Radiology Flashcards
What do you observe with Rheumatoid Arthritis on xray? (4)
erosions
joint space narrowing
osteopenia (periarticular)
soft tissue swelling (inflammation)
What are the gross deformities of Rheumatoid Arthritis? (4)
swan neck
boutenierre
subluxations (ulnar MCP deviation and cervical vertebrae)
ankylosis
Define ankylosis
rigid
consolidation of a joint
Define pannus
abnormal layer of fibrovascular tissue or granulation tissue over a joint surface
grow in a tumor-like fashion, as in joints where it may erode articular cartilage and bone.
psoriatic arthritis on xray
erosions= “pencil in cup” deformity of the phalanges
reactive arthritis: what joints?
lower extremity: feet and SI joint
define sclerosis
stiffening of a structure, usually caused by a replacement of the normal organ-specific tissue with connective tissue
Define tophus, and name the associated disorder.
gout: A nodular mass of uric acid crystals
non-agressive erosions
overhanging edges
White, chalky gross appearance
What is this the most common joint involved in gout?
first MTP
Describe the appearance of CPPD deposition on xray.
chondrocalcinosis-cartilage calcification
looks like osteoarthritis but in unusual joints (nonweightbearing joints)
- classic is the shoulder or patellofemoral joint (normally the last area of the knee to get osteoarthritis)
Define osteophytes
small abnormal bony outgrowth in response to increased joint reactive forces (buttressing)
Define buttressing
developing thickened bone in response to increase in stress (often lateral growth where bone is not found normally)
osteophyte growth in response to increased joint reactive forces
Use ultrasound for what in MSK? (5)
nerve blocks fractures tendon injury foreign body abscess vs cellulitis The limit does not exist.
ULTRASOUND TERMINOLOGY: Echogenicity
tissue’s relative ability to reflect or transmit ultrasound waves
ULTRASOUND TERMINOLOGY: hyperechoic
(white on the screen)
hard/dense reflects virtually all ultrasound waves
nerves, fascia, cortex rim of bone, CT (tendon/ligament), epiderm/dermis
ULTRASOUND TERMINOLOGY:
hypoechoic
(gray on the screen) Adipose tissue, cartilage, muscle
US can pass
ULTRASOUND TERMINOLOGY:
anechoic
(black on the screen)
reflects virtually no ultrasound waves back to probe
vein, fluid
How does a nerve appear on ultrasound?
(hyperechoic with stippled “honeycomb” structure)
Explain the appearance of blood/fluid flow on ultrasound.
In Doppler mode, flow toward the probe appears red, while flow away from the probe appears blue.
*BART, i.e., Blue Away, Red Toward
What are the uses of high frequency probes (10–15 MHz) in ultrasound?
better resolution but have less penetration.
US imaging of superficial structures
What are the uses of a low frequency probe (2–5 MHz) in ultrasound?
deeper structures
quality of the image will be substantially poorer
What ultrasound probe do you use for MSK?
linear transducer
Describe the appearance of Necrotizing fasciitis on ultrasound.
thickened, distorted fascia with adjacent fluid and may have small echogenic foci of gas.
How do cysts a appear on ultrasound?
anechoic with posterior acoustic shadowing
How does cellulitis appear on ultrasound?
initially: generalized swelling and increased echogenicity of the skin and subcutaneous tissues
worse case:cobblestone appearance: hyperechoic fat lobules become separated by hypechoic fluid-filled areas (edema)
check for wrist alignment on xray: 3 C’s
radius-lunate-capitate
Define an “open fracture.”
skin broken
infection risk
comminuted fracture
more than one fracture plane
intra-articular fracture
extends to joint surface
no step off allowed
osteoarthritis risk
XRAY: radiodense/ opaque
inhibit the passage of electromagnetic radiation
opaque white appearance of dense materials
(bone, tendons)
XRAY: radiolucent/ lucent
allow radiation to pass more freely
darker appearance of less dense materials
(fat)
XRAY: what does “sail sign” refer to
effusion
soft tissue swelling around bony fracture
how to name a bone displacement/angulation
named for location of distal bone relative to proximal: distal medial displacement
XRAY: distraction
bony fragments seperate
complications of fracture (5)
non/malunion avascular necrosis physeal arrest/fusion (growth) neurovascular injury early osteoarthritis
fractures in children (3)
torus (buckle fx), greenstick, physeal
salter harris fracture classification (5)
1 physeal plate 2 physeal + metaphysis 3 physeal + epiphysis 4 metaphysis + physeal + epiphysis 5 crush of physeal plate
seenm on XRAY: 2-3 weeks after fx
increased vascularity
wider fx line
resorption of Ca2+
remodeling
XRAY: lytic
(low density - black)
XRAY: sclerotic
higher density - white
CT: based on differences in…
attenuation/density
CT: low attenuation
black
air
CT: high attenuation
white
bone
MRI: signal intensity= hyperintense= High
bright/white
liquid/fat
MRI: signal intensity= hypointense= low
dark/black
tendons/ligaments/bones
MRI: use for T1-weighted image
anatomy
MRI: use for T2-weighted image:
liquid//edema, tumor, infarction, inflammation, infection,
fat suppression***
pathology
What is the gold standard for diagnosing bone tumors?
Conventional radiography
What is the term for “benign” bone tumors?
Indolent
What are the 3 locational divisions of bone on an axial plane?
Central: in the medulla
Eccentric: off-center in the medulla
Cortical: in the cortex (edge)
Describe an 1A margin, and its implications
- geographic
- well-defined (can draw a clear line around it)
- sclerotic around the edges (slow-growing enough that the bone can respond)
- differential diagnoses are all benign
What are the features of a non-ossified fibroma
- benign
- 1A margin
- eccentric
- very common in children and young
Describe a 1B margin
- geographic
- Well-defined border
- no sclerosis around the edges
- Can be benign or malignant
Describe a 1C margin
- geographic
- ill defined border
- diagnosis usually malignant
Describe a II margin
moth-eaten
- can tell the location but the extent is very unclear
- diagnosis usually malignant
Describe a III margin
- permeative
- hard to distinguish from moth-eaten, but tends to be even harder to locate specifically in bone
- diagnosis usually malignant, except for osteomyelitis
What are the patterns of periosteal reactions with a nonaggressive tumor growth pattern? (4)
- solid
- buttressing
- expansion
- septation
What are the patterns of periosteal reactions with an aggressive tumor growth pattern? (4)
- Codman triangle
- laminated
- hair on end
- sunburst
best study for soft tissue and joints
MRI
best study for spinal cord and brain
MRI and CT
Myelography
combines dye with X-ray to evaluate problems with the spine that CT scans and an MRI might not be able to find.
can see bones, spinal cord, and nerve roots (compression of masses)
indicators for imaging the spine/back
low back pain acute trauma neoplasms infections (abscess) MS vascular disease
best study for bones
xray
best study for reductions of fractures and guiding procedures
fluoroscpoy
best study for vessels and best contrast for bones
CT
best study for functional or metabolic information
nuclear medicine
best study for soft tissue foreign body
US
Xray: pros
cheap
rapid
good resolution
xray: cons
need several views
radiation to pt
fluoroscopy: cons
high dose of radiation to pt
CT: pros
rapid
good resolution
can see behind structures
CT: cons
decreased soft tissue contrast (volume averaging artifact)
MRI: pros
great soft tissue contrast and internal joint derangement
no radiation to pt
MRI: cons
expensive long magnetic field (no metal)
nuclear medicine: cons
limited resolution
radiation to pt
US: cons
limited contrast
air and bone limit deep field imaging
used to study stress fractures, infection, and localizing tumors
nuclear medicine
Codman triangle
triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone
sequestrum
a piece of dead bone that has become separated during the process of necrosis from normal or sound bone.
It is a complication of osteomyelitis
greenstick fx
common in flexible child bone
bone bends and cracks, instead of breaking completely into separate pieces.
