BASICS OF RADIOLOGY DEFINITIONS Flashcards
basis for contrast
Differential attenuation
any decrease in bone density, generally result of either qualitative or quantitative deficiencies of bone (osteopenia ≠
osteoporosis: osteopenia is the finding from the radiograph while osteoporosis is a condition/disease)
Osteopenia
qualitative loss of bone mass, radiographs cannot detect small changes
Osteoporosis
vitamin D deficiency
Osteomalacia
absorbed bone (seen in renal failure)
Hyperparathyroidism
no endocrine deficit but neoplasm leading to systemic osteopenic changes
Neoplastic disease
Reflex Sympathetic Dystrophy (RSD)
Disuse osteoporosis (ex. wearing cast for extended period of time)
Regional
highly localized (ex. osteomyelitis)
Focal
occurs systemically
Band-like (ex. acute lymphoblastic leukemia)
any true increase (esp. within medullary canal) in bone density without alteration in configuration
*Osteosclerosis
applied to processes which increase bone width & density
*Hyperosteosis
brightening of the bone not caused by pathology
Pseudosclerosis
Endocrine
Neoplastic- metastases of bone (prostate, breast, etc.)
Drugs- Vitamin D, fluoride
Congenital sclerosing bone dysplasias- usually assoc. with skeletal malformations
Myeloproliferative disorders
Infection, infarction, arthropathy
- ex. “the bends”
Generalized sclerosis
diminishing trabecular pattern
Calcaneal sclerosis
banding of sclerosis along normal trabecular patterns which have become thickened (but bone isn’t usually strengthened - avulsion fracture
typical)
Paget’s disease
trabecular variations appear on radiograph
Texture
osteolytic processes
Destruction
solitary cortical lysis, large >1cm
*Geographic
multiple smaller 2-5mm, can be seen from a distance
*Motheaten
numerous, very small holes <1mm
*Permeative
tumor extends into marrow space between trabeculae in advance of osteolytic edge
Local infiltrative process
giant cell tumor (GCT), chondromyxoid fibroma (CMF), active enchondroma, osteosarcoma, fibrosarcoma, and chondrosarcoma
Typical 1C lesions
bone short and wide (short and stubby), bones take on conical shape
*Undertubulation
long and over-constricted
(ex. Marfan’s syndrome - long slender bones
*Overtubulation
epiphysis, metaphysis, or diaphysis
Common causes: thalassemia, sickle-cell disease, Gaucher’s, Neimann-Pick disease, epiphyseal-metaphyseal
fracture/injury, Rickett’s (including renal osteodystrophy, biliary rickets, dilantin tx)
Splaying (flaring)
ends of bone flare out, concavity to convexity
*Erlenmeyer flask deformity
Soft tissue swelling and bony proliferative (periosteal) changes
Clubbing of distal phalanges
over-proliferating distal phalangeal tuft with soft
tissue thickening
*Acromegaly “Tuft sign”
abnormal short fingers and/or toes
Brachydactyly
abnormally large fingers and/or toes
Macrodactyly (macrodactylia)
overgrowth of a part
Macrodystrophia
often a key clue to benign or malignant processes (abnormal in adults)
Periosteal Reactions
periosteal reaction has no skips, breaks, etc.
Continuous
periosteal reaction eroded (assoc. with buttresses - benign)
Interrupted
variations in patterns, “other
Complex
single continuous layer with underlying cortex grossly intact
- homogenous new bone formation
- thicker 1 mm
- general sign of benign process
single layer and solid
divergent spiculated delicate rays of periosteal new bone
- rays emitting from common center
- highly suggestive but not pathognomonic of osseous sarcoma
- seen with osteoporosis plastic met, osteoblastoma, and hemangioma
sunburst
onion skin
- concentric planes of ossification beyond cortex
- reflects cyclical variations of tumor growth
- Lucent zones
- not always neoplastic
lamellate multi-layered
hair on end
- parallel rays of periosteal new bone projecting perpendicular to cortex
- calcification along sharpey’s fibers
- nonspecific, generally not seen with benign lesions indicating malignancy
spiculated
any interruption of periosteal reaction, except buttress
- very aggressive tumor
- upstaging sign
codman’s angle/triangle
non-aggressive lesion, seen with solid periosteal reactions
periosteal buttress````````
generally intermediate growth rate
smooth, lobulated, trabeculated
neoplastic
osteoctasia
ballooned lesions
processes occurring in and around the cortex
juxta-cortical processes
bony or cartilaginous outgrowths
exostotic
joint margin, hallmark of osteoarthritis
osteophyte
tendon/ligament used as insertion onto bone
enthesophyte
cartilaginous bone tumor, benign lesion
osteochondroma
bleeding into periosteal structures
parosteal myositis ossificans
bleeding into subperiosteal space or soft tissues which can ossify
ossified subperiosteal hematoma
calcium deposits
calcinosis
abnormal Ca2+ or PO4-
metastatic
normal Ca2+ or PO4-
dystrophic