5: Radiology - spine, arthritis Flashcards
The type of scan used depends on the ___ you want to see.
structures
What is the only thing you can see using X-ray of the spine?
Bones themselves
What do CT scans pick up?
Bones
Some soft tissue
What do MRI scans pick up?
Bone
Loads of soft tissue structures - discs, ligaments, nerves, spinal cord
What general shapes of the spine are seen on imaging?
Cervical lordosis
Thoracic kyphosis
Lumbar lordosis
Most vertebrae have the same structure, composed of a vertebral ___ and an (anterior / posterior) ___.
vertebral body
posterior arch
Vertebrae are held together anteriorly by ___ ___.
…and posteriorly by ___ joints.
anteriorly - intervertebral discs
posteriorly - facet joints
Consecutive vertebrae should be (similar / different) sizes.
similar sizes
The transverse processes of the thoracic vertebrae provide articulation with what?
Ribs
What are some notable features of C1?
And of C2?
C1 - Atlas - no vertebral body - anterior and posterior arches, articulates with odontoid process of C2 inferiorly and occipital bone superiorly
C2 - Axis - odontoid process forms joint with anterior arch of C1
Difference in vertebral size indicate ___.
pathology
What is a Hangman’s fracture?
Fracture of both pedicles of C2
If an X-ray doesn’t provide enough info about a spinal injury, what is the next scan used?
CT scan
What structures are responsible for spinal stability?
Ligaments
Normal vertebral alignment usually implies that the ___ are intact.
ligaments
Abnormal vertebral alignment usually implies that the ___ are damaged.
ligaments
Name the ligaments holding vertebrae together.
Supraspinous
Interspinous
Ligamentum flavum
Posterior longitudinal
Anterior longitudinal
What scan can used to see spinal ligaments?
MRI scan
On MRI, what colour are:
a) normal
b) damaged ligaments?
a) black
b) white
Why isn’t MRI commonly used to view the spine?
Normal / abnormal alignment usually gives info on ligament damage
When is MRI used in patients with suspected spinal injury?
Neuro symptoms not explained by X-ray / CT
What are some signs of vertebral tumours on X-ray and CT?
Bone sclerosis (INCREASED DENSITY)
Bone destruction (REDUCED DENSITY)
Pathological fractures
How do tumours look on MRI?
Early - infiltration of bone marrow
Late - compression of spinal cord
owls - pedicles are eyes, if owl is winking at you i.e pedicle is missing, bone destruction
What do intervertebral discs look like on X-ray?
You can’t see them
Space only
What scans are used to view intervertebral disc prolapse?
MRI
CT scan
i.e soft tissue stuff
MRI can pick up the ___ of discs, giving an indication of how damaged they are.
hydration
What is the only scan which picks up the spinal cord?
MRI scan
Is sciatica caused exclusively by prolapsed discs?
No, include tumours and other swellings
What is the role of imaging in arthritis?
Making diagnosis in the first place
Monitoring disease activity and treatment response
What are the main arthritidies seen in radiology?
OA
RA
Seronegative arthritidies
Gout
Which joints are affected by OA?
Weightbearing / active joints
i.e spine, hip, knee, thumbs, DIPs
Is OA symmetrical or asymmetrical?
Usually asymmetrical
What wears away in OA?
What’s the result?
Cartilage
Loss of joint space
Inflammation causes what sign in OA X-rays?
Increased bone turnover
causing SCLEROSIS
What causes subchondral cysts?
Leakage of synovial fluid into bone
What causes osteophyte formation?
Stimulation of periosteum at margins due to joint destruction
Where does bone sclerosis occur in OA?
Cortex
i.e subchondral, above and below joint
What is the main difference between OA and RA on X-ray?
Symmetrical bone involvement
Which joints are chiefly affected by RA?
Which joints are spared?
Synovial (inflammation of synovium)
DIPs spared
What is the first thing seen on a scan of an RA patient?
Soft tissue swelling
due to inflammation in early RA
What process, affecting density, occurs to the bone in RA patients?
Osteoporosis
What is a pannus?
What does it do to bone?
Inflamed, thickened synovium full of immune cells
Destroys bone
Pannus attacks bone (centrally / marginally).
marginally
What occurs at joints in late stage RA?
Subluxation
Tendons fail
What name is given to the process by which eroded bone fuses together?
Ankylosis
What are the typical features of seronegative arthritis on imaging?
SI joint / spine involvement
Ankylosis
Periarticular bone formation - osteophytes
What name is given to ossification of ligaments, often seen in diseases like ankylosing spondylitis?
Syndesmophytes
What is a straight, ankylotic spine called when seen on X-ray?
Bamboo spine
What scans are used to identify arthritis BEFORE it has caused joint damage?
Bone scans and ultrasound (to see increased vascularity secondary to synovitis)
MRI for bone marrow oedema
