| PREFACETt is always an important problem faced to obstetrician to assess fetal growth intrauterine. To date, fetal biparietal diameter ( BPD ) , Head circumference ( HC ) , abdominal circumference ( AC ) , femur length (FL) determined by two - dimensional ultrasound are routine used to assess the fetal growth intrauterine. But since fetal organs are three - dimensional objects, the most appropriate growth parameters would be weight, volume or surface area. Despite the ease of measurement in two dimensional parameters, it is apparent that these parameters are rather crude measurement for characterizing the growth of objects with complex shapes like fetal organs. Liver is the main location of nutrition substance metabolism and also is the typical represent of irregular fetal organs. In this study,fetal liver volume was measured by three - dimensional ultrasound system, in which planimetric volume measurement was applicated. Our objective was to study the correlation between fetal liver volume determined by three - dimensional ultrasound and gestational age, and to evaluate the clinical significance of measurement fetal liver volume by three - dimensional ultrasound.MATERIALS1. Study objects: Between September 2000 to November 2001, 185 sigleton pregnancies ranging from 22 to 39 weeks were studied by three - dimensional ultrasound. The women, whose age was form 21 to 39 years old(27. 6 + 3.5years old) ,with regular menstruation of 28 -30 days pattern and defined last menstrual period (LMP). The gesta-tional age was from the first day of the last menstruation. In the early three months pregnancy, women neither taken any medicine nor expo-sured to X - ray. All pregnant women had no diabetes or heat dieases. 2. Equipment: The technical equipment consist of Medison/Krez Volu-son 530D,three - dimensional ultrasound system with 3. 0-5. 0MHz abdominal transducer. The system can finish traditional two - dimensional ultrasound examination, and could progress three - dimensional ultrasound surface mode construction, transparent mode construction and -volume measurement.METHODSFirst,two dimensional scanning determined fetuses normal. Then to measure the fetal liver volume by the planimetric volume measurement. The principle of planimetric volume measurement: a series of paraller sections are laid through the organ and the areas of these sections are determined. A measuring program calculates the volume from the measured areas and the distance between the areas. Three - dimensional imaging collection: the traditional plane for measuring fetal AC was identified. The landmark of the AC plane is the umbilical portionof the portal vein deep in the liver, the fetal stomach is the secondary landmark. When the fetus was at rest, the program of three - dimensional scanning started. Suitable volume box was selected. The scanning time was about 4-10 seconds. The data were stored in 540MB MO disks. Fetal liver volume measurement; The data were loaded from MO disk,three vertical planes appeared on the screen. On A plane,we move the cursor to trace the cross - sectional liver outline , the build - in computer in three - dimensional ultrasound would automatically calculate the volume , stored the area and volume of the first plane { V = Ocm3) ,Then move the reference line slice - by - slice every 0.2cm,to trace No. 2,3......n cross - sectional liver outline,until all cross - sectional liver outline were traced and the whole fetal liver volume was obtained. We used the Excel statistical package to perform statistical calculation. First, the reproducibility of fetal liver volume assessed by three - dimensional ultrasound. The coefficient of variation from 30 repeated measurements on the same subjects from on the stored disks was calculated. Two consecutive measurements on 20 fetuses were compared by paired t - test and correlation anylysis. For the normal fetuses, regression analysis with correlation coefficients was used to determine the relationship between fetal liver volume and gestational age,p <0.05 was considered s...
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