Comparison of carotid and vertebral artery doppler measurements in supine and sitting positions

Background: Carotid and vertebral Doppler ultrasonography (USG) is the primary diagnostic tool for the detection of extra cranial atherosclerotic disease and measurement of posterior fossa blood flow volume. The examination is performed while the patient lies on supine position. However, in daily practice we occasionally encounter patients who are not able to lie down on supine position for different reasons, such as kyphosis, severe dyspnea, or severe back pain. Aim: We aimed to compare the doppler spectral measurements of carotid and vertebral arteries obtained in supine and sitting positions. Patients and Methods: Fifty-three patients were recorded in the first group, to whom carotid and vertebral (CV) Doppler Ultrasound examination was initially performed while sitting, and another 52 patients were examined as the second group where initial measurements were done in a supine position. Peak systolic velocity (PSV), end diastolic velocity (ED) from each vessel, internal carotid artery (ICA)/common carotid artery (CCA) ratio, and volume flow of vertebral artery (VA) were measured in supine and sitting positions. Also, another 83 patients with a complaint of vertigo were included in the third group but only VA measurements were compared. Results: In the first group, there was a difference between sitting and supine positions in right ICA diastolic, right and left VA diastolic, and left CCA diastolic velocities (P < 0.05). In the second group, there was a difference in sitting and supine positions in right CCA systolic, right CCA diastolic, and left CCA diastolic velocities (P < 0.05). In the third group, there was a difference in sitting and supine positions in right and left VA diastolic velocities, left VA volume flow, and total VA volume flow (P < 0.05). A strong correlation was detected between supine and sitting positions regarding right and left ICA stenoses. Alterations in waveforms were noted in three patients' unilateral VAs, in supine and sitting positions. Conclusion: Our results suggest that CV doppler examinations may be performed in the sitting positions. Examination in the sitting position may be helpful in recognizing pre-steal and retrograde flows.