| Objective:To evaluate the effects of age,sex and side on volumes of the frontal lobe and define 95%reference ranges of the left and right frontal lobe volumes and provide basic data for establishing the living Chinese adults digital standard brain,we measured the left and right frontal lobe volumes separately of the 200 right handedness healthy Chinese Han volunteers,different age groups from years of 18 to 70.Methods:To choose 200 healthy Chinese Han volunteers,right handedness,age ranged from 18 to 70 years,which were grouped as 18-30 years,31-40 years,41-50 years,51-60 years and 61-70 years.Each group had 40 people,which was composed of 20 women and 20 men.All clinical assessment including physical examinations, laboratory examinations,chest X ray,abdominal ultrasound exam,a detailed psychiatric and medical history,and mental state were normal.Procedures were fully explained to all subjects and written informed consent was obtained before enrollment in the study.MRI scans were performed on a 1.5 Tesla MR scanner (Siemens,Germany).After positioning the sections,two sequences were acquired:a axial T2 FLAIR and a T1WI-3D-MPRAGE.The latter sequence considerably improved delineation of grey and white matter and small anatomical structures of brain due to its relatively temporal and spatial resolution,a relatively high signal-to-noise ratio.It is the fundament to get the digitized human brain atlas and the key sequence to measure the frontal lobes.The whole scanning time was about 20 minutes.Measurements were performed using a self-developed software program that allows 3-dimensional reconstruction of images,observing the area of the frontal lobe, and reconstruction of 2-dimensional axial plane images which were parallel to the line connecting the anterior and posterior commissure.We used the manual method to trace the region of interest of the frontal lobes in each slice.The volumes of the frontal lobes were computed by the software.Each side of the frontal lobe delimited as superior frontal gyrus,middle frontal gyrus,inferior frontal gyrus,precentral gums,medial frontal gurus,anterior cingulated,anterior paracentral lobule, orbitofrontal,gyrus rectus and deep brain white matter.All the data were analyzed with SPSS(version 13.0).We choose different statistical methods depended on the different data type.Results:In 200 healthy Chinese Han volunteers,the value of the left and right frontal lobe volumes were 280.58±37.30 cm~3 and 282.80±36.76 cm~3,the value of the total frontal lobe volumes was 563.38±73.37cm~3.The value and the 95% reference ranges of the left and right frontal lobe volumes in 100 men were 288.49±41.88 cm~3,from 206.41 cm~3 to 370.57 cm~3 and 291.77±40.77 cm~3,from211.86 cm~3 to 371.68cm~3.The value and the 95%reference ranges of the left and right frontal lobe volumes in100 women were 272.68±30.28 cm~3,from 213.33 cm~3 to 332.03 cm~3 and 273.83±29.85 cm~3,from 215.32 cm~3 to 332.348cm~3.There were sex differences in the total frontal lobe volumes(P＜0.05).There were side differences in frontal lobe volumes of men(P＜0.05) and there was no significant differences in women(P＞0.05).Significant differences were in the different age groups(P＜0.05).There was negative correlation between the frontal lobe volumes and age in men and women(P＜0.01).For men and women,the annual shrinkage rate was 0.46%and 0.32%respectively.Conclusion:1.A large scale measurement and analysis about the frontal lobe volumes was performed in healthy Chinese Han volunteers in different sex,side and age groups for the first time.The 95%reference ranges of the left and right frontal lobe volumes in men and women was defined.2.The total frontal lobe volume of men was larger than women.The volume of the right frontal lobe was larger than the left frontal lobe in men,and the asymmetries didn't exist in women.3.The left and right frontal lobe volumes were both shrinking with age in men and women.The shrinkage of frontal lobe volumes was more rapid in men than in women.
|
PDF Full Text Request