Ultrasonographic evaluation of portal vein hemodynamics in experimentally bile duct ligated dogs.

The purpose of this study was to evaluate the relationship between the results of laboratory examinations and ultrasonographic findings, especially portal vein hemodynamics in experimentally bile duct ligated dogs. Biliary obstruction was accomplished by surgically occluding the common bile duct in five dogs. All the dogs became visibly jaundiced within 24 hours after surgery. The total protein and albumin/globulin ratio showed a gradual decrease throughout the examination period, while blood urea nitrogen reached its peak in the 6th week and decreased to pre ligation values by the 10th week. Similar trends were noted in the alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and direct and total bilirubin. Total cholesterol and fasting serum bile acid levels rapidly increased after surgery to peak values between the 2nd and 4th week, and then gradually decreased, but still remained high throughout the experiment period. The portal flow volume and velocity significantly (p < 0.05) decreased while only a slight increase was noted in the congestion index after bile duct ligation. The cross sectional area of the portal vein changed insignificantly. Bile duct and gallbladder distention was evident within the 1st week after ligation but there was little change in the echogenicity of the liver parenchyma. The results of this study suggest that the determination of Doppler ultrasound parameters of hepatic hemodynamics, especially the portal vein flow indices, may contribute to a better noninvasive assessment of the canine patient with biliary obstructive disease.

Comparison of systemic and renal hemodynamics measured by Doppler ultrasonography in canine experimental hypovolemia.

The aim of this study was to examine renal hemodynamics at the hypovolemic and recovery phases in two different hypovolemic shock models using Doppler ultrasonography, and to compare this with systemic hemodynamics. In experiment 1, the hypovolemic phase was induced in 6 mongrel dogs by removing arterial blood at 30 ml/kg for 60 min. In the recovery phase, this blood was reinfused at 30 ml/kg over 60 min. In experiment 2, hypovolemia was induced in 12 beagle dogs by rapid blood removal until blood pressure decreased to 40 mmHg and was maintained at this pressure for 30 min. Six of the dogs were then infused with 20 ml/kg hydroxyethyl starch over 5 min, and the other 6 were infused with 60 ml/kg lactated Ringer's solution also over 5 min. Parameters for systemic and renal hemodynamics were measured by using a polygraph and the Doppler method, respectively. The decrease of diastolic blood flow, resulted in an increase of vessel resistance, and was detected in the hypovolemic kidney by the Doppler method. The rapid and large volume infusion of resuscitation fluids was effective for the recovery of both systemic circulation and renal blood flow, however this induced an increase of kidney vessel resistance, a result of the autoregulation mechanism of the kidney. The changes in these parameters at the main renal artery and interlobar artery were similar.

Ultrasonography, biochemical and hematological profiles in liver disease caused by intravenous administration of dimethylnitrosamine in dogs.

The results of liver function tests and ultrasonographical findings were analysed in 7 dogs that were intravenously injected dimethylnitrosamine (DMNA 2 mg/kg body weight) on 2 consecutive days each week for 10 weeks. Typical clinical signs and similar changes in liver enzyme concentrations that develop in dogs with natural cirrhosis were observed in this canine model. Severe anaemia and a significant reduction in the platelet numbers occurred in the dogs that died in the 5th week, while in all the other dogs these parameters decreased slightly. Serum total protein and the albumin/globulin ratio decreased gradually while the alkaline phosphatase, alanine amino transferase, aspartate amino transferase and gamma glutamyl transpeptidase activities increased significantly (p < 0.05) in all dogs after beginning the administration of DMNA. Ultrasound findings of a coarsened and heterogeneous echo pattern with increased echogenicity that are characteristic of canine cirrhosis were noticed at the same time when the changes in liver enzymes became evident. Present results suggest that ultrasonography in conjunction with liver function tests may be useful in the evaluation of experimentally induced liver cirrhosis.

Ultrasonography and angiographic examination of normal canine liver vessels.

The aim of this study is to provide a description of the ultrasonographic and angiographic anatomy of the hepatic and portal veins in normal dogs. Knowledge of this anatomy is essential for the proper diagnosis and correction of hepatic vessel anomalies like portal systemic shunts. Cranial mesenteric portography was done in 10 adult mongrel dogs to visualize the portal vein and its branches while the hepatic veins were visualized using the transvenous retrograde angiography method. Longitudinal and transverse ultrasound scans of the liver were done in the same dogs in left and right lateral positions in order to determine the best positions for imaging the different liver vessels. The distribution pattern of the hepatic and portal veins could be demonstrated by both ultrasonography and contrast angiography. Hepatic arteries are not usually visualized ultrasonographically. Ultrasound provided dynamic information that could not be obtained by contrast radiography. Super imposition of all vessels in the angiographic studies made the description of the branches of the liver vessels difficult. The results of the present study suggest that both methods may provide important complementary information in the diagnosis and planning of surgical procedures for the correction of vessel anomalies in the canine liver.

Compression of spinal cord caused by spinal deformation in a cat.

An 8-month-old cat with bilateral hindlimb paresis was admitted. Radiography revealed a curvature of the thoracic spine and a partial deformation of thoracolumbar vertebrae (dorsal extrusion of the cranial and caudal edges). Compression of the spinal cord (T9-L1 and L6-7) was found by myelography. Medicinal treatment did not yield the desired result. Hemilaminectomy and laminectomy were done to relieve pressure on the spinal cord leading to improved gait. It is, however, not clear whether this syndrome was primarily caused by metabolic or genetic factors.

Quantitative measurement of canine renal arterial blood flow using Doppler ultrasonography.

The aim of this study was to estimate the accuracy of the quantitative measurement of renal blood flow using the non-invasive method, Doppler ultrasonography. First, we determined a method of approach to the renal artery in order to detect the rate and pattern of flow, using 8 adult beagles under general anesthesia. Secondly, we examined the renal arterial blood flow using the Doppler method and electromagnetic flowmeter using 7 mongrel dogs. A significant correlation (r = 0.879; p < 0.01) was found between two methods, though the Doppler system tended to indicate high values than the electromagnetic flowmeter. Our study suggests that the Doppler method is a useful non-invasive technique of measuring renal blood flow in the dog.