musculoskeletalradiologyflash.txt

Cortical destruction. Periostitis. Orientation or axis of the lesion. Zone of transition.

"Thick, wavy, uniform, or dense periostitis. Due to low-grade chronic irritation that gives periosteum time to lay down thick new bone."

"Lamellated (onion-skinned), amorphous, or sunburst-like. Periosteum does not have time to consolidate. "

Border of lesion with normal bone. Narrow: Well-defined (benign). Wide: Imperceptible (aggressive).

Destructive lesions with sclerosis from tumor new bone formation or reactive sclerosis. Occur almost exclusively in children and young adults (less than 30 years old).

"Arises from periosteum. Grows outside one, often wrapping around diaphysis without breaking cortex. Occurs in older age group than central osteosarcomas. Not as aggressive central osteosarcomas. Posterior distal femur is common location."

Cortical desmoid tumor. Myositis ossificans.

"Permeative (multiple small holes) lesion in long bone diaphysis. May have onion-skin, sun-burst, or amorphous periostitis."

Ewing sarcoma. Infection. EG.

"Bony or soft tissue mass with amorphous, snowflake calcification in an older patient (>40 years). Can't distinguish between enchondromas and low-grade chondrosarcomas. "

Benign and malignant giant cell tumors appear identical. If metastasizes (often to lung) then is malignant.

Lytic tumor without osteoid or chondroid matrix. May be permeative to a fairly well-defined area of lysis. Tend to predominate in fourth decade. May have a bony sequestrum.

"Common soft tissue tumors. In bone, appear identical to fibrosarcomas: Variable lytic lesion. May have bony sequestrum."

Half-grade fibrosarcoma. More common in soft tissue than bone. Usually are well defined lytic lesions when in bone. Often have benign periostitis with thick spicules.

Similar appearance to Ewing sarcoma (permeative or moth-eaten). Occur in older age group than Ewing sarcoma.

Renal cell carinoma. Thyroid carinoma.

Malignant fibrous histiocytoma. Liposarcoma.

Often adjacent to joints. Typically homogeneously T2 bright. May mimic fluid collection.

Benign joint lesion. Synovial metaplasia leading to multiple calcific cartilaginous loose bodies in a joint. 20% do not calcify. May mimic pigmented villonodular synovitis.

"Rare chronic inflammatory process causing synovial proliferation. Joint swelling, pain, occasionally joint erosions. No calcifications. Low T1 and T2 synovial signal (hemosiderin deposits). Rare chronic inflammatory process causing synovial proliferation."

Phleboliths. Often cause cortical holes (pseudopermeative) in adjacent bone. May mimic permeative or moth-eaten pattern.

2.5 mm.

"Blow to top of head. C1 ring fracture, lateral masses of C1 must extend beyond margins of C2 body."

"Atlantoaxial joint becomes fixed. C1�C2 bodies move en mass, instead of rotating on one another."

"Fracture of C6 or C7 spinous process, relatively innocuous."

"Unstable, serious fracture of posterior elements of C2 usually with C2 anterolisthesis on C3. Caused by hyperextension and distraction (head against dashboard). "

Disruption of posterior C-spine ligaments with anterior vertebral body compression. Usually associated with spinal cord injury.

Rupture of facet joint ligaments with dislocation due to severe flexion with some rotation. Facets are locked in an overriding position.

"Hyperflexion at the waist (lap belt). Distraction of posterior elements and ligaments with anterior vertebral body compression. Usually involves T12, L1, or L2."

Break or defect in pars interarticularis portion of lamina.

Further collapse of an acute unprotected wedge compression fracture. Results in severe neurologic deficits. Typically occurs 1 to 2 weeks after initial trauma.

fracture at base of thumb extending into carpometacarpal joint.

Comminuted fracture of thumb base extending into carpometacarpal joint.

Avulsion injury at distal phalanx base where extensor digitorum tendon inserts.

Avulsion of thumb ulnar collateral ligament at the ulnar aspect of first metacarpophalangeal joint.

Permanent median nerve impairment. Nerve can get impinged by volarly displaced lunate.

Rupture of scapholunate ligament. Scaphoid (navicular) rotates dorsally. Widened space between scaphoid and lunate.

Negative ulnar variance.

Triangular fibrocartilage tears.

Colles fracture.

Facture of ulna with dislocation of proximal radius.

Fracture of radius with dislocation of distal ulna.

Hill-Sachs deformity: indentation on posterosuperior humeral head. Bankart deformity: Bony irregularity or fragment off inferior glenoid.

Ewing sarcoma. Infection. Eosinophilig granuloma.

Multiple myeloma. Metastatic carcinomatosis. Primary lymphoma.

Radial aspect of middle phalanges. Medial aspect of proximal tibia. Sacroiliac joints. Distal clavicle.

Fluorosis.

Hypertrophic pulmonary osteoarthropathy. Venous stasis. Thyroid acropachy. Pachydermoperiostosis. Trauma.

Idiopathic thickening of cortical new bone. Accumulates near ends of long bones (dripping candle wax). Can affect several adjacent bones. May be symptomatic.

Trauma. Steroids. Aspirin. Collagen vascular diseases. Alcoholism. Idiopathic causes.

Myositis ossificans. Avulsion injury. Cortical desmoid. Trauma. Discogenic Vertebral Sclerosis. Fracture. Pseudodislocation of Humerus.

Circumferential calcification with a lucent center (malignancy may have calcified or ossific center).

Avulsion Injury.

Occur only on posteromedial epicondyle of femur. May result from avulsion of adductor magnus muscle.

Trauma. Calcium pyrophosphate dihydrate crystal disease. Rheumatoid arthritis. Avascular necrosis.

Variant of a Schmoral node. Often a sclerotic lesion adjacent to endplate. Associated disk space narrowing and osteophytosis.

Lytic defect in upper outer quadrant of patella. May mimic pathologic process.

Anatomic variant of increased cancellous bone near greater tuberosity. May mimic a lytic pathologic lesion.

"Unfused dens. Smooth, often well-corticated, inferior dens border. Hypertrophied, densely corticated anterior arch of C1. May move anterior to C2 body with flexion. Can mimic a fractured dens. "

"Curettaged and packed to prevent fracture. Those occuring in the calcaneus, however, should be left alone."

"May be patchy, mixed lytic-sclerotic or even resemble permeative process. Typically occur in metadiaphyses. Multiple bone infarcts consider sickle cell anemia or systemic lupus erythematosus. "

Failure of endochondral bone formation. Narrowing of caudal interpedicular distances. Short long bones with normal width.

Finger clubbing. Extremity periostitis.

Multiple osteochondromas or exostoses. Nearly always involves knees. Undertubulation (widened bone diameter) present at site of exostosis.

Morquio Syndrome.

Hurler Syndrome.

Notch at base of fifth metacarpal.

Painful sclerotic cortical lesion with lucent centered nidus. Occurs in patients younger than 30. Nidus is surgically removed or thermally ablated. May mimic osteomyelitis. Bone scan double-density sign versus photopenic area for osteomyelitis.

Aka Voorhoeve disease. Multiple 2- to 3-mm-thick linear sclerotic bands aligned parallel to bone long axis. Usually affects multiple long bones. Generally is asymptomatic.

"Hereditary, asymptomatic disorder. Multiple small (3 to 10 mm) sclerotic bony densities. Primarily involves ends of long bones and pelvis. May mimic diffuse osteoblastic metastases."

"Rare, familial disease. Skin thickening of face and extremities, finger clubbing, widespread periostitis."

Lacelike pattern of cortical bony destruction of multiple phalanges. May affect both hands. May have skin nodules.

Painful hip osteoporosis and no other finding. Self-limited with full resolution.

"FEGNOMASHIC. Fibrous dysplasia. Enchondroma, EG. Giant cell tumor. Nonossifying fibroma. Osteoblastoma. Metastases, Myeloma. Aneurysmal bone cyst. Solitary bone cyst. Hyperparathyroidism. Infection. Chondroblastoma, Chondromyxoid."

Eosinophilic granuloma. Aneurysmal bone cyst. Nonossifying fibroma. Chrondoblastoma. Solitary bone cyst.

Fibrous dysplasia. Enchondroma. Nonossifyuing fibroma. Solitary bone cyst.

No periosteal reaction.

Calcifications present (except phalanges). Painless (no periostitis).

Younger than 30 years.

Epiphyses closed. Abuts articular surface (long bones). Well defined with nonsclerotic margin (long bones). Eccentric. Rules do not apply to flat bone GCTs.

Younger than 30 years. Painless (no periostitis). Cortically based.

"Mention with ABC, especially in posterior elements of spine."

Older than 40 years.

Expansile. Younger than 30 years.

Central. Younger than 30 years.

Must have other evidence of hyperparathyroidism.

Always mention.

Younger than 30 years. Epiphyseal.

No calcified matrix.

Infection. Eosinophilic granuloma.

Infection. Metastatic disease. Myeloma.

Infection. Giant cell tumor. Chondroblastoma. Geode.

(FAME). Fibrous dysplasia. Aneurysmal bone cyst. Metastatic disease and myeloma. Enchondroma and eosinophilic granuloma.

(FEEMHI). Fibrous dysplasia. Eonsinophilic granuloma. Enchondroma. Metastatic disease and myeloma. Hyperparathyroidism (brown tumors). Infection.

1-30: Ewing sarcoma. Osteogenic sarcoma. 30-40: Giant cell tumor. Parosteal sarcoma. Fibrosarcoma. Malignant fibrous histiocytoma. 1' lymphoma of bone. > 40: Chondrosarcoma. Metastatic disease. Myeloma.

"No periostitis, unless fracture. May be monostotic or polyostotic. Predilection for pelvis, proximal femur, ribs (lytic posterior ribs, sclerotic anterior ribs), skull. When in pelvis proximal femur involved. McCune-Albright syndrome: Polyostotic fibrous dysplasia, cafe-au-lait spots, precocious puberty. Adamantinoma: Tibial lesion that resembles fibrous dysplasia. Cherubism: Multiple fibrous dysplasia lesions in the jaw."

"Contain calcified chondroid matrix, except when in phalanges. May cause endosteal scalloping. No periostitis. Difficult to distinguish from chondrosarcoma. Ollier disease (multiple enchondromas). Maffucci disease (multiple enchondromas with soft-tissue hemangiomas)."

Any lesion in patient under 30 years. May be polyostotic. May have soft-tissue mass. May have bony sequestrum.

Fibrous cortical defect (if less than 2cm). Asymptomatic (no periostitis). Metaphyseal. Emanate from cortex. 75% have thin sclerotic border that is scalloped and slightly expansile. Less than 30 years of age. Heal with sclerosis.

"Rare. Simulate ABCs. Expansile, soup-bubbly. Commonly occur in posterior elements of spine."

Osteoblastoma. ABC. TB. Metastasis.

"Normal shoulder, humeral head slightly overlaps glenoid. Absence of crescent sign is often seen with posterior shoulder dislocation."

Inferolaterally

Arcuate lines.

Anterior inferior iliac spine.

Symphysis pubis. Sacroiliac. Temporomandibular joint. Acromioclavicular joint.

Sclerosis. Joint space narrowing. Osteophytosis.

Stress fracture until proved otherwise.

Intraarticular fracture with bone marrow within joint.

Medial border of second cuneiform.

Calcaneal fracture should be considered.

"Diffuse idiopathic skeletal hyperostosis, DISH."

"Familial. More common in women. Symmetric and bilateral: DIP and PIP joints, base of thumb involement."

"Erosive osteoarthrits, aka Kellgren arthritis."

Degenerative joint disease. Rheumatoid arthritis. Calcium pyrophosphate dihydrate deposition disease (CPPD). Avascular necrosis.

Soft tissue swelling. Osteoporosis. Joint space narrowing. Marginal erosions. Affects proximal hands symmetrically.

Axially (RA). Superolaterally (OA).

Ankylosing spondylitis. Inflammatory bowel disease. Psoriatic arthritis. Reiter syndrome.

HLA-B27 spondyloarthropathies.

"Paravertebral ossificatio. Runs vertically, whereas an osteophyte runs horizontally."

Rheumatoid arthritis. Calcium pyrophosphate dihydrate deposition disease (CPPD). Torn rotator cuff.

"Ankylosing spondylitis: Marginal, symmetric. Psoriatic and Reiter syndrome: Nonmarginal, asymmetric."

"Ankylosing spondylitis and inflammatory bowel disease: Bilateral, symmetric SI joint disease. Reiter syndrome and psoriatic arthritis: Unilateral or bilateral SI joint disease."

Distal predominance. Proliferative erosions. Soft tissue swelling. Periostitis.

Fuzzy margins with wisps of periostitis emanating from them. Seen in psoriatic arthritis.

Reiter syndrome involves the feet more commonly than the hands. Interphalangeal joint of great toe is commonly affected.

40%

"Well-defined erosions (sclerotic margins, overhanging edges). Soft tissue nodules (may calcify in renal failure). Random distribution. No osteoporosis."

Pain. Cartilage calcification. Joint destruction.

Knee. Triangular fibrocartilage of wrist. Symphysis pubis.

Shoulder. Elbow. Radiocarpal joint. Metacarpophalangeal joints. Patellofemoral joint.

Primary hyperparathyroidism. Gout. Hemochromatosis.

Osteoporosis. Soft tissue wasting.

Ulnar.

"DJD involving 2nd - 4th metacarpophalangeal joints. 50% also have CPPD, "

Destruction. Dislocation. Heterotopic new bone.

First and second tarsometatarsal joints (Lisfranc fracture) in diabetics.

Epiphyseal enlargement. Widening of knee intercondylar notch. Gracile diaphyses.

Knee. Hip. Elbow.

Loose bodies are tightly packed in a joint. May look like tumor at MR.

"Noncalcified synovial osteochondromatosis, yet much less common."

Shoulder-hand syndrome. Reflex sympathetic dystrophy.

"Severe, patchy osteoporosis and soft tissue swelling. Typically affects hands or feet."

10 mm or more displacement of suprapetallar fat pad and anterior femoral fat pad.

Joint effusion. Patchy or mottled density. Subchondral lucency. Collapse of articular surface. Joint fragmentation. Only one side of joint involved.

Kienbock malacia.

Kohler Disease.

osteochondritis dissecans.

Medial epicondyle of knee. Dome of talus. Capitellum.

Scheuermann disease.

Freiberg infraction.

Legg-Perthes disease.

Osgood-Schlatter disease.

Osteoporosis: Decreased bone quantity. Osteomalacia: Abnormally mineralized (normal quantity) bone.

One fourth to one third.

Permeative process: Solid cortex with permeative medullary space. Pseudopermeative process: Cortex is permeative (multiple small holes).

Aggressive osteoporosis. Hemangioma. Radiation changes.

"Looser fracture: Fracture through large osteoid seams. Occur in femur, pelvis, and scapula."

Flared and irregular epiphyses. Long bones may bend.

Subperiosteal bone resorption. Most commonly involves radial aspect of middle phalanges of hand.

Spine endplate osteosclerosis resembles stripes on rugby jerseys.

Calvaria may thickened. Basal ganglia calcification.

"Failure of tissues to respond to PTH. Obesity, round facies, short stature, brachydactyly."

Calvarial thickening. Enlarged sinuses. Enlarged sella turcica. Prognathic jaw. Hypertrophied distal phalanx tufts (spade appearance).

"Periostitis of metacarpals and phalanges, particularly ulnar aspect of fifth metacarpal. Occurs in hyperthyroid patients post-thyroidectomy."

(Regular Sex Makes Occasional Perversions Much More Pleasurable And Fantastic). Renal osteodystrophy. Sickle cell disease. Myelofibrosis. Osteopetrosis. Pyknodysostosis. Metastatic carcinoma. Mastocytosis. Paget disease. Athletes. Fluorosis.

Osteopenia. 10% to 20% exhibit osteosclerosis.

Osteosclerosis. Bone infarcts. Step-off deformities (H-shape) of vertebral body endplates.

Progressive fibrosis of bone marrow in patients older than 50. Anemia. Splenomegaly. Extramedullary hematopoiesis.

"Extremely dense bones. Bone-in-bone appearance of vertebral bodies. Sandwich vertebrae, densely sclerotic endplates. "

Congenital cause of dense bones. Pathognomonic acroosteolysis with sclerosis (pointed chalk distal phalanges).

Prostate cancer. Breast cancer.

"Bony enlargement. thickened ileopectineal line. 3 distinct phases (lytic, sclerotic, mixed lytic-sclerotic,). Flame-shaped or blade-of-grass leading edge. Starts at end of a bone (except tibia)."

"Neurogenic muscle edema corresponding to a particular nerve. Suprascapular nerve: Supraspinatus, Infraspinatus. Axillary nerve: Teres minor, Deltoid. Acute pain followed by weakness. Associations: Vaccinations, Viral illness, General anesthesia."

Fluid in tendon sheath with normal underlying tendon.

Partial tendon tear. Focal or fusiform swelling of tendon with internal bright T2 signal. Thinning of tendon is a more severe form.

"Intermediate, not fluid bright, signal within a tendon. Represents myxoid degeneration."

"No, Achille's tendon lacks a sheath."

Navicular. Second and third cuneiforms. Bases of second to fourth metatarsals.

Rheumatoid arthritis.

Runs just deep to PTT. Goes underneath neck of talus. Helps support talus and arch. When PTT tears stress is placed on spring ligament.

Thin fibrous structure that binds peroneus longus and brevis tendons to posterior distal fibula.

V-shape (Chevron) or divided peroneus brevis tendon distal to fibula.

Surrounding or internal high T2 signal about or within osteochondral lesion.

Synovial sarcomas (16%). Desmoid tumors. Giant cell tumors of tendon sheath.

"Unicameral bone cyst. Epiphyseal equivalent: Giant cell tumor. Chondroblastoma. Infection.

Accessory soleus. Accessory peroneus quartus muscles.

Superior group: Anterior and Posterior tibiofibular ligaments. Inferior group: Anterior and Posterior talofibular ligaments. Calcaneofibular ligament.

"Chronic lateral ankle instability. Sinus tarsi syndrome. Anterolateral impingement syndrome.

"Torn ligaments of sinus tarsi. Results in subtalar instability. Granulation tissue (high T2, low T1) or scar (low T2, low T1) replaces normal fat (high T1) of sinus tarsi. "

"Synovial hypertrophy or scarring in lateral ankle gutter. Space between tibia and fibula bound by lateral ankle ligaments. Lateral ankle pain and inability to dorsiflex normally.

Calcaneonavicular joint. Middle facet of talocalcaneal joint.

"Large meniscus: Lens-shaped, wedged, flat and others. Lateral meniscus (3% population) more commonly involved than medial. More prone to tear. Can be symptomatic even without a tear."

"Ligament running through Hoffa's fat-pad connecting both meniscal anterior horns. May mimic an anterior horn lateral mensicus tear.

Extends obliquely from medial femoral condyle to posterior horn lateral meniscus. Ligament of Humphry (passes in front of PCL). Ligament of Wrisberg (passes behind PCL).

Biceps femoris tendon inserts onto head of fibula. Fibular collateral ligament (true lateral collateral ligament) extends from lateral femoral condyle and joint biceps femoris tendon to insert on head of fibula. Iliotibial band extends from fascia to blend into lateral retinaculum on the patella and inserts at Gerdy's tubercle of lateral tibia.

"Rarely medial patella plica may thicken and cause symptoms similar to a torn meniscus. Can be removed arthroscopically quite easily.