From the Guidelines
I strongly recommend a CT scan of the soft tissue neck with contrast to evaluate for an expanding neck hematoma, as it provides superior assessment of surrounding structures and potential vascular injury, with a high sensitivity and specificity of 100% and 97.5%, respectively, as demonstrated in a prospective study 1. When evaluating a patient with a potential expanding neck hematoma, it is crucial to prioritize imaging modalities that can quickly and accurately identify the extent of the injury.
- The use of contrast enhancement is preferred because it helps differentiate vascular structures from hematoma and better delineates the extent of bleeding, as noted in the acr appropriateness criteria for penetrating neck injury 1.
- The contrast allows visualization of active extravasation (ongoing bleeding) and helps identify the source of hemorrhage, which is essential for guiding treatment decisions.
- Without contrast, a hematoma may be visible as a hyperdense collection, but contrast provides superior assessment of surrounding structures and potential vascular injury, as demonstrated in early comparisons with catheter angiography 1.
- If the patient has significant renal impairment or contrast allergy, a non-contrast CT may be performed instead, but this may result in an underevaluation of the vasculature, as noted in the acr appropriateness criteria 1.
- Prior to the scan, the patient's renal function should be checked to ensure they can safely receive contrast, and premedication may be appropriate per ACR recommendations if there is a high risk of allergic reaction to iodinated contrast 1.
- Following the scan, close monitoring of the patient's airway status is essential, as neck hematomas can rapidly expand and cause life-threatening airway obstruction, highlighting the importance of prompt imaging and intervention.
From the Research
CT Soft Tissue Neck with or without Contrast
To check for an expanding neck hematoma, a CT scan of the soft tissue neck with or without contrast can be utilized. The following points highlight the relevance of this imaging technique:
- CT scanning can reveal hematomas in the neck, as seen in a case report where a retropharyngeal hematoma and right anterior neck hematoma were identified 2.
- In patients who develop neck hematomas after carotid endarterectomy, CT scans can help assess the airway compromise and guide airway management techniques 3.
- Contrast-enhanced CT scans can be particularly useful in identifying the source of bleeding, such as a thyrocervical artery injury, which can cause retropharyngeal hematoma and airway obstruction 4.
- When interpreting neck CT findings, a systematic approach is essential to evaluate all relevant areas, including the vascular structures and aerodigestive tract 5.
- CT angiograms of the neck can also be used to diagnose vascular injuries in strangulation victims, although the incidence of positive findings may be relatively low 6.
Key Considerations
When using CT scans to check for expanding neck hematomas, consider the following:
- The use of intravenous contrast material can help accentuate abnormally enhancing tissues and delineate any abscesses or necrotic areas 5.
- A systematic approach to interpreting neck CT findings is crucial to identify all salient findings and recognize the implications of these findings 5.
- CT angiograms can be useful in identifying vascular injuries, but the predictive value of clinical findings such as neck pain, loss of consciousness, and headache may be weak 6.