What is tomography?

Рет қаралды 32,854

Күн бұрын

Tomography aims to reveal the internal structure of a patient based on X-ray images taken from different directions. The resulting slice image is formed with a mathematical algorithm.
I am a professional mathematician studying inverse problems of medical imaging. In this video I explain how the tomographic image is calculated. The explanation is visual and aimed at a general audience.
Thanks to Markus Juvonen for his camera work!
The music in this video is purchased from Getty Images Music and used according to the copyrights.

Пікірлер: 139

@lukeconnell215 4 жыл бұрын

Wow, one of the most informative videos I've ever seen on the topic! I love this video

@Samuntiedekanava 4 жыл бұрын

Thank you so much!!

@danlior8682 3 жыл бұрын

I'll just repeat the popular sentiment. This video is an incredibly clear, and even entertaining, description of the most fundamental reconstruction algorithm. Thank you for creating and posting it Samun. I would love to see further videos on the same topic.

@Samuntiedekanava 3 жыл бұрын

Thank you so much! For further videos coming there soon, and all in English, check out my new Inverse Problems Channel.

@SurajGupta 10 ай бұрын

Simple and fantastic way to explain the concept. Very very interesting.

@Samuntiedekanava 10 ай бұрын

Glad you liked it! 😃

@Samuntiedekanava 10 ай бұрын

Check out my other channel www.youtube.com/@professor_sam as well!

@hongyuli5490 4 жыл бұрын

OMG. This instructor is Amazing!

@Samuntiedekanava 4 жыл бұрын

Thank you! May I also recommend my follow-up video Introduction to Sparse Tomography

@alvinb.kimbowa1239 9 ай бұрын

This video is unbeliveably clear, concise, practical, and very easy to understand. It's mind blowing that I have understood computed tomography in less than 20 minutes. I've been trying to understand it for over two weeks. Thanks Samun for this amazing video.

@Samuntiedekanava 8 ай бұрын

I’m so glad to hear that! 😄 You might want to check out my newest videos on this topic on my new channel www.youtube.com/@professor_sam

@rommelreal9114 4 ай бұрын

I've been studying inverse problems and tomography in a while, and by far this is the video that explains the subject best! Wish I watched this earlier!

@Samuntiedekanava 4 ай бұрын

I am happy to hear that! Check out my other tomography videos at www.youtube.com/@professor_sam

@koushikpaul5908 4 жыл бұрын

This is one of the best explanations I have ever experienced! Thank you so much for this wonderful video!

@Samuntiedekanava 4 жыл бұрын

Well, you’re welcome! I am very glad you found my video informative. It is the result of many, many talks and presentations through which the material took form.

@yelyzavetapulnova4305 2 жыл бұрын

Amazing and comprehensive explanation ! Thanks a lot 🙏🏻

@Samuntiedekanava 2 жыл бұрын

Thank you! I am so happy to hear that you liked the video! 😀

@AnweshaKhasnobish 2 жыл бұрын

Thank you for this most simplistic yet insightful explanation of the topic

@Samuntiedekanava 2 жыл бұрын

My pleasure! I’m so glad you liked it !

@agargamer6759 2 жыл бұрын

Thank you for this illuminating explanation! Some beautiful technology and mathematics underlying what is now a routine hospital scan

@Samuntiedekanava 2 жыл бұрын

I'm glad you liked it! CT is indeed a wonder combining mathematics, physics, medicine and engineering.

@haythamali6906 Жыл бұрын

Thank you for this wonderful and simple explanation. I hope to see more lectures to you in the future face to face or in this channel. I was lucky to have met you and listened to your presenation in Japan. I hope we will meet again.

@Samuntiedekanava Жыл бұрын

I am glad to hear that you liked it! I’m looking forward to seeing you the next time. Meanwhile, check out my new channel “Professor Sam”. I have more lecture videos in English coming up soon.

@lwendt1 4 жыл бұрын

This is GREAT! I'll check out more videos!

@Samuntiedekanava 3 жыл бұрын

Thank you so much! 😃

@laurensullyx 4 жыл бұрын

Great video! Best ive seen on the topic, feel like I actually understand now

@Samuntiedekanava 4 жыл бұрын

Great to hear! I did dozens of test runs with this material, so it did evolve step by step into more understandable form. I am so glad you like it.

@dongliu2650 4 жыл бұрын

Ihan hyva. Excellent introduction and nice scenarios. kiitos Samu.

@Samuntiedekanava 4 жыл бұрын

Dong, thank you so much! 😃👍🏻

@lauri2253 4 жыл бұрын

Aivan huikea video, kiitos!

@Samuntiedekanava 4 жыл бұрын

Lauri22, hauska kuulla!

@tamerdawud6930 11 ай бұрын

Nice and easy explanation, Thanks!

@Samuntiedekanava 11 ай бұрын

I’m glad to hear that you liked it! 😃👍🏻

@dianac4480 3 жыл бұрын

Great explanation! thank you!!!

@Samuntiedekanava 3 жыл бұрын

Thanks! I am glad you like it!

@toomuch_thyme 3 жыл бұрын

I love this, I started for knowledge, and finished for the entertainment!

@Samuntiedekanava 3 жыл бұрын

Excellent! I am so glad to hear that! 😃

@anitha998 3 жыл бұрын

You Sir are amazing! Loved how well you've explained this rather difficult concept!

@Samuntiedekanava 3 жыл бұрын

Thanks, Anitha! It developed through dozens of lectures, conference talks and school visits. Step by step I added animations, explanations, and of course, jokes. 😃

@Fdan36 Жыл бұрын

@@Samuntiedekanava thank you Sir. Your explanation of the development of the development of the video is as enlightening as the video itself.

@xiaogecheng3335 4 жыл бұрын

Interesting explanation, love it ! 👍🏻👍🏻👍🏻

@Samuntiedekanava 4 жыл бұрын

Thanks! 😃

@vinitpandya02 2 жыл бұрын

Excellent explanation! I couldn't get a better non-mathematical explanation from a mathematician! 😄

@Samuntiedekanava 2 жыл бұрын

Thanks! I’m glad you like it! 👍🏻

@tedwang2996 Жыл бұрын

very clear Pronunciation，and idea ez to get, love it!

@Samuntiedekanava Жыл бұрын

Thanks, Ted! I’m glad you like it! 😃

@deudaux Жыл бұрын

Thank you, this is great!

@Samuntiedekanava Жыл бұрын

Nice to hear! Check out my new channel www.youtube.com/@professor_sam There will be a full course about the same stuff but going eventually deeper

@jorgeluisochoa2704 4 жыл бұрын

Superb way of explaining. Congrats! I really learned something amazing today?

@Samuntiedekanava 4 жыл бұрын

Thank you! I am so happy to hear that. This video is a result of dozens of talks and lectures, gradually improving the way to explain. There is a sequel (kzfaq.info/get/bejne/mNGWf6x6tdzNiGg.html), and more on the way.

@paoloose Жыл бұрын

I really loved this, such a wonderful explanation

@Samuntiedekanava Жыл бұрын

Thanks, Paolo! Please check out my new English channel for more: www.youtube.com/@professor_sam

@dHewlett 4 жыл бұрын

This is fantastic! Sharing it with my Tech Bandit kids this week! Thank you so much... funny, smart and informative!

@Samuntiedekanava 4 жыл бұрын

dHewlett, thank you so much! I am so glad to hear you like the video. I did have a few test runs before the material found its final form... 😃

@Samuntiedekanava 4 жыл бұрын

dHewlett, next in the series are coming up videos on sparse-angle tomography, limited-angle tomography and time-dependent imaging. That takes us to current science.

@Samuntiedekanava 4 жыл бұрын

Here is a sequel: kzfaq.info/get/bejne/mNGWf6x6tdzNiGg.html

@monirulhoqueshraban5922 Жыл бұрын

Very nice video. Helped me a lot to understand the topic. Thank you.

@Samuntiedekanava Жыл бұрын

I am happy to hear that! 😃👍🏻

@Anilkumar-zz6lo 3 жыл бұрын

Wow superb explanation sir. Loved tour style and the content.

@Samuntiedekanava 3 жыл бұрын

Thanks, Anil! Much appreciated.

@TSSomensi 3 жыл бұрын

Outstanding content!

@Samuntiedekanava 3 жыл бұрын

Thank you! 😊

@ErichAmMeer 2 жыл бұрын

INCREDIBLE VIDEO!!!!!!!

@Samuntiedekanava 2 жыл бұрын

Thank you so much! ☺️

@FirstnameLastname-fd9cp Жыл бұрын

Excellent video. This was quite infomrative and has provided me with a good starting point to learn about this subject. Thank you for this.

@Samuntiedekanava Жыл бұрын

I am so happy to hear that! 😃

@Samuntiedekanava Жыл бұрын

Please check out my new channel “Professor Sam “. I am building there a comprehensive video series on this topic. So far there are two: Tomography 101 and 102, and soon will be more

@FirstnameLastname-fd9cp Жыл бұрын

@@Samuntiedekanava brilliant, I'll be sure to check out this channel.

@sridharvinod8667 3 жыл бұрын

great explanation. thank you.

@Samuntiedekanava 3 жыл бұрын

Thank you so much! I am so happy to hear that you liked the video.

@JollyJackfruit 3 жыл бұрын

Excellent video 👏👏👏

@Samuntiedekanava 3 жыл бұрын

Thank you! 😃

@vegetablebake 2 жыл бұрын

Very helpful, thanks.

@Samuntiedekanava 2 жыл бұрын

Thank you so much!!

@rakshitp9124 3 жыл бұрын

This is so good. Thank you so much :)

@Samuntiedekanava 3 жыл бұрын

Thank you! I am so glad to hear that you like it! 😃

@mdmubaraq 3 жыл бұрын

Thanks for explaining complicated subject in a simple way

@Samuntiedekanava 3 жыл бұрын

You’re welcome! I am very glad to hear that you liked the video. I believe that even complicated math can be explained in an understandable way.

@Samuntiedekanava 3 жыл бұрын

Mohamed, you might like this one as well: kzfaq.info/get/bejne/gMV8mZh2qd_Dh5c.html

@spider853 2 жыл бұрын

Thanks for such a wonderful video! I was wondering wouldn't the edge filter in the 2 disc scene result in 2 hollow circles?

@Samuntiedekanava 2 жыл бұрын

The photo example is indeed a bit exaggerated, for clarity. For example, it involves taking the absolute value, which the FBP process does not use. But in FBP the filter just perfectly removes the blur. If you apply it another time, though, you would indeed see two hollow circles!

@AbhishekPandey-qj7nk 3 жыл бұрын

you are a lifesaver Professor

@Samuntiedekanava 3 жыл бұрын

Thank you so much! 😊

@yelectric1893 2 жыл бұрын

Beautiful

@Samuntiedekanava 2 жыл бұрын

Thank you!! :-)

@julioreyram 3 жыл бұрын

Hahahaha so much fun while learning amazing stuff, what a lovely guy!!

@Samuntiedekanava 3 жыл бұрын

Thank you! I’m glad you liked it! 👍🏻

@Mark-te8ky 2 жыл бұрын

cool video! 😊

@Samuntiedekanava 2 жыл бұрын

Thanks!!

@VarunJS45 3 жыл бұрын

You are a very good teacher. Love from India 🙏

@Samuntiedekanava 3 жыл бұрын

Thank you so much! 😃

@sharonshajan6995 3 жыл бұрын

thankyou. this is very good quality content..

@Samuntiedekanava 3 жыл бұрын

I am so glad you like it! It is developed as a result of dozens of seminar talks, conference presentations and school visits.

@ahmedshaheen9759 3 жыл бұрын

Wow!! Thanks a lot. I am seismologist. We send sound waves into the ground and measure the response. Quite an analogous field. Thanks a lot. It helps to understand a lot of papers in the field. Is it possible to make videos for tests similar to those in this video but with the Math behind ? Thanks again

@Samuntiedekanava 3 жыл бұрын

You can find the math in my lecture videos, for example in this playlist: kzfaq.info/sun/PL5Ai_qOtp0HSVe3V8fmxDZvwHyDeTv79o

@ranitroy7994 4 жыл бұрын

Thank You so much for this beautiful explanation. I have a question about the filter that you are using in the Fourier Space. With the increase in the amplitude in the Fourier space there should be an increase in the Noise. Is that an issue faced with the current system?

@Samuntiedekanava 4 жыл бұрын

Indeed it is an issue. In practical FBP algorithms there is a variety of high-frequency cutoff or suppression filters. For example, instead of indefinitely increasing the frequency response linearly, it may become constant outside a disc. In this presentation I chose to talk about the ideal mathematical situation only, for brevity.

@ranitroy7994 4 жыл бұрын

@@Samuntiedekanava Thank You so much for the explanation.

@abhishekjadhav5957 3 жыл бұрын

Wow.. Logarithm is useful... Amazing..

@Samuntiedekanava 3 жыл бұрын

Yes, logarithms are useful! Another application of logarithm is radiocarbon dating of ancient objects.

@tongzhou4997 3 жыл бұрын

hello kitty is definitely a highlight

@Samuntiedekanava 3 жыл бұрын

I think so, too!

@jaswanthbeere3836 Жыл бұрын

amazing

@Samuntiedekanava Жыл бұрын

Thanks 😊

@rohandeshmukh1815 2 жыл бұрын

Great video thanks! But why are your other videos in other language (probably finnish)

@Samuntiedekanava 2 жыл бұрын

There is so little science stuff available in KZfaq in Finnish! I am trying to offer Finnish kids starting points to math and science. However, most videos have English subtitles. And: check out Inverse Problems Channel, for example this video: kzfaq.info/get/bejne/gMV8mZh2qd_Dh5c.html

@ilpokantonen6129 4 жыл бұрын

Entä jos kappaleet eivät ole staattisia? Luulen, että liikkuvia kappaleitakin voidaan kuvata tomografialla. Liikkeitä voi olla kahdenlaisia: paikka liikkuu tai muoto liikkuu. What if the object isn't static? I think that moving objects can also be imaged by tomography. There are two types of movements: the place moves or the shape moves.

@Samuntiedekanava 4 жыл бұрын

Erinomainen kysymys. Tämä on yksi tutkimusaiheistani parhaillaan. Liikkuvan kohteen kuvaaminen onnistuu kohtuullisen hyvin esimerkiksi videon käsittelyyn kehitetyn optisen virtauksen avulla. Täytyypä tehdä oma videonsa siitä!

@emmah3514 4 жыл бұрын

May I reuse 5:28 to 5:38 to illustrate how reconstruction works in my school presentation? I'll be sure to give you credit!

@Samuntiedekanava 4 жыл бұрын

Sure, please go ahead! That’s why I made the video: for spreading information. 😃👍🏻

@emmah3514 4 жыл бұрын

@@Samuntiedekanava thank you so much :D

@FabledRanoo 2 жыл бұрын

please i need books and sources about tomography ( not computed tomography ) but tomograph overall

@Samuntiedekanava 2 жыл бұрын

Check out Mueller&Siltanen: Linear and nonlinear inverse problems with practical applications (SIAM 2012)

@FabledRanoo 2 жыл бұрын

@@Samuntiedekanava thank you so much

@Anilkumar-zz6lo 3 жыл бұрын

Sir please make some video on FFT and Image processing techniques.

@Samuntiedekanava 3 жыл бұрын

I will! Right now I only have this, and unfortunately in Finnish. kzfaq.info/get/bejne/pNGTla5py6i9ZJs.html

@sepidehmajd593 2 жыл бұрын

The last moment is creepy, but the rest informative

@Samuntiedekanava 2 жыл бұрын

Thank you! 😃👍🏻👍🏻👍🏻

@sepidehmajd593 2 жыл бұрын

@@Samuntiedekanava I am going to do my master thesis in hydraulic tomography and it contains invers modeling, I saw one of your videos about inverse problems and that was wonderful, I appreciate it

@AkhilVennam 4 жыл бұрын

Sir, you made yourself these animations ? With those graphs ?

@Samuntiedekanava 4 жыл бұрын

I did the animations myself using MATLAB software. If you are interested I am happy to share them.

@AkhilVennam 4 жыл бұрын

@@Samuntiedekanava yes sir. I like them. Happy to have them. Really cool. My mail : vennamakhil@gmail.com Or else, share the link here sir.

@frodobaggins3974 3 жыл бұрын

Back projection... It amazes me that this method is still widely used. We now have many better algorithms, and contemporary computers have the power to handle them. SIRT would be one example, but there are others.

@Samuntiedekanava 3 жыл бұрын

However, iterative algorithms such as ART, SIRT and variational regularization, do make use of the transpose of the measurement matrix. And that is actually (unfiltered) backprojection. So it does stay relevant! 😃

@user-pj7oy3qy8u 3 жыл бұрын

This is Great!!!ㄷㄷ OMG...ㅠㅠ

@Samuntiedekanava 3 жыл бұрын

Thank you so much! 😃

@jegadeesangovindarajan972 4 жыл бұрын

nice work easy to understand ..... can we do the same animation in python

@Samuntiedekanava 4 жыл бұрын

Yes, definitely. You just need an implementation of the Radon transform. And a lot of coding.

@shannondoyle5143 3 жыл бұрын

it's batman :D hahaha this is great, enjoyed the tests

@Samuntiedekanava 3 жыл бұрын

Great! I’m glad to hear that! 😃👍🏻

@HeikkiMakes 4 жыл бұрын

Olipas mielenkiintoinen ja ihan sattumaa että tässä lounaalla tämän katsoin. Meille on töihin ehkä tulossa joku 3D röntgen skannausvärkki jos saadaan hankerahoitus kasaan. Sillä pääsisi ilmeisesti nanotarkkuuteen ja kappaleet olis jotain nyrkin kokoisia. Yritysten rahaa puuttuu...

@Samuntiedekanava 4 жыл бұрын

Heikki Makes, kuulostaapa mielenkiintoiselta! Juväskylän yliopistossa muistan myös nähneeni nanotomografialaitteen noin kymmenen vuotta sitten. Kehitystä on varmasti tapahtunut laitepuolellakin!

@HeikkiMakes 4 жыл бұрын

@@Samuntiedekanava Luulisi ainakin hintojen tulleen alaspäin. Tämä laite, jos hanke toteutuu, tulee Mikkeliin Xamkille (Kaakkois-Suomen ammattikorkeakoulu).

@Samuntiedekanava 4 жыл бұрын

@@HeikkiMakes, aivan loistavaa.