MSK Radiology Flashcards
Interventional Radiology
Helps with:
- Biopsy
- Joint Injection
- Vertebral Augmentation
- Epidural Injection
- Nerve Block
- Tendon injection
Radiologic Exampination
a. Need at least 2 orthogonal (90 degree) views of affected bone
i. prefer frontal and lateral view
b. Additional or special views might be needed
i. such as scaphoid view of wrist
ii. axillary view of shoulder
c. Position is important
d. Want to compare views with prior exams
i. Critical to see older pictures to know what baseline and what has changed
What are two extra views that are helpful in the MSK realm?
- Scaphoid view of wrist
2. axillary view of shoulder
Radiographs are the starting point for the musculoskeletal exam
a. Radiographs are the key starting point in the evaluation of the MSK system
b. Radiographs provide information regarding:
- bones
- joints
- muscle
- fat
- neurovascular structures
c. Appropriate technique critical
d. Seek clinical history and mechanism of injury
e. Abnormal soft tissue findings are often indirect signs of subtle fractures or arthritis
One view is NO view
Cannot determine anything with just one view
How can x-rays soft tissue pictures help with diagnosis?
Abnormal soft tissue findings are often indirect signs of subtle fractures or arthritis
Especially when looking at soft tissue around joint and fat pads
Bone Anatomy
a. Describe what type of bone
b. Long Bones:
i. Epiphyseal - end part of the bone
ii. Metaphyseal- between the end of the bone and the middle
iii. Diaphyseal- the middle part of the long bone
When describing a bone abnormality
- Exact anatomic location in bone
- Fracture pattern and alignment
i. describe the distal fragment relative to the proximal fragment
ii. describe in relation to anatomical position
Long Bone wiki
Long bones, especially the femur and tibia, are subjected to most of the load during daily activities and they are crucial for skeletal mobility.
They grow primarily by elongation of the diaphysis, with an epiphysis at each end of the growing bone.
The ends of epiphyses are covered with hyaline cartilage (“articular cartilage”). The longitudinal growth of long bones is a result of endochondral ossification at the epiphyseal plate.
Advanced Imaging Techniques
- Computed Tomography (CT)
i. Excellent spatial resolution
ii. Evaluation of bone structure
iii. Depicts complex bony geometry - Magnetic Resonance Imaging (MRI)
i. Excellent soft tissue contrast
ii. Characterzes soft tissue abnormalities - Ultrasound
i. Dynamic evaluation
ii. Characterizes soft tissue abnormalities - Nuclear medicine/PET
i. metabolic information
Computed Tomography (CT)
i. Excellent spatial resolution
- x rays are still better at spatial resolution
ii. Evaluation of bone structure
- good for bone anatomy in compex areas like spine
- also complex area like pelvis
iii. Depicts complex bony geometry
Drawbacks
-not always good for certain soft tissues (like joints and such)
Magnetic Resonance Imaging (MRI)
i. Excellent soft tissue contrast
- great for menisci, labrums,
- can see sprains and such
ii. Characterizes soft tissue abnormalities
- also use for tissues and infections
Drawback:
i. some people cannot get MRI
ii. takes a long time
$$$$$
Ultrasound
i. Dynamic evaluation
- good for tissues that are closer to surface
- harder to see deeper tissues or stuff behind reflectors
ii. Characterizes soft tissue abnormalities
Nuclear medicine/PET
metabolic information
Cross Sectional Imaging Planes
- Coronal
- will cut front to back - Sagittal
- cut left to right - Axial
- cut superior to inferior
Trauma
a. Radiograph allows for rapid evaluation with excellent spatial resolution
b. Remember, always get multiple views
Trauma and CT
- a. CT allows for reconstruction in any plane from axial dataset
i. can create the other planes due to capturing tons of axial plane images
b. Helps to demonstrate complex fractures
c. May add IV or intraarictular contrast
d. Higher radiation exposure
i. too much CT scan is bad
Trauma and MRI
a. MRI allows for reconstruction in any plane
b. Excellent soft tissue contrast
c. May add IV or intra-articular contrast
d. Contraindications
i. Susceptible to motion
ii. Cumbersome in acute setting
iii. also cant use on certain patients and $$$
Arthritis
a. Radiographs show articular surfaces with excellent spatial resolution
b. Demonstrate erostions and other evidence of inflammatory arthritis (Rheumatoid Arthritis)
c. Show productive bony growth in osteoarthrosis
d. Inexpensive and document changes with time and treatment
Septic Arthritis
a. Radiographs show loss of normal cortical bone and joint space narrowing
b. May demonstrate effusion as displacement of surrounding musculature
c. Demineralization of bone suggests hyperemia and an inflammatory or infectious process is present
d. Other imaging types:
i. Cross sectional imaging may depict abnormal fluid collections or other evidence of infection
ii. Ultrasound may demonstrate effusion and direct aspiration
iii. CT may demonstrate bony destruction or cartilage loss
iv. MRI useful in characterization of bone marrow abnormalities
How other imaging helps Septic Arthritis
i. Cross sectional imaging may depict abnormal fluid collections or other evidence of infection
ii. Ultrasound may demonstrate effusion and direct aspiration
iii. CT may demonstrate bony destruction or cartilage loss
iv. MRI useful in characterization of bone marrow abnormalities
Bone and Soft Tissue Lesions
a. Imaging directed toward detection of lesions and classification as aggressive or non-aggressive
i. non-aggressive= benign
ii. Aggressive= can be malignant
b. Evaluation begins with radiographs (x-ray)
c. CT, MRI, and ultrasound provide additional information
d. Comparison with prior studies and history is critical
Non-aggressive bone lesion
a. Well circumscribed lesion with “Geographic” margin”
b. Sclerotic margin suggests slow rate of growth
c. Location near growth plate suggestive of certain class of lesions
d. Patient age narrows differential diagnosis
Radiographs provide evaluation of lesion margins, periosteal reaction, presence of matrix or soft tissue mass
Aggressive bone lesion
a. Ill defined lesion margin
b. Permeatvie destruction of bone
c. Patient age narrows differential diagnosis
