Dear sir, I have a quick question that I’d be grateful for your clarification. When the Dixon technique is run on a t1 sequence, on the water-only image, is the blood supposed to be hyperintense, or is it still supposed to be hypointense as on routine t1?
Hi there! Great question. When using the Dixon technique on a T1w sequence, the blood should typically still appear hypointense on the water-only image, similar to how it appears on a routine T1 sequence. Essentially, the Dixon method helps in separating fat and water signals, but it doesn't inherently change the relaxation properties of the tissues. So, if blood is hypointense on a standard T1w image, it should remain hypointense on the water-only image as well. Hope this helps!
@@everything-mri thank you Sir! Really appreciate this explanation!! It’s just that when it comes to ‘water-only’, I was confused because ‘eh, does blood belong to the category of something water-based as well??’ Hence my confusion. So if everything water-based should give hyperintense signals on water-only on T1 - but blood doesn’t fall under that category? Because I was under the impression that blood was dark on routine t1 as it’s a fluid and there’s a lot of ‘free water’ in it?
If Dixon doesn’t change the inherent relaxation property, and that’s why blood is still dark - then why is water bright on IP and water-only images on T1 sequence, after we run the Dixon?
@@rachlruby You're asking really good questions. Well done for being so proactive and I am very glad to try clarifying this matter! So, blood can be tricky because it’s a complex mixture, not just free water. On a routine T1 sequence, blood is typically dark due to the relaxation properties of hemoglobin and blood flow, not just because it’s a fluid. In the Dixon technique, water-only images isolate signals from free water molecules, like in tissues, but blood’s unique composition and flow make it hypointense on T1 weighting. While water is bright on in-phase and water-only images, blood remains dark due to its specific properties, even though we can say it contains water.
@@everything-mri Thank you sir, I’m super happy that you resolve this area of confusion for me! You are awesome for giving such clear answers! And based on what you said - here’s the last thing I need clarification for. Because I’d initially assumed that on fat-only images, both water and blood signals would be suppressed? So if we inject gadolinium, then on fat-only images, there should be no enhancement in areas with bloodflow, since the blood signals are already suppressed?
FatSaturation of Siemens is not SPIR. That is CHESS. SPIR combine the attributes of CHESS (fat-selective RF pulse and spoiler) and STIR (inversion recovery nulling of fat signal)
Thank you for flagging this. With "SPIR" we were in fact referring to the generic name regardless the vendor, to point out the differences between such a sequence and SPAIR and STIR. But thank you for suggesting the fact that it falls under another name on some specific vendors, I am sure this will clarify things to a lot of people 🙏🏻
Thank you for your message. I am not sure I fully understood your question, can you build on that and provide further details? Overall, I always recommend to do such process manually as the machine may miscalculate the frequency of the tissue to suppress and therefore the efficiency of the sequence may be inevitably impacted! Hope this partially answer you question
@@everything-mri wow, thank you for your response. Before the t1 fat sat vibe (spair fat sat) scan starts, a window of water and fat sat peak pop up that allows us to manually select the peak. There is the water and water peak on the diagram, do I need to manually select one and hit apply ? And for normal breast without implants spair image which peak should I choice and apply.
Thank for claryfing this further. So, if you acquire sequences that involve spectral saturation in breast MRI, when the frequency selection window shows up, you can choose with the right click to zoom in and look with the mouse for the 0! That’s the ideal saturation point. Then click apply and run. That’s usually the peak on the right. If you want to suppress the silicone instead, you need to usually choose the peak on the left!
Hello. There are many books that you can purchase online regarding MRI to start from the basics. One we can reccommend is definitely this one, from our dear friend Doug Boyd: boydsimaging.com/boyds-comprehensive-guide-to-mri-book/
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Perfect useful information
Thank you so much. Happy to hear that 😊
Well explained! Thank you.
Thank you so much 🙏🏻
Thanks Julien
Thank you so much pro
thank you so much pro
Dear sir, I have a quick question that I’d be grateful for your clarification. When the Dixon technique is run on a t1 sequence, on the water-only image, is the blood supposed to be hyperintense, or is it still supposed to be hypointense as on routine t1?
Hi there! Great question. When using the Dixon technique on a T1w sequence, the blood should typically still appear hypointense on the water-only image, similar to how it appears on a routine T1 sequence. Essentially, the Dixon method helps in separating fat and water signals, but it doesn't inherently change the relaxation properties of the tissues. So, if blood is hypointense on a standard T1w image, it should remain hypointense on the water-only image as well. Hope this helps!
@@everything-mri thank you Sir! Really appreciate this explanation!! It’s just that when it comes to ‘water-only’, I was confused because ‘eh, does blood belong to the category of something water-based as well??’ Hence my confusion. So if everything water-based should give hyperintense signals on water-only on T1 - but blood doesn’t fall under that category? Because I was under the impression that blood was dark on routine t1 as it’s a fluid and there’s a lot of ‘free water’ in it?
If Dixon doesn’t change the inherent relaxation property, and that’s why blood is still dark - then why is water bright on IP and water-only images on T1 sequence, after we run the Dixon?
@@rachlruby You're asking really good questions. Well done for being so proactive and I am very glad to try clarifying this matter! So, blood can be tricky because it’s a complex mixture, not just free water. On a routine T1 sequence, blood is typically dark due to the relaxation properties of hemoglobin and blood flow, not just because it’s a fluid. In the Dixon technique, water-only images isolate signals from free water molecules, like in tissues, but blood’s unique composition and flow make it hypointense on T1 weighting. While water is bright on in-phase and water-only images, blood remains dark due to its specific properties, even though we can say it contains water.
@@everything-mri Thank you sir, I’m super happy that you resolve this area of confusion for me! You are awesome for giving such clear answers! And based on what you said - here’s the last thing I need clarification for. Because I’d initially assumed that on fat-only images, both water and blood signals would be suppressed? So if we inject gadolinium, then on fat-only images, there should be no enhancement in areas with bloodflow, since the blood signals are already suppressed?
Very useful but can i get that useful information in written form.. because it is easy to learn after watching this informative video ♥️
We will definitely work on this as well. Thanks in the meantime for the support 🙏🏻
@@everything-mri yup we are waiting eagerly ♥️
I think i prefer STIR because of ( less inhomogeneity, so more contrast resolution ), moreover my dr like STIR more.
thannnk you
FatSaturation of Siemens is not SPIR. That is CHESS. SPIR combine the attributes of CHESS (fat-selective RF pulse and spoiler) and STIR (inversion recovery nulling of fat signal)
Thank you for flagging this. With "SPIR" we were in fact referring to the generic name regardless the vendor, to point out the differences between such a sequence and SPAIR and STIR. But thank you for suggesting the fact that it falls under another name on some specific vendors, I am sure this will clarify things to a lot of people 🙏🏻
We use spair t1 vibe for breast , do we need to verify the fat peak or manually select the fat peak before the post contrast portion?
Thank you for your message. I am not sure I fully understood your question, can you build on that and provide further details?
Overall, I always recommend to do such process manually as the machine may miscalculate the frequency of the tissue to suppress and therefore the efficiency of the sequence may be inevitably impacted! Hope this partially answer you question
@@everything-mri wow, thank you for your response. Before the t1 fat sat vibe (spair fat sat) scan starts, a window of water and fat sat peak pop up that allows us to manually select the peak. There is the water and water peak on the diagram, do I need to manually select one and hit apply ? And for normal breast without implants spair image which peak should I choice and apply.
Thank for claryfing this further. So, if you acquire sequences that involve spectral saturation in breast MRI, when the frequency selection window shows up, you can choose with the right click to zoom in and look with the mouse for the 0! That’s the ideal saturation point. Then click apply and run. That’s usually the peak on the right. If you want to suppress the silicone instead, you need to usually choose the peak on the left!
I want documents on MRI to learn can you help me
Thanks
Hello. There are many books that you can purchase online regarding MRI to start from the basics. One we can reccommend is definitely this one, from our dear friend Doug Boyd: boydsimaging.com/boyds-comprehensive-guide-to-mri-book/