4 курс / Лучевая диагностика / ПРИМЕНЕНИЕ_КОМПЛЕКСНОЙ_МАГНИТНО_РЕЗОНАНСНОЙ_ТОМОГРАФИИ_ПРИ_РАЗЛИЧНЫХ
.pdf201
On the basis of the grades 1 to 4, the tectum-splenium-cyst ratio and ADC coefficient revealed that, in the group of volunteers with cysts > 10 mm, 8 of 16 people, representing 50% of this group, were at high risk for central venous hypertension (grades 3 and 4). Interestingly, only volunteers in this group were with grade 4.
A comparative analysis using the Kraskell-Wallis method revealed a statistically significant difference between the third group and the second and first groups.
The third group had a higher grade on average than the first and second groups (p1,3 = 0.004, p2,3 = 0.013), which supports the importance of using the calculation of this indicator (Table 7).
Table 7 — Comparison of groups by Grade
Grade |
Without PGC |
With small |
With large |
p-value |
|
|
PGC (less |
PGC (over |
|
|
|
than 10mm) |
10mm) |
|
|
|
|
|
|
Grade 1, |
14 |
13 |
5 |
p1,3 ≤ 0.05; |
person |
|
|
|
p2,3 ≤ 0.05 |
|
|
|
|
|
Grade 2, |
0 |
0 |
3 |
|
person |
|
|
|
|
|
|
|
|
p> 0,05 |
Grade 3, |
2 |
3 |
6 |
|
person |
|
|
|
p> 0,05 |
|
|
|
|
|
Grade 4, |
0 |
0 |
2 |
|
person |
|
|
|
|
|
|
|
|
p> 0,05 |
In the second group, there were no signs of aqueduct stenosis and tectal plate compression in those with PGC less than 10mm. However, three subjects were classified as grade 3, based on a Thalamus ADC Ratio of more than 1.01.
In a third control group, those without PGC also showed no signs of aqueduct stenosis and tectal plate compression, but grade 3 was assigned to 2 volunteers, which may be due to other causes of venous outflow abnormalities.
Рекомендовано к изучению сайтом МедУнивер - https://meduniver.com/
202
3.1.2. MR morphometry
During the analysis of the MR morphometry and resting state functional MRI data, all patients were conditionally divided into 2 groups: the main group with PGC and the control group without the presence of a cyst.
Based on MR morphometry using a generalised linear model with cluster correction, significant differences in cortical thickness were observed in both left and right hemispheres in those with PGC, compared to control groups.
A statistically significant cluster located in the postcentral gyrus (p=0.00420) was detected in the left hemisphere in individuals with PGC. The data are presented in Table 8.
Table 8 — Volumetric measures of left hemisphere cortical thickness in patients
with PGC compared to control group (p < 0.05)
Cortex |
Max |
Vtx |
Size |
MNI |
MNI |
MNI |
CWP |
CWP |
CW |
NV |
Wght |
area |
|
Ma |
(m |
X |
Y |
Z |
|
Low |
PHi |
txs |
Vtx |
|
|
x |
m^2 |
|
|
|
|
|
|
|
|
|
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Postcen |
4.92 |
119 |
94.4 |
-40.2 |
-34.5 |
51.1 |
0.004 |
0.003 |
0.00 |
22 |
488.7 |
tral |
06 |
428 |
4 |
|
|
|
2 |
4 |
500 |
5 |
1 |
gyrus |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Note: Max — maximum voxel significance in the cluster, VtxMax — vertex at maximum, Size(mm^2) — cluster size in square millimetres, MNIX, MNIY, MNIZ — MNI305 coordinates, CWP — cluster p-value (CWP=Cluster-Wise P-value), CWPLow — lower 95% confidence interval of CWP, CWPHi — upper 95% confidence interval of CWP, NVtxs - number of vertices in cluster.
It was found that the detected cluster was clearly located in the medial cortex and did not extend beyond other areas according to the atlases used to represent the data supplied with FreeSurfer: the DesikanKilliany atlas and the Destrieux atlas, which contained smaller fragments.
203
A B
C D
Figure 14 — Colour mapping of the absolute difference in left hemisphere cortical thickness obtained by subtracting the morphometric metrics of the control group from the morphometric metrics of the group of individuals with PGC on a 2D sweep (A) and 3D reconstruction (B) using the Desikan-Killiany atlas and the Destrieux atlas (C, D)
To visualise the changes detected was performed a subtraction of the derived cortical metrics between the control group and PGC patients, followed by reconstruction of both a 3D hemispheric model and a 2D sweep to eliminate visualisation problems caused by the complex pattern of sulcus and gyrus (Figure 14).
Рекомендовано к изучению сайтом МедУнивер - https://meduniver.com/
204
A statistically significant cluster located in the superior parietal gyrus (p=0.02660) was detected in the right hemisphere in individuals with PGC. The data are presented in Table 9.
Table 9 — Volumetric measures of right hemisphere cortical thickness in patients
with PGC compared to control group (p < 0.05)
Cortex |
Ma |
VtxM |
Size( |
MNI |
MNI |
MNI |
CWP |
CW |
CW |
NVt |
Wg |
area |
x |
ax |
mm^ |
X |
Y |
Z |
|
PLo |
PHi |
xs |
htV |
|
|
|
2) |
|
|
|
|
w |
|
|
tx |
|
|
|
|
|
|
|
|
|
|
|
|
Upper |
3.8 |
3879 |
922. |
30.5 |
-55.0 |
41.2 |
0.02 |
0.02 |
0.02 |
212 |
410 |
parietal |
979 |
2 |
46 |
|
|
|
660 |
45 |
870 |
4 |
4.3 |
gyrus |
|
|
|
|
|
||||||
|
|
|
|
|
|
|
|
|
|
2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Note: Max - maximum voxel significance in the cluster, VtxMax - vertex at maximum, Size(mm^2) - cluster size in square millimetres, MNIX, MNIY, MNIZ - MNI305 coordinates, CWP - cluster p-value (CWP=Cluster-Wise P-value), CWPLow - lower 95% confidence interval of CWP, CWPHi - upper 95% confidence interval of CWP, NVtxs - number of vertices in cluster.
The same phenomenon of the location of this cortical cluster in the structure of only one gyrus is repeated similarly in the left postcentral gyrus. The data are clearly demonstrated in Figure 15.
Thus, it was found that patients with PGC have areas of increased cortical thickness in the parietal lobes of both hemispheres compared to healthy volunteers.
205
A B
C D
Figure 15 - Colour mapping of the absolute difference in right hemisphere cortical thickness obtained by subtracting the morphometric metrics of the control group from the morphometric metrics of the group of individuals with PGC on a twodimensional sweep (A) and three-dimensional reconstruction (B) using DesikanKilliany atlas, and Destrieux atlas (C, D)
3.1.3 Resting state functional MRI
Based on the post processing data of two groups was identified a statistically significant decrease in connectivity in individuals with PGC in 6 different resting neural networks: 1) Default Mode (passive mode network), 2) SensoriMotor (sensorimotor
Рекомендовано к изучению сайтом МедУнивер - https://meduniver.com/
206
network), 3) Salience (significance detection network), 4) DorsalAttention (dorsal attention network), 5) FrontoParietal (part of executive control network), 6) Language (language network). One of the main components of each network was taken in turn as areas of interest by processing fMRIrs data in each of the networks,
The DefaultMode network includes the ventromedial and dorsomedial prefrontal cortex, lateral parietal cortex and posterior cingulate cortex (PCC) along with adjacent portions of the precuneus. Analysis of the data using the connectivity mapping technique based on initial values, with selection of the posterior cingulate as the area of interest, revealed 2 significant clusters of decreased connectivity in individuals with PGC compared to control group (p<0.05) (Table 10).
Table 10 — Areas of reduced activation in the resting state network DefaultMode
in individuals with PGC compared to control group (p < 0.05)
Area of |
Area of the brain |
Field by |
Size |
p-value |
interest |
|
Broadman |
(voxel) |
|
|
|
|
|
|
Posterior |
Left postcentral sulcus |
2,3,40 |
1205 |
0.000000000 |
cingulate |
(74%) |
|
|
0001 |
cortex |
Left precentral sulcus |
|
|
|
(PCC) |
(16%) |
|
|
|
|
|
|
|
|
|
Right postcentral sulcus |
3,4,40 |
478 |
0.000033 |
|
(57%) |
|
|
|
|
Right |
|
|
|
|
precentral sulcus (24%) |
|
|
|
|
|
|
|
|
The data in the table show that the largest cluster of decreased functional connectivity detected in relation to the posterior cingulate gyrus was visualised in the predominantly right and left postcentral sulcus cortex projections (Figures 16, 17).
207
A B C
Figure 16 — Colour mapping of the absolute activation difference obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. A decrease in activity is visualised in the predominantly left postcentral sulcus projection in the axial (A), frontal (B) and sagittal planes (C)
A B C
Figure 17 — Colour mapping of the absolute activation difference obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. A decrease in activity is visualised in the predominantly right postcentral sulcus projection in the axial (A), frontal (B) and sagittal planes
(C)
The SensoriMotor network includes functional areas in the primary motor cortex, cingulate cortex, dorsal and ventral premotor cortex and supplementary motor area. It also includes the primary and sensory cortices of the parietal lobe.
These areas are conventionally divided into superior and lateral areas, each of them was assessed separately. In this network were identified 6 clusters of connectivity
Рекомендовано к изучению сайтом МедУнивер - https://meduniver.com/
208
impairment with the lateral part of the network and 1 cluster with the superior part
(Table 11).
Table 11 — Areas of reduced activation in the resting state network Sensori Motor
in subjects with PGC compared to control group (p < 0.05)
Area of |
Area of the brain |
Field by |
Size |
p-value |
interest |
|
Broadman |
(voxel) |
|
|
|
|
|
|
Lateral |
Left precuneus cortex (85%) |
7,31 |
587 |
0.000002 |
part of the |
Left postcentral sulcus (8%) |
|
|
|
network |
|
|
|
|
Right precuneus cortex (85%) |
7,31 |
304 |
0.000004 |
|
|
Right cuneate cortex (24%) |
|
|
|
|
|
|
|
|
|
Cortex of the left insula (30%) |
13,47 |
299 |
0.000002 |
|
Left putamen (17%) |
|
|
|
|
|
|
|
|
|
Cingulate gyrus (92%) |
24,32 |
293 |
0.000006 |
|
Right paracingulate gyrus (2%) |
|
|
|
|
|
|
|
|
|
Cingulate gyrus (34%) |
9,32 |
287 |
0.000011 |
|
Left paracingulate gyrus (29%) |
|
|
|
|
|
|
|
|
|
Right angular gyrus (70%) |
40,13 |
186 |
0.000015 |
|
Supramarginal gyrus (26%) |
|
|
|
|
|
|
|
|
Upper part |
Cingulate gyrus (66%) |
24,32 |
760 |
0.000014 |
|
Right paracingulate gyrus (11%) |
|
|
|
|
|
|
|
|
The table shows that the largest identified clusters of decreased functional connectivity, relative to the lateral network, were visualised in the projection of predominantly left and right precuneal cortices, insula cortex, cingulate gyrus, right and left paracingulate gyrus (Figures 18, 19, 20, 21, 22).
209
A B C
Figure 18 — Colour mapping of the absolute difference in activation obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. Decreased activity is visualised in the predominantly left precuneus projection in the axial (A), frontal (B) and sagittal planes (C)
A B C
Figure 19 — Colour mapping of the absolute difference in activation obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. Decreased activity is visualised in the predominantly right precuneus projection in the axial (A), frontal (B) and sagittal planes (C)
Рекомендовано к изучению сайтом МедУнивер - https://meduniver.com/
210
A B C
Figure 20 — Colour mapping of the absolute difference in activation obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. Decreased activity is visualised in the predominantly left insula cortical projection in the axial (A), frontal (B) and sagittal planes (C)
A B C
Figure 21 — Colour mapping of the absolute activation difference obtained by subtracting the functional metrics of the control group from the functional metrics of the PGC patient group. Decreased activity is visualized in the predominantly cingulate cortex and right paracingulate gyrus projection in the axial (A), frontal
(B) and sagittal (C) planes