Bone infarction
Updates to Article Attributes
Body
was changed:
A bone infarction is a term used to refer to osteonecrosis within the metaphysis or diaphysis of a bone. A medullary infarct is a fairly equivalent term to bone infarct but is less frequently used. The term may also be applied to some cases involving the epiphysis, but should not be used to describe subchondral osteonecrosis subchondral osteonecrosis, when in which case avascular necrosis is preferred preferred. Bone infarctions have numerous causes and have fairly distinctive imaging features on conventional radiography, CT and MRI.
Pathology
Infarction begins when blood supply to a section of bone is interrupted. Once an infarct is established, a central necrotic core develops which is surrounded by a hyperaemic ischaemic zone. With time collagen granulation tissue becomes layered around the necrotic core. Demarcation between the normal surrounding marrow, the ischaemic zone and the necrotic core accounts for many of the radiographic appearances of bone infarcts.
Causes
General causes of osteonecrosis include:
- trauma
- Caisson disease
- haemoglobinopathies, e.g. sickle cell disease 1
- radiotherapy
- connective tissue disorders
- renal transplantaion
- corticosteroid excess (both endogenous and exogenous)
- pancreatitis
- gout
- Gaucher
'sdisease - alcohol
The above list applies to both bone infarct and subchondral avascular necrosis, however some conditions are more likely to lead to one over the other. Sickle cell disease and Gaucher's disease for instance very commonly cause bone infarcts and less commonly cause subchondral AVN.
Radiographic features
General features include:
- medullary lesion
- serpiginous border
- most common in metaphyses
- often symmetrical
/and/or multiple infarcts
Plain film
There is significant delay between infarct onset and development of radiographic signs. Classic description is of medullary lesion of sheet-like central lucency surrounded by shell-like sclerosis with serpiginous border. DiscreateDiscrete calcification and perisotitisperiostitis may also be seen.
CT
Generally does not reveal much more than the plain film.
MRI
An important feature in differentiating bone infarct from other medullary lesions is that the central signal usually remains that of normal marrow. The The marrow is not replaced.
-
T1
-
serpigionousserpiginous peripheral low signal due togrannulationgranulation tissue and to lesser extent sclerosis - peripheral rim may enhance post gadolinium
- central signal usually that of marrow
-
-
T2
- acute infarct may show ill-defined non-specific area of high signal
- double-line sign: hyperintense inner ring of granulation tissue and a hypointense outer ring of sclerosis
- absence of double-line sign does not exclude bone infarct
- central signal usually that of marrow
-
GE
- gradient(gradient echo)- will also show double-line
- oedema obscured by susceptibility
Nuclear medicine
-
bone scan
- no uptake (cold spot) where blood supply absent
- mildly increased uptake at periphery during acute phase
Complications
- a bone infarct may occasionally dedifferentiate to a tumour such as 4-6
Differential diagnosis
General imaging considerations include:
- enchondroma: chondroid matrix, central marrow signal is absent
- healing non-ossifying fibroma
- normal red marrow: will not extend beyond physeal scar
- marrow tumour: central marrow signal is absent
-<p>A <strong>bone infarction</strong> is a term used to refer to <a href="/articles/avascular-necrosis">osteonecrosis</a> within the <a href="/articles/metaphysis">metaphysis</a> or <a href="/articles/diaphysis">diaphysis</a> of a bone. A <strong>medullary infarct</strong> is a fairly equivalent term to bone infarct but is less frequently used. The term may also be applied to some cases involving the epiphysis, but should not be used to describe subchondral osteonecrosis, when <a href="/articles/avascular-necrosis">avascular necrosis</a> is preferred.</p><h4>Pathology</h4><p>Infarction begins when blood supply to a section of bone is interrupted. Once an infarct is established, a central necrotic core develops which is surrounded by a hyperaemic ischaemic zone. With time collagen granulation tissue becomes layered around the necrotic core. Demarcation between the normal surrounding marrow, the ischaemic zone and the necrotic core accounts for many of the radiographic appearances of bone infarcts.</p><h5>Causes</h5><p>General causes of osteonecrosis include</p><ul>- +<p>A <strong>bone infarction</strong> is a term used to refer to <a href="/articles/avascular-necrosis">osteonecrosis</a> within the <a href="/articles/metaphysis">metaphysis</a> or <a href="/articles/diaphysis">diaphysis</a> of a bone. A <strong>medullary infarct</strong> is a fairly equivalent term to bone infarct but is less frequently used. The term may also be applied to some cases involving the epiphysis, but should not be used to describe subchondral osteonecrosis, in which case <a href="/articles/avascular-necrosis">avascular necrosis</a> is preferred. Bone infarctions have numerous causes and have fairly distinctive imaging features on conventional radiography, CT and MRI.</p><h4>Pathology</h4><p>Infarction begins when blood supply to a section of bone is interrupted. Once an infarct is established, a central necrotic core develops which is surrounded by a hyperaemic ischaemic zone. With time collagen granulation tissue becomes layered around the necrotic core. Demarcation between the normal surrounding marrow, the ischaemic zone and the necrotic core accounts for many of the radiographic appearances of bone infarcts.</p><h5>Causes</h5><p>General causes of osteonecrosis include:</p><ul>
-<li>haemoglobinopathies e.g. <a href="/articles/sickle-cell-disease">sickle cell disease </a><sup>1</sup>- +<li>haemoglobinopathies, e.g. <a href="/articles/sickle-cell-disease">sickle cell disease </a><sup>1</sup>
-<li><a href="/articles/gaucher-disease">Gaucher's disease</a></li>- +<li><a href="/articles/gaucher-disease">Gaucher disease</a></li>
-</ul><p>The above list applies to both bone infarct and subchondral avascular necrosis, however some conditions are more likely to lead to one over the other. Sickle cell disease and Gaucher's disease for instance very commonly cause bone infarcts and less commonly cause subchondral AVN.</p><h4>Radiographic features</h4><p>General features include</p><ul>- +</ul><p>The above list applies to both bone infarct and subchondral avascular necrosis, however some conditions are more likely to lead to one over the other. Sickle cell disease and Gaucher disease for instance very commonly cause bone infarcts and less commonly cause subchondral AVN.</p><h4>Radiographic features</h4><p>General features include:</p><ul>
-<li>often symmetrical / multiple infarcts</li>-</ul><h5>Plain film</h5><p>There is significant delay between infarct onset and development of radiographic signs. Classic description is of medullary lesion of sheet-like central lucency surrounded by shell-like sclerosis with serpiginous border. Discreate calcification and perisotitis may also be seen. </p><h5><strong>CT</strong></h5><p>Generally does not reveal much more than the plain film.</p><h5>MRI</h5><p>An important feature in differentiating bone infarct from other medullary lesions is that the central signal usually remains that of normal marrow. The marrow is not replaced.</p><ul>- +<li>often symmetrical and/or multiple infarcts</li>
- +</ul><h5>Plain film</h5><p>There is significant delay between infarct onset and development of radiographic signs. Classic description is of medullary lesion of sheet-like central lucency surrounded by shell-like sclerosis with serpiginous border. Discrete calcification and periostitis may also be seen.</p><h5><strong>CT</strong></h5><p>Generally does not reveal much more than the plain film.</p><h5>MRI</h5><p>An important feature in differentiating bone infarct from other medullary lesions is that the central signal usually remains that of normal marrow. The marrow is not replaced.</p><ul>
-<li>serpigionous peripheral low signal due to grannulation tissue and to lesser extent sclerosis</li>- +<li>serpiginous peripheral low signal due to granulation tissue and to lesser extent sclerosis</li>
-<a href="/articles/double_line_sign">double-line sign</a>: hyperintense inner ring of granulation tissue and a hypointense outer ring of sclerosis</li>- +<a href="/articles/double-line-sign">double-line sign</a>: hyperintense inner ring of granulation tissue and a hypointense outer ring of sclerosis</li>
-<strong>GE - gradient echo</strong><ul>- +<strong>GE (gradient echo)</strong><ul>
-<a href="/articles/angiosarcoma-of-bone">angiosarcoma of bone</a> : extremely rare</li>- +<a href="/articles/angiosarcoma-of-bone">angiosarcoma of bone</a>: extremely rare</li>
-</li></ul><h4>Differential diagnosis</h4><p>General imaging considerations include</p><ul>- +</li></ul><h4>Differential diagnosis</h4><p>General imaging considerations include:</p><ul>
-<a href="/articles/enchondroma">enchondroma </a>: chondroid matrix, central marrow signal is absent</li>-<li>healing <a href="/articles/non-ossifying_fibroma">non-ossifying fibroma</a>- +<a href="/articles/enchondroma">enchondroma</a>: chondroid matrix, central marrow signal is absent</li>
- +<li>healing <a href="/articles/non-ossifying-fibroma-1">non-ossifying fibroma</a>
-<li>normal <a href="/articles/bone_marrow">red marrow </a>: will not extend beyond physeal scar</li>-<li>marrow tumour : central marrow signal is absent</li>- +<li>normal <a href="/articles/bone-marrow">red marrow</a>: will not extend beyond physeal scar</li>
- +<li>marrow tumour: central marrow signal is absent</li>
Images Changes:
Image 1 MRI (STIR) ( update )
Caption
was changed:
Case 1: Gaucher's disease
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