a To determine volumes of corpus callosum and intracranial volumes of Vietnamese normal adults. Subjects and methods: Analyzing volumes of corpus callosum and intracranial volumes from cranial magnetic resonance images taken from 455 Vietnamese healthy subjects (males 47.03%), and ranging in age from 17 to 87 years. Results: The total volume of corpus callosum was indifferent between genders (males: 3.40 ± 0.47 cm3 ; females 3.32 ± 0.44 cm3 ; p = 0.06), but volumes of rostrum, genu, and splenium regions were larger in males than those in females. The intracranial volume in females (1387.35 ± 96.72 cm3 ) was 10.76% smaller than that in males (1536.58 ± 103.46 cm3 ) (p < 0.001). The corpus callosum was getting smaller with ageing, which appeared in men more obviously and dispersedly at truncus and isthmus subregions, whereas in women that tendency was at central-truncus only. Conclusions: Findings from this morphological study on corpus callosum and intracranial volumes contributed to the reference anthropometric values of current Vietnamese adults using non-invasive imaging tools.
Journal of military pharmaco-medicine no6-2019 MEASURING THE CORPUS CALLOSUM AND INTRACRANIAL VOLUMES OF VIETNAMESE NORMAL ADULTS USING MAGNETIC RESONANCE IMAGING Tong Quoc Dong1; Nguyen Le Chien1; Dang Tien Truong1 Hoang Van Luong1; Tran Hai Anh1 SUMMARY Objectives: To determine volumes of corpus callosum and intracranial volumes of Vietnamese normal adults Subjects and methods: Analyzing volumes of corpus callosum and intracranial volumes from cranial magnetic resonance images taken from 455 Vietnamese healthy subjects (males 47.03%), and ranging in age from 17 to 87 years Results: The total volume of corpus callosum was indifferent between genders (males: 3.40 ± 0.47 cm ; females 3.32 ± 0.44 cm ; p = 0.06), but volumes of rostrum, genu, and splenium regions were larger in males than those in females The intracranial volume in females (1387.35 ± 96.72 cm ) was 10.76% smaller than that in males (1536.58 ± 103.46 cm ) (p < 0.001) The corpus callosum was getting smaller with ageing, which appeared in men more obviously and dispersedly at truncus and isthmus subregions, whereas in women that tendency was at central-truncus only Conclusions: Findings from this morphological study on corpus callosum and intracranial volumes contributed to the reference anthropometric values of current Vietnamese adults using non-invasive imaging tools * Keywords: Corpus callosum; Intracranial volume; Anthropometry; Vietnamese adults; MRI INTRODUCTION With the development of modern analytical techniques, methods for evaluation of brain morphological characteristics and their changes based on magnetic resonance imaging (MRI) have been being conducted at many research centres abroad, and had also attracted interest over the past decade in Vietnam [2, 3] There have been noninvasive studies using MRI in healthy people as well as in people with brain damaging diseases to investigate changes of brain morphology, yet an issue on normal values of brain structures with age and sex in healthy adults is still open, raising a requirement for building-up reference ranges of brain structures with this novel imaging technique Situating in the centre of the human brain consisting of approximately 200 250 million myelinated axons [7], the corpus callosum (CC) forms the largest commissural white matter bundle, connecting the hemispheres and brain cortical regions [9] Vietnam Military Medical University Corresponding author: Tran Hai Anh (anhhtr@yahoo.com) Date received: 10/07/2019 Date accepted: 12/08/2019 128 Journal of military pharmaco-medicine no6-2019 Therefore, changes in the brain structures or functions in both physiological (age, sex) or pathological states might affect the CC and compromise this morphogical structure The total intracranial volume relates to hard tissue and relatively stable, hence it has often been regarded as a reference measurement for adjustment in analyzing brain soft tissues, including the CC [4] From above mentioned issues, the present study was conducted in order to: Determine the corpus callosum and intracranial volumes of Vietnamese normal adults using MRI SUBJECTS AND METHODS Subjects MRI were taken from 455 right-handed Vietnamese adults (214 males, 19 - 82 years old; 241 females, 17 - 87 years olds), who visited the outpatient ward at 108 Military Central Hospital from Nov 2017 to Nov 2018 They had no history of neuropsychiatric disorders or chronic diseases, and had informed consent to participate in the study Image data analysis and processing were performed at Department of Physiology, Vietnam Military Medical University Methods * MRI procedure and analysis: Three-dimensional brain scans were taken by a 1.5 Tesla MRI scanner system (Siemen, Germany), using the T1-weighted sagittal sequence with parameters: slice thickness mm, TR = 15 ms, TE = ms, NEX = ms, flip angle = 30°, 25 x 25 cm FOV; matrix = 256 x 256, with more than 300 contiguous slices on each subject Brain image scans were then reviewed and confirmed by specialist physicians that of subjects having no damages of central nervous system The imaging data were stored in DICOM format, compressed to NIFTI, rendering and analyzing for brain regions using FreeSurfer software version 6.0.0 [5] Volumetric values (cm3) of the total corpus callosum volume and its subregions (figure 1) as well as intracranial volume were taken into account Figure 1: Corpus callosum and its subregion (Hampel et al, 1998 [6]) 129 Journal of military pharmaco-medicine no6-2019 * Data analysis: Subjects were categorized by gender and divided into groups of age, ranging from 17 to 87 years old The volumes of total corpus callosum and its subregions were compared among age groups within sex by a co-variance analysis (ANCOVA); the differences in age and the proportion of subjects among groups were compared using the Student’s t.test and proportional comparisons (Chi-square tests) The analyses were made with SPSS 22.0 (IBM Inc., USA) and a significant difference was set as p value of less than 0.05 RESULTS Demography of subjects Table 1: Age and gender of subjects Male Female p 214 (47.03) 241 (52.97) 0.21 45.57 ± 14.04 44.62 ± 12.25 0.44 ≤ 24 14 (22.14 ± 2.03) (20.44 ± 2.79) 25 - 34 45 (30.47 ± 3.00) 51 (30.43 ± 2.74) Age group 35 - 44 47 (39.62 ± 2.84) 56 (40.30 ± 2.75) (n, X ± SD) 45 - 54 42 (49.83 ± 2.87) 71 (49.14 ± 3.01) 55 - 64 44 (59.34 ± 2.65) 46 (58.11 ± 2.62) ≥ 65 22 (68.41 ± 3.87) (62.6 ± 1.96) Gender, n (%) Mean age 0.012 The results on table showed no significant differences in mean age and the gender proportion of subjects However, the proportions of males and females among age groups were significantly different (p = 0.012) This difference can be attributed to the variety in the proportion of subjects by gender among groups of 45 - 54 and from 65 years old Table 2: Corpus callosum and intracranial volumes (cm3) in both genders Male Female (x̅ ± SD) (x̅ ± SD) Total corpus callosum volume 3.40 ± 0.47 3.32 ± 0.44 0.06 Rostrum and genu 0.88 ± 0.13 0.84 ± 0.12 0.002 Anterior truncus 0.52 ± 0.11 0.50 ± 0.12 0.052 Central truncus 0.52 ± 0.12 0.53 ± 0.13 0.32 Posterior truncus and isthmus 0.51 ± 0.11 0.51 ± 0.09 0.67 Splenium 0.97 ± 0.15 0.93 ± 0.13 0.004 1536.58 ± 103.46 1387.35 ± 96.72 < 0.001 Intracranial volume 130 p Journal of military pharmaco-medicine no6-2019 Results in table showed that though the total corpus callosum volume was indifferent between males and females, the volume of the rostrum-genu and splenium of the corpus callosum in females were smaller than that of males (p = 0.002 and p = 0.004, respectively) The intracranial volume in females was also marked smaller than that in males (p < 0.001) The difference in intracranial volume between genders would have certain effects on the size and volume of internal brain structures Therefore, in evaluation of the corpus callosum volume in this study, the intracranial volume was regarded as a covariance Change of corpus callosum volume by age groups Table 3: Values of corpus callosum volumes (cm3) in males of age groups Age group Corpus callosum volumes Total volume Rostrum and genu Anterior truncus Central truncus Posterior truncus and isthmus Splenium ≤ 24 (x̅ ± SE) 3.42 ± 0.12 0.84 ± 0.03 0.52 ± 0.03 0.57 ± 0.03 0.54 ± 0.03 0.95 ± 0.04 25 - 34 (x̅ ± SE) 3.51 ± 0.07 0.87 ± 0.02 0.57 ± 0.01 0.58 ± 0.02 0.53 ± 0.02 0.95 ± 0.02 35 – 44 (x̅ ± SE) 3.53 ± 0.06 0.90 ± 0.02 0.55 ± 0.01 0.55 ± 0.02 0.54 ± 0.02 0.98 ± 0.02 45 – 54 (x̅ ± SE) 3.42 ± 0.07 0.91 ± 0.02 0.50 ± 0.02 0.50 ± 0.02 0.51 ± 0.02 0.99 ± 0.02 55 – 64 (x̅ ± SE) 3.25 ± 0.07 0.86 ± 0.02 0.47 ± 0.02 0.47 ± 0.02 0.48 ± 0.02 0.97 ± 0.02 ≥ 65 (x̅ ± SE) 3.16 ± 0.09 0.87 ± 0.03 0.45 ± 0.02 0.43 ± 0.02 0.44 ± 0.02 0.97 ± 0.03 F (5,207) 3.66 1.41 7.98 9.32 3.50 0.44 pcommon 0.003 0.22 < 0.001 < 0.001 0.005 0.82 (The volume values shown were adjusted with the total intracranial volume) Analyzing on males (table 3) showed that except for a might increase in volume of the splenium even ageing, the corpus callosum continuously grew to about 35 - 44 years old and then began to shrink (p = 0.003) Moreover, the callosal shrinkage by ageing occurred mainly in the truncus and isthmus (included the anterior, p < 0.001; central, p < 0.001; posterior truncus and isthmus, p = 0.005) 131 Journal of military pharmaco-medicine no6-2019 Table 4: Values of corpus callosum volumes (cm3) in females of age groups Corpus callosum volumes and genu Anterior truncus Central truncus Posterior truncus and isthmus Splenium 3.33 ± 0.14 0.79 ± 0.04 0.56 ± 0.04 0.61 ± 0.04 0.52 ± 0.03 0.86 ± 0.04 3.39 ± 0.06 0.83 ± 0.02 0.52 ± 0.02 0.58 ± 0.02 0.52 ± 0.01 0.94 ± 0.02 3.37 ± 0.06 0.85 ± 0.01 0.50 ± 0.01 0.53 ± 0.02 0.53 ± 0.01 0.96 ± 0.02 3.27 ± 0.05 0.84 ± 0.01 0.49 ± 0.01 0.52 ± 0.01 0.51 ± 0.01 0.92 ± 0.01 3.28 ± 0.06 0.86 ± 0.02 0.48 ± 0.02 0.50 ± 0.02 0.51 ± 0.01 0.94 ± 0.02 3.11 ± 0.15 0.86 ± 0.04 0.43 ± 0.04 0.44 ± 0.04 0.48 ± 0.03 0.90 ± 0.05 F (5,234) 1.02 0.67 1.60 3.70 0.57 1.62 pcommon 0.41 0.64 0.16 0.003 0.73 0.16 ≤ 24 (x̅ ± SE) 25 - 34 Age group (x̅ ± SE) 35 - 44 (x̅ ± SE) 45 - 54 (x̅ ± SE) 55 - 64 (x̅ ± SE) ≥ 65 (x̅ ± SE) Total Rostrum volume (The volume values shown after adjusted with the total intracranial volume) In females, the shrinking phenomenon of the total corpus callosum as well as its subregions was unobservable (p = 0.41), except for the central segment (p = 0.003) Moreover, the central volume also reached the peak value earlier than that in males, at the group “To 24”, and then gradually decreased with age DISCUSSION Anthropometrics of cranial sizes and volumes of the Vietnamese population, along with understandings of morphological changes in functional brain regions aids in determining normal ranges of values that are references for studies on pathological conditions in human However, negligence of inter-individual variability of brain structure and head size could cause deviations in the determination of volumes of brain structures [1] Several studies analyzing volumes of brain regions on MRI images of normal human showed that 132 intracranial volume in women was smaller than that in men Buckner et al (2014), by manually measuring intracranial volume, concluded that this volume was 10 - 20% greater in men than in women and it was minimally affected by age [4] Le Huu Hung (1995) also measured intracranial volume on the Vietnamese population and demonstrated that it was 8.43% greater in men than in women, with respective values of 1363.97 ± 103.2 cm and 1257.91 ± 92.2 cm3 [1] In this study, the total intracranial volume in men was 1536.58 cm3, which was 10.76% greater Journal of military pharmaco-medicine no6-2019 than that in women (1387.35 cm3) The results reported by Le Huu Hung were smaller than ours, which could be attributable to the discrepancy in measuring methods between two studies Our study measured cranial size on MRI of alive human while previous studies measured on archaeological crania, which could have shrunk due to dehydration after death or in the process of cadaver preservation Besides, changes in socio-economic status between present and previous times require more novel studies to establish systematically reference ranges of human anthropometrics The present study analysed volume of corpus callosum in both genders in correlation with age and intracranial volume Our results showed that corpus callosum decreased in size at certain ages, and more significantly and obviously in men than in women In men, the corpus callosum reached the peak at the age of 35 - 44 years old, then started to shrink mainly at the truncus In women, the corpus callosum did not present an obvious change in total volume in adults and its shrinkage was clearly observed only in the central truncus Those findings were different from many abroad studies on volume of the corpus callosum Takeda et al (2003) analysed several indexes of the corpus callosum of Japanese normal population in relation with age by manually measuring on MRI, which showed that changes occurred mainly at the genu portion with no difference between males and females [10] Junle et al (2008) analysed biometric indexes of the corpus callosum on T1weighted MRI of 286 healthy Chinese from 20 to 86 years old found that among six regions of the corpus callosum, the length of the genu, 1/3 anterior, central and 1/3 posterior truncus, and splenium tended to declined over age [8] However, they noted a bigger volume of the corpus callosum in females than in males [8] Those inconsistencies may due to discrepancies in ethnics and measuring methods on MRI, and negligence of co-variants affecting intracranial volume in data analysis Another study by Prendergast et al [9] on cranial MRI of 305 American adults showed that the corpus callosum developed maximally at the age of 32.2 for men and of 40.1 for women, which was consistent with our findings, but the decrement occurred mainly at the CC genu portion CONCLUSIONS Investigation on brain MRI showed that the intracranial volume of Vietnamese adults presently had different properties than those of previous studies, and the corpus callosum of the Vietnamese people also had compromised traits differed from those of other ethnicities and races Therefore, our findings in the present study contributed to the anthropometrics reference of current Vietnamese adults REFERENCES Lê Hữu Hưng Đặc điểm hình thái nhân chủng sọ người Việt đại Luận án Tiến sỹ Y học Trường Đại học Y Hà Nội 1995 Nguyễn Giang Hòa, Nguyễn Duy Bắc, Nguyễn Minh Hải CS Biến đổi khoảng cách liên móc thể tích vùng hải mã phim cộng hưởng từ sọ não bệnh nhân Alzheimer Tạp chí Sinh lý học Việt Nam 2011, 15 (2), tr.15-21 133 Journal of military pharmaco-medicine no6-2019 Phạm Thành Nguyên, Lâm Khánh, Nguyễn Duy Bắc Nghiên cứu đặc điểm hình thái đồi thị người trưởng thành bình thường cộng hưởng từ khuếch tán 3.0 Tesla Tạp chí Y - Dược học Quân Số chuyên đề Hình thái học 2017, tr.64-71 Buckner R.L, Head D, Parker J et al A unified approach for morphometric and functional data analysis in young old and demented adults using automated atlas-based head size normalization: reliability and validation against manual measurement of total intracranial volume NeuroImage 2004, 23 (2), pp.724-738 Fischl B FreeSurfer Neuro Image 2012, 62 (2), pp.774-781 Hampel H, Teipel S.J, Alexander G.E et al Corpus callosum atrophy is a possible indicator of region- and cell type-specific neuronal degeneration in Alzheimer disease: 134 A magnetic resonance imaging analysis Archives of Neurology 1998, 55 (2), pp.193-198 Jarbo K, Verstynen T, Schneider W In vivo quantification of global connectivity in the human corpus callosum Neuro Image 2012, 59 (3), pp.1988-1996 Junle Y, Youmin G, Yanjun G et al A MRI quantitative study of corpus callosum in normal adults Journal of Medical Colleges of PLA 2008, 23, pp.346-351 Prendergast D.M, Ardekani B, Ikuta T Age and sex effects on corpus callosum morphology across the lifespan Human Brain Mapping 2015, (7), pp.2691-2702 10 Takeda S, Hirashima Y, Ikeda H et al Determination of indices of the corpus callosum associated with normal aging in Japanese individuals Neuroradiology 2003, 45, pp.513-518 ... on the size and volume of internal brain structures Therefore, in evaluation of the corpus callosum volume in this study, the intracranial volume was regarded as a covariance Change of corpus callosum. .. though the total corpus callosum volume was indifferent between males and females, the volume of the rostrum-genu and splenium of the corpus callosum in females were smaller than that of males... including the CC [4] From above mentioned issues, the present study was conducted in order to: Determine the corpus callosum and intracranial volumes of Vietnamese normal adults using MRI SUBJECTS AND