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Neuroradiology Case of the Week

Case 223

J. Carmen Timberlake, MD, and P-L Westesson, MD, PhD, DDS

Clinical Presentation: A two-week-old infant presented with lethargy and hypoxia and was admitted for rule-out sepsis evaluation.

Imaging Findings: Routine brain MR imaging was performed with and without contrast. Abnormal high signal in right transverse sinus on T1 and T2-weighted images consistent with right transverse sinus thrombosis. No evidence of acute infarct.

Diagnosis: Transverse sinus thrombosis

Discussion:

Common causes of venous sinus thrombosis in children:

• Septic/infectious causes:

  – Encephalitis
  – Bacterial meningitis
  – Otitis media
  – Mastoiditis
  – Retrograde orbital infections

• Aseptic causes:

  – Severe dehydration in infancy
  – Hypercoagulopathy
  – Cyanotic congenital heart disease
  – Leukemic infiltrates

Causes of venous sinus thrombosis in adults:

• Acute dehydration
• Chemotherapeutic agents
• Hypercoagulable states and coagulopathies
• Iatrogenic (indwelling venous catheters)
• Malnutrition
• Pregnancy
• Trauma

Complications:

• infarction (in approximately 50% of cases)
• seizures
• hemorrhage
• hemorrhagic infarction.

CT findings:

• Cord sign = high density cord or dot (clot) in the vein. Triangle of high density in sagittal sinus on noncontrast CT.
• Delta sign = enhancement around a clot in the sinus.
• Appearance of medullary veins indicating collateral venous drainage.

MR findings:

• Acute thrombus:

  – Isointense on T1WI
  – Absence of flow void on T1WI
  – Hypointense on T2W
  – Signal void on gradient echo

• Subacute thrombus:

  – Hyperintense on T1WI and T2WI
  – Gray signal (representing lack of flow) on phase contrast angiography

References:

1. Behrman RE, Kliegman RM, and Jenson HB. Nelson Textbook of Pediatrics, 16th edition. W.B. Saunders Company, 2000.
2. Grossman RI and Yousem DM. Neuroradiology: The Requisites, Second Edition. Mosby, 2003.