Three-Dimensional Imaging of the Hypopharynx and Larynx by Means of Helical (Spiral) Computed Tomography

Abstract

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.

A new method for determining the optimal CT threshold for extracting the upper airway

“…In addition, patient motion, such as breathing or swallowing, often causes blurring. 6 Conversely, helical CT can scan the entire neck within a single breath-hold (30 s) in most patients because it has the ability to acquire consecutive scans. 4,5 In addition, thick-section images can be obtained with helical CT.…”

Three-Dimensional Imaging of Laryngeal Cancers Using High-Speed Helical CT Scanning

“…However, this method has not been widely used in the otorhinolaryngeal field particularly for laryngeal cancer [10][11][12][13].…”

“…In spite of these advantages, mentioned above, helical CT has not been widely employed in the field of head and neck surgery. Little has been reported on the 3-D reconstruction of the larynx by helical CT including not only the cartilage but also the soft tissues [10][11][12][13]. In particular, the clinical utility of helical CT for laryngeal cancer has not been evaluated adequately.…”

A New Method of Reconstructing the Human Laryngeal Architecture Using Micro-MRI

“…Histological slicing has been used in other organ systems to create 3D reconstructions after two-dimensional (2D) segmentation 5 ; however, this method is problematic in laryngeal modeling because different laryngeal tissues have different deformation ratios during the slicing process, obscuring the true anatomical shape. Computed tomography (CT) has also been used for laryngeal imaging and reconstruction [6][7][8] and in surgical planning, 9 but CT is not able to clearly reflect soft tissue. Models created using magnetic resonance imaging (MRI) are more successful because of its superior ability to image soft tissue.…”