Children with blunt abdominal trauma often get a CT as the first line imaging to evaluate for intra-abdominal organ injury. CT scans have some downsides with regard to radiation exposure, costs, and need for transport. Contrast enhanced ultrasonography has recently shown some promise as a way to detect intra-abdominal organ injury and may be able to replace the need for conventional CT scanning, without the need for ionizing radiation and the ability to be performed at the bedside.

In children with abdominal trauma, computed tomography (CT) of the abdomen is considered the gold standard for the initial evaluation of solid organ injuries. The major drawbacks to CT include risks due to radiation exposure and necessity of transport of the patient. Ultrasound without contrast uses safer non-ionizing radiation and can be performed at the bedside, however it has been shown to have variable sensitivity and specificity for identifying intra-abdominal organ injury. Newer studies using contrast enhanced ultrasound (CEUS) have shown promise for improving the sensitivity and specificity of this imaging modality.

Hypothesis(es) and Aims:

Hypothesis: Contrast enhanced ultrasound (CEUS) has good sensitivity and specificity as compared to a gold standard conventional CT scan for the identification of intra-abdominal solid organ injury in hemodynamically stable children with blunt abdominal trauma. Specific Aims:

Primary Aim: To determine the test characteristics CEUS / conventional ultrasound for the detection of intra-abdominal solid organ injury, as compared to a gold standard CT scan, in hemodynamically stable children with blunt abdominal trauma

Design:

This will be a prospective cohort study to evaluate the test characteristics of contrast enhanced ultrasound (CEUS) for the detection of intra-abdominal solid organ injury in children with blunt abdominal trauma, as compared to a gold standard CT scan. Study subjects will be age 0-18 years, presenting with hemodynamically stable blunt abdominal trauma and for whom an abdominal CT scan is planned. The exclusion criteria will be a known allergy to the ultrasound contrast agent, co-existing penetrating abdominal trauma, or known congenital or acquired heart disease. Sample size calculations assume a baseline prevalence of disease in approximately 20% of patients receiving a CT scan, and target a sensitivity of at least 95% with a two-sided confidence interval precision of 8%, yielding an estimated sample size of 146 patients. The primary outcome will be calculation of sensitivity and specificity of CEUS as compared to a gold standard CT scan.

Inclusion Criteria:

1. Hemodynamically stable (defined as not needing massive transfusion protocol and not undergoing an emergent surgical procedure within the next hour)
2. History of or suspicion for blunt abdominal trauma
3. Abdominal CT ordered or obtained

Exclusion Criteria:

1. History of allergic reaction to Lumason, sulfur hexaflouride, sulfur hexafluoride lipid microsphere components, or other ingredients in Lumason (polyethylene glycol, distearoylphosphatidylcholine (DSPC), dipalmitoylphosphatidylglycerol sodium (DPPG-Na), palmitic acid)
2. Co-existing penetrating abdominal trauma
3. Known congenital or acquired heart disease