Evaluation of swallowing using 320-detector-row multislice CT. Part I: single- and multiphase volume scanning for three-dimensional morphological and kinematic analysis.

ABSTRACT

A 320-detector-row multislice computed tomography (320-MSCT) scanner can acquire a volume data set covering a maximum range of 16 cm and can generate axial images 0.5-mm thick at 0.5-mm intervals. Three-dimensional (3D) images reconstructed from the thin axial slices include multiplanar reconstruction and 3D-CT. Single-phase 3D images are reconstructed from 0.175-s data, and multiphase 3D images are created in 29 phases at intervals of 0.1 s. Continuous replay of these 3D images produces four-dimensional moving images. In order to determine the feasibility of the morphologic and kinematic analyses of swallowing using 320-MSCT, single-phase volume scanning was performed on three patients and multiphase volume scanning was performed on one healthy volunteer. The single-phase 3D images clearly and accurately showed the structures involved in swallowing, and the multiphase 3D images were able to show the oral stage to the early esophageal stage of swallowing, allowing a kinematic analysis of swallowing. We developed a reclining chair that allows scanning to be performed with the subject in a semisitting position, which makes swallowing evaluation by 320-MSCT applicable not only to research on healthy swallowing but also to the clinical examination of dysphagia patients.