Ultrasound May Be Sound for Head Trauma

Head injuries in kids can be spotted with ultrasound avoiding radiation exposure with CT

(RxWiki News) Head injuries are very common in childhood, accounting for 600,000 visits to the emergency department each year in the United States. Clinical examination alone may not be able to detect internal damage.

Computed tomography (CT) scans are performed in cases of head trauma where skull fractures are suspected, to detect brain injuries that might need intervention. One potential drawback to using CT is that it involves radiation.

Could ultrasound be used to rule out skull fractures instead of exposing kids to radiation from CT scans? According to a new study, the answer may be "yes."

This study's results showed that point-of-care ultrasound conducted at the doctor's office can accurately predict the presence of skull fractures.

"Ask your doctor about ultrasound for head trauma diagnosis."

The study was conducted by Joni E. Rabiner, MD, from Division of Pediatric Emergency Medicine at Children’s Hospital at Montefiore/Albert Einstein College of Medicine in Bronx, New York, and colleagues.

The objective of the study was to find out how point-of-care ultrasound performed by physicians compared with CT for the diagnosis of skull fractures in children.   

Seventeen pediatric emergency physicians, 16 of whom had performed fewer than 25 ultrasounds before, attended a 30-minute session to learn how to use ultrasound to diagnose skull fracture. They also participated in a 30-minute hands-on session where they practiced their technique. At anytime during the study, they were permitted to refer to a reference manual with complete instructions and images.

The researchers recruited 69 patients with head injuries ranging from 7 days to 21 years of age, with a mean age of 6.4 years.

Before the ultrasound was performed on the patients, the physicians collected data to record clinical features such as scalp hematoma, loss of consciousness, disorientation and/or skull fracture that could be felt on the surface of the skin and history of vomiting. The physicians also recorded their impression of the possibility of skull fracture before the scan.

A positive ultrasound was defined as the physician’s diagnosis of a split in the skull bone or any type of unevenness found.

Physicians diagnosed nine positive ultrasound scans, of which seven were actually skull fractures as confirmed with CT imaging.

The remaining 60 patients were diagnosed as negative for skull fracture on ultrasound. Of these 60 patients, 59 had been identified correctly and only one patient showed skull fracture on CT scan.

The case that was missed was of a 7-month old baby boy who had a history of head trauma. The ultrasound was performed directly over the part that had a localized collection of blood, called hematoma. But on CT, it was found that the fracture was not directly underneath the hematoma but right next to it.

The study authors recommended scanning the areas around the hematoma in the future instead of just the area beneath it.

Thus, the results showed that point-of-care ultrasound could detect skull fractures with a sensitivity of 88 percent and a specificity of 97 percent. In other words, the accuracy was very high since the scans diagnosed a small percentage of patients who did not have a fracture as having a fracture.

Also, the ultrasound scans are expected to miss an extremely small percentage of patients who really have a fracture because they are diagnosed as negative.

“There are several advantages of using point-of-care ultrasound in the detection of skull fractures," wrote the authors. “First, ultrasound can be performed rapidly, which can allow earlier detection of skull fracture as a marker for suspected intracranial injury and neurosurgical consultation. Second, point-of-care ultrasound has the potential to reduce CT use and ionizing radiation exposure in children”.

The authors also pointed out that ultrasound for skull fractures may be very useful in areas where there is no access to CT scans.

"Ultrasound is becoming the ER physician's tool of choice for evaluating and diagnosing patients with acute medical and traumatic symptoms," said dailyRx contributing expert Chris Galloway, MD. 

"This is a very intriguing study showing that the high sensitivity of ultrasound in skilled hands someday might reduce CT scanning in children with head trauma. While we always want to minimize radiation exposure in everyone, I would not give up the CT scanner just yet as ultrasound is not available at all hours in an ER, and ultrasound skills are highly variable between users," said Dr. Galloway, who was not involved in the study.

Though ultrasound requires a skilled clinician, the authors believe that the results of this study can be generalized since the physicians who participated were novices in the field and did not have specialized training prior to the study. But future research and larger studies are required to find out whether ultrasound can completely replace CT scans in screening for fractures in kids with head injuries.

This study was published online on May 20 in Pediatrics, the official journal of the American Academy of Pediatrics.

The researchers did not receive any external funding and have not disclosed any conflicts of interest or relevant financial relationships.

Review Date: 
May 18, 2013