cueFlash

Glossary of MSK radiology: DDx and disease properties

Start Studying! Add Cards ↓

Bubbly or lytic bone lesion
FEGNOMASHIC

Fibrous dysplasia
EG, Enchondroma
GCT
NOF
Osteoblastoma
Mets, Myeloma
ABC
SBC
Hyperparathyroidism
Infection
Chondroblastoma
Multiple lytic bone lesions
FEEMHI

Fibrous dysplasia
Enchondromas
EG
Mets, myeloma
Hyperparathyroidism
Infection
Rib lesions
FAME

Fibrous dysplasia
ABC
Mets, myeloma
Enchondroma, EG
Lytic epiphyseal lesion

(also apophyseal, carpal and tarsal bones, patella)
COGEM

Chondroblastoma (if <40 yo)
Osteomyelitis
GCT, geode
EG
Mets/myeloma (if >40yo)
Lytic lesion in posterior elements of spine
OAT

Osteoblastoma
ABC
TB
Lytic bone lesion in a patient over 30 -
which lesions to LEAVE OUT of the ddx?
CANES

Chondroblastoma
ABC
NOF
EG
SBC
Bony sequestrum in a lytic lesion
FILE

Fibrosarcoma
Infection
Lymphoma
EG
osteoid osteoma (mimic)
Causes of geodes
CARD and T

CPPD
AVN
RA
DJD
Trauma
Sclerotic bone lesion
If over 40, METS (P,B,HL)

20-40 yo:
chondroblastoma
ABC
NOF
EG
SBC
fibrous dysplasia
infection
HPT (healing brown tumor)
osteoid osteoma
giant bone island
Bone lesion with endosteal scalloping
Fibrous dysplasia
enchondroma
cartilaginous tumor
Aggressive lytic bone lesion under age 10
Ewing's
Osteosarcoma
Lymphoma
Osteomyelitis
EG
Aggressive lytic bone lesion
age 10-20
Osteosarcoma
Ewing's sarcoma
Lymphoma
Osteomyelitis
Aggressive lytic bone lesion
age 20-30
Osteosarcoma
Lymphoma
Ewing's
MFH
Osteomyelitis
Aggressive lytic bone lesion
age 30+
Myeloma/mets
Lymphoma
Chondrosarcoma
Fibrosarcoma/MFH
Osteosarcoma
Osteomyelitis
Permeative bone lesion in child:
Ewing’s and other round cell CA
infection
EG
Permeative lesion in older pt
infection
mets, myeloma
MFH
reticulum cell sarcoma
Soft tissue tumors
MFH
liposarcoma
synovial sarcoma
synovial osteochondromatosis
PVNS
hemangiomas
Malignant transformation of bony lesions:
fibrous dysplasia
fibrosarcoma, OSA, MFH
Malignant transformation of bony lesions: Paget’s
OSA
Malignant transformation of bony lesions:
osteomyelitis with draining sinus
SCC
Malignant transformation of bony lesions: radiation tx
OSA, chondrosarcoma, MFH
Malignant transformation of bony lesions: bone infarct
fibrosarcoma, MFH
Malignant transformation of bony lesions: Ollier’s
chondrosarcoma
Malignant transformation of bony lesions: Maffucci’s
chondrosarcoma
Malignant transformation of bony lesions: osteochondroma
chondrosarcoma
Cortical holes
(pseudopermeative lesion)
- osteoporosis
(metacarpal cortex < 1/4-1/3 of metacarpal)
- radiation
- hemangiomas
Focal cortical thickening
stress fracture
infection
osteoid osteoma
Mets to bone (typical blastic and lytic)
PBKTL
P – mostly blastic
B – mixed
K – purely lytic
TL – mostly lytic
Hallmarks of DJD
joint space narrowing (asymmetr)
subchondral sclerosis
osteophytes
subchondral cysts
lack of osteoporosis or erosions
Joints that exhibit erosions with OA
TMJ
SI
AC
pubic symphysis
Hallmarks of RA
-hands – proximal. Ulnar dev.
-bilaterally symmetric
-marginal erosions (incl uln styloid & triquetr)
-periart & diff osteoporosis, subchondral cysts
-ST swelling
-jt space narrowing (JSN)
-carpal instability, rotator cuff tear
-distal clavicle resorption
-protrusio acetabuli, A-a subluxation
-2˚ DJD – severe JSN >> sclerosis & osteophytes
Hallmarks of fibrous dysplasia
- NO periosteal rxn
- mention adamantinoma if in tibia or jaw
- Typical: pelvis, prox femur, ribs, skull
- "long lesion in long bone"
- expansile medullary lytic lz w/ground glass; well-def sclerotic margin
- bowing deformities; base of skull sclerotic
- hot on bone scan
- cherubism-mandible & maxilla
- craniofacial -facial & frontal bones
- pseudoarthrosis of tibia
- Mccune Albright -polyostotic FD with café-au-lait spots &precocious puberty)
Hallmarks of enchondroma
- must have Ca++ expt in phalanges
- no periostitis
- tubular bones
- chondroid calcifications
- endosteal scalloping
- pain is malignant
- Ollier’s enchondromatosis, Mafucci’s enchondromatosis with multiple ST hemangiomas)
Hallmarks of EG
- age<30
- lytic lesion can look aggressive
- skull lesion beveled-edge appearance
- sequestrum
- floating tooth
- vertebra plana
- lung dz, pituitary, RES
Giant cell tumor characteristics
- epiphyses closed
- epiphyseal & abuts articular surf in long bones
- eccentric
- well-def NONsclerotic border except flat bones
- long tubular bone> spine/sacrum, 50% @knee
Lytic lesion, considering NOF, features to think of
- age<30
- no periostitis
- cortically based
- metaphysis
- also mention chondromyxoid fibroma
Characteristics of ABC
- age<30, painful
- expansile, eccentric
- fluid-fluid levels on MR
- post elem spine, metaph long bones, pelvis
- also mention osteoblastoma
Characteristics of SBC
- age<30
- central, no periostitis
- prox humerus, prox femur, calcaneus
- fallen fragment sign
features of multiple myeloma
- age>40
- plasmacytoma in ilium & sacrum,
- cold on bone scan; do skel survey
- vert bodies destroyed before pedicles
- axial skeleton, long bones, punched-out lytic lesions, generalized osteopenia
features of osteosarcoma
- ill-defined intramedullary metaphyseal mass
- extends through cortex
- osteoid or chondroid matrix
- aggressive periost rxn (Codman or sunburst)
- telangiectatic form - purely lytic, mimics ABC
- parosteal form - low-grade, seen in post distal femur w/ more mature ossification centrally
Hallmarks of HLA-B27 spondyloarthropathies
bony ankylosis
proliferative new bone formation
predom axial (spinal)
syndesmophytes
arthritic involvement of SI joints

Differential and considerations
- AS (bamboo spine, Andersen lesion and pseudoarthrosis),
- IBD (like AS)
- psoriasis (distal jts, sausage digit, pencil-in-cup, acroosteolysis, proliferative erosions, STS, periostitis, ankylosis, arthritis mutilans deformities, heel spur w fuzzy margins
- Reiter’s syndrome (like psoriasis but feet>hands, IP joint great toe),
- DJD, gout
- infection
- HPT

bilat + symmetric SIJ + marginal symmetric syndesmophytes – usually AS or IBD
unilateral or asymmetric SI jt – NOT AS and IBD, consider psoriasis and Reiter’s
Large joint involvement in arthritis
- DJD (superolateral migration in hips, medial compartment of knee most affected),
- RA (axial migration in hips),
- CPPD
- AS (resembles RA)
- PVNS, synovial osteochondromatosis,
- infection (S. aureus most comm, Salmonella in sicklers; + effusion, + joint destruction, crosses vert discs, periosteal rxn, bone destruction, Brodie’s abscess is well-defined lytic lesion with thick sclerotic border, sequestrum)
- amyloidosis (nodular synovitis with erosions resembling RA)
- ochronosis (DSN with vacuum, disc calcifications, generalized osteoporosis, secondary OA)
Arthropathy distribution in hands and wrists:
Distal – OA, psoriasis, Reiter’s
Proximal – RA, CPPD
Ulnar styloid - RA
Bilateral symmetry of arthropathy
- Primary OA (middle-aged F in hands only, 1st CMC, gull-wing erosive pattern)
- RA
- multicentric reticulohistiocytosis (mult erosions mostly phalanges NO osteoporosis)
Monoarticular arthritis
CHRIST:
- Crystal arthropathies
- Hemophilia
- RA
- Infection
- Synovial (synovial osteochondromatosis, PVNS)
- Trauma
Hallmarks of gout
- erosions w/ sclerotic borders or overhanging edges
- soft tissue nod (can calcify w/ renal failure)
- in hands –random dist, NO osteoporosis
- podagra (1st MTP jt)
- often have chondrocalcinosis
- preserved joint space
- olecr/prepatellar bursitis
Madelung’s deformity
HITDOC:
- Hurler’s
- Infection
- Trauma
- Dyschondrosteosis
- Osteochondromatosis
- Chromosomal anom (Turner’s)
Erlenmeyer flask deformity
CHONG
- Craniometaphyseal dysplasia
- Hemoglobinopathies
("hair on end" skull
extramed. hematopoiesis)
- Osteopetrosis
- Neimann-Pick
- Gaucher's
Arthritis with normal mineralization
DJD
CPPD
Gout
multi. reticulohistiocytosis
PVNS
synovial osteochondromatosis
Epiphyseal enlargement and gracile diaphyses
- hemophilia (hemarthrosis, 2˚ OA, wide intercond notch, big trochlear notch, subchondral cysts; pseudotumor – ST mass w/ adj bone destruction, hematoma, Ca++ common)
- JRA (diff ankylosis of post articular joints, periosteal new bone, STS, short metacarp)
- paralysis
Causes of AVN
ASEPTIC
-Anemia (SC), Amyloid
-Steroids
-Ethanol
-Pancreatitis, Pregnancy
-Trauma
-Idiopathic (L-C-P)
-Caisson dz, CVD
Tendon rupture
steroids
RA
DM
HPT
gout
Polydactyly
familial
chondroectodermal dysplasia
trisomy 13
Meckel-Gruber
Radial hypoplasia
VACTERL
Holt-Oram syndrome
Thrombocytopenia-absent radius syndrome
Distal tuft resorption
PINCH FO

Psoriasis
Injury (thermal)
Neuropathy (DM, leprosy)
CVD (Raynaud's, scleroderma)
Hyperparathyroidism
Familial (Hajdu-Cheney)
Other - PVC tox
Periostitis without underlying bony lesion
- Trauma
- HPO (pain, long bones; lung/ pleural CA, mets, chron PNA)
- Venous stasis (legs)
- Thyroid acropachy (post thyroidectomy, metacarpals & phalanges, esp ulnar aspect of 5th metacarpal)
- Pachydermoperiostosis (like HPO but rarely painful)
Ivory vertebral body
LIMP
– Lymphoma
- Infection
- Mets, myeloma
- Paget’s
Ddx for diffuse dense bones
Neoplasm
Mets, Myelofibrosis
Mastocytosis, Lymphoma
Congenital
Craniotubular dysplasia
Osteopetrosis
Pyknodysostosis
Sickle cell
Metabolic
Paget's
Renal osteodystrophy
Fluorosis
Hypervitaminosis A&D
Periosteal reaction in children
SCALP NIT
-Scurvy (dense metaph lines)
-Caffey's (tib, ulna, mandib)
-A hypervitaminosis
-Lymphoma/leukemia
-Physiologic, prostaglandins
-Neuroblastoma
-Infection
-Trauma
Widened pubic symphysis
bladder exstrophy
infection
mets
trauma
pregnancy
Hallmarks of collagen vascular diseases
osteoporosis and ST wasting in the hands, usually no erosions

SLE - ulnar deviation of phalanges, nonerosive, resembles Jaccoud’s arthropathy

Scleroderma - ST Ca++, acroosteolysis, severe resorption of 1st CMC with radial subluxation of 1st metacarpal

Dermatomyositis - widespread ST Ca++, radial subluxation of IP joint of thumb
CPPD-associated disorders
primary HPT
gout
hemochromatosis
(DJD 2nd-4th MCP jts with squaring of metacarpal heads with drooping osteophytes, generalized osteoporosis)
Hallmarks of CPPD
- pain
- cartilage Ca++ (knee, triangular fibrocartilage of wrist, pubic symphysis)
- joint destruction from secondary DJD (shoulder, elbow, radiocarpal jt, patellofemoral jt)
- subchondral cysts, can mimic gout
Lytic skull lesion
SCD
HPT
Paget’s
FD
TS
infection
mets, myeloma
EG, epidermoid
hemangioma
Lytic finger
- Enchondroma
- Glomus tumor (pain, terminal phalanx)
- Epidermoid inclusion cyst
- Mets
- Infection
- Sarcoid
- Erosive arthropathy
Dense metaphyseal lines
- Growth recovery lines
- Lead
- Healing rickets
- Scurvy
Important features of
achondroplasia
- shortened long bones w/ narrowing of interpedicular distance in caudal direction
- posterior vert body scalloping
Important features of melorrheostosis
- thickened cortical new bone like “dripping candle wax”
- follows sclerotome
Important features of mucopolysaccharidoses
- flattened vertebral bodies with anterior beak
- flared iliac wings and broad femoral necks
- pointed proximal 5th metacarpal base w/notch look to ulnar aspect
- posterior vertebral body scalloping
Important features of
multiple hereditary exostosis
- osteochondromas
- metaphyseal
- lesion grows away from joint, undertubulation, knees, proximal femur, axial more prone to degeneration
Important features of
osteoid osteoma
- pain, age<30
- lucent nidus surr by reactive sclerosis in cortex of long bone
- can be on concave side of painful scoliosis
- “double density” sign on bone scan
Important features of
osteopathia striata
- multiple 2-3mm thick linear bands of sclerotic bone aligned parallel to long axis of bone
- asymptomatic
Important features of
osteopoikilosis
- asymptomatic
- mult small sclerotic densities @ ends of long bones & pelvis
- hereditary
Important features of
acromegaly
- skull thickening
- enlarged sinuses & sella
- hypertrophied terminal tufts w/ spade appearance
- posterior vertebral body scalloping
- elongated & wide vert bodies
- heel pad thickening
Important features of
transient osteoporosis of the hip
- pain
- self-limited
- low T1 signal
- hot on bone scan
Features of intraosseous lipoma
- asymptomatic
- proximal femur, fibula, calcaneus
- may have central calcified nidus
Lytic lesion in sacrum
- Mets
- Chordoma (sacral, clivus, vert body - expansile lytic lz w/ST component)
- Plasmacytoma
- Chondrosarcoma
- GCT
Posterior vertebral scalloping
- dural ectasia (NF, Marfan’s, Ehlers-Danlos)
- syrinx
- spinal canal tumor
- Congenital (achondroplasia, mucopolysacchar, OI)
- Acromegaly
Protrusio acetabuli
- RA
- Paget’s
- AS
- Trauma
- IBD
- Osteomalacia
Distal clavicle resorption
RA
HPT
osteomyelitis
weightlifting
trauma
scleroderma
Platyspondyly
Diffuse
----Dwarfism
----OI
----Morquio’s
----epiphyseal dysplasia
----Cushing’s

Solitary or multifocal
EG
infection
trauma
mets, myeloma
lymphoma, leukemia
SCD
osteonecrosis
Charcot joint
features
6 Ds

Dense subchondral bone (sclerosis)
Degeneration (attempted repair)
Destruction (margins may appear surgical)
Deformity
Debris (loose bodies)
Dislocation (nontraumatic)
Wormian Bones DDx
-Pyknodysostosis
-Osteogenesis Imperfecta
-Rickets in healing
-Kinky Hair Syndrome
-Cleidocranial Dysostosis
-Hypothyroidism
-Otopalatodigital syndrome
-Pachydermoperiostosis
-Primary Acro-osteolysis (Hajdu-Cheney)
-Syndrome of Down
-Idiopathic (can be normal, esp.<6 mo.)
DDx:
Arthritis Affecting the DIPs
Psoriatic Arthritis
Osteoarthritis
Erosive osteoarthritis
Multicentr reticulohistiocytosis
Arthritis With Periostitis ddx
Juvenile Rheumatoid Arthritis
Infectious arthritis
Reiter’s syndrome
Psoriatic Arthritis
Charcot joint causes
DS6

Diabetes (insensitivity to pain)
Syphilis (Tabes Dorsalis)
Steroids
Spinal cord injury
Spina bifida
Syringomyelia
Scleroderma
DDx
Lytic Lesion Surrounded by Marked Sclerosis
BOOST

Brodie’s Abscess
Osteoblastoma
Osteoid osteoma
Stress fracture
Tuberculosis
Causes of basilar invagination
Paget’s disease
Fibrous Dysplasia
Rickets
OI, Osteomalacia
Achondroplasia
Cleidocranial dysplasia
Hyperparathyroidism, Hurler’s
"Rugger Jersey” Spine
"OH My"

Osteopetrosis
Hyperparathyroidism
Myelofibrosis
Vertebra Plana ddx
Myeloma / Metastases
EG / Ewing’s
Lymphoma / Leukemia
Trauma (fx)/TB (infection)
Posterior vertebral body scalloping ddx
NO MAAM

Neurofibromatosis (NF)
Osteogenesis Imperfecta (OI)
Marfan’s syndrome
Achondroplasia (dwarf)
Acromegaly
Mucopolysaccharidosis
Osteoblastic metastases
"5B's Lick Pollen"

Bronchogenic (carcinoid)
Bladder
Breast
Brain (medulloblastoma, GBM)
Bowel (mucinous, carcinoid)
Lymphoma
Prostate Ca
Dense base of skull DDx
-Fibrous dysplasia
-Engelmann’s (kids, cort thickening midshaft long bones inv periost & endost surf)
-Von Buchem’s disease (adults)
-Paget’s disease, -Pyknodysostosis
-Meningioma
-Osteopetrosis
Heel pad thickening
(> 25mm) DDx
Myxedema,
Acromegaly
Dilantin
Callus
Obesity
Peripheral edema
Atlanto-axial subluxation
DDx
RA
Trauma
Down’s'
Morquio’'s
Short 4th metacarpal
DDx
Idiopathic
PseudoHPT
PseudopseudoHPT
Turner's
Basal cell nevus syndr (mandibular cysts, dural Ca++)
Widened teardrop in hip DDx
- Infection
- Trauma
- PVNS (erosions, preserved jt space)
- Synovial osteochondromatosis
- AVN
MRI characteristics of PVNS
Villous or lobulated masses
T1 - INT to HI
T2 - INT to HI
Effusion
Capsulosynovial thickening
MRI characteristics of synovial chondromatosis
Well defined rounded masses
T1 - LO
T2 - LO
Effusion
Capsulosynovial thickening
MRI characteristics of lipoma arborescens
Villous or lobulated masses
T1 - HI
T2 - LO
Effusion
Capsulosynovial thickening
DDx
Skeletal MRI shows bright ring with dark center
Common
- Osteoid osteoma
- Bone infarct
- Osteochonditis dissecans
- AVN
Uncommon
- Brodie's abscess
- EG
- Melanoma mets
Soft tissue mass on MRI
T2 bright with dark center
Neurofibroma
Sarcoidosis
Acute hematoma
Soft tissue mass on MRI
moderate to marked T1 bright
Lipoma
Hematoma
Well-diff liposarcoma
Myxoid liposarc or myxosarc
Soft tissue mass on MRI
Homogeneously T1 dark
Cyst
Ganglion
Lymphocele
Hygroma
Seroma
Soft tissue mass on MRI
mildly T1 bright rel. to muscle
Neurilemmoma or neurofibroma
Hemangioma
Abscess
Solid malignancy (sarc or carci)
Hemorrhagic mass
DDx for lipohemarthrosis of the knee
* tibial plateau fracture
* ACL avulsion fracture
* patellar dislocation w/ osteochondral injury
Arthritis affecting the DIPs
Psoriatic Arthritis
Osteoarthritis
Erosive osteoarthritis
Multicentric reticulohistiocytosis
Arthritis with Periostitis
Juvenile Rheumatoid Arthritis
Infectious arthritis
Reiter’s syndrome
Psoriatic Arthritis

Add Cards

You must Login or Register to add cards