Carstens Ann, Kirberger Robert M, Grimbeek Richard J, Donnellan Cynthia M B, Saulez Montague N
Section of Diagnostic Imaging, Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa.
Vet Radiol Ultrasound. 2009 Sep-Oct;50(5):492-501. doi: 10.1111/j.1740-8261.2009.01570.x.
Radiographic measurement of tracheal dimensions in the horse may be useful in evaluating upper and lower respiratory tract conditions due to the gradient of pressure changes between these areas. Lateral radiographs of the trachea of 15 normal sedated Thoroughbred horses were made at inspiration and expiration and magnification-corrected mean airway heights measured were, respectively: larynx: 5.89 and 5.86 cm; trachea at the third cervical vertebra (C3): 4.17 and 4.04cm; at the fifth cervical vertebra (C5): 3.62 and 3.59 cm; at the first thoracic vertebra (T1): 3.4 and 3.23cm; and carina: 3.85 and 4.12 cm. The ratio of airway height to nearby vertebral body lengths, at inspiration and expiration were, respectively: laryngeal height at C3: 0.56 and 0.56; tracheal height at C3: 0.4 and 0.39; at C5: 0.37 and 0.37; at T1: 0.59 and 0.59; and carina height: 0.91 and 0.94. The ratio of tracheal height to the thoracic inlet at inspiration and expiration was, respectively, 0.15 and 0.15. There was not a statistically significant association between airway diameter and phase of respiration. No association was found between tracheal height and body mass or height at the withers. Radiographic tracheal height can be measured independent of respiratory phase in sedated horses. It is suggested that the ratio of tracheal height to an adjacent bony landmark is more reliable for comparison between horses and tracheal height measurement should be made at C5, due to a lower standard deviation. If only thoracic radiographs are made, measurements of tracheal height at the thoracic inlet may be valuable.
由于马的上呼吸道和下呼吸道之间存在压力变化梯度，因此对马的气管尺寸进行影像学测量可能有助于评估上下呼吸道状况。对15匹正常镇静纯种马的气管进行了侧位X线片拍摄，分别在吸气和呼气时进行，并测量了经放大校正后的平均气道高度，结果如下：喉部：5.89和5.86厘米；第三颈椎（C3）处的气管：4.17和4.04厘米；第五颈椎（C5）处：3.62和3.59厘米；第一胸椎（T1）处：3.4和3.23厘米；以及隆突：3.85和4.12厘米。吸气和呼气时气道高度与附近椎体长度的比值分别为：C3处的喉部高度：0.56和0.56；C3处的气管高度：0.4和0.39；C5处：0.37和0.37；T1处：0.59和0.59；以及隆突高度：0.91和0.94。吸气和呼气时气管高度与胸廓入口的比值分别为0.15和0.15。气道直径与呼吸阶段之间没有统计学上的显著关联。未发现气管高度与体重或肩隆高度之间存在关联。在镇静的马匹中，可以独立于呼吸阶段测量X线片上的气管高度。建议气管高度与相邻骨性标志的比值在马匹之间进行比较时更可靠，并且由于标准差较低，应在C5处进行气管高度测量。如果只拍摄胸部X线片，测量胸廓入口处的气管高度可能有价值。
