Thanks for the words of support, these comments help me know I’m on the right track.

You’re welcome. Thanks for dropping the comment.

Glad it was helpful Erik☺️

No problem

Thanks Dark Horse, please share with your friends and coworkers

Also check out our channel for other videos especially the one on iterative recon

@@TheNettforce 👍

You’re welcome, glad you liked it

Thanks, really appreciate it.

@@HowRadiologyWorks Anyway, just have one question. When it comes to 3D reconstruction, are we gonna use the same approach (spreading evenly but in 3D rotation)?

@@binhnq_tokyo_shorts_24 yes we follow the opposite of the path of the x-rays during acquisition. So all pointed from the detector cells to the focal spot. In modern scanners this is a cone shape so it is called cone-beam CT

Thanks for teaching the next generation 😀

Glad it was helpful! Thanks Rad Resident. Where about in the world are you?

@@HowRadiologyWorks Hey. I'm located in Algeria

Glad to hear that! Thanks for the comment

You’re welcome. We have separate videos on the filter and back-projection too if you need more details.

Glad to hear that! Thanks for the comments, they are the fuel for me.

You’re welcome Harsh

Awesome, thank you! Share the Rad Love with your colleagues

We have another video on iterative reconstruction which you may have encountered. FBP is typically used as the first guess for iterative CT so it is still important.

@@HowRadiologyWorks yea u think i have seen it. I will revise the channel. Thanks a lot for your response.

Ali the Filter is just done once before the backprojection

@@HowRadiologyWorks Thanks 🌹

Thanks jicheng.

Thanks Kandavel, I can work on it. Luckily the backprojection part is the same so I think you are just asking for a more practical description of the filtering process right?

@@HowRadiologyWorks yes sir ,thank you

Yea please pass along this channel to others at your college

The raw data is corrected by what we call calibrations. It is still in the sinogram space, it is filtered along rows and then backprojected

@@TheNettforce thanks sir !

The FBP algorithm is one way to figure out the attenuation values from the line integrals. Also iterative reconstruction is another method. These methods are called image reconstruction and take many views of line integrals to perform the reconstruction.

@@HowRadiologyWorks so do i need to study calculus to understand how to get these squares value because I cannot conceptually its so hard

Peator the line integral is just a fancy way of saying add up the voxel values along a line. When we take an X-ray image this part is done automatically. Then we need to find the values for the image voxels. So the FBP converts the data to images

@@HowRadiologyWorks so how many photons or line integral pass per square cm or mm Also what if pixel size is 1mm and within this 1mm there is many or two different attenuation structure like small calcification smaller than micrometer and air what ct number is assigned to it the average but how they gonna count the attenuation cofe I tried to add the voxels values like from above and 45 degree and right but some lines pass between these two different square values Srry if im confusing u im newbie

Peator a few questions here: 1) depending on the dose there are usually something like 10,000 X-ray photons per detector

Thanks Nauka for the constructive feedback, I will try to improve the audio more over time

Peator please continue to like, comment and share. I don’t have a donate mechanism setup yet.

Thanks for your feedback.