Imaging of the Larynx and Hypopharynx

Abstract

The larynx and hypopharynx are imaged with either computed tomography (CT) or magnetic resonance (MR). A standard CT examination is done with the patient in the supine position; the patient is also instructed to resist swallowing or coughing. Axial slices are obtained from the base of the skull to the trachea with a scan orientation parallel to the true vocal cords. Iodinated contrast material (total dose: 35–40 g iodine) is given intravenously with an automated power injector. Images are obtained during quiet breathing rather than during apnea because the abducted position of the true vocal cords facilitates evaluation of the anterior and posterior commissures. Acquisitions with 3-mm collimation at pitch 1 and overlapping reconstruction intervals of 2 mm are the minimum settings necessary to evaluate the larynx. With multi-slice CT scanners, a slice thickness of 1.3 and overlapping reconstructions every 0.6 mm are used routinely by many investigators, including ourselves, as these settings yield high-quality 2D-reconstructions in the coronal or sagittal plane.