Three-dimensional imaging of the hypopharynx and larynx by means of helical (spiral) computed tomography. Comparison of radiological and otolaryngological evaluation.

A new computed tomography (CT) technology, helical (spiral) CT, allows the entire neck to be imaged in only 30 seconds. Although multiplanar and three-dimensional (3-D) imaging could be performed with conventional CT, the volumetric acquisition provided by helical (spiral) CT allows significantly improved quality and easier reconstruction for more applications. These 3-D models show an airway appearance similar to that obtained with laryngography. Independent review of the 3-D images in 12 patients with lesions by two radiologists and one otolaryngologist was performed to assess 1) image quality, 2) ability to judge lesion extent, and 3) assistance in understanding the lesion compared to that provided by routine axial scans. Rating scores of 1 to 5 were assigned, with 5 representing the best quality or greatest value. The results showed that both groups scored image quality equally: 4.7. Lesion extent for the radiologists was 2.6, while the otolaryngologist's ranking was 3.7 (p < .01). In assisting understanding of lesions versus axial scans, radiologists ranked 3-D images 2.1, while the otolaryngologist ranked them 3.1 (p < .01). In summary, 3-D models provide a complementary imaging technique in understanding upper airway disease.