|
Magnetic
Resonance -
Technology
Information
Portal |
Welcome to MRI Technology • |
|
|
 | Info
Sheets |
| | | | | | | | | | | | | | | | | | | | | | | | |
 | Out-
side |
| | | | |
|
| | | | | |
| Result: Searchterm 'Imaging'
found in 88 messages |
| Result Pages: 1 2 3 4 5 6 7 8 9 10 11 12 [13] 14 15 16 17 18 |
More Results:  Database (547) News Service (1520) Resources (268) |
|
|
Reader Mail
Wed. 12 Dec.07,
10:07
[Reply (1 of 2) to:
'double ir physic'
started by: 'soontorn siriserussa'
on Sun. 2 Dec.07]
 Category:
Sequences and Imaging Parameters
|
| double ir physic |
Different types of double inversion recovery (DIR, 2IR) sequences are used to improve the suppression of blood signal (black blood technique) or to null the signals from two different tissue types (e.g. white matter and cerebrospinal fluid).
The black blood technique (used in cardiovascular MRI) works with two inversion pulses, where the first pulse is nonselective and the second pulse is slice-selective. TI is set to a value at which the signal of the recovering inverted blood is zero (http://www.mr-tip.com/serv1.php?type=db1&dbs=Double%20Inversion).
The second technique (also named gray matter only) is used in brain imaging to improve the detection of lesions, for example in the diagnostic of multiple sclerosis. Two 180° pulses with different TI are used to suppress two different types of tissue simultaneously.
Hope this helps
|
|  View the whole thread | | |
andri anto
Mon. 14 May.07,
14:26
[Start of:
'Help!!!'
0 Reply]
Category:
Sequences and Imaging Parameters
|
| Help!!! |
Anyone!!! give me data about Sequences and Imaging Parameters for MRI Thosiba. I'm at drandri_77@yahoo.com
Help me please....
|
| | Reply to this thread
(login or register first) | |
Reader Mail
Tue. 6 Mar.07,
22:48
[Start of:
'fluid PD vs T2 weighting'
1 Reply]
Category:
Sequences and Imaging Parameters
|
| fluid PD vs T2 weighting |
Can anyone explain me, why - considering SE sequences with the same TR - fluid in a PD weighting (short TE) should have less signal than in a T2 weighting (long TE)? eg:
Fig 10, p 1397; radiographics resident tutorial: contrast mechanisms in spin echo MR imaging; Radiographics 1994; 14; pp 1389-1404
I would expect that the signal intensity of any tissue (regardless of it Proton density of T2-relaxation time) should decrease with increasing echo time.
Thank you
|
| | View the whole thread | Reply to this thread
(login or register first) | |
Brice Johnson
Wed. 14 Feb.07,
21:12
[Reply (2 of 3) to:
'LUNGS MRI'
started by: 'CLAUDIO RIBERTI'
on Fri. 20 Oct.06]
Category:
General
|
| LUNGS MRI |
the people you are looking for are the Duke CIVM, they are the real experts who pioneered hyperpolarized gas imaging of the lungs and hold all relevant patents to it.
http://www.civm.duhs.duke.edu/
|
| | View the whole thread | | |
peter hobden
Wed. 14 Feb.07,
15:35
[Reply (1 of 3) to:
'Geometric distortion'
started by: 'ergun ahunbay'
on Tue. 2 Jan.07]
Category:
Artifacts
|
| Geometric distortion |
Dear Listers,
I have some questions about the image distortions in MRI:
1) Are the magnetic field inhomogeneities the only cause of image distortions? Does RF-inhomogeneities cause distortions or just signal inaccuracies?
There are other factors that can affect the /amount/ of distortion. Run an EPI sequence and change the bandwidth and see the image change shape.
There are other causes of image distortion which are not necessarily directly related to field homogeneity.
It is a complicated question you are asking here!
2) Is it accurate to say that a spiral sequence would not have distortion due to magnetic field inhomogeneity(, but it would have blurring). Would there be image geometric distortions with a spiral imaging?
I guess you are talking about spiral filling of k-space?? The sampling time reduction will help to reduce distortion to some extent.
|
| | View the whole thread | | |
| |
| | Result Pages : 1 2 3 4 5 6 7 8 9 10 11 12 [13] 14 15 16 17 18 | |
|
| |
 | Look
Ups |
| |
|
MR-TIP.com uses cookies! By browsing MR-TIP.com, you agree to our use of cookies. | | | [last update: 2024-02-26 03:41:00] |
|
|
bottom
top
