What are some criteria that help you decide on the appropriate imaging modality?
- Body part of interest
- Differential diagnosis consideration
- Age of patient
- Patient history
- Cost of exam
- Radiation dose
Guidelines for Choosing a Modality:
1. What is the clinical question?
2. What test is most likely to answer this question? (Which are available?)
3. If more than one test will work -- think about safety for the patient first, then think about cost of the procedure
What a is good way to approach an imaging study?
Develop a consistent search pattern for evaluation
What is a reformated image?
Technology takes the image and reforms it to make it more anatomically relevant
How many views do you need in radiographs?
At least two!
One view is NO view.
What are some pitfalls of radiography?
Inappropriate projection -- pathology may be seen only on one view
Poor quality exam
Satisfaction of search
Timing of exam
Lack of correlation between imaging findings and clincial findings
Specifics: Vascular channels, accessory bones, developmental abnormalities
What imaging modality uses radioactive isotopes?
What are sesamoid bones? What is the largest sesamoid bone in the body
Bone embedded wtihin a tendon where the tendon passes over a joint.
What are a couple of examples of developmental anomalies that are seen on x-ray?
Limbus vertebral body
Pneumonic for going through possible differentials when imaging:
What sign can a periosteal reaction around a tumor cause?
What are some examples of abnormal calcifications?
Soft Tissue Hemangiomas
What is a helpful sign of injury but doesn't always manifest radiographically?
In knee, elbow, ankle, wrist, fingers
What is lipohemarthrosis?
Mixture of fat and blood in joint capsule following trauma -- can be seen in radiograph
What characteristics should you use to describe a fracture?
- Intraarticular involvement
- Open vs. closed
- Associated injuries
What is a Jone's Fracture?
Fracture at the base of the 5th metatarsal
Likelihood of non-union needs to be followed
What is a Rolando fracture?
A cominuted intra-articular fracture through the base of the 5th metatarsal
What is an avulsion fracture?
When a fragment of bone tears away from main mass of bone due to physical trauma (with ligament)
What is a Segond fracture? What injury is likely to accompany it?
Avulsion fracture of the knee that involves lateral aspect of the tibial plateau. Frequently associated with ACL tear.
What are some radiographic findings with osteoarthritis?
- Asymmetric joint loss
- Predictable pattern
What are some types of inflammatory arthritis to watch out for?
- Rheumatoid arthritis
- Seronegative syndromes: ankylosing spondylitis, reactive arthritis, psoriatic arthritis
- Deposition diseases: gout, pseudogout
Age vs. appearance
When the images do not fit the patient's age, must consider an alternative diagnosis.