PARALLEL IMAGING

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Күн бұрын

Пікірлер: 68

@eppurse 3 жыл бұрын

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.

@Nguyen_MRI 3 жыл бұрын

Thanks for comment 👍

@johnthomas4713 3 жыл бұрын

ok cool, we try to separate but I did not appreciate the significance. Shoulders especially, really large men squeeze into the coil

@eppurse 3 жыл бұрын

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. kzbin.info/www/bejne/Y33Ym5eriM-Ioqc

@bboydoctor 3 жыл бұрын

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?

@SC-gh6gd 3 жыл бұрын

Thanks for the heads up. I did not know that. Where can I get this info? Thanks.

@badrlinux6786 4 жыл бұрын

great work like always bro 👌keep going 👍

@frankiechankf1 4 жыл бұрын

Thanks for sharing

@VishalSharma-p5y Жыл бұрын

this one is. really helpful THANKYOU

@klompmer 4 жыл бұрын

Damm! Offtopic, Nice Intro 🤯🤯🤯

@SC-gh6gd 3 жыл бұрын

Awesome video 👍

@SauravChandraB 3 жыл бұрын

Great video, I learnt something today - thanks! Subscribed

@gulnaragayeva170 3 жыл бұрын

Please go on 👍👍👍

@iracvillar5576 Жыл бұрын

Great, congratulation!! But When to use the msens technique

@Nguyen_MRI Жыл бұрын

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?

@332meshoo 4 жыл бұрын

Keep it up bro 👌🏼we locking up for ur new big fan from Saudi Arabia 🇸🇦 hospital

@Nguyen_MRI 4 жыл бұрын

Thanks for kindly words.

@abrabr6720 4 жыл бұрын

وفقك الله يارب

@merythsmirnoff6263 4 жыл бұрын

Thanks so much I really appreciate your videos

@hunnymun1 2 жыл бұрын

Thank you, Bac it was simple but very helpful to understand!👍👍😀

@abrabr6720 4 жыл бұрын

Thanks much brother Keep it going

@ashutoshthakursingh9128 4 жыл бұрын

Thanks sir and happy Diwali from India🇮🇳 Good night sir

@mohamedkhalil4890 4 жыл бұрын

Thank you so much :)

@pro-scanimaging9681 3 жыл бұрын

If you had to choose between ipat and reducing an average for a claustrophobic patient which do you advise and why ?

@Nguyen_MRI 3 жыл бұрын

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

@pro-scanimaging9681 3 жыл бұрын

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

@assasin1011 3 жыл бұрын

What software download are you using to practice sequences

@Nguyen_MRI 3 жыл бұрын

Not any specific. Directly at scanners only

@ryandraeger6392 4 жыл бұрын

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?

@Nguyen_MRI 4 жыл бұрын

Hi. I haven’t noticed anything from my experience.

@kevinfeng7013 4 жыл бұрын

we dont use pi for any Sag spine and/or axial spine images?

@eppurse 3 жыл бұрын

Need an anterior coil. See my explanation above

@johnthomas4713 4 жыл бұрын

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.

@Nguyen_MRI 4 жыл бұрын

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.

@eppurse 3 жыл бұрын

do you have compressed SENSE yet?

@Nguyen_MRI 3 жыл бұрын

@@eppurse only for cardiac we have. How come?

@eppurse 3 жыл бұрын

@@Nguyen_MRI Cardiac uses two coils, yes? PI always requires two coils, and you must transect both coils for it to work

@Nguyen_MRI 3 жыл бұрын

@@eppurse yes thats true.

@jfbrko290 Жыл бұрын

Have you done a video on propeller/blade k-space filling by chance? I tried looking but no luck :(

@Nguyen_MRI Жыл бұрын

Unfortunately, no

@jfbrko290 Жыл бұрын

@@Nguyen_MRI would be an interesting topic to go over all the setup and settings that would go into creating BLADE sequences though!

@lmuscae1 Жыл бұрын

i second a video on propeller and blade, but a practical video about settings and a demonstration. Thanks and great videos!

@luizgonzagajr7755 4 жыл бұрын

Excellent ..... I wanted you to do a flow artifact tutorial on the heart scan. Thank you in advance ... Jesus bless you always 🙏 ...

@patrickivancruz1421 2 жыл бұрын

Hi, What does “PE” means on accelaration factor under GRAPPA?

@Nguyen_MRI 2 жыл бұрын

Phase encoding.

@mrmimu 4 жыл бұрын

Thanks for sharing this awesome technique I think there is no PI in spine imaging

@kevinfeng7013 4 жыл бұрын

can Bac explain why we dont use pi on spine please?

@joejoslin6268 4 жыл бұрын

@@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.

@bboydoctor 4 жыл бұрын

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?

@eppurse 3 жыл бұрын

Please see above how I expounded on this and any addl coments are welcome!

@mehfil-e-imroj 2 жыл бұрын

Make a video at SNR TOPIC

@jalilmahmud5071 4 жыл бұрын

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

@eppurse 3 жыл бұрын

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!