The use of multislice CT angiography has increased detection of vascular injury in patients suffering head and neck trauma, prompting debate on whether whole-body screening or focused attention on the head and neck is more useful. Both methods had their proponents at an RSNA session on emergency radiology.
Rates of blunt cervical vascular injury (BCVI) detection have increased from between 0.1% and 0.8% to between 1% and 5%, depending on the selection criteria used for scanning, said keynote presenter Dr. Stuart E. Mirvis, a professor of diagnostic radiology at the University of Maryland.
Up to 20% of patients with BCVI have no classic risk factors, and about 30% of patients experience injuries to multiple vessels. Early use of anticoagulants can reduce the risk of stroke and other adverse outcomes in these patients.
Some injuries are more closely associated with vascular injury than others. Identifying patients at high risk of cerebrovascular injury (CVI) can help physicians determine whether focused CTA scans are warranted while the patient is still on the table, said Dr. Nila H. Alsheik of the University of Wisconsin-Madison.
Alsheik's retrospective review of 1975 patients presenting to a Level 1 trauma center showed that patients with injuries that affect the carotid canal are most likely to experience CVI. Nearly half of the patients presenting with midface or mandibular fractures also showed evidence of vascular injury.
A retrospective study of 276 patients in Boston concluded that cervical spine or skull base fractures are more likely to indicate vascular injuries than other craniofacial injuries, according to Dr. John Kim of Boston University School of Medicine. The study found that patients with fractures in the skull base or spine were 4.2 times more likely to have vascular injury than those without. About 4% of all CTA examinations performed for neck trauma were positive for vascular injury to a major vessel.
While these studies concentrated on focused scanning of the head and neck, other researchers compared the efficacy of whole-body CTA (WBCTA) versus focused CTA. Whole-body MSCT should be considered the method of choice for BCVI screening in multisystem trauma patients, according to research presented by Dr. Alessandro Lemos of Fondazione Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, IRCCS in Milan.
Lemos found that WBCTA was comparable to focused CTA in terms of sensitivity, specificity, and diagnostic accuracy in an analysis of 1041 patients. WBCTA demonstrated a sensitivity of 65%, specificity of 99%, and diagnostic accuracy of 92%, while focused CTA achieved a sensitivity of 63%, specificity of 96%, and diagnostic accuracy of 90% with cervical artery injuries.
Whole-body MSCT is time-efficient, results in lower radiation dosage than focused CT, and allows simultaneous evaluation of vascular and parenchymal structures, Lemos said. In a comparison of five cases, mean scan time using WBCTA was 15.6 seconds, compared with 27.2 seconds using focused CTA. Tests on a medical phantom found that radiation dosage for WBCTA was 26 mSv to 32 mSv, compared with 30.2 mSv to 36.2 mSv for focused CTA.
