Bone Imaging Part 1 Flashcards
Almost all radiographic evaluation of bone begins with ___views exposed at ___ degrees of each other. This is called __________
2 views
90 degrees
Orthogonal
What are some downfalls of plain films for bone imaging?
They cannot view the entire circumference of tubular bone and are not good for evaluating soft tissue injuries
MRI is excellent for evaluating components of the ______________ and _____________musculoskeletal structures
Medullary canal
non-osseous
What is used to categorize bone marrow disorders? What are the categories?
MRI
Reconversion (reversal of normal conversion), marrow replacement (by metastatic cells), myeloid depletion (loss of red marrow due to chemo/rads), myelofibrosis (replacement of marrow by fibrous tissue due to chemo/rads)
___________ is frequently used as contrast medium for CT and MRI
Gadolinium
T1 weighted images emphasize _____
Fat
T2 weighted images emphasize _____
Water
CT is subject to scatter with __________ objectects
Imbedded metallic objects
CT uses ______________ to created images. One head CT = 8 months of _______________
ionizing radiation
Background radiation
What is the most common type of low energy fracture in elderly patients? What type has the highest mortality?
Distal radius is most common (FOOSH)
Femoral neck has highest mortality
What causes poor bone stock?
Osteoporosis, cancer (femoral neck is MC), bone cyst, bed ridden/wheelchair bound, metabolic disease
What is a Toddler’s fracture and how does this happen?
Stable spiral fracture of the mid shaft of the tibia. This is a twisting injury as a result of getting their leg caught on a slide or running.
What are causes of fractures in non-ambulatory children?
Osteogenesis imperfecta, abuse, tumor
High energy fractures usually occur in what population?
Usually young males
What are common causes of high energy fractures?
Occupational, sports, MVC, fall from height, doing something stupid…
What is the second most common cause of death in the younger population after MVC?
Fall from height
What can happen if you have soft tissue involvement with a high energy fracture?
Vascular compromise and compartment syndrome (both surgical emergencies)
T or F: multiple bones or significant comminution is not typically seen with high energy fractures
False. this is common
_____________ are described as a disruption in the continuity of all or part of the cortex of a bone
Acute fractures
Fracture where the bone is broken through and through
Complete fracture
Fracture where only part of the cortex is fractured? Examples of this type of fracture?
Incomplete fracture
Green stick and torus
What are some radiographic features of acute fractures?
Fracture lines are more lucent
Abrupt discontinuity of the cortex
Edges of the fracture are ragged and rough
Where do sesamoid fractures almost always present?
In the thumb, posterolateral knee, and great toe
What are accessory ossicles and where are these commonly found?
Accessory epiphyseal or apophyseal ossification centers that do not fuse with the parent bone
Mc found in the foot
What is the difference between dislocation and subluxation and where do they occur?
Dislocation is complete loss of contact between the bones in a joint and subluxation is when the bones in a joint are in partial contact with each other.
They both only occur at joints.
How do you describe the number of fragments in a fracture?
Simple (two fragments) vs comminuted (multiple fragments)
How can you describe the direction of the fracture line
Transverse (<30° angulation), oblique (>30° angulation), spiral
How can you describe the relationship of the fragments?
Displacement, angulation, shortening, rotation
How do you describe the communication of fractures to the outside?
Open vs closed fracture
Fracture description mnemonic
OLD ACIDS
O- open or closed
L- location
D- degree
A- articular involvement
C- communited/type
I- intrinsic bone quality
D- displacement, angulation, rotation
S- soft tissue injury
If a fracture produces two fragments it is called a __________ fracture. If the fracture produces more than two fragments it’s called a ____________
Simple
Comminuted
What is it called when a portion of the shaft exists as an isolated fragment?
Segmental
What is it called when a fracture produces a central fragment that has a triangular shape
Butterfly fragment
Fracture line is perpendicular to the long axis of the bone
Transverse fracture
Fracture line is diagonal in orientation relative to the long axis of the bone
Diagonal or oblique
Fracture of a twisting force or torque
Spiral
abnormalities of the position of bone fragments secondary to fractures describe the relationship of the ____________ fragment relative to the _____________ fragment
Distal fracture
Proximal
Amount by which the distal fragment is offset. Described in either terms of percent or fractions
Displacement
Angle between the distal and proximal fragments
Angulation
How much overlap there is of the ends of the fragments
Shortening
Unusual abnormality affecting long bones. Can relate to one join in comparison to another as well.
Rotation
T or F: closed fractures have NO communication with the outside, and open fractures ARE exposed to the outside atmosphere
True
What kind of fracture is common in younger patients, occurs at anatomically predictable places, and causes the bone fragment to pull from the parent bone by contraction of a tendon or ligament
Avulsion fractures
What kind of fracture usually occurs as a result of numerous micro fractures, and may not be diagnosable until after periosteal new bone occurs or the patient presents with pain.
Stress fracture
What should you order if you suspect a stress fracture but the X-ray is normal?
Bone scan- usually will diagnose a stress fracture within 6-72 hours after injury
What are common locations for stress fractures?
Shafts of long bones, calcaneus, and the 2nd and 3rd metatarsals (March Fractures)
Fracture of the distal radius with dorsal angulation of the distal fragment, caused by FOOSH, frequently associated with fracture of the ulnar styloid
Collies’ fracture
Fracture of the distal radius with ventral angulation (reverse colles’). Caused by a fall on the back of a flexed hand.
Smith’s fracture
Transverse fracture of the 5th metatarsal about 1-2cm from the base, caused by plantar flexion of the foot and inversion of the ankle.
Jones fracture
Fracture of the head of the 5th metacarpal with palmar angulation of the distal fracture fragment, usually caused by punching something
Boxer’s fracture
What finding do you see on the supracondylar anterior fat pad and what does it mean?
Sail sign- indicates presence of effusion
Where can you find the most reliable evidence of supracondylar effusion
Posterior fat pad
What is the most common peds elbow fracture
Supracondylar
In what population is a radial head fracture more common
Adults
What is the most common type of Salter Harris fracture. Describe this type. Usually seen around what age?
Type 2- fracture goes through the metaphysis with no joint involvement. Usually seen around age 10
Salter-Harris Classification
Type 1- Straight across
Type 2- Above
Type 3- lower or below
Type 4- two or through
Type 5- erasure of growth plate or crush
What kind of change in bone density is seen on plain film and CT with a generalized overall whiteness (sclerosis) of bone
Increased- generalized
Diffuse loss of visualization of normal network of bony trabeculae and loss of visualization of the normal cortico-medullary junction is consistent with what change in bone density?
Increased- generalized
Carcinoma of the prostate causes osteoblastic activity leading to what change in bone density?
Increased- generalized AND focal
Osteopetrosis is a rare hereditary defect in osteoclastic activity leading to ____________ in density. What are patients to this prone to and why?
Increased- generalized
They are prone to pathological fractures because these bones are inferior to normal bone due to the defect
____________ can affect the cortex and medullary cavity. Those that affect the cortex produce ______________ and those that affect the medullary cavity produce ______________
Focal sclerotic lesions
Periosteal new bone formation
Punctuate, amorphous sclerotic lesions
Increased focal densities due to carcinoma of the prostate are most often seen where? How is this best diagnosed?
Vertebrae, ribs, pelvis, humeri, and femora
Radionucleide bone scan
A vascular necrosis results from cellular death and collapse of affected bone. This can lead to what change in bone density?
Increased- focal
What type of imaging is most sensitive for Avascular necrosis
MRI
Causes of avascular necrosis
Sickle cell dz, polycythemia Vera, vasculitis, trauma, exogenous steroids, Cushing dz, leg-calve-perthes dz.
What change in bone density does Paget disease cause?
Increased- focal
What is Paget disease and who does it usually effect?
Chronic disease of the bone caused by varying degrees of increased bone resorption and increased bone formation of mechanically inferior bone thats susceptible to fractures
most often affects older men
Chronic paramyxovirus infection is related to what disease
Paget dz
What bone is most frequently involved in Paget disease
Pelvis
Thickening of cortex, accentuation of the trabecular pattern, increase in size of bone affected are hallmark findings of what?
Paget dz
With generalized decrease in bone density, bones will have and overall ___________ in lucency
Increase
Accentuation of the normal corticomedulary junction. Cortex stands out because of the decreased density of the medullary cavity. Compression of the vertebral bodies are all radiographic finding of what?
Generalized decrease in bone density
What are causes of pathological fractures due to generalized decrease in bone density?
Osteoporosis, hyperparathyroidism, rickets, osteomalacia
Characterized by low bone mineral density, common in postmenopausal women (increased bone resorption due to osteoclastic activity), begins around 45-55 and is characterized by a loss of total bone mass
Osteoporosis
What are additional risk factors for osteoporosis?
Exogenous steroids, Cushing, estrogen deficiency, inadequate physical activity, alcoholism
Osteoporosis predisposes to pathological fracture in what common locations?
Femoral neck, compression fractures of the vertebral bodies, and fractures of the distal radius
_____ % of bone mass must be lost to be recognized on X-ray
50%
What is the most accurate scan for osteoporosis
DEXA
Hyperparathyroidism is a cause for _______________ ______________ in bone density
Generalized decrease
Excessive secretion of pth which increases reabsorption by increasing osteoclastic activity returning calcium to the bloodstream
Hyperparathyroidism
What are the 3 forms of hyperparathyroidism and what causes each?
Primary- caused by a single adenoma and results in hypercalcemia
Secondary- results from hyperplasia of the glands due to calcium imbalances and phosphorus levels (ckd)
Tertiary- pts w long-standing hyperparathyroidism
Decreased bone density, subperiosteal bone resorption on the radial side of the middle phalanges of the index and middle fingers, erosion of distal clavicles, salt and pepper skull, brown tumors in long bones
Hyperparathyroidism
Rickets causes a __________ ____________ in bone density
Generalized decrease
Related to abnormal vitamin D ingestion, absorption or activation leading to failure to calcify the osteoid matrix, especially at sites of max growth in children
Rickets
Rickets only occurs in what population
Children whose growth plates have not closed
Fraying or cupping at the metaphysis of long bones, widening of the epiphyseal plates, soft and pliable bones leading to bowing of the femur and tibia
Rickets radiological findings
Osteomalacia causes ___________ _____________ in bone density
Generalized decrease
Caused by failure to calcify the osteoid metric of bone in adults, most commonly caused by CKD. Can also be a post-gastrectomy complication from impaired absorption of vitamin D and C
Osteomalacia
Decrease in bone density, thickening of the cortex, coarsening of the trabecular pattern, hallmark pseudo fracture
Osteomalacia radiographic findings
What are pseudofractures and where are they commonly located
Fracture that happens at multiple sites at the same time, frequently bilateral and symmetrical.
Medial femoral neck and shaft, pubic and ischial rami, metatarsals and calcaneus
Looser zones, cortical infraction and milkman lines are all other names for __________
Pseudofracture
Decreased focal lesions are most often caused by
Focal infiltration of bone by cells other than osteophytes
Osteolytic metastatic disease causes _________ ___________ in bone density
Focal decrease
There must be a _______% reduction in bone mass for osteolytic metastatic disease to be recognized on plain radiograph
50%
What imaging is more sensitive for osteolytic metastatic disease
MRI
Irregularly shaped, lucent bone lesions that can be permeative, geographic or mottled
Osteolytic metastatic disease
What are causes of osteoblastic metastatic disease
Prostate cancer, breast cancer, lymphoma, carcinoid tumors
What are causes of Osteolytic metastatic disease
Lung cancer, breast cancer, renal cell carcinoma, thyroid carcinoma
________ is the most common Osteolytic lesion in females
Breast cancer
Multiple myeloma can cause ________ _________ in bone density
Focal decrease
What is the most common primary malignancy of bone in adults
Multiple myeloma
Can occur as a soap-bubbly solitary form in the spine or pelvis or as a disseminated form with multiple punched out lytic lesions through the axial and proximal appendicular skeleton
Multiple myeloma
What is more sensitive for detecting multiple myeloma
Conventional radiographs
Diffuse, severe osteoporosis, plasmacytomas, and later on, multiple small, sharply circumscribed lytic lesions of the same size
Multiple myeloma radiographic findings
Osteomyelitis can cause ________ ___________ in bone density
Focal decrease
Focal destruction of bone by a blood borne infectious agent, most commonly staph aureus
Osteomyelitis
In children, osteomyelitis tends to occur at the _____________ bc of its rich blood supply
Metaphysis
Focal cortical bone destruction, periosteal new bone formation, inflammatory changes, involving the joint space in adults
Osteomyelitis radiographic findings
Why is radionucleide bone scan better for early diagnosis of osteomyelitis?
Conventional radiographs can take up to 10 days to display findings
