SM 226a - MSK Imaging Flashcards
Which imaging modality is most commonly used during musculoskeletal procedures?
Which kinds of procedures?
Fluoroscopy
Used when injecting contrast (for arthrography), or steroids
Used to guide synovial fluid sampling
What are the imaging recommendations for evaluating neck pain?
- Plain x-ray series
- Consider MRI if x-rays are normal but there signfiicant pain or other symptoms
What is the role of ultrasound in the evaluation of musculoskeletal pathologies?
Evaluation of superficial soft tissues
Tendons, ligaments, nerves
Relative or absolute contraindication to MRI?
Aneurysm clips
Relative
(Consider postponement or other imaging modalities if posisble)
Describe the scoring system for Dual X-ray absorptiometry
-
T-score: Difference between bone mineral density of patient and the standard young adult population
- <1 SD from the mean = normal
- 1-2.4 SD from the mean = osteopenia
- >2.5 SD from mean = osteoporosis
- >2.5 SD from mean + one or mor low-trauma fractures = severe osteoporosis
- Z-score: Difference between bone mineral density of patient and the standard for patients that age (same ranges)
Relative or absolute contraindication to MRI?
Stimulator
Absolute
Which imaging modality usually guides soft-tissue procedures?
Ultrasound
What information can we learn from PET imaging?
Identify areas of increased metabolic activity
Useful in finding and evaluating cancer metastasis
What are the uses of image-guided biopsy?
Evaluate a known lesion of unknon etiology
Confirm a diagnosis
Staging of disease
Relative or absolute contraindication to MRI?
Patient’s weight exceeds the weight limit
Absolute
What are the advantages of bone scintigraphy?
What are the disadvantages?
- Advantages
- Sensitive
- Provides physiologic information about bone homeostasis
- Localize areas of high bone turnover/deposition
- Identify sites fo tumor or metastasis
- Can do whole-body imaging
- Disadvantages
- Not specific
- Time-intensive (4-6 hours)
- Exposure to ionizing radiation
What imaging modality will uncover areas of rapid bone turnover?
Bone scintigraphy
(A type of nuclear medicine)
What is a myelogram used for?
What can we learn?
Contrast is introduced into the thecal (dural) sac; contrast injection is guided by CT or fluorscopy
CT evaluates where the contrast has gone
This helps us see if there is a bone or soft tissue pathology that is affecting where the contrast goes after it is injected
What are the contraindications to arthrography?
Contrast allergy
Same as contraindications to MRI
What are the advantages of fluoroscopy?
What are the disadvantages?
- Advantages
- Dynamic imaging
- Limitations
- Radiation exposure to patient and operator
What is bone scintigraphy?
What is it used for?
A whole-body bone scan
- Normal result = normal bone
- Abnormal result indicates an area of the body with high bone turnover, but does not reveal the specific pathology
- Provides physiologic information
Relative or absolute contraindication to MRI?
Pacemaker
Absolute
What are the imaging recommendations for evaluating a neoplasm
- Plain x-ray
-
MRI with contrast
- If osseous, must image joint to joint
- Ex: if concerned about femur, get knee through hip
- Contrast helps us see if there is active blood flow (necrosis or hemorrhage)
- If osseous, must image joint to joint
- CT
-
Nuclear medicine study
- Bone scintigraphy or PET CT to identify osseous metastasis