nghiên cứu đặc điểm hình thái đồi thị và đường liên hệ đồi thị vỏ não trên hình ảnh cộng hưởng từ sọ não ở người việt nam trưởng thành TT TIENG ANH

MINISTRY OF EDUCATION

MINISTRY OF

AND TRAINING

DEFENCE

VIETNAM MILITARY MEDICAL UNIVERSITY
---------

PHAM THANH NGUYEN

RESEARCH ON MORPHOLOGICAL CHARACTERISTICS
OF THALAMUS AND CONNECTION OF THALAMUS –
CORTEX IN MRI OF HUMAN BRAIN OF HEALTHY
VIETNAMESE ADULTS
SPECIALITY: BIOMEDICAL SCIENCE
CODE: 9720101

SUMMARY OF THESIS


Hanoi - 2021


Scientific works are completed at:
MILITARY MEDICAL UNIVERSITY
Full name of supervisors:
1. Associate Prof. Dr. Lam Khanh
2. Prof. Dr. Nguyen Duy Bac

The first opponent: Prof. Dr. Pham Minh Thong
The second opponent: Associate Prof. Dr. Ngo Xuan Khoa
The third opponent: Associate Prof. Dr. Do Duc Cuong

The thesis will be protected before the Board of thesis
review at Military Medical University at ………. a.m/ p.m
on…………,2021

The thesis can be found at:
1. National Library
2. Library of Military Medical University


1
Imperativeness
The thalamus is a complex of gray nuclei located in the brain.
Recent advances in neural imaging technology have given new insights
into the anatomical structure of the human brain and are changing
human understanding of the hippocampus. It is now possible to
differentiate subnuclear structures to examination of functional
connections of different areas of the brain through functional magnetic
resonance imaging (fMRI), through studies of the brain in autopsy or
through animal experiments.
Investigating the anatomical links in one brain region and among
brain regions helps us to understand the functional activities and the
coordination of functional activities of those brain regions. Research has
been conducted on animals using noninvasive methods to learn about
the conduction tracts (bundles) in the brain, but studies involving
pathways in the human brain are very limited. Injecting fluorescent

pigments after autopsy allows the transmission bands (bundles) to be
identified but only seen at distances about 10 millimeters. With further
links may be determined by large bundle anatomy or histological study
of distal degeneration following a localized lesion, but such studies are
based on a relatively small number of The patient has no information.
The creation of nerve path images by Diffusion Tensor Imaging DTI is based on anisotropic diffusion of water molecules in the axons. DTI
is a new and modern technique that provides full awareness of the
connections in the brain. In addition, recent developments in diffuse tension
magnetic resonance imaging have enabled us to determine the pathways of
the bands (bundles), mainly in the living brain.
The image of sensory pathways through the thalamus connecting
to brain regions is very important in clinical practice and has not been
studied in Vietnam.
The objectives of the study are to:


2
1. Describe the morphological features of the thalamus on the
3.0 tesla magnetic resonance image in healthy Vietnamese adults.
2. Determine morphological characteristics of the thalamus cortex on the 3.0 tesla DTI image in healthy Vietnamese adults.
Practical meaning and further contributions
This thesis provides data of the changes in length, width, height
as well as the volume of the right and left thalamus on the 3.0 MRI
films in ordinary Vietnamese adults. At the same time, this thesis also
identifies morphological characteristics: length, number of fibers, FA,
ADC of the thalamocortical tracts on magnetic resonance diffusion
tensor imaging (DTI) 3.0 in ordinary Vietnamese adults. These are
valuable scientific data of morphological characteristics of the thalamus
and the thalamocortical tracts on MRI 3.0 images in normal Vietnamese
adults. This is the first study in Vietnam to apply a new and modern

technique, which helps to fully understand the links in the brain, the
recent development in magnetic resonance diffusion tensor imaging
techniques helps us to determine the path of the tracts (bundles), mainly
in the living brain.
STRUCTURE OF THE THESIS
The thesis includes: 129 pages
Question: 2 pages; Overview: 38 pages; Research subjects and
methodology: 18 pages; Research results: 37 pages; Discussion:
31 pages; Conclusion: 2 pages; Recommendation 1 pages
The thesis also has 40 Tables, 7 Charts, 35 Figures; 141
References (1 in Vietnamese and 140 in English)


3
CHAPTER 1
LITERATURE REVIEW
1. Anatomical and functional characteristics of the thalamus
1.1. Anatomical characteristics of the thalamus
1.1.1. Outline
The thalamus, shaped like an egg, is the two largest gray nuclei of
the central gray nuclei and is a major component of the medial cerebrum,
together with the hypothalamus forming the side of the third
interventriculare. The boundary between the two regions is marked by a
furrow (hypothalamus) that runs from the foramen interventriculare to the
aperture aqueductus cerebri. In most individuals, the bilateral thalamus is
connected through the thin slit of the third ventricle by adhesion
interthalamica, also known as the gray edge.
1.1.2. Outward form of the thalamus
The thalamus is ovoid, with large heads facing back, the large
axis facing forward, inward, and slightly upwards, with the large axis on

the opposite side at an angle of about 60 °, extending backwards. The
thalamus are about 3cm long, 2cm high, 1.5cm thick, with 4 sides:
inside, outside, back (upper), abdomen (bottom); 2 heads: front, back;
and 3 shores are more or less identified: the inner upper shore, the outer
upper shore and the inner lower shore.
1.1.3. The inner form of the thalamus
1.1.4. The role of the thalamus
The thalamus is the main transition station to the cortex, described as a
"gateway" to the cortex. Almost everything we can know about the
outside world, or about ourselves, is based on information passing
through the thalamus.
1.1.4.1. Environmental awareness is an activity related to the thalamus
1.1.4.2. The importance of the cerebral cortex - thalamus - cortex for perception
1.1.4.3. Perception to act or action to perceive? Parallel processing of
sensory and motor signals


4
1.2. Neurotransmitters
1.2.1. Sensory nerve pathways
1.2.1.1. Outline of the sensory neurotransmitters
1.2.1.2. Somatic sensory pathways posterior column – medial lemniscus
The Dorsal Column-Medial Lemniscal Pathway
The dorsal column-medial lemniscal pathway (DCML) carries
the sensory modalities of fine touch (tactile sensation), vibration and
proprioception. There are three groups of neurones involved in this
pathway – first, second and third order neurones.
First Order Neurones
Second Order Neurones
Third Order Neurones

1.2.1.3. Unconscious Sensation
Posterior spinocerebellar tract
Anterior spinocerebellar tract
1.2.1.4. The Anterolateral System
First Order Neurones
Second Order Neurones
Third Order Neurones
1.2.2. Descending motor pathways
Corticospinal tract
1.3. Diffuse tensor imaging and its application in studying the
structure of the thalamus and neurotransmitters
1.3.1. Overview of diffuse tensor imaging and some related factors
Method
DTI is based on an innovation of the MRI technique, which
increases the sensitivity to very small three-dimensional movements of
water molecules in the tissue. In Cerebrospinal fluid (CSF) the
movement of water molecules is isotropic, which means that diffusion


5
is equivalent in all directions, that is, water diffuses freely. However, in
white matter diffuses in a directional way, also known as anisotropic.
Due to the structural properties and delineation of myelin in the
bundles of nerve fibers, the water molecules in these bundles are
confined diffuse along the axons of the bundle of nerve fibers.
Therefore, DTIs are used to identify and characterize the white matter's
conduction bundles and thus can provide researchers with the properties
of the connection pathways in the brain.
1.3.2. DTI applications in brain structure research
1.3.3. Some methods and initial application of DTI in determining the

structural features and nuclei of the thalamus
1.3.4. Determination of the connections of the thalamus to the cortex
using DTI
1.3.5. DTI applications in research on the thalamus and
neurotransmitters in Vietnam
So far, with the available documents, we have only seen the work of
authors Nguyen Tri Dung, Pham Ngoc Hoa, and Cao Thien Tuong in 2010
studying the use of DTIs in distinguishing brain abcess from necrotic brain
tumors in capsule form. There is no research study on morphological
characteristics of the hippocampus and the connections of the thalamus
with regions of the cerebral cortex by this technique.
CHAPTER 2
SUBJECTS AND METHODS
2.1. Participants and data acquisition
2.1.1. Location and duration of research
This thesis was conducted at the Imaging Department of the
108th Military Central Hospital, from June 2015 to December 2016.
2.1.2. Subjects of study
This study used data sets and methods of analyzing and filming
cranial CHT films of 50 normal people, aged 18 years and older,
without any brain diseases or neurological damage.


6
Including:
- Criteria for selecting research subjects
Select the subject without any skull abnormalities; history or
currently traumatic brain injury, any diseases that cause central nervous
damage such as Alzheimer's, brain tumors, or any neurological, psychiatric
and chronic neurological diseases. All research subjects were MRI captured

with basic pulse sequences and DTI pulses.
- Exclusion criterias
Subjects are excluded from the research if they have one of the
diseases such as central neurological damage pathologies, for example,
Alzheimer's, brain tumors, or neurological, psychiatric and chronic
neurological diseases...
2.2. Research methods
2.2.1. Study Design
This is a Cross sectional study.
2.2.2. Study equipments
Achieva 3T resonance imaging machine (Phillips, Netherlands)
has 16-channel cranial coil and DWI and DTI imaging software. Image
Processing Workstation with Extended MR Workspace 2.6.3.1
2.3. Research indicators
2.3.1. . General characteristics of the research participants
General characteristics: Age, gender
2.3.2. Morphology of thalamus on MRI 3.0 tesla
The length of the right and left thalamus (mm).
The width of the right and left thalamus (mm).
The height of the right and left thalamus (mm).
The volume of the right and left thalamus (ml).
2.3.3 Morphology of thalamocortical sensory tract on
DTI 3.0 tesla
- The number of branches of thalamocortical tracts on the 3D image.
- The length of thalamocortical tracts on the 3D image.
The right and left thalamocortical tracts’ dimensions on 3D images:


7
- Types of thalamocortical tract graphs (divided in 2, 3, 4, 5, 6...

branches and branches to the opposite side when connected to the
cerebral cortex).
- FA, ADC values of thalamocortical tracts on 3D image.
2.4. Data processing
The figures are analyzed according to the biomeded statistical method:
Data processing: using SPSS 22.0 software
Variables are constantly expressed as means and deviations (X ±
SD); median value and percentage (%).
The research data is processedand calculated using the t- test
algorithm on SPSS software. Statistically significant differences are
determined when p < 0.05.
Analyzes the linear correlation between X and Y variables with a
standard distributionwith a Pearson correlationnumber.
CHAPTER 3
RESULTS
3.1. Age and gender characteristics of research subjects
Table 3.1. Statistics on age groups, gender and the corresponding
distributions of research subjects
Age
Age
Total
20 – 39
40 - 59
≥ 60
n
n
n
n
Group
(%)

(%)
(%)
(%)
9
14
3
26
Male
(18)
(28)
(6)
(52)
12
9
3
24
Female
(24)
(18)
(6)
(48)
21
23
6
50
Total
(42)
(46)
(12)
(100)

8
Comment:
We divided the participants into 3 age groups: 20 - 39, 40 - 59,
and ≥ 60. In which, the most of research subjects are in two groups of
20 - 39, 40 - 59, accounting for 88%, so the majority of research
subjects was the adult and in the middle ages. Research subjects were
relatively evenly distributed in the 52% male and 48% female.
3.2. Morphological characteristics of the thalamus
3.2.1. General characteristics of the size and volume of the thalamus
Table 3.2. General characteristics of the sizes and the volume of the
thalamus subjects in study (n = 50)
Content
n
Mean
Min
Max
Left length (mm)
50
31,12 ± 1,82
24,70
34,00
Right length (mm)
50
31,23 ± 1,57
27,20
34,10
Left width (mm)
50

16,46 ± 0,82
14,50
18,30
Right width (mm)
50
16,46 ± 0,69
14,90
18,30
Left height (mm)
50
16,77 ± 1,16
12,60
20,10
Right height (mm)
50
16,79 ± 1,19
12,60
19,70
Left volume (ml)
50
6,42 ± 0,52
5,22
7,19
Right volume (ml)
50
6,43 ± 0,53
5,22
7,17
Total volume of 2 sides (ml) 50
12,86 ± 1,06

10,44
14,36
Comment:
The table shows the overall size characteristics of the cortical
thalamus of the research subjects, with the number of people in the study
is 50, the average length on the left is 31.12 mm, the right is 31.23 mm,
mean of left width and right are both 16.46 mm, average left height
(16.77 mm), right (16.79 mm), left volume (6, 42 ml), right (6.43 ml), left
maximum (34.0 mm) minimum (24.7 mm), right maximum (34.1 mm)
minimum (27 , 2 mm), maximum left width (18.3 mm) minimum (14.5
mm), maximum right width (18.3 mm) minimum (14.9 mm), maximum
left height (20.1 mm) minimum (12.6 mm), maximum right height (19.7
mm) min (12.6 mm), maximum left volume (7.19 ml) minimum (5,22
ml), maximum right volume (7,17 ml) minimum (5,22 ml).


9
3.2.2. Characteristics of the thalamus length
Bảng 3.3. Comparison of the left and right mean length of the thalamus
(mm)
Group
n
± SD
p
Male
Left
26
31,30 ± 1,98
0,47
Female

24
30,92 ± 1,64
Male
Right
26
31,38 ±1,50
0,46
Female
24
31,05 ± 1,66
General
Left
50
31,12 ± 1,82
0,756
Right
50
31,23 ± 1,57
General
100
31,17 ± 1,69
% Left - Right difference
50
1,02 ± 2,44
Comment:
Table 3.3 shows that the length of the left thalamus in male is 31.30
mm, which is 30.92 mm larger than the length of the left thalamus in
female, but there is no difference that is statistically significant with p>
0,05. The length of the right thalamus for men is 31.38 mm, greater than
the length of the right thalamus for women is 31.05 mm, but there is no

difference with p> 0,05. The mean lengths of the right and left thalamus
(31.23 mm and 31.12 mm) were not statistically significant with p> 0.05.
3.2.3. Characteristics of the thalamus width
Table 3.5. Comparison of the left and right medium width of the
thalamus (mm)
Gender
Width
n
± SD
p
Male
26
16,76 ± 0,66
0,06
Left
Female
24
16,14 ± 0,86
Male
26
16,74 ± 0,54
0,002
Right
Female
24
16,16 ± 0,72
Left
50
16,46 ± 0,82
0,979

General
Right
50
16,46 ± 0,69
General
100
16,46 ± 0,76
% Left - Right difference
50
1,32 ± 1,97


10
Comment:
Table 3.5 shows that the width of the left thalamus in men tends
to be greater than the width of the thalamus in women, but this
difference is not statistically significant with p> 0.05. However, the
width of the right thalamus for men is 16.74 mm, larger than the width
of the right thalamus for women, 16.16 mm, which is statistically
significant with p <0.05. The width of the thalamus on both sides is also
similar: left (16.46 mm) and right (16.46 mm) with p = 0.979.
3.2.4. Height characteristics of the thalamus
Table 3.7. Compare the average height on the right and left sides of the
thalamus (mm)
Gender
Height
n
± SD
p
Female

24
16,67 ± 1,39
0,53
Left
Male
26
16,87 ± 0,91
Female
24
16,70 ± 1,47
0,59
Right
Male
26
16,88 ± 0,87
Left
50
16,77 ± 1,16
0,946
General
Right
50
16,79 ± 1,19
General
100
16,78 ± 1,17
% Left - Right difference
50
1,26 ± 1,48
Comment:

The results in Table 3.7 and Figure 3.3 show that the height of the
left and right thalamus for men is 16.87 mm and 16.88 mm higher than
the height of the left and right thalamus of women. 16.67 mm and 16.70
mm respectively. The height of the thalamus on the left (16.77 mm)
corresponds to the right (16.79 mm) with p = 0.946.


11
3.2.5. Volumetric characteristics of the thalamus
Table 3.9. Comparision between the left and right volumes of the
thalamus (ml).
± SD
p
Gender
Volume
n
Female

Left side

24

6.18 ± 0.52

26

6.65 ± 0.43

24

6.19 ± 0.52

26

6.65 ± 0.44

Left side

50

6.42 ± 0.52

Right side

50

6.43 ± 0.53

General

100

12.86 ± 1.06

% left - right difference

50

0.16 ± 0.17

Male
Female

Right side

Male
General

0.001
0.001
0.99

Comments:
Table 3.9 compares the thalamus volume on the left and right in
two genders. Overall, it is clear that the volume of the thalamus in male
is greater than that of female on both sides, and the difference is
statistically significant with p < 0.05. In general, 6.42 ml is the number
of the thalamus volume on the left and the number on the right is 6.43
ml. Consequently, the volume of the thalamus in both sides are
relatively similar. The total volume of the thalamus is 12.86 ml.


12
3.3. Morphological characteristics of the thalamus - cortex
3.3.1. Characteristics of the size of the thalamus - cortex
3.3.1.1. Characteristics of the length of the cortical thalamus
Table 3.20. Length of the thalamus - cortex
The length of the thalamus General (2
cortex
Group

sides)
Left
Right
n
50
50
100
Median
123.14
130.64
126.33
value
± SD
121.21 ± 13.49 130.17 ± 11.44 125.69 ± 13.24

p

0.028
0.001

Comments:
The results in Table 3.20 show that the median length of the
thalamus- cortex on the right is longer than that of the left side, having
statistical significance with p < 0.05. In the figure, each side of the
thalamus - cortex has median length 130.64 mm and 123.14 mm
respectively. The similarity is also seen in the average length of the
thalamus – cortex, with 130.17 mm on the right compared to that of the
left side at 121.21 mm, and the difference is statistically significant with
p < 0.05.
Table 3.21. Compare the average length of the thalamocortical tracts by

gender on both sides
Gender
The average length of the
± SD
p
thalamocortical tracts
Left
118,94 ± 13,70
0,012
Female
Right
127,85 ± 9,37
Average
123,39 ± 12,45
Left
123,32 ± 13,22
0,016
Male
Right
132,32 ± 12,88
Average
127,82 ± 13,70


13
Comment:
Table 3.21 shows the average length of the thalamocortical
tracts between left and right in females is 118,94 mm and 127,85 mm
respectively. The female's average length of the thalamocortical tracts
on the right is longer than the left, a statistically significant result with

(p < 0,05). The male’s average length of the thalamocortical tracts on
the left is 123,32 mm and the right is132,32 mm; which mean the
average length of the thalamocortical tracts on the right is longer than
the left - a statistically significant result with (p < 0,05).
3.3.1.2. The morphological characteristics about the number of
thalamocortical tracts’s fibers
Table 3.23. The number of fibers's the left and right thalamocortical
tracts (fibers)
Giới tính
The number of Media
n
p
fibers
n
Left
347,0
24
0,773
Male
Right
398,5
24
Average
366,5
48
Left
295,5
26
0,405
Female

Right
401,5
26
Average
355,5
52
Left
315,00
50
0,549
Both
Right
401,50
50
(Two genders) Average
365,50
100
Comment:
Table 3.23 shows median value about the number of fibers of
thalamocortical tracts’s female in the left is 347,0 and the right is 398,5.
The median value about the number of fibers of thalamocortical tracts’s
female between the left and the right is not statistically significant with
p > 0.05. the number of fibers of thalamocortical tracts’s male in the left
is 295,5 fibers and in the right is 401,5 fibers. The number of fibers of


14
the thalamocortical tracts in the left is lower than the right which is not
statistically significant with p > 0.05.
Median value about the number of fibers of thalamocortical

tracts in the left is 315 fibers, in the right is 401,5 fibers; The number of
fibers of the thalamocortical tracts in the right is higher than the left. but
the difference is not statistically significant, with p > 0,05.
Table 3.24. Compare the average length of the
thalamocortical tractson the right and the left in gender (fibers)
Male Female Average
(n = 26) (n = 24) (n = 50)
The thalamocortical tracts
p
Median Median Median
value
value
value
Number of fibers on the left
295,50 347,00 315,00
0,396
Number of fibers on the right
401,50 398,50 401,50
0,777
Comment:
Table 3,24’s result shows the number of fibers on the right
side is almost the same for both gender, while the number of male's
fibers on the left side is lower than female. but the difference is not
statistically significant, with p > 0,05.
3.3.2. Morphological forms of the thalamocortical tracts
Table 3.30. Statistics of the number and distribution of branching
morphologies of the thalamocortical tracts
group
Morphological
Left

Right
Total
forms
n
%
n
%
n
%
2 branches
2
(2)
3
(3)
5
(5)
3 branches
11
(11)
14
(14)
25
(25)
4 branches
20
(20)
22
(22)
42
(42)

5 branches
10
(10)
6
(6)
16
(16)
6 branches
7
(7)
5
(5)
12
(12)
Opposite branches
6
(50)
6
(50)
100
(100)


15
Comment:
Table 3.30 results show that the thalamocortical tracts’ branches
are polymorphism. In which, the group of 4 branches accounts for 42%,
the group of 3 branches accounts for 25%, the group of 5 branches
accounts for 16%, the group of 6 branches accounts for 12% and the
least group of 2 branches accounts for 5%. From the image we can see

shows that there are branches with equal proportions on the right and
left, each accounting for 50%.
3.3.3. Characteristics of fractional anisotropy (FA) and apparent
diffusion coefficient (ADC) of the thalamocortical tracts
3.3.3.1. Characteristics of fractional anisotropy (FA) of the
thalamocortical tracts
Table 3.32. Compare the average value of the FA between the left and
the right
FA
Gender
n
± SD
p
Male
26
0,483 ± 0,022
Left
0,235
Female
24
0,474 ± 0,026
Male
26
0,482 ± 0,022
Right
0,659
Female
24
0,479 ± 0,025
Left

General
50
0,479 ± 0,024
0.716
(2 sides)
Right
50
0,480 ± 0,023
General (2 sides)
100
0,479 ± 0,023
Comment:
Table 3.32 and Figure 3.6 show the mean FA value between left and
right, we see these value are equal with no difference between left and
right with p> 0.05. Mean FA values between left and right for men and
women were similar and there was no difference between left and right
with p> 0.05.
3.3.3.2. Characteristics of apparent diffusion coefficient (ADC) of the
thalamocortical tracts.


16
Table 3.34. Compare the mean ADC value between left and right
(10-3mm2 / sec)
FA
Gender
n
± SD
p
Male

26
0.830 ± 0.051
Left
0,805
Female
24
0.827 ± 0.060
Male
26
0.826 ± 0.044
Right
0,130
Female
24
0.806 ± 0.045
Left
50
0,829 ± 0,055
0,236
General
Right
50
0,816 ± 0,045
General (2 sides)
100
0,823 ± 0,050
Comment:
Table 3.34 and Figure 3.7 show that mean ADC values between
left and right for both men and women have no differences between left
and right with p> 0.05. Mean ADC values between left and right for

men and women had no difference between left and right with p> 0.05.
CHAPTER IV
DISCUSSIONS
4.1. Age and gender characteristics of research subjects
Our research sample has 26 males, accounting for 52%, and 24
females, accounting for 48%. The male / female ratio is approximately
1.08, all of the participants are adults and they spread across all groups
from young to middle-aged and old age.
Compared with the world, studies on the structure of the
thalamus, the number of subjects participating in our research is limited,
lower than in the study of author Fikret S. et al (2005) performed on
161 normal Turks (100 males, 61 females), or author Mohammad RM
(2008) studied 97 healthy Iranians (44 males, 53 females).


17
A study with a similar sample size with our study is the study of
structures under the cortex (thalamus included) on MRI images
conducted by Wang XY et al (2016) performed on 53 healthy Han
Chinese. Study subjects were also divided into 3 groups: 30 young
people (15 females); 12 middle-aged people (6 females) and 11 elderly
people (4 females).
4.2. Morphological characteristics of the thalamus
4.2.1. Characteristics of the size and volume of the thalamus
Characteristics of the length of the thalamus
Regardless of gender, in our study, the mean length of the left
(31.12 mm) and the right (31.23 mm) thalamus with (p = 0.756> 0.05).
Similar to our results, the study of Brierley JB et al (1959) on 53
cerebral hemispheres from 47 bodies showed that the thalamus length
does not distinguish right and left within the limit (31-38 mm), average

value 34.5 mm. The study by Mohammadi et al. resulted in mean
lengths of the left (33.40 ± 1.65 mm) and right (33.39 ± 1.51 mm)
thalamus. Rayyan Tutunji's study on 12 18-year-olds showed the
average length of the thalamus: 33.20 mm, there was no statistically
significant difference between the right, left, or between men and
women.
Width characteristics of the thalamus
- Regardless of gender, in our study, the width of the thalamus on
both sides is similar: left (16.46 mm) and right (16.46 mm) with (p =
0.979). Research results of Muhammad et al. Width of the left thalamus
(22.11 ± 1.12 mm) and right (22.00 ± 1.14 mm). In an autopsy study,
Van Buren and Maccubbin, (1962) performed an autopsy on 16 patients
(aged 3 to 78) with no neuropathy and showed that the upper thalamus
width was within 12.5 to 21 mm. Rayyan Tutunji's study on 12 18-yearolds showed the average width of the thalamus: 21.55 mm.
Height characteristics of the thalamus


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Our research results show that all three dimensions, length,
width, and height of the left and right thalamus are lower than the
results of published world publications, possibly due to the subject. Our
research is that Vietnamese people have a smaller figure than the
author's research subjects such as Mohammadi is indigenous Fars in
northern Iran and Fikres SEN's research subject is Turkish. States.
Morphological characteristics of the volume of the thalamus
In this study, we also compare the thalamus volume between
the two hemispheres, the results showed that the right is larger than the
left, this result is similar to some previous studies. However, in Damle
and Ahsan's study the opposite results are found: the volume of the left
thalamus is greater than the right. The difference between studies may

be related to either the age of the subjects because there is a relationship
between the age and the thalamus’s volume of two hemispheres or
depending on research methods. The change in volume with age may be
related to the decrease and degeneration of neurons or the synapses
between nerve cells. But so far, the neurological mechanism of
asymmetry in the two hemispheres has not been determined.
4.3. Characteristics of the thalamocortical tracts
4.3.1. Length characteristics of the thalamocortical tracts
When measuring fiber thalamus-cortex's dimension, our results
show that the average length on both sides is 125.69 mm. The average
length of the right thalamocortical tracts (130.17 mm) is longer than the
left (121.21 mm), the difference between the two is statistically
significant with p <0.05. In the study of Kamali et al. investigating the
sensory pathways in the brainstem, the results showed no difference in
length on the right and left. It is possible that different anatomical
locations can also leads to structural differences. In addition, it has
functional differences in general and in particular sensory conduction


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between the right and the left of the the brain. Thus it leads to a
difference in the length of the cortical thalamus between the two sides.
4.3.2. Relationship between gender with the length of the
thalamocortical tracts
When measuring the length of the left thalamocortical tracts and
the right thalamocortical tracts, the results are for men with average
lengths of 123.32 mm and 132.32 mm, and for women of 118.94 mm
and 127.85 mm. When comparing the mean lengths on the left and right
by gender, the length of thalamocortical tracts in men tends to be longer
than that of women, but the difference is not statistically significant

with p > 0.05. A comparison of the length of the fiber thalamocortical
tracts between the two genders shows that the male tends to be longer
than that in women, this may be due to the fact that the male brain is
larger than that of the female, but the difference is not statistically
significant possibly because the number of analyzes is not large enough.
4.3.3. The number of fibers of the thalamocortical tracts
Theoretically, the number of talamocortical tracts is proportional
to the number of nerve cells in the central cortex to which they are
connected. People with more axons, they will have more cells in the
central regions of the thalamocortical tracts and vice versa..
The results of statistical analysis show that the median number of
fibers of the left thalamocortical tracts is 315 fibers and the right is
401.5 fibers, it showed count of fiber of the thalamocortical tracts. This
result is somewhat contrary to the conclusion of Alkonyi B, when
considering the common white matter in the two hemispheres, the
author concludes that the left thalamus has a significantly higher overall
cortical connection than the right thalamus. This can be hypothesized
that since the majority of study subjects are right-handed, the
transmittance may also be different between the right and the left. In


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order to clarify this subject, we need to have a large-scale study with
enough study objects.
4.3.6. Forms of the thalamocortical tract
The results in our study show thalamocortical fibers branching
polymorphic. In particular, the group of 4 branches is topped the list
(42%), followed by the group of 3 branches with 25%, the group of 5
branches and the group of 6 branches account for 16% and 12%
respectively and the group of 2 branches reaches the lowest rank, with

5%. The image obtained shows that there are branchings on the right
and left sides equivalent to each side accounting for 50%. However,
there is no difference between the right and the left in the number of
branching forms. Therefore, the distribution to the cerebral cortex of the
thalamocortical tract is more abundant than that of the corticospinal
tract in some studies such as Seo JP and his associates research on 36
healthy adults, found corticospinal tracts originated from the primary
motor cortex (36.9%), from the motor sensory cortex (31.7%), from the
secondary motor cortex (24%) and from the dorsal motor cortex (6.7%).
4.3.7. Characteristics of the fractional anisotropy (FA) and apparent
diffusion coefficient maps (ADC) of the thalamocortical tract
4.3.7.1. Characteristics of the fractional anisotropy (FA) of the
thalamocortical tract
When comparing the average FA value between the left and the
right, we found that there is no difference between the left and the right
with p > 0.05.
The research comparing the FA values of the thalamocortical tract
between healthy people and people with cerebral palsy, Shoko Y. and
his partner concluded that the FA index of the thalamocortical tract in
children with cerebral palsy was significantly lower than in healthy
children in the comparison group. However, in the study of Thomas and


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his associate, the decrease in the FA index in patients with cerebral
palsy has not been confirmed.
4.3.7.2. Characteristics of apparent diffusion coefficient (ADC) of the
thalamocortical tracts
Apparent Diffusion Coefficient (ADC) measures the diffusion
amplitude of water molecules in the nerve organization, when the value

of ADC is low, it means that the pathways in the white matter are tightly
organized, intact, and ADC value is high when the pathway loses its
normal structure, the pathway is damaged.
In our study, the mean ADC values between the left and the right were
(0.829 ± 0.055) 10-3 mm2 / sec and (0.816 ± 0.045) 10-3 mm2 / sec,
respectively. This value has no difference between left and right side
with p > 0.05. Morita et al's study on 19 patients with brain tumor (16
men, 3 women, aged 39 to 70), including 12 patients with normal motor
function and 7 patients with abnormal motor function were assessed by
myotonus, pathological reflexes: Hoffmann, Babinski, ... The results
showed that the ADC index of the thalamocortical tracts of patients with
abnormal movements increased compared to patients with normal motor
functions with p < 0.01.
CONCLUSION
Through research on 50 subjects using diffusion tensor imaging
(DTI), we draw the following conclusions:
1. Morphology of the thalamus in a normal adult on 3 tesla
magnetic resonance image has the following characteristics:
- The average thalamus length of
+ Both genders on the left side are 31.12 mm and the right side is
31.23 mm;
+ In Female on the left is 30.92 mm and on the right is 31.05
mm;


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+ In Male on the left is 31.30 mm and the one on the right is
31.38 mm.
- Average thalamus width of
+ Both genders on the left side are 16.46 mm and the right side is

16.46 mm;
+ Female on the left side is 16.14 mm and on the right side is
16.16 mm;
+ Male on the left side is 16.76 mm and the one on the right is
16.74 mm.
- Average thalamus height of
+ Both genders on the left side are 16.77 mm and the right side is
16.79 mm;
+ Female on the left side is 16.67 mm and on the right side is
16.70 mm;
+ Male on the left side is 16.87 mm and on the right side is 16.88
mm.
- The average thalamus volume of
+ Both genders on the left side are 6.42 ml and the right side is
6.43 ml;
+ Female on the left is 6.18 ml and on the right is 6.19 ml;
+ Male on the left is 6.65 ml and on the right is 6.65 ml.
2. Morphology of the tractus thalamocortical tracts in normal
adults on the 3.0 tesla diffusion tensor image has the following
characteristics:
- The median length value of the thalamocortical tracts of the
both genders on the left is 123.14 mm and on the right is 130.64 mm.
- Average length of thalamocortical tracts
+ Both genders on the left side are 121.21 mm and the right side
are 130.17 mm;