CT screening for head and neck vascular injury wins favor in ER

CT screening of head and neck vascular injuries by emergency departments could lead to more aggressive therapies that result in improved outcomes, according to a pair of papers presented Monday at the 2005 RSNA meeting.

The studies, by researchers in Berlin and at Brown University, examined trends for screening trauma patients. The use of CT to identify occult injury that might otherwise escape treatment received favorable reviews by both.

The study from Berlin compared findings from ultrasound exams used to screen carotid arteries for injury to the results of CT angiography scans for the same indication. The ultrasound exams were acquired over five years and the CT scans over a one-year period.

The results were dramatic. The ultrasound scans of 1471 patients produced a sensitivity of 38.5% and a specificity of 100%. One year after installation of a multislice CT device, CTA scans performed on 407 ER patients yielded a sensitivity of 100% and a specificity of 99.1%, with one false positive.

Today the facility's protocol calls for CTA in all instances of possible carotid trauma, said principal investigator Dr. Grit Rademacher. The team now skips traditional angiography and, after one year of experience, is confident that all injuries can be caught in the first scan.

The paper from Brown documented a surge in CTA and a corresponding plunge in MRA and angiography procedure volume following the installation of a 16-slice CT scanner.

Using a liberal screening protocol for cerebrovascular neck injuries, scans increased from 9.1 per month to 43 per month, said presenter Dr. Chad B. Rabinowitz.

The paper compared scans during two nine-month periods. Before installation of the multislice scanner, the number of conventional angiograms ordered totaled 2.4 per month, while the number of MRA exams totaled 6.7 per month. In this group, eight patients were diagnosed with injuries.

After the installation of the 16-slice scanner, the number of CTA exams ordered totaled 43 per month, with 26 patients initially diagnosed with injuries. Follow-up conventional angiography confirmed injuries in 15 of these patients.

Between the control and study periods, the number of patients undergoing evaluation for cerebrovascular injury increased 373%. Positive studies decreased from 9.8% to 3.9%, but the total number of actual diagnosed injuries increased 87.5%.

Most of the interpretations rely on axial images, with occasional use of coronal and maximum intensity projection images, Rabinowitz said. Positive findings are confirmed with angiography.