MRI - CONCATENATIONS - BACK TO BASIC

Concatenations can be difficult to understand, but yet another important parameter. This parameter is not only for the image quality, but also for the scan time reduction. I hope this video will give you a better understanding of what it is.
Remember to check out and support my PATREON here: / bacmri
Thanks for watching, following and support.
#S_MAGNETIC_VLOG #MRI #SIEMENSHEALTHINEERS #CONCATENATIONS #MEDICAL_IMAGING #MRI_TECHNOLOGIST #MEDICINE #MRI_RADIOGRAPHER #MRIRADIOGRAPHER #RADIOLOGY #PATREON
References:
Luke Bergs - Tropical Soul (Vlog No Copyright Music): rb.gy/86ed

[@moneeb343]

These "Back To Basic" series are so so sooooo good! Thank you!

[@Pimon8188]

Again a great video! And very important to also talk about the basics. Thanks so much for this valuable content!

[@MRI197]

This was very helpful thank you!! Keeping putting out these videos please love watching them to learn and refresh the important stuff!!

[@vivianetoledovts]

Wow! That’s really great! Thank you! I didn’t know about the “crosstalk” artifacts.

[@Lethmyr_]

Thanks :) Could you do a video about turbo factor? How to use it efficiently and optimal TFs for different sequences? T1, T2, STIR, PD?

[@DrunkenViet]

thank you for this! as a newbie tech, your explanations are simple and clear. Please keep coming up with more content. I'd love to see a video on phase encoding and FOV phase concepts.

[@iansze2652]

It's always best practice when you require more slices for coverage, ALWAYS do a final check of your parameters to ensure your weightings are still within range (i.e. T1, T2, PD), as adding slices will always affect TR times.

[@anniesshenanigans3815]

I definitely use it. I didn't know about the zero gap !! Thanks!!

[@leggyReid4c]

Here taking notes. Thank you , thank you.

[@dr.magnet9033]

thank you, before this video I did not know how to use these parameters correctly.

[@fraanmendieta]

great video! i will try it at work this week and see how it goes

[@philiplledo2510]

Very informative. Thanks

[@mina2306]

Very useful video , tnx.

[@LilCash217]

Can you make a video on TR values for each sequence on 3t. Etc the min and max tr for pdfs, t1,t2…. Thank you

[@SUJITHARADTECH-wo2od]

What is the difference between averages and concatenation?

[@Nguyen_MRI]

Is this a parameter you have in mind in your daily work?

[@brahimmb5495]

Yes thanks 🙏

[@dvalled18]

Of course! And also the turbo factor is another important parameter to adjust the TR and the acquisition time...

[@mirelamihaila1884]

Hey. I found your videos so helpfull especially those back tot basic, could you please do a video about the Pd, T1, T2 ranges. Thank you și much!

[@bassamalameri8804]

ماشاء الله تبارك الله ♥

[@SonaRezadoust]

i use concatenation when i have very long breath hold in abdominal examinations

[@Nguyen_MRI]

Yes good choice.

[@hunnymun1]

I used cancet. when I scan t1 post contrast study many times. When there is SAR issue, TR increases like over than 1000, then I needed to decreased TR to keep the TR contrast for t1 images by increasing cancetenation. but thanks for the idea bet relationship bet. cancat and gap factor. 👍

[@Nguyen_MRI]

thanks for your input :)

[@sajidali-pq6ws]

Hi Bac... Great video as usual.... My question is Siemens Magnetom-c open MRI dixon swap method please...

[@mihaimoldo]

Great video Bac. You get used to concats pretty early on if you read anything about TR , however I didn't consider to use it when doing 0 gap sequences , even though it makes sense and you would think it's a solution to cross talk readily at hand, I never checked if the sequence has 1 concat or 2. You've given us a new simple trick to use in our daily routine . Thanks ! Btw some books refer to the 0 slice gap as cross excitation and reserve the cross talk artifact for multi slice groups overlapping such as the Lumbar Axials where the slice group cross each other . Same artifact ofc but in practice cross excitation is usually very subtle while cross talk is a black band easily detected . Maybe it's a pedantic distinction but I find it useful in practice .

[@Nguyen_MRI]

Yeah very much agreed. ☺️

[@mihaimoldo]

@@Nguyen_MRI forgot to add one bonus of using more than 1 concat in Siemens at least is that you can see in Inline Display Tab half of the images acquired , when 1 concat is done, this allows you to check if the pacient is moving before the sequence is completed in total . For example , if your sequence is 4 min and has 2 concatenations , after 1 concat is done you can see at the minute 2 mark half of the images acquired , so if the pacient moves considerably you can stop the sequence and not waste 2 more minutes for nothing .

[@Nguyen_MRI]

@@mihaimoldo yeah a big bonus. But sometimes it just doesn’t show. I’m not sure why it does and another it doesn’t. 🧐

[@mihaimoldo]

@@Nguyen_MRI most likely a software bug.

[@Nguyen_MRI]

@@mihaimoldo I keep wishing so but I’ve seen this across old to newest software 😂. It’s awesome when it works though.

[@alisuleiman3069]

I would to Thank you a lot for your help But can I ask you how to you use the respiratory trigger correctly on siemens Cause I can't active it by physico

[@Nguyen_MRI]

It depends on sequences. Some are possible others not.

[@aruizglz]

Debería traducir al español. Gracias

[@selimakko9811]

👍🏻

[@Ifeanyi736]

Great video! Can you describe in a nutshell how the distant factor affect or causes cross talk.? I didn't get that part properly. Thanks

[@Nguyen_MRI]

mriquestions.com/cross-talk.html

[@reemsuwan7483]

Hi .can you please give us about adabatic pulse

[@Nguyen_MRI]

mriquestions.com/adiabatic-pulses.html

[@bboydoctor]

Hi Bac, the cross talk artifact should be minimized, even with one concatenation and no distance factor, by choosing the interleaved excitation mode. Can you confirm that?

[@Nguyen_MRI]

hi marco, very interesting question you ask here. the sequences are done with interleaved excitation mode. what is your experience regarding this relationship of distance factor - concats - crosstalk?

[@bboydoctor]

Actually I never tried to compare sequences to check if cross talk causes a reduction of the average signal because if we excite even slices first and then the odd ones, I don't see how the artifact can occur. But if you tell me that in your experiment you used the interleaved mode the it means that it does occur anyway. One thing that I pay attention to when I don't use distant factor is to use a normal or low SAR RF pulse type to have a sharper slice profile.

[@Nguyen_MRI]

@@bboydoctor interesting. 👍

[@samuelpistis]

I agree. Selectively exciting even slice profiles before odd ones solves the conundrum.

[@franciscosepulveda2432]

i cant enter to mri shark anymore… this site has been replaced? anybody know?

[@mootoochunasamy389]

Is concatenation present on the 1.5t ge?

[@Nguyen_MRI]

If im not wrong it’s called acquisition.

[@weweali6]

Hi sir how are u thanks for your nice videos plz in which software version can we find DRB in Siemens mri Thanks

[@Nguyen_MRI]

More info here: www.siemens-healthineers.com/no/magnetic-resonance-imaging/options-and-upgrades/clinical-applications/deep-resolve-boost

[@weweali6]

Very thank sir

[@Grazieeee-f9q]

Do you use a concatenations of 2 in STIR sequences? I heard that the lower the TR the better the suppression it would be.

[@Nguyen_MRI]

I use the same approach for stir. However, lower the tr for better fat suppression is new to me. I carefully control the TI for optimal fat suppression though. Interesting.

[@mihaimoldo]

Doesn't make any sense since your TI time is directly related to the TR. There's also a freeze suppress tissue option next the TI so it automatically changes the TI if you change the TR. STIR by definition has homogeneous fat suppression due to numerous 180° inversion pulses, thats why it was the first fat suppression technique used in the first lower fields MRIs, sadly it's susceptibile to motion and pulsation artifacts . But in newer machines especially higher fields like 3T , normal Fat sat or Dixon is preferred due to being faster and less SAR (especially important at 3T) technique .

[@Grazieeee-f9q]

@@mihaimoldo I only used the freeze option in flair. I have never heard this for stir.

[@mihaimoldo]

@@Grazieeee-f9q yeah it's rarely used in STIR . in FLAIR however is used because the TR is lower than the TR necessary for the liquid true T1 time , since the calculation is 5x T1 of the tissue for IR, that would make it in reality 15000 TR, when in most it's kept at 9000 due to time constraints . However lowering the TR in STIR for a better suppression makes no sense . Making it higher than the minimum required is what many do, the higher the TR the more signal , but ofc higher acquisition time . That's why in siemens a T2 spine STIR has higher TR than the minimum required for those nr of slices.

[@Nguyen_MRI]

It’s a bit funny because stir is one of the oldest fat suppression technique, the very first thing you read and learn. it seems easy to understand, but yet it keep surprising me through the years. 😂👍. Nevertheless, old but still powerful for certain things.

[@orcaartist]

I also increase concats when dealing with some breath-hold sequences as it will drop the breath-hold time but increase the scan time. Can you please do a video covering distance factor and cross talk? That’s new to me.

[@Nguyen_MRI]

Hi. Here you go. kzbin.info/www/bejne/iKHKi5SOlthpfas

[@aleiatar]

Hi Bac, great video as usual! I have a question about the TR in T1 sequences... In your opinion which is the TR range of a T1 on a 3T. I used to put the limit at 800ms and 900ms in case of a fat sat.

[@Nguyen_MRI]

Same here as you do.

[@billyidolman4666]

Does anyone else find this confusing as heck??