The Study Of The Development Of The Fetal Hepatic Veins By Doppler Ultrasound And MR Of High Field

The developmental condition of fetal hepatic veins is significant for investigating fetal liver state, but there are few investigations about imagings. Due to the difficultys in showing hepatic veins and many errors in measurement about fetal hepatic veins during early pregnancy, fetals during middle and later pregnancy were seclected. After scanned by multi-functional Doppler ultrasound and MRI of high field, the types how the left, middle and right hepatic veins go into the inferior vena cava, the branches and internal diameter of the hepatic veins, the angles between the hepatic veins, and the hemodynamic state were analyzed. This study can enrich and improve the radiologic knowledge of hepatic vein development, so as to benefit the diagnosis of fetal abnormalities and provide radiologic evidence. The Doppler flow spectrum can provide valuable information for the diagnosis of the congenital heart disease with high right atrial regurgitationer.Objective:To reveal the development of the fetal hepatic veins in middle and later pregnancy by Doppler ultrasound and MRI of high field to provide evidence for the diagnosis and treatment of the disease of the abnormally developmental hepatic veins.Methods:(1)118 normal single-pregnancy fetuses of 26 to 40 weeks gestational age were selected. The fetuses were considered to be anatomically normal and developmentally appropriate by routine ultrasound examination. After scanned by multi-functional Doppler ultrasound, the types how the left, middle and right hepatic veins go into the inferior vena cava, the branches and internal diameter of the hepatic veins, the angles between the hepatic veins, and the hemodynamic state were analyzed. (2)30 fetal corpse samples (14-38weeks) were scanned by 3.0T MRI. the types how the left, middle and right hepatic veins go into the inferior vena cava, the branches and internal diameter of the hepatic veins were analyzed.Results:(1) Ultrasound:57(48.3%) cases of the middle and left hepatic vein joined together before they went into the inferior vena cava (TypeⅠ); 53(44.9%) cases in which the left, middle and right hepatic veins joined the inferior vena cava respectively (TypeⅡ);8 (6.8%) cases in which the middle and right hepatic veins joined together or before they went into the inferior vena, and in which the right-posterior hepatic vein even appeared (TypeⅢ). The internal diameter of the hepatic veins gradually increased with the gestational age. The internal diameters of the left, middle and right hepatic veins were (0.34±0.04) cm, (0.35±0.04) cm and (0.36±0.05) cm respectively. There were high coefficient correlations between them and the gestational weeks.1-4 branches of the hepatic veins could be observed. The angle between the right and middle hepatic veins was (56.8±14.2)°, the angle between the middle and left hepatic veins was (50.7±19.4)°and the angle between the left and right hepatic veins is (98.4±20.3)°. A three-phase blood flow spectrum could be observed in the hepatic vein and the inferior vena cava. The a/s decreased gradually with the gestation, There were no significant differences in the data listed above.(2) MRI:11 (36.7%) cases of the middle and left hepatic vein joined together before they went into the inferior vena cava (TypeⅠ); 4 (13.3%) cases in which the left, middle and right hepatic veins joined the inferior vena cava respectively (TypeⅡ);15 (50%) cases in which the middle and right hepatic veins joined together or before they went into the inferior vena, and in which the right-posterior hepatic vein even appeared (TypeⅢ).1-12 branches of the hepatic veins could be observed. The internal diameters of the left, middle and right hepatic veins were (0.26±0.090)cm,(0.257±0.094)cm,(0.26±0.09)cm respectively.Conclusions:The development of the fetal hepatic vein is different from that of adults'. The branches of the hepatic vein are varied. This study can enrich and improve the radiologic knowledge of hepatic vein development, so as to benefit the diagnosis of fetal abnormalities.