Introduction: The scout image on head CT contains valuable information beyond being a reference line for axial imaging in traumatic head injury. The purpose of this study is to determine how reliably the head CT scout image can show significant Type II odontoid fractures of patients who undergo head trauma. This analysis can be critical in patients with a limited extremity exam, heavily sedated or paralyzed patients, and those hospitals that do not routinely obtain CT of the cervical spine in patients with significant head injury.
Methods: We performed a clinical review of 80 consecutive patients who underwent head CT for head injury at our Level 1 trauma hospital from 2010-2011 with a diagnosis of a C2 fracture. Patients were excluded if the fracture was not a type II fracture, a chronic fracture, or if both cervical and head CT scans were not performed. Using PACS, we confirmed Type II Odontoid fractures in 18 of these patients (18/80 = 23%). We then queried 18 consecutive cervical CT scans, within the study period, that were normal and randomized the scout head CTs of both the patients with fractures and those without. Three physicians, including a neurosurgeon and an orthopedic spine surgeon, were blinded to the results and asked to determine which scout head CTs had a true Type II fracture without looking at the associated cervical CT.
Results: Eighteen patients (7 M/11 F) were identified with type 2 odontoid fractures with an average age of 80 years (27-94). The three observers correctly identified the type II fractures 81%, 86%, and 100%of the time. Agreement of observers with actual status using the AC1 was 0.63, 0.72, and 1.0 %.
Conclusions: The scout image on head CT is rarely scrutinized for C2 fractures, but can be a valuable resource for analyzing such commonly associated cervical spine injuries in the setting of head trauma.
Patient Care: This study may improved the management of cervical trauma patients. This becomes especially important in hospital systems where a CT of the cervical spine is not a routine part imaging the head injured patient.
Learning Objectives: By the end of this session, participants will be able to: 1) recognize common skeletal anatomy of a head CT scout image, 2) understand the value of a lateral head CT scout image beyond serving as a scout line, 3) recognize findings that suggest a potential C2 fracture.