The Study On The Correlationship Between Normal Fetal Kidney Volume And Gestational Age Using Post-mortem Magnetic Resonance Imaging

ObjectiveTo study the development of normal fetal kidney with gestational age by measuring fetal kidney width (FKW), kidney thickness (FKT), kidney length (FKL) and fetal kidney volume (FKV) using post-mortem magnetic resonance imaging.MethodsMRI volumetric measurement was performed in22fetus specimen ranging from20to27weeks gestation age without any urinary abnormality, which was confirmed by MRI. Transverse sections were taken with slice thickness0.9mm,space between slices0.5mm to measure the FKW, FKT, FKL, FKV.Resultsl.The mean FKW increased from (0.97±0.16) at GA20w to(1.40±0.12)cm at GA27w,.r=0.739(P<0.01),a linearly positive relationship of FKW with GA was confirmed(P<0.01);2.The mean FKT, increased from (1.11±0.23) at GA20w to(1.40±0.08)cm at GA27w,.r=0.584(P<0.01),a linearly positive relationship of FKT, with GA was confirmed(P<0.01);3.The mean FKL increased from (1.78±0.10) at GA20w to(2.60±0.32)cm at GA27w,.r=0.718(P<0.01),a linearly positive relationship of FKL with GA was confirmed(P<0.01);4.The mean FKV increased from (1.26±0.29) at GA20w to(3.34±0.25) cm3at GA27w,.r=0.870(P<0.01),a linearly positive relationship of FKV with GA was confirmed(P<0.01). 5. Through this study of fetal specimens kidney at20w to27w using3.0T MR, a clear boundary between kidney cortex and medullary was visable since23weeks gestation age.Conclusions1.The accuracy and reliability of MRI measurements of FKW, FKT, FKL,FKVwere high.MRI measurement was able to provide reliable assistant reference data apart from USG. With multiple plane imaging, MR could supply clinical obstetric work with reliable reference data.2. The mean FKW,FKT,FKL and FKV is increased at GA20w to GA27w with a linearly positive relationship.