The Development Of Fetal Spinal Cord:Assessment With Postmortem MRI

PART I Length of fetal lumbar cord of 16-42 gestational age: assessment with 3.0T postmortem MR imagingObjectiveTo provide reference to assess the development of fetal spinal cord and diagnose diseases related to it.Materials and methodsPostmortem MR imaging was performed on 70 fetuses of 16 to 42 gestational age by 3.0T MRI scanner.Lumbar cord is defined by spinal nerve root. To discuss the regularity of development of fetal lumbar cord after measuring the length of fetal lumbar cord.ResultsThere’s a significant linear correlation between the lumbar cord and gestational age(GA). Equation was calculated, length of lumbar cord(LLC)=0.126×GA-0.599 (r2=0.868,P<0.05); There is no difference between males and females.ConclusionsFetal lumbar cord can be well showed by postmortem MR imaging. There’s a significant linear correlation between LLC and gestational age. The results can be reliable evidence to assess the development of fetal lumbar cord.PART II Contrast reasearch between length of fetal spinal cord and spine of 16-42 gestational age:assessment with 3.0T postmortem MR imagingObjectiveTo assess the development of fetal spinal cord by using 3.0T MRI and discuss the relationship between fetal spinal cord and spine.Materials and methodsPostmortem MR imaging was performed on 70 fetuses of 16 to 42 gestational age by 3.0T MRI scanner (Sequence:Dual echo steady state water excitation T2WI). After measuring the length of cervical cord, thoracic cord and lumbar cord which were defined by spinal nerve root, the data of fetal spine is compared with it.ResultsThere’s a significant linear correlation between three parts of spinal cord and gestational age(GA). Equations are calculated, length of cervical cord(LCC)= 0.103×GA+0.476 (r2=0.889, P<0.05); length of thoracic cord(LTC)=0.232xGA+ 0.543 (r2=0.915, P<0.05); length of lumbar cord(LLC)=0.126><GA-0.599 (r2=0.868,P<0.05); There is no difference between males and females. There are two peaks in development of cervical cord which is in 22～24 and 40～42 gestational weeks. The peak of thoracic cord is in 19～21 gestational week and the peaks of lumbar cord are in 22～24 and 40～42 gestational week. Cervical spine is longer than cervical cord after about 20 gestational week, thoracic spine is longer than thoracic cord after about 32 gestational week, lumbar spine is always longer than lumbar cord.ConclusionsFetal lumbar cord can be well showed by postmortem MR imaging. There’s a significant linear correlation between LLC and gestational age. The results can be reliable evidence to assess the development of fetal lumbar cord.