Spiral CT of the larynx.

PURPOSE To compare conventional and spiral CT studies of the larynx. METHODS Ten patients had both conventional and spiral CT studies of the neck using 5-mm section collimation and 5-mm increments. The spiral scans also were reconstructed at 2-mm increments. Five patients had two spiral CT larynx studies with 5-mm and 2-mm collimation. Two observers independently rated the visibility of laryngeal structures and absence of motion artifact in the studies and assigned values from 1 (poor) to 4 (excellent). RESULTS The spiral scan images showed less motion artifact (1.9 versus 3.6) and better anatomic detail (2.3 versus approximately 2.6). Thinner reconstruction intervals and sections gave better anatomic detail (2.3 versus approximately 3.3). Interobserver kappa was 0.65. CONCLUSION Spiral is better than conventional CT scanning when studying the larynx.