From the Guidelines
For a 4-day-old head hematoma in a newborn, ultrasound is the recommended first-line imaging study due to its safety, lack of radiation, and ability to differentiate between various types of collections. This approach is prioritized to minimize radiation exposure and potential long-term risks associated with other imaging modalities, while still providing valuable diagnostic information 1.
Key Considerations
- The choice of imaging depends on the clinical presentation, with larger, expanding, or symptomatic hematomas warranting more urgent evaluation.
- Most cephalohematomas (collections between the periosteum and skull) and caput succedaneum (swelling of the scalp) are benign and resolve spontaneously within weeks without imaging.
- However, persistent or concerning features such as increasing size, crossing suture lines, overlying skin changes, or associated neurological symptoms should prompt imaging evaluation to rule out more serious conditions.
Additional Imaging Modalities
If the ultrasound findings are concerning or inconclusive, a non-contrast CT scan may be considered as the next step, particularly if there is suspicion of an underlying skull fracture or intracranial hemorrhage 1. MRI might be utilized in specific cases where more detailed soft tissue evaluation is needed, though it typically requires sedation in infants. The use of MRI can provide valuable information on the location and size of hemorrhage, evidence of mass effect, and hydrocephalus, and may show evidence of an underlying structural lesion 1.
Clinical Decision Making
The decision to proceed with imaging should be based on a thorough clinical assessment, taking into account the patient's age, clinical presentation, and risk factors for underlying conditions. The American College of Radiology (ACR) Appropriateness Criteria provide guidance on the selection of imaging modalities for patients with head trauma, including newborns with head hematomas 1.
From the Research
Imaging Studies for Head Hematoma
For a 4-day-old head hematoma, the following imaging studies are recommended:
- CT scanning is the current first imaging technique to be used after head injury, in those settings where a CT scan is available 2
- The first scan is usually done without contrast enhancement to demonstrate scalp, bone, extra-axial hematomas, and parenchymal injury 2
- MRI is more sensitive for all posttraumatic lesions other than skull fracture and subarachnoid hemorrhage, and can demonstrate parenchymal spinal cord injury 2
- If the CT does not demonstrate pathology adequate to account for the clinical state, MRI is warranted 2
Specific Considerations
- CT angiography can be used to predict the site of hemorrhage, especially when performed within 30 days of bleeding events 3
- The "spot sign" on CT angiography is a well-known indicator of active bleeding, but mimics have been identified, including micro AVM, posterior communicating artery aneurysm, Moya Moya, and neoplasm-associated calcification 4
- MRI can demonstrate the "spot sign" and multiple foci of active bleeding, supporting the "avalanche" hypothesis of hematoma expansion 5