Atlanto-occipital dislocation: case report and discussion.

Atlanto-occipital dislocation (AOD) is a devastating condition that frequently results in prehospital cardiorespiratory arrest and accounts for 15% of fatal spinal trauma. Atlanto-occipital dislocation occurs 5 times more commonly in children than adults, and is believed to be caused by hyperextension. Because of improvements in prehospital resuscitation, more victims with AOD now survive to reach the emergency department. Neurologic injury is usually severe secondary to ligamentous disruption that allows the cranium to move with respect to the cervical spine, and associated facial and head injuries are common. There are, however, reports of survivors without neurologic deficits. We present the case of a 46-year-old woman who suffered an AOD after a motor vehicle crash and we discuss the diagnosis of this condition. The signs of AOD are often subtle, and the possibility of this diagnosis must be kept in mind in all patients with a neck injury, even in the absence of neurologic signs. A systematic approach to assessing the cranio-cervical relationship on the lateral cervical x-ray and the appropriate use of CT scanning is essential to identifying AOD. Through this case report we hope to familiarize clinicians with mechanisms of injury and appropriate imaging interpretation that will assist in the diagnosis of AOD.

Selections from the buffet of food signs in radiology.

Certain pathologic conditions have classic radiologic manifestations that resemble various types of food. These "food signs" are highly memorable and easily recognizable and include findings that resemble various fruits and vegetables; meat, fish, and egg dishes; pasta, rice, grains, and bread (carbohydrates); desserts, cakes, and candy; and dishes, cutlery, condiments, and so on. It is important that radiologists recognize these classic signs, which will allow confident diagnosis on the basis of imaging findings alone or narrowing of the differential diagnosis.