Application Of Ultrasound In The Diagnosis Of Liver Disease In Dogs

Doppler ultrasound is widely used in clinical veterinary. And especially suitable for the major abdominal cavity organs examination of dogs and cats. However, due to the special location and complex structure, the ultrasound examination of the liver is more difficult and more complicated than the other organs in the abdominal cavity. In this study, in order to get the ultrasonographic approach and anatomy of the normal liver, doppler ultrasound diagnostic apparatus was used to detect the canine liver to provide the basis for clinical diagnosis combined with canine liver ultrasound case analysis.Four adult healthy beagle dogs aged 2~3 years were selected as animal models. The same position of the same dog was scanned by a linear array probe with a center frequency of 8.0 MHz and a convex array probe with a center frequency of 3.5 MHz. The ultrasonic images of the liver were compared. And the advantages and disadvantages of the linear array and the convex array probe were analyzed and summarized from the point of view of the diagnostic value of the image. Through the implementation of ultrasound preparation and application of the special position scanning, operation specifications and technical points for scanning the liver were described. In order to get the atlas of ultrasonographic anatomy of the normal liver, we should use convex array probe from a subxiphoid location to get the sagittal and transverse scanning plane of the liver. The distribution and direction of hepatic blood vessels were displayed by color doppler flow imaging, and pulsed wave doppler was used to identify and differentiate PV and HV in liver. Through the analysis of the image features of canine liver disease, we summarized the methods of differential diagnosis.The results showed that a 7.5~10 MHz ultrasound probe is suitable for small dog. But for large dogs, a 5 MHz ultrasound probe is much better. Clinically, we should select the appropriate probe according to the size of the animal and the purpose of the examination. In order to reduce the impact of intestinal contents, the preparation before ultrasonic scanning is necessary. The special position scanning is especially suitable for the visualization of the entire liver. The first and sixth sagittal sections of the reference section of the liver can be used for clinical evaluation of liver size. Normal liver bile duct system and intrahepatic branches of the hepatic artery are usually not visible. The main branch of the portal vein is slightly curved to the right. The PV and HV were approximately parallel in the same lobe, which were useful sonographic markers. Hepatic vein, caudal vena cava, portal vein and abdominal aortic pulse spectrum showed typical patterns, which were easy to be distinguished and identified. The ultrasound image features of cyst, mass, gallbladder mucous cyst and moderate to severe liver passive congestion are typical and easy for us to make a preliminary diagnosis after ultrasound examination. The diagnosis of portal vein shunting is difficult. We need a veterinary radiologist or internist with advanced training to scan and evaluate the liver.