L1 Fundamentals Flashcards
Radiolucent
film black w/out absorption
less dense material
can see through
Radiopaque
white with w/out penetration
more dense material
can’t see through
Radiolucent to Radiopaque tissues
Gas
Fat
Water
Bone
Contrast Media
Heavy metal
Factors that impact image quality
- thickness of body part
- motion
- scatter
- magnification
- distortion
Motion
causes blurring
can overcome by shortening the exposure time and using an intensifying screen that is found in all film holders
Scatter
produced by deflection of some of the primary x-ray beam
a grid is used to reduce scatter
Magnification
as an object moves toward the source of x-ray beam, shadow becomes larger
Distortion
occurs when the object is not perpendicular to x-ray beam
Plain Films
- same as x-ray
- most common diagnostic imaging format
- no contrast material is used to enhance various body structures
ABCS for X-ray
Alignment
Bone
Cartilage
Soft Tissues
Alignment
- size of bone
- count number of bones
- normal contour and shape bones
- position of bone in relation to joint
Bone
- bone density
- weight bearing surfaces
- texture
Cartilage
- joint space
- subchondral bone
- growth plates and epiphysis
Soft Tissue
- gross size
- joint capsule outline
- periosteum
Radiographic signs of fracture
- focal discontinuity in structure
- displacement
- focal alteration in smooth contour
- change in the shape
- linear region of sclerosis
- lucent line
- avulsion fragment
- double density
- abnormal fat pad
Radiographic signs of open fractures
- soft tissue defects
- bone fragment protruding beyond soft tissues
- gas in soft tissues
- intraarticular gas
- presence of foreign body
- missing bone fragments
Radiographic Findings in Stress Fractures
- normal
- soft tissue swelling
- graying of cortex
- multiple transverse lucencies
- fracture line
- periosteal reaction
- endosteal sclerosis
- fuzzy linear densities
- curvilinear sclerosis
- cortical thickening
Hallmarks of OA
- joint space narrowing
- bone spurs
- sclerotic borders
- subchondral bone cysts
Jefferson Fx
burst fracture of C1
Hangman’s Fx
fracture through posterior element of C2
Clay Shoveler’s Fx
C7 spinous process fracture
Salter-Harris system
physial fractures in kids
1. Physis
2. Metaphysis and physis
3. Physis and Epiphysis
4. Through physis, metaphysis, epiphysis
5. Crush/compression
Bone Scan
- uses marker to reflect increased blood flow and metabolsim
- useful for dx of subtle fractures, avascular necrosis, decreased blood flow, mets, osteomyelitis, prosthetic loosening
- high sensitivity, low specificity
Ultrasoundography
- used for soft tissue pathology, tendon, muscle tears, nerve entrapment, healing fracture, defect in cartilage
- low cost and portable, no known hazards
- limited view, more operator dependent, deep structures are not visible
Compute Tomgraphy
- combines x-ray with compute
- provides 3d images in any plane
*best for loose bodies, subtle/complex fx, degenerati e changes, serious trauma, spinal stenosis - provides axial images only, limited tissue imaging, high radiation
Magnetic Resonance Imaging
- non-ionizing imaging
- does great with soft tissue
- poor with bone, expensive, time consuming, not comfortable for patient
- cannot be done with metal in the body
- multiple sequencing allows for multiple images
Advantages of CT over MRI
- less expensive
- greater availability
- faster image times
- less operator time
- thinner slices
- greater resolution power for cortical bone
- can image on patients with metal implants
Advantages of MRI over CT
- greater contrast resolution of soft tissue
- greater ability to image organs
- no ionizing radiation
- greater imaging quality in nonaxial planes
- no artifact from bone
- less risk in missing disease processes
MRI Sequencing
T1 = best for anatomic structure
T2 = contrasting normal vs abnormal tissue
water, CSF, acute hemorrage, soft tissue appears dark on TI and bright on T2
ABCDS for MRI
Alignment
Bone
Cartilage
eDema
Soft Tissue
