Study On Blood Circulation Doppler Ultrasound Monitoring And New Method Of Gestational Age Prediction In Small Dogs

The purpose of this experiment is to(1)study the blood circulation of small dogs(placental artery,placental vein,umbilical artery,umbilical vein,using a combination of two-dimensional ultrasound,color Doppler and pulsed Doppler).Blood flow velocity and index of the posterior vena cava,carotid artery,and thoracic aorta were measured,including peak systolic velocity(PSV),diastolic velocity(EDV),mean velocity(MNV),resistance index(RI),and pulsatility index.(PI)and contraction and relaxation ratio(S/D),initially established a reference range for the normal value of the main blood flow characteristics of small blood vessels in the development of small canine fetuses;(2)through the small dog fetus placental thickness(GP),lens(long axis and short axis),measurement of length of ulnar and ulna,obtained five new methods for ultrasound prediction of gestational age;(3)preliminary creation of small canine fetus with placental artery,placental vein,umbilical artery,umbilical vein,and posterior The sonographic,thoracic aorta,and pulmonary arteries throughout the pregnancy have audio-visual features that provide a basis for clinical pregnancy diagnosis.In this experiment,75 children of pregnant small dogs were continuously monitored by SIUI Apogee 1200V veterinary ultrasonic diagnostic apparatus and 7.5MHZ.linear array probe until delivery.Pregnancy dogs were started from the 16th day after ovulation(3 weeks after fertilization)using two-dimensional ultrasound monitoring.The method of exploration was to cut the abdominal wall or both sides of the abdominal wall with a 7.5MHz linear array or fan-shaped probe for lateral,longitudinal and oblique directions.The three-dimensional plain cut surface observation can be judged as pregnant when one or more gestational sacs are seen.Two-dimensional ultrasound combined with color Doppler and PW Doppler examinations were performed every 2 days from the 4th week of pregnancy(day 21st to 28th day after mating)until birth.The data recorded for gestational age predictions are expressed as mean±standard deviation.In this experiment,the following conclusions were obtained by monitoring the small-female maternal-placental-fetal blood circulation vascular:(1)The maternal placental artery and fetal umbilical artery were monitored at 4 weeks after insemination,and the thoracic aorta was in the 5th week after insemination.Monitoring began,and the carotid artery began monitoring at 6 weeks after insemination.(2)The peak systolic velocity,end-diastolic velocity and average velocity of the maternal placental artery,fetal umbilical artery,thoracic aorta and carotid artery gradually increase with the increase of gestational age,and only the maternal placental artery declines in the last week of pregnancy;The resistance index,pulsation index and systolic peak velocity/diastolic peak velocity of arterial blood flow decreased significantly with the increase of gestational age before the 8th week of gestation(P<0.05)until the 8th-9th week after insemination.,basically kept constant(P>0.05).(3)The maternal placental vein and fetal umbilical vein were monitored at 4 weeks after insemination,and the posterior vena cava was monitored at 5 weeks after insemination.The peak systolic velocity,end-diastolic velocity and average velocity of the three venous vessels gradually increased with the increase of gestational age.The resistance index,pulsation index and systolic peak velocity/diastolic peak velocity of the three vascular blood flow gradually decreased with the increase of gestational age.In this experiment,SPSS21.0 was used to perform linear regression analysis on the experimental data.The formulas of five new ultrasound predictions of gestational age were obtained.(1)The long axis of the lens was Y=0.02X-0.78,and the short axis of the lens was Y=0.02X-0.71.The applicable range is d≧36;(2)ulna Y=0.06X-1.95,tibia Y=0.05X-1.81,applicable range is d≧36;(3)placental thickness Y=0.02X-0.35,applicable range is 24≦d≧40,where X is the gestational age,Y is the length of the relevant measurement index(cm),and d is the number of days of pregnancy.In this experiment,the sonographic characteristics of placenta-fetal blood circulation in small bitches were monitored,and the sonographic and arteriovenous,umbilical cord arteriovenous,fetal thoracic aorta,posterior vena cava and pulmonary artery of small dogs were initially explored.feature.A preliminary assessment of gestational age can be performed by establishing a series of small bitch placenta-fetal echocardiographic echograms,predicting the date of delivery,and more accurately diagnosing many abnormal pregnancies in the fetus.