Three dimensional (3D) display of the pharyngeal air space change by a compensation posture for dysphagia using cone-beam CT

吞咽姿势的改变会改变口咽间隙的形状。第一项研究的目的是利用锥形束CT的三维数据来分析这种变化，为了观察重力的影响，10名志愿者被取坐位进行锥形束CT（CBCT），并在仰卧位进行多层螺旋CT（MSCT），要求吞咽唾液以预测休息位置。不幸的是，只有3名志愿者在吞咽后变为休息位。从这7例数据来看，软腭受重力影响较小。另外，舌骨、会厌和食管入口受重力影响较大，且有老化趋势。为了分析头部向一侧旋转对咽间隙形态的影响，我们采用头部向右侧旋转的CBCT。2名志愿者进行了视频内窥镜检查。据说，旋转侧的梨状窦会因该区域的压力而消失，但另一侧会扩大。从我们的CT数据，我们重建了3D图像.旋转侧梨状窦不完全缩小，反而扩大。对侧梨状窦也增大。在梨状窦上平面，咽部由椭圆形变为泪滴形。对侧增大，旋转侧缩小。大多数研究都使用内窥镜进行分析，并且在旋转时不允许直接观察梨状窦。

Change postures in swallowing changes the shape of oropharyngeal space. The purpose of first research was to analyze this change using 3 dimensional data from cone-beam CT.To see the effect of gravity, 10 volunteers were taken in sitting position with cone-beam CT (CBCT) and in supine position Multislice CT (MSCT) asking saliva swallow to anticipate rest position. Unfortunately, only 3 volunteers became rest position after swallow. From these 7 cases' data, soft palate was a little affected by the gravity. Further, hyoid bone, epiglottis and esophageal entrance were more affected by the gravity and have a tendency of aging.To analyze the effect of head rotation to one side to the shape of pharyngeal space, we took CBCT with head-on and rotated to the right side. Videoendoscopy was taken in 2 volunteers. It was said that the piriform sinus in the rotated side will disappear because of the pressure to this area, but another side will be enlarged. From our CT data, we reconstructed 3 D images. The piriform sinus was not shrunk completely in the rotated side but rather enlarged. The opposite side of piriform sinus also enlarged. But in the level of the upper piriform sinus, the shape of the pharynx changed to a tear-drop shape from the oval one. The opposite side was enlarged and rotated side was shrank. Most of the researches to analyze this they use endoscopy and it does not allow the direct observation of the piriform sinus when rotated.