Three things to remember when using parallel imaging, Be sure that there is a separation between the coil surface and the part. a towel or other thin padding makes the scanner tune to deeer tissue, increasing resolution and minimizing "shine". Shine is bad. This is true in all coil use but parallel imaging is vulnerable to this issue. It is why I fill a coil with towels, "sponges" or pads to keep them a little distanced from the coil surface. Remember, you need two coils opposite each other to use parallel techniques. Second, make sure the coils are not able to move. A coil moving is a copper wire moving through a magnetic field, which is a generator, and you will generate artifacts. An example is when scanning a lumbar spine, pelvis, or abdomen, and you use an anterior coil required by parallel techniques, if the coil is moved by the patient's breathing it will disrupt the local homogeneity. Using parallel imaging technique is so susceptible to motion, there will be artifacts if the coil moves at all. Lastly here, you MUST be sure coils are properly arranged; two coils on either side of the part, and parallel imaging only used when the plane of the slice crosses the planes of the coils. Mneumonic I just now created (patent pending lol) is "in parallel imaging the slices can't be parallel to the coils". If you are doing the same torso region mentioned above with a posterior and anterior coil, you can use parallel imaging only in the axial or sagittal planes. No parallel in the coronal planes. I even shut it off when I do a steep additional axial series through a sacrum or L5-S1 formina if the angle is steeper than say, 30 degrees, because I would not have coil at either end of my imaging plane. Hope this helps.
A washcloth may be all you can use, and trying this tilt technique may help some. But I have had to scan professional athletes who touch either side. Sad, some scanners just can't. Newer ones with wide bores can work better, some with wider homogeneic zones help too, but of course few have these yet. th-cam.com/video/-LujduSjUlE/w-d-xo.html
So, in your opinion, assuming that the coils cannot move at all, that there is a separation between them and the parts examined and that the slices being imaged are perpendicular to them, would it be a good choice to combine PI and Averages to reduce movement artifact and preserve the SNR?
hi thanks for your question. actually a very good one. well, it all depends on area of interest and what coil you are using, scanner and field strenght. on claustrophobic i guess you want to scan faster. with the newest tecnhology available i would of course use that for speed focus. but i guess you are wondering about more basic old school what to do in such situations. i would in these cases think about the base resolution. it doesnt matter trying to get sharp images if the patient cant lie still right.... so going down a little bit on the base resolution will already give you less scantime and more snr to play with. next step would be reducing an average, but also remember avg 2 and pat on will suppress the flow artifact. again depends on what you are scanning. neverthless, in the end i rather have an "ok" clinical image with short scantime rather than high resolution images with alot of movements in it. but also one last thing i want to mention. again depends on coil and scanner, higher pat tend to bring trouble, so i dont go from pat 2 to 3 just to speed up. other parameters i would choose first in such cases. hope you got your answer to the question. thanks
Thanks bac Well I’m aware of minimising scan time , my specific question was if I had to choose ipat or average which one - but I guess reducing average and reducing ipat pat2 reduces time the same - I think all coils such as knee head foot work in the same way Thankyou anyway
When choosing to use Parallel Acquisition, beside the SNR and the scan time, we should also consider that it helps in reducing artifacts such as movement and susceptibility. Be that as it may, would it be wise to combine IPAT and Averages to reduce movement artifact and preserve the SNR?
Our rads have some MSK sequences using only SE not turbo SE, we we cant run grappa on SE. However do they notice the difference? lol they probably can on their high end monitors. I can see structures on their monitors that I cant see aswell on the Siemens console.
Heheh yeah the screen is extreme indeed. I guess the problem is if they are used to see SE then suddenly structures can be a bit different on tse, they will notice.
@@kevinfeng7013 It can be used on spine imaging under certain rules. It will depend on the phase encoding direction and the number of coil elements in that direction. For axial spines you usually cannot use iPat unless you use the body array coil in addition to the spine coil. When using Siemens high coil density MSK coils you can achieve high acceleration factors due to the high number of available elements.
Do you notice a difference in SAR when you use Grappa? I have noticed on some other vendors that PI only effects SAR on 3T vs 1.5T. What has your experience been?
thank you bac.but..Iam diong mri for knee joint and when I open (pat2.pi.)by quality (F-H,flex coil). the (pi2)becomes Red in color ,why does this happened?and how to eleminate this and make it works
do you have two coils on the patient, or one coil with opposing coils inside it? The scanners nowadays with correct you like a college prof- in red ink!
Three things to remember when using parallel imaging,
Be sure that there is a separation between the coil surface and the part. a towel or other thin padding makes the scanner tune to deeer tissue, increasing resolution and minimizing "shine". Shine is bad. This is true in all coil use but parallel imaging is vulnerable to this issue. It is why I fill a coil with towels, "sponges" or pads to keep them a little distanced from the coil surface. Remember, you need two coils opposite each other to use parallel techniques.
Second, make sure the coils are not able to move. A coil moving is a copper wire moving through a magnetic field, which is a generator, and you will generate artifacts. An example is when scanning a lumbar spine, pelvis, or abdomen, and you use an anterior coil required by parallel techniques, if the coil is moved by the patient's breathing it will disrupt the local homogeneity. Using parallel imaging technique is so susceptible to motion, there will be artifacts if the coil moves at all.
Lastly here, you MUST be sure coils are properly arranged; two coils on either side of the part, and parallel imaging only used when the plane of the slice crosses the planes of the coils. Mneumonic I just now created (patent pending lol) is "in parallel imaging the slices can't be parallel to the coils". If you are doing the same torso region mentioned above with a posterior and anterior coil, you can use parallel imaging only in the axial or sagittal planes. No parallel in the coronal planes. I even shut it off when I do a steep additional axial series through a sacrum or L5-S1 formina if the angle is steeper than say, 30 degrees, because I would not have coil at either end of my imaging plane.
Hope this helps.
Thanks for comment 👍
ok cool, we try to separate but I did not appreciate the significance. Shoulders especially, really large men squeeze into the coil
A washcloth may be all you can use, and trying this tilt technique may help some. But I have had to scan professional athletes who touch either side. Sad, some scanners just can't. Newer ones with wide bores can work better, some with wider homogeneic zones help too, but of course few have these yet.
th-cam.com/video/-LujduSjUlE/w-d-xo.html
So, in your opinion, assuming that the coils cannot move at all, that there is a separation between them and the parts examined and that the slices being imaged are perpendicular to them, would it be a good choice to combine PI and Averages to reduce movement artifact and preserve the SNR?
Thanks for the heads up. I did not know that. Where can I get this info? Thanks.
Please go on 👍👍👍
this one is. really helpful THANKYOU
Thanks for sharing
Damm! Offtopic, Nice Intro 🤯🤯🤯
Awesome video 👍
great work like always bro 👌keep going 👍
Thanks much brother
Keep it going
Thanks so much I really appreciate your videos
Thank you, Bac
it was simple but very helpful to understand!👍👍😀
Thanks sir and happy Diwali from India🇮🇳 Good night sir
Keep it up bro 👌🏼we locking up for ur new big fan from Saudi Arabia 🇸🇦 hospital
Thanks for kindly words.
وفقك الله يارب
Great video, I learnt something today - thanks! Subscribed
Thank you so much :)
Great, congratulation!! But When to use the msens technique
very good question, im been using siemens for over 15y, i havent seen a good opportunity using msense. always grappa before msense. do you use msense?
If you had to choose between ipat and reducing an average for a claustrophobic patient which do you advise and why ?
hi thanks for your question. actually a very good one. well, it all depends on area of interest and what coil you are using, scanner and field strenght. on claustrophobic i guess you want to scan faster. with the newest tecnhology available i would of course use that for speed focus. but i guess you are wondering about more basic old school what to do in such situations. i would in these cases think about the base resolution. it doesnt matter trying to get sharp images if the patient cant lie still right.... so going down a little bit on the base resolution will already give you less scantime and more snr to play with. next step would be reducing an average, but also remember avg 2 and pat on will suppress the flow artifact. again depends on what you are scanning. neverthless, in the end i rather have an "ok" clinical image with short scantime rather than high resolution images with alot of movements in it. but also one last thing i want to mention. again depends on coil and scanner, higher pat tend to bring trouble, so i dont go from pat 2 to 3 just to speed up. other parameters i would choose first in such cases. hope you got your answer to the question. thanks
Thanks bac
Well I’m aware of minimising scan time , my specific question was if I had to choose ipat or average which one - but I guess reducing average and reducing ipat pat2 reduces time the same - I think all coils such as knee head foot work in the same way
Thankyou anyway
we dont use pi for any Sag spine and/or axial spine images?
Need an anterior coil. See my explanation above
When choosing to use Parallel Acquisition, beside the SNR and the scan time, we should also consider that it helps in reducing artifacts such as movement and susceptibility.
Be that as it may, would it be wise to combine IPAT and Averages to reduce movement artifact and preserve the SNR?
Please see above how I expounded on this and any addl coments are welcome!
Our rads have some MSK sequences using only SE not turbo SE, we we cant run grappa on SE. However do they notice the difference? lol they probably can on their high end monitors. I can see structures on their monitors that I cant see aswell on the Siemens console.
Heheh yeah the screen is extreme indeed. I guess the problem is if they are used to see SE then suddenly structures can be a bit different on tse, they will notice.
do you have compressed SENSE yet?
@@eppurse only for cardiac we have. How come?
@@Nguyen_MRI Cardiac uses two coils, yes?
PI always requires two coils, and you must transect both coils for it to work
@@eppurse yes thats true.
Make a video at SNR TOPIC
Have you done a video on propeller/blade k-space filling by chance? I tried looking but no luck :(
Unfortunately, no
@@Nguyen_MRI would be an interesting topic to go over all the setup and settings that would go into creating BLADE sequences though!
i second a video on propeller and blade, but a practical video about settings and a demonstration. Thanks and great videos!
Thanks for sharing this awesome technique I think there is no PI in spine imaging
can Bac explain why we dont use pi on spine please?
@@kevinfeng7013 It can be used on spine imaging under certain rules. It will depend on the phase encoding direction and the number of coil elements in that direction. For axial spines you usually cannot use iPat unless you use the body array coil in addition to the spine coil. When using Siemens high coil density MSK coils you can achieve high acceleration factors due to the high number of available elements.
Excellent ..... I wanted you to do a flow artifact tutorial on the heart scan. Thank you in advance ... Jesus bless you always 🙏 ...
Do you notice a difference in SAR when you use Grappa? I have noticed on some other vendors that PI only effects SAR on 3T vs 1.5T. What has your experience been?
Hi. I haven’t noticed anything from my experience.
What software download are you using to practice sequences
Not any specific. Directly at scanners only
Hi,
What does “PE” means on accelaration factor under GRAPPA?
Phase encoding.
Crack 🩻✔️
Hey Good Wise Teacher,
Can you please teach us how to scan "pubalgia"? Thank you in advance!
pubs.rsna.org/doi/full/10.1148/rg.285075217
@@Nguyen_MRI thanks much
radiographics has really good article on athletic pub, including scan prescriptions
Sir is parallel imaging applicable to all sequences ?
Yes most sequences.
thank you bac.but..Iam diong mri for knee joint and when I open (pat2.pi.)by quality (F-H,flex coil). the (pi2)becomes Red in color ,why does this happened?and how to eleminate this and make it works
do you have two coils on the patient, or one coil with opposing coils inside it? The scanners nowadays with correct you like a college prof- in red ink!
A là người việt ạ?
Hi, do you think it is possible to have your direct contact for a proposal?
Sure can find me at LinkedIn or here : Bac.nguyen@aristra.com
K space
the final frontier?
@@eppurse LOL