Assessment of Cerebral Arterial Flow Volume Changes with Carotid Vertebral
Artery Duplex Doppler Ultrasound in Young-Middle-aged Subclinical
Hashimoto Thyroiditis Patients
Authors: Aksu Yusuf , Kahveci Servet , Tiryaki Şaban , Şahin Murat , Mutlu Fezan 
Published: December 2022

Objectives:
To demonstrate cerebral arterial flow volume changes during the hypothyroid,
euthyroid, and hyperthyroid phases and comparing between laboratory findings and cerebral arterial
flow changes with carotid-vertebral duplex Doppler ultrasound (CVA-DUSG) in subclinical Hashimoto
thyroiditis (HT) patients.

Methods:
According to the TSH level, 3 groups were constructed between patient cases. Group 1 (n=29)
was the subclinical hyperthyroid group. In this group, the TSH level was between 0.0005 and 0.3 IU/ml.
Group 2 (n=175) was the euthyroid group. TSH level in this group was between 0.3 and 4.2 IU/ml. Group
3 (n=76) was the subclinical hypothyroid group. In this group, the TSH level was above 4.2 IU/ml. The
control-group (group 4) (n=71) included healthy people. In this group, the TSH level was between 0.3 and
4.2 IU/ml. After obtaining at least three consecutive waves from the bilateral internal cerebral artery and
bilateral vertebral artery, volume flows were calculated using CVA-DUSG. Volume flows were calculated
as peak systolic velocity + end diastolic velocity/2 × mean arterial diameter. The mean ICA(Internal
Carotid Artery) and VA(Vertebral Artery) diameter was measured per ICA and VA. Total cerebral artery
flow volume was defined as right ICA + right VA flow volume and left ICA + left VA flow volume. We
also demonstrated topographic cerebral artery blood flow changes. Total ICA flow volume was used to
assess the anterior part of the brain, total VA flow volume was used to evaluate the posterior part of the
brain, right ICA + right VA flow volume was used to assess the right part of the brain, and left ICA + left
VA flow volume was used to verify the left part of the brain.

Results:
There were significant differences between RVA(Right Vertebral Artery) flow volume, LICA
(Left Internal Carotid Artery) flow volume, total flow volume, TSH, and T3 and T4 levels in all groups
according to the Dunn's multiple comparison test.(p<0.001) Mean TSH level was 0.03 (0.005-0.06) IU/ml
in group 1, 2.8 (1.8-3.97) IU/ml in group 2, 7.32 (6.14-9.93) IU/ml in group 3, and 1.76 (1.17-2.49) IU/ml
in the control group. The mean T3 level was 4.18 (3.55-5.38) in group 1, 2.88 (2.63-3.16) in group 2, 2.82
(2.49-3.15) in group 3, 3.14 (2.92-3.15) in the control group. The mean T4 level was 1.92 (1.29-2.5) in
group 1, 1.16(1.03-1.31) in group 2, 1.01 (0.91-1.16) in group 3, 1.12 (0.97-1.30) in the control group
(group 4). Mean total flow volume was 793 (745-898) ml/min in group 1, 742 (684.25-822.5) ml/min in
group 2, 747 (692-824) ml/min in group 3, and 700 (673-675) ml/min in the control group. We also
demonstrated topographic cerebral arterial volume flow changes with CVA-DUSG. There was a significant
difference among all groups in the right and anterior parts of the brain (p < 0.001), and there was a
significant difference between groups 1 and 4 in the left part of the brain (p = 0.009).

Conclusion:
This study demonstrated that total cerebral arterial volume flow increased in the hyperthyroid
phase of subclinical HT cases without any internal carotid and vertebral artery diameter changes
compared with the euthyroid and hypothyroid phases of subclinical HT and healthy cases. We also
verified topographic cerebral arterial blood flow changes in subclinical HT cases with a real-time, easily
applicable modality (CVA-DUSG) that does not include X-ray or contrast agents. There was a significant
difference between all groups in the right and anterior parts of the brain and there was a significant
difference between groups 1 and 4 in the left part of the brain.