

4. How does natural selection play a role in the selection of long or short TEs?

Natural selection can influence the length of TEs by favoring those that provide a selective advantage to the organism. For example, if a long TE contains a beneficial gene, it may be more likely to be retained in the genome through natural selection.

5. Can the length of a TE change over time?

Yes, the length of a TE can change over time through various mechanisms, such as mutations, insertions, and deletions. These changes can alter the function and activity of the TE, potentially impacting its selection as long or short.

Similar threads

  • Other Physics Topics
Replies
27
Views
785
  • Introductory Physics Homework Help
Replies
3
Views
581
  • Quantum Physics
Replies
3
Views
2K
Replies
8
Views
1K
  • Other Physics Topics
Replies
2
Views
3K
  • Electrical Engineering
Replies
6
Views
2K
  • Quantum Interpretations and Foundations
3
Replies
79
Views
5K
  • Science Fiction and Fantasy Media
Replies
7
Views
2K
Replies
3
Views
2K
Back
Top