A Study Of Reference Images Of Chest CT Tomography In Healthy Adult Dog

Purpose:To set up chest CT tomography of healthy adult dog for provision of scientific references of chest CT tomography images of the animal and for application of CT technology in clinical diagnosis of chest diseases in dogs.Methods:(1) 4 health adult dogs were selected for this study of chest CT tomogrphy after being checked by palpation,percussion,auscultation,and by examination of body temperature,respiratory rate,heart rate,breathing motion chest X-ray and blood parameters.Dogs were placed in the prostrate position on table-board of CT and were scanned in spacing of 5mm after general anesthesia.Scanned images of lung window and mediastinal window were obtained by CT tomography and were treated with digital camera and scanner.The major organs,arteries,veins,bones,soft tissue in scanned images at every level were labeled.(2) 4 dogs were sacrifice by euthanasia after being scanned by CT tomography and were perfusion through the femoral artery with 10%formaldehyde solution of 3-5 litres for small adult dog,5-7 litres for medium adult dog and 8-12 litres for large adult dog.Duration of perfusion was persisted in 24-48 h.The dogs were placed in freezers to be frozen in the prostrate position for 7-14d and cross-sections of chest were made by band saw in interval of 9.5-10.5mm.The saw consumption rate was of 1.0-1.5mm.All images of each cross-section of chest were obtained by high-power digital camera and the major organs,arteries,veins,bones,soft tissue in the images were labeled.Results:Results of CT tomography:(1) 16 images of lung window and mediastinal window are obtained respectively.(2) lungs,heart,blood vessels and other tissues are all in focus in the CT scanned images.Lungs are composed of the right and the left, the left lung is divided into anterior lobe and posterior lobe,the former is divided into front part and back part.Right lungs are divided into anterior lobe,middle lobe and posterior lobe.Left main bronchus,right main bronchus,bronchial and vascular are very obvious in different scanned images.Between right lungs and left lungs,the mediastinum,trachea,esophagus,ascending aorta,descending aorta,superior vena cava,heart and large vascular tissue are observed clearly.(3) Boundaries between the left atrium and the right atrium,and between left ventricular and right ventricular are lack of clear on the CT scanned images of heart.(4) Thoracic vertebrae,bladebone, ribs,sternum and muscle tissue around the chest can be identified distinctly.(5) Interfaces of small blood vessels,small nerves and muscle tissues are not clearly defined on the CT scanned images. Results of fault cross-sections of the frozen body:(1) 9 images of fault cross-sections of the frozen body are obtained.(2) Interfaces of lungs,heart,arteries, veins,trachea,bone,muscle and other tissues are all evident markedly in the images of fault cross-sections of the frozen body.Appearances of the lungs in the fault cross-sections are same of the CT scanned images.Between the right lungs and the left lungs,the mediastinum,trachea,esophagus,ascending aorta,descending aorta, superior vena cava,heart and large vascular tissue are clearly identified.(4) Interfaces of left atrium,fight atrium,left ventricular and right ventricular are clear to be seen in the images of fault cross-sections.(5)Appearances of thoracic vertebrae,bladebone, ribs,sternum and muscle tissue around the chest can be identified distinctly.Conclusion:(1) Results are just the same between the images of chest CT tomography and fault cross-sections of the frozen body.(2) The results of chest CT tomography in dogs show that thorax is symmetrical,rib bone and soft tissues are normal.(3) CT scan images in lung window showed that all the lung lobes are absolutely clear,lung transmittance is good,and there are no any shadows;(4) CT scan images in mediastinal window show that mediastinal is upright,heart shadow and shape of vascular are all normal.There are no tumor and mediastinal lymph node enlargement.No pleural effusions are obtained and pleural membrane is normal.(5) The images of chest CT tomography are the same of chest X-ray inspection,but are better intuitive and more obvious than X-ray examination.The results indicate that chest CT diagnosis is superior to X-ray inspection.