1. The real life “super power” and how we use it to save lives
X-Ray Vision
The real life “super power” and how we use it to save lives

2. Imaging device is placed here
What is an x-ray?
A form of energy
Released from an x-ray generator and travels through a subject
Received by an imaging device (a “plate”)
X-ray generator
An x-ray is NOT an image! It is the form of energy used to create the image.
X-ray beams
Imaging device is placed here

3. A radiograph is…
The image created by x-ray beams reaching a plate after passing through a subject
Radiology is the study of x-rays and other high energy radiation

4. Let’s apply that to radiography
Light
Opaque: light does not pass through Translucent: light passes through, but diffuses
If something is opaque, light does not pass through it.
If something is translucent, light will pass through, but the image becomes fuzzy as light particles scatter and diffuse
Let’s apply that to radiography

5. Metal Bone Soft tissue Fat Air (gas)
Radiopaque
Opaque: does not let light through
Radiopaque: x-rays do not penetrate the subject, so it appears white
5 degrees of radiopacity
From most radiopaque to least radiopaque (radiolucent)
Metal
Bone
Soft tissue
Air is radiolucent, meaning x-rays pass through it completely.
Fat
Air (gas)

6. Can you identify the 5 degrees of radiopacity on this radiograph?

7. MRI Ultrasound CT scan When do we radiograph?
Radiographs are important tools, but are not the answer to every problem They don’t show internal structure of organs They are two dimensional They can’t show movement or color
Radiographs are very helpful, but sometimes we need better tools. Ultrasounds, MRIs, and CT scans are useful if we need to see internal structures or how things are moving.
MRI
Ultrasound
CT scan

8. Ventral Medial Lateral
The lingo
It’s important to know anatomical directional terms in order to properly name a radiograph Dorsal: upper side or back Ventral: underside or abdominal Lateral: side Medial: middle
Dolphin’s Dorsal fin
Ventral
Medial
Lateral

9. Views Dorsoventral view Named based on how beams enter and exit
Example: entering the back, exiting the stomach
Dorsoventral view
Now YOU try!
Entering the stomach, exiting the back:
Ventrodorsal view

10. A lateral view! It gets tricky…
What is a radiograph called when the beams are entering the right side of the body and exiting the left?
The beams are entering laterally and exiting laterally, so instead of calling the view a “lateral lateral”, clinicians simply call it a “lateral”.
It isn’t called a medial lateral or lateral medial, because the beams aren’t exiting the middle of the body. That would be silly.
A lateral view!

11. Cranial and caudal
Cranial: towards the head Caudal: towards the rear

12. A little more complicated
*On limb radiographs, we don’t call top-to-bottom views “dorsoventral” or “ventrodorsal”
We call them “craniocaudal”
and “caudocranial”

13. Reading a Radiograph
Looking at a black and white, two dimensional image of living, colorful, three dimensional structures can become very confusing 1. Use symmetry when you can. Compare both sides, legs, or whatever else that might be useful. 2. Pull your face away from the screen and scan the whole x-ray before you jump into the details. 3. After you have scanned the whole radiograph look very closely for subtle changes.

14. The Body Parts
Thorax
Abdomen
Skull
Pelvis
Pelvic Limb
Thoracic Limb

15. VD (or DV) Lateral Thorax Heart Diaphragm Esophagus
The “chest” of the animal
Structures to capture:
Esophagus
Heart
Lungs
Ribs
Spine
Diaphragm
Heart
Diaphragm
There is a bright spot on the VD view. The veterinary technician that this picture came from did not note it as being abnormal.
Since lungs are full of air, they are radiolucent.
The diaphragm is the faint line in front of the more radiopaque liver.
Esophagus
Lateral

16. Congestive heart failure
Abnormal
Congestive heart failure
Lung cancer
Tension pneumothorax (collapsed lung)

17. VD (or DV) Lateral Abdomen Spleen Intestines Liver
The “stomach” of the animal
Structures to capture:
Liver
Intestines
Spleen
Kidneys
Bladder
Spine
Spleen
Intestines
The kidneys can’t be seen in these radiographs. Normally they are easier to see in fat animals because the fat can be seen. The bladder is ventral but hard to detect.
Liver
Lateral

18. Abnormal Urinary bladder stones
Gastric Dilitation and Volvulus (GDV, aka “Bloat”)
Fractured spine
GDV:

19. VD (or DV) Lateral Skull Teeth Mandible Orbit Endotracheal tube
The skull serves as defense for the brain
Many bones compose the skull and any one of them can become damaged
The teeth and jaws attach to the skull and can be seen in a radiograph
Mandible
Orbit
Endotracheal tube
The orbit is the boney structure where the eye sits.
Mandible is the lower jaw.
Dogs are often radiographed under anesthesia as they are going in and out of surgery. The endotracheal tube shows up as a radiolucent tube.
Lateral

20. Shooting accident, 26 pellets to the head
Abnormal
Fractured mandible
Shooting accident, 26 pellets to the head
26 pellets in a dog’s head, here is the story:
Because your students will probably want to know, she survived!!!!
She lived!

21. VD (or DV) Lateral Pelvis Pelvis Hip joint Femur Femur Tibia Os penis
Structures to capture
Pelvis
Hip joint
Femur
Spine
Urinary bladder
Male: os penis
Hip joint
Femur
Lateral
The os penis is the bone found in many animal penises. Cows, horses, and people do not have them. This is not a crucial point, so if you feel your class will not receive this well, you can feel free to edit it out.
Femur
Tibia
Os penis

22. Thoracic Limb CdCr arm Lateral arm Scapula Humerus Radius Ulna
CrCd Forearm
Lateral Forearm

23. Pelvic limb CrCd Femur Lateral Femur Femur Tibia Fibula Lateral Stifle
The “stifle” refers to the genual joint, or the “knee” of most animals (except the horse, because horse people are just weird).
Tibia
Fibula
Lateral Stifle
CrCd Stifle

24. Fractures 4 types of fractures to consider: Transverse (Long) oblique
Spiral
Comminuted
Fractures are quite complex, so to keep it simple we will talk about 4 general types of fractures

25. Transverse fracture Axis of the long bone
The fracture passes at right angles to the axis of the long bone
Axis of the long bone

26. Oblique Fracture
The fracture passes at an oblique angle to the axis of the bone

27. Spiral fracture The fracture line spirals along the axis of the bone
Result of twisting injury

28. Comminuted Fracture
This fracture results in more than 2 separate bone components
Disclaimer: this is a human radiograph

29. What species?
Sometimes it’s easy to figure out what species of animal a radiograph is of

31. We have to know our species differences!
But sometimes…
It gets a lot harder
Cloven hooved animals:
Cows
Pigs
Goats
Sheep
Buffalo
So how do we determine?
We see a cloven hoof. What sort of animals do we think of having cloven hooves? So how can we tell what species our radiograph is of?
Teaching species differences takes the entire first year of vet school. In order to keep this presentation, we did not go into great detail. We wanted to offer an example to teach students the difficulty, and introduce comparative anatomy if you so choose.
We have to know our species differences!

32. Cloven Hooved Animals bear weight on two digits
Cows, goats, sheep, and buffalo bear weight on two digits
They have two full digits and two vestigial digits
Pigs bear weight on two digits They have four full digits
Vestigial: residual. Over time, these animals didn’t need those other two digits, so the bones stopped forming. These radiographs are not ideal, but we very rarely take radiographs of “normal” feet. Both of these animals were suffering from osteomyelitis and have experienced some bones loss. But you can gather the main idea even with some of the bone missing.

33. Can you identify the species?
The Hand or: Carpus, Metacarpus and Phalanges
Horse Carpus or “Knee”
Dog Paw
Cat paw
Can you identify the species?

34. What objects do you think are shown in this radiograph?
Taking two views is a very important lesson in radiology. These pictures should show your students that one look is never enough. What may not show up in one view will become very apparent in another view

35. You can’t be sure of anything until you’ve taken two views
It takes two…
You can’t be sure of anything until you’ve taken two views

36. What did this snake eat?