| This study is intended to establish 2D sonographic atlas of vital organs of beagles fetal in different developmental stages,summary the Sonographic features of fetus before delivery for providing reference for clinical cyesiognosis,and expect to explore new methods to predict gestational age by measuring relevant dates,and explore the application conditions and Value by using ultrasound imaging technology in pregnant bitches.This study tracked and monitored the fetus of eight beagles by using Shantou SIUI Apogee 1200V experimental instrument type ultrasound.Ultrasound monitoring starts on 1.0th day after breeding,collecting data once every 2 days after the observation target appeared until delivery.This test is mainly observed the 2D sonogram changes of fetal urinary system,digestive tract,fetal placenta,heart,kidney and placental blood supply in different periods throughout pregnancy.This study measured the length of the major axis of the kidney,the thickness of the placenta,the area ratio of stomach bubble and abdominal circumference,the thickness of i intestinal mucosa muscle in different periods.Over the tracking and monitoring,fetal kidneys were first observed at day 42th or so,clearly differentiation of the cortex and medulla is observed at 48 days or so.In addition to the clearly separation of the renal pelvis and ureter,the acoustic echo structure of kidneys is similar to ripe dog at 52th day or so.Renal blood flow display starting from kidney arteriovenous and gradually diverging branch into renal cortex liking fan-shaped.the small blood vessels branches can be seen liking coral in the end of cortex 2 days before delivery.The blood flow at junction of cortex and medulla form a closed loop in the renal arteriovenous horizontal cross-section of kidney.The long axis of the kidney has been increasing state,growing 0.182±0.042cm every two days in average,kidney size up to 2.481±0.123cm before labor.Data analysis showed that the difference is extremely significant,it may be further studied as a new method for late pregnancy gestational age identified.Evident strip placenta has formed at 27th day or so,thick 0.126±0.0157cm.the placenta grow rapidly from 29th to 43th day,growth slows down from 43th to 47th day.,in a stable period of similar thickness after 47th day,and up to a thickness of 0.488±0.0454cm,Placental thickness measurement does not apply gestational age identification,but can roughly estimate gestational age.Ultrasonography showed the edge of the placenta began to appear small dark echo-free zone around 34th day,and its Size and number increasing with time,No internal flow signals were observed,echogenic flashing spot were observed in placental 3 days before labor,they were confirmed as calcifications.Blood flow signals can be fistly observed in the placenta at 30th day or so.Placental blood flow in conjunction with the parent was growing over time more and more abundant,showed cord-like,but no significant blood flow signal has been observed in the edge of the placental.Intestinal located in the bumps of fetal abdomen at 27th day or so,and into the abdominal cavity at 32th day or so.Intestinal echo the is similar to surrounding tissue as homogeneous hypoechoic before 32th day.Intestine was irregular edge echo uneven rough granular hyperechoic mass around 35th to 48th day.The intestinal lumen appears around 47th days,Intestinal mucosa and muscle begin to form showed hypoechoic,the mucosa and muscle layer was dark echo-free zone at 48th day,and up to a thickness of about 0.07cm.It continue thickening up to a thickness of 0.11+0.0176cm the day before delivery.Most of mucosa and muscular of the intestine appears points of light echo,like cast a veil few days before delivery,the more obvious the closer to delivery.The best timing of fetal cardiac examination is around 46th to 55th day,at this time,heart size suitable and structure clearly,and bones acoustic shadowing has a smaller influence.This study proved that 4D ultrasound technology is useful when monitoring pregnant dogs.The best timing of surface imaging is around 35th to 48th day,a good quality image of the whole body of a fetus can be detected.When scanned around 48th to 53th day,the quality of the images may be lower and only partial of a fetus can be detected.It’s hard to acquire a good image after 53th day unless there is abundant amniotic fluid and not many floaters.The quality of images is correlative with the degree of bone calcification under osteal mode.The spine can be detected from 44th day with a low quality image.The best quality images can be found during 45th to 54th day with a whole spine present in one view,which only can be clearly observed in seperate views after 54th day.This study establish 2D sonographic atlas of vital organs of beagles fetal in different developmental stages;discover and summarize the sonographic features of fetal kidney,intestine and placenta before delivery;Provide more basis for determination of fetal development maturity,a more accurate prediction of delivery dates,the judgment of dystocia in clinical,then better ensure the safety and healthy of pregnancy bitches and fetus;and found that changes in the long axis of the kidneys can be used as a new method to predict gestational age for further study;obtain the three-dimensional atlas of fetal bone and surfaces in different period and the optimal imaging time,Summed up the scanning technique and parameter adjustment method.Lay the foundation for better and faster 4D ultrasound imaging technology used in pet clinically.It enrich the content of clinical ultrasound pregnancy examination,make ultrasound to better serve pet clinical pregnancy examination. |
