Musculoskeletal #20

72-year-old alcoholic patient with intractable dorsal pain and legs numbness and weakness.

What do you see?

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IMAGING FINDINGS:

Thoracic spine compression fracture with posterior displacement of the posterior wall of the vertebral body compromising the spinal canal, cord compression and associated myelopathy. T2W image shows fluid and hypointense bubble-like artifact consistent with vacuum cleft in the collapsed anterior vertebral body

DIAGNOSIS:

Kümmel disease (osteonecrosis and collapse of the vertebral body)

TEACHING POINTS:

Intravertebral vacuum cleft and fluid within the collapsed vertebral body is a characteristic feature
Differential diagnosis includes a pathologic (tumoral) fracture, and the presence of air strongly favors osteonecrosis

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MR T2-weighted and CT images to highlight the characteristic features of Kümmel disease

Intravertebral fluid seen on T2 image and air on CT image

Neuroradiology #28

A 24-year-old female patient with headache. What do you see?

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Multinodular and vacuolating neuronal tumor (MVNT): Cortical ribbon-juxtacortical T2 hyperintense (a-b) round to oval nodular lesions, not suppressed on FLAIR images (c) and usually no enhancement (d) may show fair enhancement rarely, without diffusion restriction (not shown)

Musculoskeletal #19

54-year-old man with dorsolumbar irradiated left leg pain and paresthesias

What are the imaging findings?

CT: Slightly insufflating lytic lesion in the left pedicle, with thickened vertical trabeculae (“polka dot sign”) 
MRI: The lesions show high signal on T2 and STIR sequences, with small foci of T1 hyperintensity within the lesions suggesting fatty component. Soft tissue component with the same characteristics and avidly enhancing. Note the spinal canal secondary stenosis, cord displacement and compression

What is the most likely diagnosis

Aggressive vertebral hemangioma with soft tissue component

Neuroradiology #27

48-year-old male patient, HIV (+); presented to emergency with headache, confusion, N/V.

What do you see?

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T2 hyperintense lesions of left caudate nucleus, left putaminal and right dentate nucleus , with perilesional edema.

Small corticomedullary T2 hyperintense lesions with faint enhancement.

Caudate and putaminal lesions demonstrates faint peripheric contrast enhancement whereas cerebeller lesion has strong peripheric and central nodular enhancement.

Caudate and cerebellar lesion have tiny microhemorrhages on SWI, a clue for diagnosis.

Toxoplasmosis

· Most common opportunistic CNS infection and most common cause of a mass lesion in AIDS
· Basal ganglia, thalamus, corticomedullary junction and cerebellum frequently involved
· Microhemorrhages can be seen on SWI, lesions may have ring or nodular enhancement
· Major ddx is lymphoma:
– Lymphoma is usually solitary whereas solitary lesions are uncommon in toxoplasmosis.
– Microhemorrhages are uncommon in lymphoma

Musculoskeletal #18 – Flashcard

27-year-old patient with neurofibromatosis-type 1 (NF-1). Bone lesions found on PET-CT

What are the imaging findings?

Multiple bilateral multiloculated eccentric metaphyseal lucent lesions with thin sclerotic rim

What is the most likely diagnosis?

Multiple non-ossifying fibromas in a patient with NF-1

Teaching points

Very common benign lesion in young adults. Tend to heal or involute. Vast majority asymptomatic. Large lesions may be painful or weaken the cortical predisposing to pathological fracture (rare). Multiple in NF-1

Neuroradiology #26 – Long case

Where is the abnormality?

Right temporal lobe

What is it like?

Effacement of the temporal horn of the right lateral ventricle and subtle hypodensity within the right temporal lobe

What would you do next?

CT with contrast and MRI

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What are the MRI signal characteristics?

High-signal intensity lesion on FLAIR with significant edema and mass effect. Ring enhancement on post-contrast images

Emergency #27 – Flashcard

Elbow pain after a fall. What do you see?

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Findings

Large joint effusion with the displacement of the anterior fat pad. Mild posterior soft tissue swelling over the olecranon. Fracture line along the lateral aspect of the radial neck. Radial head and articular surface are normal

Diagnosis

Nondisplaced radial head fracture

Teaching points

– Check not only the bones and joints but also the soft tissues
– Search and interpret the findings in two different positions
– Pain always withholds a story behind

Musculoskeletal #17 – Long Case

2-year-old girl, referring to emergency department after a fall.

What do you see?

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– An expansile lytic lesion with ill-defined margins (green arrow) is seen on the diaphysis of fibula.

– Lamellated periosteal reaction (red arrow) suggests an aggressive lesion.

Differential diagnosis of an aggressive lytic lesion in a 2-year-old child includes:
– Osteomyelitis
– Ewing’s sarcoma
– Langerhans cell histiocytosis
– Leukemia/lymphoma

What should be done next?

An MRI scan

Intramedullary hyperintense lesion with extensive surrounding soft tissue and bone marrow edema on coronal STIR image (a) is seen. The lesion is hypointense on T1 WI (b).

Cortical destruction is shown on axial PD image (arrow in c).

Postcontrast coronal (a) and axial fat-suppressed (b) T1-weighted images show extensive enhancement in the lesion and the surrounding soft tissue

Histopathologic examination revealed Langerhans cell histiocytosis.

Langerhans Cell Histiocytosis (LCH)

– LCH is characterised by idiopathic infiltration and accumulation of abnormal histiocytes within various tissues.

– Bone is the most commonly affected tissue in children, with a predilection for axial bones, and femur is the most commonly affected long bone.

– Radiographic appearance of the lesions depends on the site of involvement and the phase of the disease.

Skull: Calvarium is more affected than the skull base, typically seen as single or multiple well-defined lytic lesions on radiography; T1 hypointense, T2 hyperintense with significant enhancement on MRI. Temporal bone is the most common affected part of skull base seen as destructive lesions with a soft tissue component.
Spine: Vertebral bodies are affected with relative sparing of posterior elements. A typical vertebra plana appearance may be encountered with total collapse.
Long bones: Ill-defined lytic lesions with/without cortical destruction are seen usually located at diaphysis or metaphysis. Periosteal reaction may be present. Extensive bone marrow and soft tissue signal changes on MRI may also be helpful in the diagnosis.