ABSTRACT
Objective To explore the change of signal value in the fetal frontal lobe with gestational age in normal second-third trimester fetuses.Methods MRI findings of 125 normal second-third trimester fetuses were divided into 5 groups according to gesta-tional age (unit:week)including 1 7-21,22-26,27 -31,32 -36,37 -40,respectively.The signal values were measured in inferior frontal,middle and upper,respectively.Results The signal value of fetal frontal lobe in 5 groups were 387.38 ± 1 66.75,354.46 ± 1 74.78,342.24±141.23,338.90±1 10.94,310.23±1 18.62,respectively.The signal value was 341.77 ±149.22,35 1.00±145.1 6, 342.85±140.61 in inferior frontal,middle and upper,respectively.The signal value of frontal lobe was 350.34±147.68 in the left and 340.73±144.29 in the right.There were no significant statistical differences on fetal frontal lobe signal value in each group (P>0.05).But the signal value in the frontal lobe had a gradually decreasing trend with fetal age,along with the signal value in the central frontal was higher than the other two parts of the frontal lobe and the left is slightly higher than the right.Conclusion The signal values in frontal lobe of normal second-third trimester fetuses were gradually decreased as gestational age increasing,with the signal values in central frontal lobe was higher than that of in margin of frontal lobe,and the left side was slightly higher than the right.