Author: M.Reza Fardanesh
Radiograph CT MRI - T1 MRI - T2 or STIR MRI - Post-contrast T1 Radionuclide Gross Pathology Histology Additional comments
Osteoid Osteoma Image a. round calcified, sharply demarcated nidus w/normal surrounding bone.
Image b. Post enucleation.
Periosteal rxn, thickening of anteromedial cortex, & low-attenuation nidus (arrow) w/central mineralization. Reactive sclerosis of bone marrow (*) adjacent to nidus. low-signal-intensity nidus (arrow) nidus w/high signal intensity peripherally & heterogeneous signal intensity centrally. Note Periosteal elevation (arrowheads). low-signal nidus w/strong enhancement (periphery of nidus enhances > central portion). Note edema in surrounding bone marrow (*) & soft tissue (arrowheads). Nidus (*) extending to facet cartilage (arrows). Interconnecting trabeculae, background fibrovascular tissue, & minimal surrounding sclerosis. (original magnification, x150; hematoxylin-eosin stain).
 
Osteoblastoma markedly expansile lesion involving spinous process & laminae (arrows), w/vague sclerosis. marked expansion of C3 lesion w/defined sclerotic rim (arrows). Matrix mineralization (arrowheads) can simulate rings & arcs of chondroid tissue. Mass (arrows) can encroach on spinal canal (arrowheads). extensive mineralization of mass, which has relatively low signal intensity. expanded, bohulated mass (*) w/whitish tissue that represents osteoid matrix.
     
Sclerosing Osteomyelitis multiple pyramid-shaped lytic lesions w/surrounding sclerosis in metaphyses of tibia & fibula (straight arrow); lesions extend across growth plate into epiphysis (wavy arrow). Multiple apophyseal lesions also present in tarsal bones (arrowheads). Note generalized osteopenia. lytic areas in right mandibular ramus (arrow) with sclerosis & bony expansion, w/associated overlying soft-tissue swelling. decreased marrow signal intensity (arrow) & cortical interruption. increased marrow signal intensity (arrow). enhancement within subcutaneous tissues, consistent w/cellulitis near an ulcer site (arrow). Dynamic (left), blood pool (center), & bone (right) images from a three-phase bone scan: focal hyperperfusion, focal hyperemia, & foci of increased bone uptake, respectively, in right great toe. fragments of bone surrounded by fibrous stroma, in which there are scattered inflammatory cells & macrophages (original magnification, ×100; H-E stain).
Enostosis Nonspecific sclerotic focus in anterior portion of L-3 (arrowhead). densely sclerotic lesion w/irregular spiculated border just beneath anterior cortex to left of midline (arrowheads). cortical bone (arrows) w/irregular margins (arrowheads) (original magnification, xl 50; H-E stain).
         
Bone infarct Image a (initial): periosteal new bone formation (arrows), w/normal bone texture.
Image b (6 weeks later): distortion of bone texture, w/incorporation of region of periosteal rxn into cortical bone & resultant cortical thickening, & linear serpiginous areas of sclerosis in left tibial shaft.
Mixed sclerotic & osteolytic lesion, here seen within greater wing of left sphenoid bone (arrow). Note thickening of sphenoid & petrous bones in this example. area of slightly heterogeneous signal intensity within left sphenoid bone. No fatty marrow is seen within lesion. areas of high signal intensity in left mandibular ramus (arrowhead) & sphenoid bone (arrow). mandibular ramus (arrowhead) & sphenoid bone (arrow) lesions demonstrate homogeneous enhancement. Medial (left) & lateral (right) views of the left (L) tibia from late static phase 99mTc MDP scintigraphy show an area of decreased tracer uptake w/in proximal shaft (arrowheads).
   
AVN Example: AVN of talus
Image 3a&b: marked sclerosis of talar dome (arrow).
Image 4: increased opacity = osteonecrotic segment.
Image 5: lobulated subchondral lucency (black arrows) = necrotic segment outlined by peripheral sclerosis. Depression at articular surface (white arrow) = talar collapse.
Image 1: mixed hypoattenuating-sclerotic pattern along medial half of talar dome is outlined by serpiginous sclerotic line (arrows). mixed imaging pattern is consistent w/osteonecrosis.

Image 2: diffuse sclerosis involving majority of talus (white arrows), w/focal sparing of lateral talar dome (black arrow)
serpiginous low-signal-intensity line in talar dome (arrows). high-signal-intensity line in talar dome (arrow) outlines an avascular segment. Image c: thinned cartilage stained green by alcian green dye (helps ID mucopolysaccharides). Staining of articular cartilage is less green than expected (white arrow). Curvilinear fibrous tissue band (black arrows) appears as pale pink band outlining area of necrosis.
Image d: Highpower decalcified section shows viable tibia (Ti) & necrotic talus (Ta) on either joint side. Trabeculae on viable side show smooth endosteal contours (white arrows); On necrotic side, subjacent bone contains fragmented trabeculae (black arrows) & patchy eosinophilia (black arrowheads) consistent w/saponification.
     
Enchondroma arcs & rings pattern of mineralized chondroid matrix (arrowheads). Endosteal scalloping (arrows in a) can be seen. lobulated lesion (arrowheads) w/heterogeneous primarily intermediate signal, w/focal areas of low signal from mineralization (large white arrows) & high signal from entrapment of residual normal fatty marrow (small arrows). Incidental full thickness rotator cuff tear (black arrow). primarily high in signal, w/low-signal areas again 2nd to mineralization (white arrows). Incidental full thickness rotator cuff tear (black arrow). Delayed bone scintigmam: faint uptake (grade 1 - less than anterior iliac crest) within lesion (arrow). lobular growth pattern & white chondroid matrix (*). Focal shallow endosteal scalloping (arrow) correlates well w/imaging appearance. chondroid tissue (*) surrounding islands of fatty marrow (arrows).
 
Paget's Disease Image a: large area of subchondral lysis w/sharp inferior margin (arrowheads).

Image b: lytic lesion in tibial tubercle w/blade-of-grass appearance superiorly & inferiorly (arrows).
posterior thickening & mixed lysis & sclerosis (area between arrows). diffuse calvarial thickening remains low signal intensity w/both pulse sequences (*). diffuse calvarial thickening remains low signal intensity w/both pulse sequences (*). Example of sarcomatous transformation of Paget disease to malignant fibrous histiocytoma shows marked enhancement. Whole-body scintigram demonstrates increased radiotracer accumulation in proximal right femur & in deformed & enlarged tibias. incomplete fractures w/callus (between arrowheads). intracortical, nonsubchondral location (*) & sharp superior margin (arrow).
Osteoblastic Metastases Example: dense osteosclerosis (breast Ca) Example: extensive multifocal osteoblastic metastases (prostate Ca). Technetium-99m methylene diphosphonate bone scan demonstrates intense, near-diffuse osseous radiotracer uptake with minimal renal activity (“superscan”). Example of pt w/prostate Ca.
         
Sickle Cell Anemia Diffusely sclerotic bones & thickened trabeculae d/t medullary infarction & dystrophic calcification. Well-circumscribed foci of semilunar serpiginous sclerosis in femoral epiphyses (arrows) consistent w/avascular necrosis. Thickening of skull base, especially in sphenoid & petrous bones. A mixed sclerotic & osteolytic lesion within greater wing of left sphenoid bone (arrow) = prior bone infarction. Areas of intermediate signal d/t persistence of appendicular red marrow in the medullary cavities (arrowhead) make assessment of osteomyelitis difficult. Additionally, soft-tissue infection present in this pt [low-signal-intensity fluid collection within pre-Achilles fat space (arrow)]. abnormal heterogeneous signal intensity in L1 & L2 vertebrae compatible w/infarction. Example: Bone infarction in sickle cell
Medial (left) & lateral (right) views of left (L) tibia from late static phase 99mTc MDP scintigraphy show area of decreased tracer uptake within proximal shaft (arrowheads), suggestive of infarction.
extensive ulceration of lower leg of an adult patient with sickle cell disease.
   
Progressive diaphyseal dysplasia Image 9: right & left forearms show bilateral & symmetric cortical thickening involving both periosteal and endosteal surfaces. Medullary canals are narrowed & there is characteristic sparing of epiphyses.
Image 10: right & left tibia & fibula demonstrate symmetric cortical thickening in diaphyses of long bones.
diffuse osseous sclerosis of skull base. T1- weighted (a) & short inversion time inversion-recovery (b) images show characteristic unilateral cortical thickening involving right femur, w/no involvement of left femur.