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Background
Though commonly seen in forensic radiology with a postmortem incidence of 17-76% in victims of fatal strangulation or hanging, nonfatal fractures of the hyoid-larynx complex (HLC) are infrequently reported despite common potential mechanisms including direct trauma or hyperextension. Nonfatal HLC fractures are rare, with the incidence reported to be between 0.002% and 1.15% of all fractures. Incidence is, however, likely to be underestimated for many reasons, including that satisfaction of search may draw the eye towards more immediately life-threatening injuries in the same anatomic space. The most common mechanism of HLC fracture, blunt laryngeal trauma, is associated with a high in-hospital morbidity and mortality up to 40%, largely due to relatively asymptomatic patient presentation in subtle cases. The radiologist, therefore, may be the primary physician responsible for identifying HLC fractures that would otherwise be overlooked in the complex trauma patient. Thyroid or cricoid cartilage fractures may in some cases require emergent or planned surgery, further solidifying the radiologist’s role in timely diagnosis.

Educational Goals / Teaching Points
The purpose of this educational exhibit is to aid the viewer in developing a search pattern for rare but important HLC fractures in patients presenting to the emergency department with nonfatal HLC injury, particularly on nontargeted CT for blunt and penetrating trauma. Using a cased-based format, we will detail relevant HLC anatomy, spatial relations, and variants, and propose a search pattern based primarily in manipulation of multiplanar thin-slice CT for blunt trauma. Pearls and pitfalls of diagnosis will be correlated with follow-up imaging and patient course when appropriate. Attention to specific presenting symptoms will direct the viewer to situations in which subtle HLC injury may be considered.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The HLC itself will be reviewed in this presentation, as well as the associated ligaments and joints that work in concert with the bony and cartilaginous structures to perform crucial roles in upper esophageal motility, respiration and phonation. As the goal for the interpreting radiologist is to diagnose fractures or injury associated with emergent presentations, the primary modalities explored will involve nontargeted CT and CTA of the head, neck, and cervical spine. We will use manipulation of CT with multiplanar thin-slice reconstruction and 3D color renderings to help illustrate important associated findings and interpretation pearls.

Conclusion
The HLC is the dynamic and mobile shield of the airway, with numerous critical anatomic relationships throughout the anterior neck. Though infrequent, HLC fractures can contribute to significant patient morbidity and mortality. This case-based presentation will help the radiologist develop a search pattern to assist in delivering providing prompt and accurate diagnoses in this complex space.