X-rays! (No specs required)

It’s March 14 (3.14): happy Pi Day, everybody!

Steve Purchase, a dentist, found himself alone with a dental X-ray machine and a Raspberry Pi one evening, so he did the obvious thing. I thought the small images he produced were really interesting, and asked him if he could come up with any higher resolution pictures. He went a bit above and beyond on my request.

I am a dentist, so am using the films I have available in work. I used a large extra-oral film of about 30cm x 15cm for the first images you saw. For these latest images, I have used my best resolution films which are a lot smaller than a Pi,  being only 3cm x 4cm.  I have stitched together parts from about 16 images to create the master image.


The X-ray machine I used for this is a Trophy CCX 70kV set.  The films are re-useable phosphor plates which are scanned into a PC using a DenOptix QST scanner made by a company called Gendex.

As always, you can click on any of these pictures to enlarge them.

These Pis are colourised artificially. The original capture is monochrome:

I’ve resized the largest pictures for this page, but you can find a 15MB .png of the monochrome image at Photobucket. The above image of twelve colourised Pis is also available as a larger .png – all the other pictures I’ve used here are the original .jpgs.

Different colourisations make different features of the Pi more obvious and easier for the eye to parse: for example, the ball grid array (BGA) assembly of the stacked processor/memory package on package (POP) in the middle of the board is crystal-clear here, with its tiny dots of solder…

…while the image below highlights the maze of tracks in all the layers of the board much more efficiently than the b/w original does.

We’ll be printing some of these off to stick on the walls at Pi Towers. Thank you very much indeed, Steve. More power to your tartar-scraping elbow, and to that sucky thing that you stick under people’s tongues to get rid of all the spit.


alex avatar

I love it. Excellent work Steve. Thanks for sharing.

Skizz avatar

Let’s hope he’s not accidentally given his Pi super powers with that does of radiation! Spider-Pi? Captain Pi-merica! Pi-clops! Pi-neto! (I’ll get my coat)

raspberrypivictim avatar

Would it be possible to have the original DICOM image ?

Thank you very much in advance !

Steve Purchase avatar

You are welcome to have the DICOM image. I have sent you a PM on the forum.

Andrew Scheller avatar

Hi Steve, could you send me a PM on the forum too? (I’m AndrewS on there).
I’ve got a couple of questions…

Ric S avatar


Cia91 avatar

Wow, great work!!

I can’t find the large version of the first photo, i want to make a poster!! :D

liz avatar

I hope Steve will swing by later and point us at it.

Steve Purchase avatar

I have tried to post some links to the larger images but my message hasn’t appeared. Possibly it’s been filtered by the forum software. I uploaded the files to Mega, I wonder if that is the problem?

Any ideas about how to get the links on here?

Andrew Scheller avatar

Maybe if you emailed Liz directly, she’d be able to add the link as an update to the blog article?

liz avatar

Please do!

Awesome avatar

I’d buy a poster of some these… perhaps the Foundation could come to an arrangement with Steve to sell some in the Raspberry Pi store?

Steve Smith avatar

New desktop wallpaper coming up….

Frank Driver avatar

Great work Steve, although now that you have blown the X-Ray budget taking photos of the Raspberry Pi does this mean no more X-Rays for your NHS patients?

Mike avatar

The article says “The films are re-useable phosphor plates”. The only other cost would be the electricity to power the X-Ray machine, so it was probably a very inexpensive exercise.

TriggerTX avatar

Unless he’s in the U.S. where the costs would be borne by his private business.

Steve Purchase avatar

My practice is virtually 100% NHS, in Nottinghamshire, UK. Like Mike says, the cost is minimal and no budgets were harmed as I did these in my own time!

Andrew Scheller avatar

So were you able to determine if your Pi needed any fillings?
I think I can guess what flavour the filling would be… ;-D

Ravenous avatar

Those are really interesting to see, especially the one highlighting the various PCB layer traces.

That one in particular should be shown to everyone on the forum who asks for yet another bespoke version of a Pi PCB…

The BGA traces under the CPU/RAM are interesting too. Kind of like my sloppier stripboard soldering efforts :(

(I’m not thinking of how much sixteen X-rays would have cost me at my dentist by the way!)

liz avatar

About those people on the forum asking for a bespoke Pi. NOTHING STOPS THEM. I get a few emails a week from people who just don’t understand that no, we can’t change the whole manufacturing process just to make 500 variant Pis for them. They also don’t understand that dropping parts would make things more, not less expensive, because of the cost of stopping and reprogramming the line.

Sometimes my politeness is tested.

Alan Heath avatar

As Billy Bragg once sang, “A virtue never tested is no virtue at all.” :)

Andrew Scheller avatar

To clarify: the “blobby” BGA bits under the CPU/RAM aren’t where the soldering has “gone sloppy” ;-) It’s just that (since this is an Xray) you’re also seeing the capacitors (and their solder) that are mounted to the back of the board. And the “blobbyness” around the edge of the CPU/RAM is because the SoC and RAM use different ball pitches http://www.raspberrypi.org/wp-content/uploads/2012/09/2012-09-21-10.58.22.jpg

P1nky avatar

These images remind me of my time identifying faults on the manufacturing line. I was working in one of the first companies to do BGA work in the UK, and was one of 3 qualified to play with operate the x-ray system.
There are times I regret becoming a sysadmin, the hardware stuff was always more fun!

George Reid avatar

Great stuff but does the Pi still work after all this x-ray bombardment?

ukscone avatar

Well Mr Pi how are you today? Horrible weather isn’t it?


Ravenous avatar

“I am not an animal, I am a human being”

(Just wanted to see if there are any more Police Squad! fans out there.)

Andy avatar

I thought the quote was “I am not a number”

Oh sorry, wrong programme. Irrational of me.

Om avatar

Awesome work………..

Pete avatar

on my desktop … Many thanks!

Ken MacIver avatar

Andy Warhol;
Eat your heart out

Definiteley shoud be a A0 print at R-Pi Central\Towers\World HQ

Gee The Rabid Inventor avatar

On the red one you can make out the coils in the RJ45 connector that caused all the troubles in the early days. :) Happy Pi Day One And All.

Andrew Scheller avatar

(I thought I’d already posted this, but maybe I’d clicked away before hitting Post Comment?)

Fantastic images! They’ll allow me to add another dimension to these images that I created almost a year ago: http://elinux.org/RPi_xray_wallpapers :-)

Another vote for making an even higher-res image available, if possible, it’d make one of my current image-processing projects easier…

Barry Matthias avatar

I have an idea?
On some dental scanners the scan runs on an arc scanning the patients teeth. Was wondering if you could take this scan and reconstruct a 3d image. This should be possible as you should be able to describe the arc mathematically and hence using a form of transposition convert the image to a 3d model as is done in 3d modelling. The only concern is how to determine the distances of each point.
Anyway the main reason for this is to generate a 3d model of each tooth so in the event of you loosing one a replacement is fabricated to replace the one the dentist extracts as the tooth stays in the jaw due to the gums and a cacuum.

Theoretically it should work with a bit of 3d mathematics.

Jim Manley avatar

As Arte Johnson’s Nazi soldier character would say on Rowan and Martin’s 1960s TV show “Laugh-In”, “Vellllly intellesthting!”

Sooooo … I’m guessing that the overvoltage bit has been blown (among other things, like every semiconductor junction) in the Pi by the 70 KeV X-ray stream? What did that poor Pi do to deserve such mistreatment? My Pii are quivering in terror having just been forced to display this Pi porn being passed off as “scientifically valuable and necessary”!

To paraphrase Charleton Heston from the 1973 science fiction flick, “Soylent Green is Pi-eople!” :D

Steve Purchase avatar

I am glad to confirm that the Pi works fine after being zapped with a 70kV beam. This voltage is only applied to the x-ray generator, and not the Pi.

Rich Kavanagh avatar

How cool?!??? :)

jay avatar

Steve, Thanks for your time .. I too enjoy all the ways we ‘look’ at things…


RicardoRix avatar

I work for an X-Ray machine manufacturer . I didn’t realise xray images would be so interesting I could have done this last August.


We have a 0.2mm diode detector in the making, see if I can get an image.

Pete Lomas avatar

Brilliant images – If it’s OK I would like to print one to go on my home office wall. It will remind me of all those ‘happy’ hours in front of the monitor figuring out how to get all the tracks out from underneath that damn chip (sorry Eben). Love it really ;-)

Melanie Taylor avatar

Sounds like the gauntlet has been thrown – I have access to a mammography machine (v. high res). Can’t do the artificial colouring but I think I might be able to sneak a picture.

JBeale avatar

If you have a greyscale image, it is very easy to do the coloring in any number of different software programs. For example in the open-source “GIMP” program, you first convert the greyscale image to RGB type (if it isn’t already) and then use the Gradient Map filter (“Colors->Map->Gradient Map”) to convert it into a false color image, using the current gradient map setting. You can do a similar thing in Photoshop, for example: http://ficpics.com/basic-gradient-maps-tutorial-for-photoshop/

Jim Keine avatar

It would be awesome to see a cat scan………

ukscone avatar

I don’t think Mooncake would sit still long enough to be x-rayed

liz avatar

She does if anaesthetised…

Andrew Scheller avatar

Does she have a maze of tracks in all her layers too?

liz avatar

No, but it’d sure be interesting to find out where all those biscuits go.

Andrew Scheller avatar

(Replying to Liz’s comment, but the blog doesn’t allow replies to be nested deep enough!)
If she’s a housecat I’m sure you have a ‘tray’ of evidence somewhere…

don isenstadt avatar

these are great pictures and glad to see that no PIs were harmed in the process. I would like to make a tee shirt transfer from one as well as hang one on the wall which I assume would be ok? ie. public domain?… thanks!

brigo avatar

Just ordered a T-shirt!

James Faulkner avatar

Hi Steve,
I would like permission to use part of one of your images for my website. I hope this would be ok. My e mail address is JGregoryFaulkner{at}gmail.com
kindest regards

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