 | Info
Sheets |
| | | | | | | | | | | | | | | | | | | | | | | | |
 | Out-
side |
| | | | |
|
| | | | | |
| Result: Searchterm 'Second'
found in 24 messages |
| Result Pages: [1] 2 3 4 5 |
More Results:  Database (79) News Service (51) Resources (6) |
|
|
Clifford Thornton
Thu. 30 Jun.16,
17:48
[Start of:
'Max. SAR per second - Whole Body (Normal, 1st Controlled, 2nd Control)'
0 Reply]
 Category:
Safety
|
| Max. SAR per second - Whole Body (Normal, 1st Controlled, 2nd Control) |
Hello fellow imaging technologists & professionals!
I'm involved in the development of a new type of cardiovascular medical device.
This device employs MRI technology/scans to power, guide, and control the medical devices and their active elements.
I conducted some research into the following question, "How much x-ray energy is allowed within a human every sec from a MRI machine?"
With regards to SAR rates, I understand that these are the upper-limits for the various settings for a full-body scan:
Normal setting: Whole body SAR - 2
1st Level Controlled: Whole body SAR - 4
2nd Level Controlled: Whole body SAR - >4
Would you agree with these calculations that I performed, and if not, why? And what would be a better way to calculate this?
For WHOLE BODY SAR:
-SO IF IN NORMAL MODE FOR MRI, THE MAX. ALLOWABLE SAR IS "2" OVER A 6 MIN. PERIOD, THEN
-6 MIN. = 360 SECONDS
-2 / 360 = 0.00555
FOR 1ST LEVEL CONTROLLED:
-SO IF IN 1ST LEVEL CONTROLLED FOR MRI, THE MAX. ALLOWABLE SAR IS "4" OVER A 6 MIN. PERIOD, THEN
-6 MIN. = 360 SECONDS
-4/ 360 = 0.01111
Other questions -- What is the difference between normal setting, 1st conrolled and 2nd controlled?
What is the clinical purpose of these various settings?
Any insights that you would be willing to share in regards to the above would be greatly appreciated!
I was trained and registred as a diagnostic echocardiographer, specializing in cardiovascular ultrasound, therefore I need help with MRI information/specifications. I am now focusing on the medical device field, but this technology/device happens to be highly dependent on MRI technology.
Any help from the group would be greatly appreciated!!
Thanks & regards,
Clifford Thornton
|
| |  Reply to this thread
(login or register first) | |
Reader Mail
Fri. 30 Dec.16,
07:16
[Start of:
'Second contrast dosage on COW MRA'
0 Reply]
Category:
Applications and Examinations
|
| Second contrast dosage on COW MRA |
Did anyone know how much Gadovist should I inject after first time COW MRA is failed on 1.5T Philips TOF sequence.
First time dosage is 0.15ml/kg
(Patient with normal kidney function eGFR>60)
|
| | Reply to this thread
(login or register first) | | |
|
Brian Smith
Wed. 16 Nov.22,
12:33
[Start of:
'Siemens Espree Help'
1 Reply]
Category:
Protocols
|
| Siemens Espree Help |
Hello all. My facility switched from Siemens Espree 1.5T to Philips Ingenia 1.5T a year ago. I recently picked up a second job at a small imaging facility. I have forgot almost everything about this machine and the protocols saved on the machine are horrific! The full time tech that works there is green and doesn't know what can and can't be changed.
Does anyone have any protocol information for this machine? I just don't have the time to rebuild all these protocols and am looking for a good base or some that a tech has tuned to their liking. Any help is greatly appreciated!
|
| | View the whole thread | Reply to this thread
(login or register first) | |
Herbert Müller
Thu. 5 May.22,
01:33
[Reply (11 of 12) to:
'90 excitation pulse vs 180 inversion pulse'
started by: 'Bjorn Redfors'
on Sat. 27 Jun.09]
Category:
Basics and Physics
|
| 90 excitation pulse vs 180 inversion pulse |
Hello,
I dont know if anyone has, for him/herself, answered this question. I know it is an old thread. But this is the question which also botheres me the most in NMR/MRI.
I refer now to a picture, which is illustrated in the book from Tim Claridge (High resolution NMR techniques).
Here, a RF pulse (lets say a 90 degree pulse) is said to have two effects on the initial z-magnetisation. First, it allows energy transfer between the two Zeeman-states in a way, that i equalizes the population difference between them. So there is no z- magnetisation anymore after 90 degree pulse. Th esecond effect is, that it induces phase-coherence. And this phase coherence is then responsible for the x-magnetisation, which is measured.
And now I have the same question. Why is this phase coherence lost (or is it not?), when applying an initial 180-degree pulse. Understandable for me is, why the population difference in z is reversed, but I dont understand, why there is no xy magnetisation anymore.
Maybe some of you have figured out the answer in the meantime?
Greetings
|
| | View the whole thread | | |
Avi Rokach
Mon. 7 Dec.20,
09:45
[Start of:
'MRI and hearing loss'
1 Reply]
Category:
General
|
| MRI and hearing loss |
Hi,
I have tinnitus and pressure in the ear for 2.5 months and hearing loss in the left ear in 3khz (20db)
I was with 2 doctors and they give me a different MRI
The first gives me an MRI for the brain and Skull base and the second gives me an MRI for the ears?
What is the difference between them and what is best for me to find the tinnitus case?
Thanks!
|
| | View the whole thread | Reply to this thread
(login or register first) |
| |
| | Result Pages : [1] 2 3 4 5 | |
|
| |
 | Look
Ups |
| |
bottom
top
