SE-EPI DWI is predominantly T2-weighted because of the 180-degree refocusing pulse, which corrects for dephasing due to field inhomogeneities. T2* effects from the EPI readout are minor.
I wanted to ask this, because he repeatedly stated that the image was T2*-weighted. But it should be T2-weighted because of the rephasing 180° RF Pulse, right?
i think vlogger is correct, because DWI has the same bad geometric distortion and signal loss (e.g. at air/tissue interface) as T2* fMRI does, but that 180 pulse throws me off too. so it would be nice if he clarified.
Why is the B0 a T2* image if there is a 180 degree RF pulse used and a longer TE? - would the 180 degree RF pulse counter the T2* effects and make a T2 image?
Excellent series, your videos have been invaluable for FRCR revision. Do you mind sharing whether the question bank will be made available to radiopaedia all access pass holders, and roughly what time frame this might be? Thanks
Even though we confirm with ADC that restriction is true why do we still value dwi more than ADC and dwi together? Like in pirads we can count high signal on dwi even with normal ADC. In general hyperintensity on dwi even without hypo on ADC should be at least suspicious.
Ive a question . How do Diffusion gradients in same directions lead to rephasing? If they were in opposite directions id get it cuz laggers become leaders but it is in the same direction so the leader will still be going faster than the lagger on the second gradient? I am considering a voxel with all in phase and then gradient along one plane in my model and applying the previous leader lagger model.
The 180 degree RF pulse causes the ‘leaders’ to become the ‘laggers’. If there was no RF pulse the diffusion gradients would need to be in opposite directions. However the 180 degree RF pulse means that the two diffusion gradients will effectively be equal and opposite.
SE-EPI DWI is predominantly T2-weighted because of the 180-degree refocusing pulse, which corrects for dephasing due to field inhomogeneities. T2* effects from the EPI readout are minor.
I wanted to ask this, because he repeatedly stated that the image was T2*-weighted. But it should be T2-weighted because of the rephasing 180° RF Pulse, right?
I had the same understanding.
Same question
Same question ~ In the previous lecture, he said it includes both T2* and T2. I didn’t fully understand, but I assumed it was beyond our scope.
i think vlogger is correct, because DWI has the same bad geometric distortion and signal loss (e.g. at air/tissue interface) as T2* fMRI does, but that 180 pulse throws me off too. so it would be nice if he clarified.
Why is the B0 a T2* image if there is a 180 degree RF pulse used and a longer TE? - would the 180 degree RF pulse counter the T2* effects and make a T2 image?
Most awaited lecture❤❤
Why is B0 a T2* W image when there is a 180 degree pulse applied at TE/2, shouldn’t it be a T2WI ?
🤦 I FINALLY understand this! Thank you so much!
Wow! Thank you so much. That’s very generous. So glad this helped!
Please can u make a detail lecture on ct scan...❤
Excellent series, your videos have been invaluable for FRCR revision.
Do you mind sharing whether the question bank will be made available to radiopaedia all access pass holders, and roughly what time frame this might be? Thanks
Thank you, much awaited
Thanks brother...because of you I understand MRI Physics...keep it up❤
Can you do a SWI susceptability weighted imaging tutorial please? Thanks so much for your work, or ngaa mihi nui as we say in Aotearoa, NZ.
thanks so much!
Even though we confirm with ADC that restriction is true why do we still value dwi more than ADC and dwi together? Like in pirads we can count high signal on dwi even with normal ADC. In general hyperintensity on dwi even without hypo on ADC should be at least suspicious.
B0 creates T2 not T2* because of 180 pulse, correct?
Kindly make videos of nuclear imaging.stay blessed.
Thank you for your great explanations! Helps a lot!! Could you please do a video about diffusion tensor imaging?
Should I learn this as an aspiring neurosurgeon?
After a long time, thnks a lot for the lectures. Love from india
Nicely understood…..please make a video on ct and mri anatomy of orbit
How many videos are there going to be in the MRI series?
Thank you!!❤
Thank you so much! This was very helpful
You are my hero
Ive a question . How do Diffusion gradients in same directions lead to rephasing?
If they were in opposite directions id get it cuz laggers become leaders but it is in the same direction so the leader will still be going faster than the lagger on the second gradient?
I am considering a voxel with all in phase and then gradient along one plane in my model and applying the previous leader lagger model.
The 180 degree RF pulse causes the ‘leaders’ to become the ‘laggers’. If there was no RF pulse the diffusion gradients would need to be in opposite directions. However the 180 degree RF pulse means that the two diffusion gradients will effectively be equal and opposite.
@@radiologytutorials somehow it makes sense now. Thank you. Master Sorcerer.
❤❤
❤❤
you're genius
Excellent series
Really helpful
Yay! :)))
❤❤
❤❤
😊😊
Thank you so much Dr
Wonderful
Simply the best. As always.
Thank you ☺️
Thank you very much indeed!
My pleasure 👍🏼