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X Rays

Introduction
Public summary: 

Have you ever had an x-ray? Have you ever wondered how they work? Take a look at our collection of exciting x-rays and MRI scans, test your anatomical knowledge and diagnostic skills and find out about the physics behind the images.

A collection of x-rays and other forms of medical diagnostic imagery.
Useful information
Kit List: 

X-ray light box.
Collection of X-rays and MRIs.
Kettle lead with 'right-angled' end that fits.

Packing Away: 

The radiographs live in an envelope in the back of light box and in a black case.
The kettle lead has a tendency to go missing, it should be stored in one of the medic boxes (e.g. the Boris box where it doesn't take up too much space).

Frequency of use: 
5
Explanation
Explanation: 

Photo of X-rays in use
- General - What is it? Do they know when are they taken (when someone might have a fracture) and where? Asking whether they know anyone who's had one or had a plaster cast can be a good way to get their attention/persuade them that you are not a child-eating ogre.

How do x-rays work? you can talk about the production of X rays to older kids - it involves very high voltages across metal releasing photons which travel along and get stopped by things which are dense and/or which have high molecular mass (this is why calcium shows up, and explains blood being somewhat radioopaque because of its iron content - you can see blood in the heart, and you can also visualise it on CT scans, which are just X rays taken at loads of different levels and cunningly put together).

Smaller kids will appreciate something a bit like light which can go through softer things eg. skin but not harder things eg bone, metal implants. Of course then explaining a barium enema can be tricky, but you could describe it as "special liquid which can be seen on X rays".

- Ask lots of questions, get them to work out what everything is for themselves (our skeleton can help with this). If they're young it will probably take them half an hour to work out what they're looking at.

- Legs - which way up? Broken bones - Why do the kids think we take different views?-, kneecap, hip joint, bone growth can be discussed if they look clever, with the views we have of immature bones, which are still cartilagenous at the epiphyseal growth plates.

- Chest - heart, lungs, diaphragm, collarbone, ribs

- Putting stuff into body to see on x-rays -intestines, arteriograms (not everything in your body is a vein…), why have arteries

- Skull-compare with skeleton, what you can see, eyes, nose, mouth, teeth, sinuses

- pathological X-rays are great, especially to talk about hip replacements and whatever fun pathologies there are!

Basically, you can go through the x-rays however you like and develop your own spiel, but as it's one of my favourites I thought I'd write down roughly what I do!

-Start with talking about why you might have an x-ray.
-Ask them how x-rays are made. I talk about a 'special kind of light' (if they're older, you can start talking about the electromagnetic spectrum, especially if they've had a look at our UV and IR experiments) that can go through soft bits of the body but not hard bits like bone.
I get them to tell me what they would see behind me if I stood with a big light in front of me and a wall behind (my shadow). So then what would you see if they shone x-rays at me instead (a shadow of just my bones - you can talk about x-ray film here too if you like).
-What are bones for? (support, locomotion, protection - see Skeleton explanation)
-Skull x-ray - why do we have big spaces in our skull? (decrease weight)
- why do some of the teeth look different? (fillings - can talk about x-rays not passing through metal)
-Chest x-ray - identify the bones (ribs, clavicles, spine)
- identify the organs (big spaces are air-filled lungs, the thing in the middle is the heart - they're always amazed by how low and central it is)
- but I said x-rays go through soft bits? What is the heart made of? How can we see it on the x-ray? Actually, x-rays can't go through metal. Do bones have metal in them? (calcium - they usually know this or will get it with prompts about why you should drink milk to keep your bones strong) What is the heart full of? (blood) Does blood have metal in it then? (iron - they may not know this. If you like you can then talk about iron and haemoglobin and red blood cells - there are lots of tangents to go off in on this experiment, depending on what they're interested in!)
-Hand and foot x-rays - did they know they have so many bones in their foot? Compare their hands to Boris if he's nearby.
-Arm angiogram - two things you can do with this: talk about the angiogram and contrast medium etc. If doing this, compare with the barium enema. Alternatively, this radiograph is clearly of a young child - large spaces between metacarpals/phalanges, few carpals visible. Can compare to adult hand x-ray and talk about calcification, can even relate to foetal skull, especially if the model is within reach. There is a radiograph of the pelvis which is also of a child, the growth plates in the femur are clearly visible so you can compare them and talk about how space between the bones is needed for growth and you can judge the age/developmental level of a child from an x-ray.
-Pelvis - see above for growth plates. Yes, it is male (always gets some giggles if they spot the shadows!)
-Double contrast barium enema - compare with the angiogram and talk about how we can use contrast media to see things otherwise not visible on x-rays.
-Humerus with screws - get them to work out what the screws are, talk about how some breaks are so bad/misaligned that pins and screws are needed to realign the bones.

MRI images
-First point - these images were donated by a committee member, so they are not anonymised as all the radiographs (which are teaching images) are. This is fine - you just might need to know as we have in the past had members of the public tell us off for using identifiable images, but it's ok as we do have full permission!
-I usually only go on to these with older/interested kids.
-Start by asking if the images look different to the radiographs. Ask if they've heard of MRI scans/seen people on TV going into those big scanning machines. Get them to work out what part of the body you're looking at, and that it's like you've sliced across the spine in two different directions. Point out that you can see soft tissues. Talk about why this might be more useful than an x-ray (you can see more than just the bone in fine detail!)
-My explanation of MRI is a bit rough: the machine contains an extremely strong magnet. This makes all the water molecules in your body line up in the same direction like lots of little magnets (they may have played with compasses in magnetic fields at school). The machine then fires radio waves at the body. This knocks all the little spinning water molecules slightly out of line, but a different amount out of line depending on the environment of the molecule (i.e. where it is). When the radio wave is turned off, the molecules all flick back to where they were in the magnetic field, releasing energy. This energy release is captured by sensors and turned into an image.

List of Radiographs (correct as of January 2019):

Human:
1. Gastrointestinal Tract- gas/barium
2. Gastrointestinal Tract
3. Chest
4. Hands
5. Pinned Femur
6. Dislocated Shoulder
9. Left foot
10. Spinal cord at shoulder level
11. Pelvic Fracture
12. Knee- displaced patella
13. Forearm
14. Skull 2 views- radiodense (bright white) tooth = filling
15: Dislocated Elbow
16: Angiogram Lung
3xMRI of spinal cord

New batch of Animal X-Rays from Queens Veterinary Schools Hospital - these have had patient/owner details cut out and could rip along cutting lines so try to avoid this! (Jennifer's X-rays folder):
1. Dog, fractured right femur, urinary catheter in place
2. Dog, plate used to repair fractured femur
3. Dog, plate has been used to repair the fractured femur, urinary catheter in place
4. Cat, normal cervical spine
5. Dog, normal spine of a dog
6. Dog, normal thorax of a dog
7. Dog, leg extended. normal pelvis
8. Cat, fractured left femur
9. Cat, fractured left femur
10. Cat, internal repair of a fractured femur
11. Cat, domestic shorthair, external fixator on the tibia, rushpin technique on the femur to allow repair without damage to the growth plates
12. Dog, cranial cruciate ligament rupture- soft tissue within the joint, tibia is mildly displaced cranially. Also evidence of osteoarthritis.
13. Dog, TPLO (Tibial Plateau Levelling Osteotomy) used to repair the cranial cruciate ligament rupture
14. Dog, normal stifle for comparison
15. Horse, lateromedial radiograph, front foot and hind foot. Can see the shoes, nails attaching the shoes, phalanges, navicular bone, proximal sesamoids and the start of the metacarpus/metatarsus. Radiopaque hairline marker helps assess the angles within the foot and possibly help diagnose laminitis

Other animal x-rays in this folder (blue stickers):
2. Male dog angiogram - can ask about what the most important organs are (can see these as those with greatest blood supply), contrast these with limbs which have far less blood supply - important in reducing heat loss, and possible because there are no major organs in limbs and most muscles are proximal (meaning the distal limbs are mainly bone and connective tissue, which require very little blood supply)
4. Arteries of the head (dog and sheep) - can ask about why the brain needs such a good blood supply - very important organ with high energy and oxygen demand (one of the few organs which cannot survive any period of hypoxia - neuron cell death begins 4-6 minutes after blood flow stops). It also has many different large arteries going into the brain, as if there was only one and it got damaged/blocked this would cause death as brain tissue cannot survive long without oxygen (about 2-3 minutes). As it is, only a small area of the brain will be damaged - this is what a stroke is - as the other arteries will continue to supply most of the brain.
- Following on for this, can ask why the nose also has high blood supply (esp. clear in sheep) - smell is a vital sense for survival in both sheep (prey) and dogs (predators) and requires energy and oxygen to allow adequate sensitivity for their needs
9. Dog intestine and pelvis lateral view - black areas in abdomen are gas build up in intestines which is normal

Other Animal X-Rays in black case:
For some there's an information sheet which shows which x-ray is which and tells you about the animals and pictures you can put the x-rays up against to show how the skeleton fits in the body:
Common marmoset
European rabbit
Joey kangaroo
Pumpkinseed sunfish
Frontsa cichlid (fish)
Green tree python
Western diamondback rattlesnake
Infant green iguana
Dwarf crocodile eggs
Veiled chameleon
Box turtle with eggs
Red-tailed hawk
Turkey vulture
Leaf Frog

Others:
1. Puppy angiograms x2 dorsoventral and lateral views - same interesting points as dog angiogram
3. Cat Barium Contrast study - shows the presence of megaoesophagus = dilation of the oesophagus which means that most food cannot get to the stomach (instead will be regurgitated, will see weight loss because of this), can feed animals in special chairs that sit them upright like a human so gravity can help food reach the stomach.
6. Bird skull
7. Puppy pelvis - shows left hip displacement and growth plates
8. Dog intestines barium contrast study - shows food in stomach and poo in rectum

Risk Assessment
Date risk assesment last checked: 
Sun, 13/01/2019
Risk assesment checked by: 
Polly Hooton
Date risk assesment double checked: 
Fri, 25/01/2019
Risk assesment double-checked by: 
Matt Worssam
Risk Assessment: 

Looking at x-rays.

Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Light box Electrical hazard from light box. 2 4 8 See electrical parts RA (attached) 2 3 6
Light box (fluorescent tube) Flicker from the fluorescent tube in the light box has the potential to induce seizures in individuals with photosensitive epilepsy - this is very unlikely but has happened once! 2 4 8 Discourage people from staring too closely at the light box for prolonged periods, if they complain of feeling unwell switch the box off and advise them not to look at it further. Switch off the light box if necessary. Call a first aider in the event of injury. 1 4 4
Light box (weight) Possible risk of light box falling off table onto people. 3 3 9 Ensure that the light box is not close to the edge of the table and is in a stable position. Call first aider in case of injury. 2 3 6
This experiment contains mains electrical parts, see separate risk assessment.
0
Images
Publicity photo: 
Experiment photos: