Radiology Charts

Author: Micah Cohen	Radiograph	CT	MRI - T1	MRI - T2	MRI - T1 post-contrast	Scintigraphy	Additional comments
Hemangioma	Lytic with 'sunburst/honeycomb' trabecular matrix centrally. Expands/erodes outer table while leaving inner table intact early on. May expand inner table later. Sclerotic margin in ~30%	Expansile lesion with radiating 'honeycomb' trabecular pattern	Isointense with mixed hyper (fat) and hypo (iron storage complexes) intensities	Hyperintense (Iron storage complexes)	Progressive enhancement with enhancing dural tail		Benign vascular tumor, more common in women and in frontal and parietal bones. Usually cavernous subtype

Eosinophilic Granuloma	Lytic, usually non-sclerotic borders. 'Beveled edge' appearance with uneven destruction of calvarial tables. May display a button sequestrum	Granulomas slightly denser than grey matter	Hypointense	Heterogeneously hyperintense. No significant surrounding edema, unlike EG involving remainder of appendicular skeleton	Avid enhancement with enhancement of adjacent dura		Monostotic disease of younger patients which most commonly affects calvarium. Parietal bones most commonly involved. Spontaneous resolution is common

Leptomeningeal cyst	Single or multiple lucent defects in calvaria						Most commonly in children <3 yrs old. Caused by traumatic disruption of pia and arachnoid. Occuring in 0.6% of all skull fractures. Fracture grows over time as is exposed to csf pulsations- 'growing fracture

Paget's Disease	Classic 'cotton-wool' skull appearance. Involves whole thickness of calvarium. Progresses through lytic, mixed (with cortical and trabecular thickening) and blastic (with sclerosis and skull thickening) phases Image 2	Lucent rim surrounds lesion in lytic phase Image 2	Depends on stage of disease. Mixed phase is heterogeneously hyperintense while blastic phase is hypointense	Depends on stage of disease. Mixed phase is heterogeneously hyperintense while blastic phase is hypointense			Unknown etiology. Involves skull in ~50%

Mets/Myeloma	Mets-mostly lytic (other than prostate and osteosarcoma) with poorly defined margins and soft tisue extension. Usually multiple, though can be solitary. MM- multipe punched out lytic lesions that are well defined, of uniform size, with nonsclerotic borders Image 2	Mets-mostly lytic (other than prostate and osteosarcoma) with poorly defined margins and soft tisue extension. Usually multiple, though can be solitary. MM- CT provides imroved detection of radiographically occult lesions. May appear as diffuse osteopenia without well defined lesions Image 2 Image 3	Mets-hypointense. MM-similar to mets. May have no MR signal abnormality	Mets- osteoblastic are hypointense, osteolytic are hyperntense. MM-Similar to mets. May have no signal abnormality	Mets-Areas of diploic enhancement other than veins and arachnoid granulations may represent mets. Blastic mets may not enhance. MM-similar to mets	Mets-usually have some sort of secondary bone formation and will be hot on bone scan. MM-purely lytic without secondary bone formation so no uptake of bone scan	Mets-Usually painless, as opposed to mets to skull base. Most commonly breast, lung, prostate, renal, thyroid. MM- Malignant bone marrow neoplasm of monoclonal plasma cells. Presents with pain

Fibrous Dysplasia	Ground glass matrix from immature woven bone and fibrous tissue with expansion of outer table and preservation of inner table. Sclerotic margins	Best modality for visualizing ground-glass matrix	Hypointense with relative isointensity of more fibrous areas	Heterogeneous with fibrous areas appearing hyperintense and more cellular/osseous regions appearing hypointense	Variable enhancement pattern		Sporadic genetic disorder or adolescents and adults. Most commonly involves frontal and temporal calvaria. Mono or polyostotic forms

Tuberculosis	Non-specific, solitary, well circumscribed lytic lesions. Frontal and parietal bones most commonly involved. Replacement of inner, outer, or both tables by granulomas. Even rarer form with diffuse infiltration of diploe	Lysis of inner or outer table with bone sequestra and adjacent enhancing soft tissue. Added utility in evaluation for intracranial extension	Marrow infiltration of diploic space with hpointense T1 signal	Marrow infiltration of diploic space with high T2 signal	Enhancement of diploic marrow and surrounding dura		Extremely rare with involvement in ~ 0.2-1.3% of pts with skeletal TB. Nonspecifc appearance, should be considered in young patients in endemic regions

Hyperparathyroidism	Classic salt and pepper appearance from calvarial trabecular resorption. Can see an accentuated temporal line in early stages of disease from subligamentous bone resorption under temporalis muscle	Classic salt and pepper appearance from calvarial trabecular resorption. Can see an accentuated temporal line in early stages of disease from subligamentous bone resorption under temporalis muscle					Osteitis fibrosa from diffuse subperiosteal, endosteal, trabecular, subligamentous bone resorption indicative of 'hungry bones

Osteomyelitis	Lytic lesions. Overlying soft tissue swelling in acute phase. Can see sequestra	Lytic lesions. Overlying soft tissue swelling in acute phase. Can see sequestra Image 2	Decreased signal with infiltration of the marrow	Increased signal	Enhancement Image 2		Similar to osteomyelitis in other bones with osseous lysis, periosteal reaction, soft tissue swelling, sequestra, involucra, cloacas, sinus tracts, adjacent cellulitis/phlegmon/abscess. Often from trauma or spread from adjacent sites of infection. Complications include meningitis, parenchymal abscess, empyema.

Lambdoid Defect	Focal lysis adjacent to lambdoid suture posterior to parietal and occipital mastoid sutures. Accompanying ipsilateral mastoid process hypoplasia can be seen						Pathognomonic of neurofibromatosis. Also referred to as 'asterion defect'. Reflects focal hypoplasia or agenesis

Epidermoid/Dermoid	May expand both tables of calvarium. Sclerotic borders	Epidermoids-homogeneous and similar density to CSF. Dermoids-heterogeneous, may have peripheral or internal calcifications	Epidermoids-variable intensity. Dermoids- hyperintense from sebacious secretions	Both are hyperintense	Epidermoid-no enhancement. Dermoid-may show wall enhancement		Unilocular ectodermal inclusion cysts. Epidermoids contain sloughed keratin from thin epithlial lining while dermoids contain a thicker lining with dermal appendages. Epidermoids are more lateral. Dermoids more midline

Osteoma	Homogeneous dense oval/round lesion, more commonly arising from outer table of calvarium. Bony stalk usually seen without diploic disruption.	Homogeneous dense oval/round lesion, more commonly arising from outer table of calvarium. Bony stalk usually seen without diploic disruption.	Hypointense	Heterogeneously hypointense	Non-enhancing		Most common calvarial lesion. Benign, painless, usually incidentally found. Mature osseous matrix.

Osteosarcoma	Can be lytic, blastic, or mixed. Wide zone of transition	Useful in detection of mineralization within associated soft tissue component	Hypointense due to osteoid formation	Heterogeneous depending upon amount of matrix	Heterogeneous enhancement with possible soft tissue mass		When occurs in skull, usually as a result of malignant transformation in older patients

Intraosseous Meningioma	Can be indistinguishanble from plaque-like meningiomas if dural invasion seen at time of discovery, as most expand through calvarium. Prominent hyperostosis with minimal parenchymal changes seen	Isodense to hyperdense to brain parenchyma Image 2	Hypointense	Iso to hyperintense	Homogeneous enhancement		Account for 1% of meningiomas, originating in diploe

Ricket's	Osseous sclerosis and bone thickening due to abundant non-mineralized osteoid production	Osseous sclerosis and bone thickening due to abundant non-mineralized osteoid production Image 2					Systemic disease of childhood caused by a lack of available phosphate/calcium for adequate osteoid mineralization. Results in bowing of long bones with widening of physes and fraying of metaphyses secondary to abundant unmineralized osteoid production. Causes sclerosis and bone thickening in skull. Can result in small posterior fossa with resultant Chiari 1 malformation.

Lukenshadel		Focal areas of poor ossification with surrounding bands of denser ossification Image 2					AKA 'lacunar skull', caused by dysplasia of membranous bone. Usually resolves by 6 months of age. No relation to underlying hydrocephalus as with 'copper-beaten skull'. Association with neural tube defects such as Chiari II malformations and encephaloceles

Copper Beaten Skull	Convolutional markings along inner table of calvarium secondary to increased intracranial pressure from craniosynostosis	Convolutional markings along inner table of calvarium secondary to increased intracranial pressure from craniosynostosis					Gyral impressions, AKA convolutional markings, along inner table of calvarium secondary to chronically increased intracranial pressure in developing in infants/children. Most commonly secondary to craniosynostosis, hydrocephalus, and intracranial mass. Seen most frequently during periods of rapid brain growth ~ 2-3 and 5-7 yrs of age.

Thalassemia	Hair on end appearance due to trabecular remodeling						Anemia results in trabecular marrow hyperplasia with cortical thinning and diploic expansion. Remodeling of the trabecula perpendicular to the curvature of the calvarium creates a 'hair on end' appearance

Osteogenesis Imperfecta	Multiple fractures, thin cortices, wormian bones (i.e. multiple bones within the sutures), decreased ossification at skull base	Osteoporosis Circumscripta: image 1 Osteoporosis Circumscripta: image 2					Defect in type I collagen synthesis resulting in osteoporosis and bone fragility. Four subtypes with more benign types I and IV, more aggressive type III and lethal type II. Features include multiple fractures with main differential being child abuse

Mount Sinai's Radiology Charts