MRI Findings in Acute Osteomyelitis

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What radiographic feature is typically seen in acute osteomyelitis?

Periosteal reaction (correct)

Chronic sclerotic changes

Endosteal scalloping

Central necrosis

Which MRI finding is characteristic of acute osteomyelitis?

Decreased signal in the medullary cavity

High signal intensity on STIR images (correct)

Low signal intensity on T1-weighted images

Enhancement of the bony trabeculae

What is the term for a sequestrum in chronic osteomyelitis?

Sclerosis of the cortex

Dead, devascularized bone (correct)

Area of new bone formation

Pus-filled cavity

Which imaging modality is preferred for evaluating bony changes in chronic osteomyelitis?

CT scan Signup and view all the answers

What radiographic finding suggests chronic osteomyelitis rather than an acute presentation?

Peripheral sclerosis Signup and view all the answers

What is the primary etiological agent responsible for acute osteomyelitis in infants?

Bacterial infection Signup and view all the answers

Which imaging feature is more likely to be observed in chronic rather than acute osteomyelitis?

New bone apposition Signup and view all the answers

In acute osteomyelitis, which long bones are most commonly affected due to poor nutrition and unhygienic surroundings?

Femur Signup and view all the answers

In plain radiography for acute osteomyelitis, what must be compromised for noticeable changes to appear?

Fat planes Signup and view all the answers

What imaging modality is particularly useful in the early detection of changes in osteomyelitis compared to plain radiography?

Magnetic Resonance Imaging (MRI) Signup and view all the answers

What are sequestrum and involucrum commonly associated with in the context of chronic osteomyelitis?

Bone necrosis and new bone formation Signup and view all the answers

Which of the following is NOT a predisposing factor for osteomyelitis as mentioned in the text?

Elevated platelet count Signup and view all the answers

Which imaging modality is considered most sensitive and specific for identifying soft tissue/joint complications in acute osteomyelitis?

MRI Signup and view all the answers

What does the bone marrow signal look like on T1-weighted images in acute osteomyelitis?

Low signal Signup and view all the answers

What is a sequestrum in the context of osteomyelitis?

A piece of devitalized bone separated from surrounding bone Signup and view all the answers

Which imaging modality is superior to MRI and plain film for depicting bony margins and identifying a sequestrum or involucrum in osteomyelitis?

CT scan Signup and view all the answers

What are the overall sensitivity and specificity percentages of CT imaging in chronic osteomyelitis according to the text?

67% sensitivity, 50% specificity Signup and view all the answers

What does a sequestrum represent in the context of CT imaging in osteomyelitis?

Piece of devitalized bone separated from surrounding bone Signup and view all the answers

What is the hallmark of chronic osteomyelitis?

Infected dead bone within a compromised soft tissue envelope Signup and view all the answers

What is the function of a cloaca in osteomyelitis?

To provide a pathway for drainage of purulent and necrotic material Signup and view all the answers

What is the function of an involucrum in osteomyelitis?

To prevent infection from spreading to surrounding tissues Signup and view all the answers

What is the purpose of a sinus tract in chronic osteomyelitis?

To provide an opening for drainage to the skin surface Signup and view all the answers

Which imaging technique is useful in identifying a sequestrum in osteomyelitis?

Computed Tomography (CT) Signup and view all the answers

In acute osteomyelitis, what is characteristic of a cloaca?

Forms at the site of the initial infection Signup and view all the answers

What is the radiological finding known as involucrum in chronic osteomyelitis?

Cortical thickening representing periosteal new bone formation Signup and view all the answers

Which radiological finding is characteristic of Brodie abscess?

Oval configuration lytic lesion surrounded by reactive sclerosis Signup and view all the answers

What is the likely diagnosis in a patient with a sclerosing lesion with a thick rim of ossification on MRI imaging?

Sclerosing osteomyelitis of Garre Signup and view all the answers

What does a sequestrum represent in the context of osteomyelitis?

Separate sclerotic fragment of bone Signup and view all the answers

Which imaging modality best demonstrates a sclerotic fragment of bone separate from the rest of the humerus in chronic osteomyelitis?

Coronal CT with bone windows Signup and view all the answers

What would an oval configuration lytic lesion oriented along the long axis of the bone surrounded by a thick dense rim most likely represent on imaging?

Brodie abscess in subacute pyogenic osteomyelitis Signup and view all the answers

Which symptom is commonly associated with Stage I osteonecrosis?

Osteopenia Signup and view all the answers

What is the classic 'Crescent sign' seen in Stage III osteonecrosis indicative of?

Subchondral lucency and collapse Signup and view all the answers

Which imaging technique confirms the presence of sequestrum and involucrum in osteomyelitis?

X-rays Signup and view all the answers

At which stage of osteonecrosis does the shape of the femoral head remain preserved?

Stage IIIa Signup and view all the answers

What imaging evidence suggests AVN in later stages like Stages IV and V of osteonecrosis?

Arthritic changes Signup and view all the answers

Which condition may Stage VI osteonecrosis become indistinguishable from?

Osteoarthritis Signup and view all the answers

What is the most common bone affected by osteonecrosis?

Femoral head Signup and view all the answers

Sclerosis, subchondral cysts, and osteopenia are common findings in which stage of osteonecrosis?

Stage II Signup and view all the answers

Which imaging technique is abnormal in Stage I osteonecrosis?