What is a Doppler test?
High freq ultrasound to measure the amount of blood flow through your arteries and veins
2 types of interactions occur during X-rays, what are they?
Penetrate and Scatter
How does an Ultrasound work?
Putting electric current through a piezoelectric crystal produces sound waves. When the sound waves return, you squeeze the crystal to convert sound to an electric current.
SONAR = Sound Navigation and Ranging
Ultrasonic devices are used to detect objects and measure distances.
Faraday cage
MRI uses same bandwidth as ABC radio hence needs to be in a copper lined room to block it out (64 Hz)
What can’t ultrasound penetrate through?
Bone, fat and gas
Nuclear medicine uses a scintillation crystal - what is it?
Gamma camera
What chemicals do we use for different areas?
Bone - phosphonate
Kidney - Mag3
Heart - Sestamibi
Thecal sac
The thecal sac or dural sac is the membranous sheath of dura mater that surrounds the spinal cord and the cauda equina. The thecal sac contains the CSF in which the spinal cord ‘floats’.
Where does pain from the lumbar spine get referred to?
Buttocks and legs -distributed along sciatic nerve
Name 2 methods that are infeffecitive for imaging spinal injuries
US - sound doesn’t penetrate bone
NM - doesn’t give info about pathology
LUMBAR VERTEBRA
- Side profile
- Anterior profile
square to rectangular
rectangular with “overhangs”
Spondylolisthesis
It is the forward displacement of a vertebra, especially the fifth lumbar vertebra, most commonly occurring after a fracture. Backward displacement is referred to as retrolisthesis
-Facet joints fail & lead to excessive forward movement & compression of nerves
Desiccation of nucleus pulposus
Process of extreme drying leads to proteoglycans of nucleus resembling coconut and no longer spongy.
What happens due to desiccation of nucleus?
Leads to annular cracks, where defect in the annulus allowing nucleus to squeeze through, causing compression on the nerves.
Disc bulge
“grand dad’s underpants” loss of elasticity & weakness of annulus fibrosis
Herniation
Protrusion - Focal extension (neck breadth > depth)
Extrusion – more extreme extension (neck breadth
Spondylitis (different to Spondylolisthesis)
- Degenerative arthritis of the spine
- Disc desiccation – loss of disc height, secondary arthritis
- Compression of trefoil appearance due to osteophytes growing off vertebral bodies
Spinal canal stenosis – What is it & treatment?
Laminectomy - a surgical operation to remove the back of one or more vertebrae, usually to give access to the spinal cord or to relieve pressure on nerves.
-Epidural steroid – cortisone anti-inflammatory drug inserted into epidural space (between bone & thecal sac
Knee is 2 shallow symmetrical sockets that are highly constrained
Knee is 2 shallow symmetrical sockets that are highly constrained
Radiographic anatomy : ball and socket (concentric rings x 2)
•rings to maintain stability
–similar to shoulder
What are the 5 layers?
Which layers are most prone to wear and tear?
- bones – layer 1
- meniscus – layer 2
- ligaments – layer 3 (most important)
- capsule – layer 4
- tendons – layer 5
Layer 1 and 2 are most prone to wear and tear
Segond fracture
Segond fracture is an avulsion fracture of the knee that involves the lateral aspect of the tibial plateau and associated with ACL tear.
Would you use X-ray or CT for patients with plasters around their leg? Why?
CT - it is cross sectional where X-ray would make it 3D to 2D
Diaphyseal aclasis
An inherited autosomal dominant disorder in which multiple osteochondromas are seen throughout the skeleton - sprouting bits of bone coming off all bones of the body
Degenerative osteoarthritis
Wearing away of articular cartilage - leading to bone spurs
How to fix articular surface that has worn out?
Knee Arthroplasty - Replacing bone of femoral condyle and tibial plateau with metal that will articulate smoothly. Polyethylene in between the metal (allows for articulation). Lasts 10 to 20 years.
What colour are menisci, tendons and lig. in MRI? Water is white on T_
Black - anything without water is black
Water is white on T2
IN MRI - What colour is cortical bone? Trabecular bone? Cartilage?
Cortical - black
Trabecular - white (contains bone marrow that is fatty)
Cartilage is grey
ACL and PCL do not heal like other ligs. in the knee, hence how do you treat it?
Take a part of the patella or semitendinousus tendon and reconstruct it where the ACL used to be
Where does joint effusion occur? How do we look at the joint?
Suprapatellar pouch using an arthogram
An arthrogram is a test using X-rays to obtain a series of pictures of a joint after a contrast material (such as a dye, water, air, or a combination of these) has been injected into the joint
Role of patella in relation to patellar tendon
Protects the tendon as it passe over bone and increases its strength.
Patellar tendinopathy
Overuse injury affecting your knee. It is the result of your patella tendon being overstressed aka jumper’s knee
What happens to patella bone in patellar tendon rupture?
The bone goes up into the thigh