Posture-induced changes in the vessels of the head and neck: evaluation using conventional supine CT and upright CT

Abstract

Since the venous system is affected by gravity, upright computed tomography (CT) in addition to conventional supine CT has great potential for evaluating postural changes in the venous system. We evaluated the morphological differences in the head and neck vessels by performing a contrast CT study in both the supine and the sitting positions. In this study, the 20 included participants (10 men and 10 women) were healthy adults aged 30 to 55 years. The cross-sectional area of the cervical vessels, craniocervical junction veins, and intracranial vessels were obtained quantitatively. Venous sinuses and venous plexuses that were difficult to measure were evaluated qualitatively. The average change in areas from a supine to an upright posture was − 77.87 ± 15.99% (P < 0.0001) in the right internal jugular vein (IJV), − 69.42 ± 23.15% (P < 0.0001) in the left IJV, − 61.52 ± 12.81% (P < 0.0001) in the right external jugular vein (EJV), and − 58.91 ± 17.37% (P < 0.0001) in the left EJV. In contrast, the change in the anterior condylar vein (ACV) from a supine to an upright posture was approximately + 144% (P < 0.005) on the right side and + 110% (P < 0.05) on the left side. In addition, according to the qualitative analysis, the posterior venous structures including the anterior condylar confluence (ACC) of the craniocervical junction became more prominent in an upright posture. Despite these changes, the intracranial vessels showed almost no change between postures. From a supine to an upright position, the IJVs and EJVs above the heart collapsed, and venous channels including the ACCs and ACVs opened, switching the main cerebral venous drainage from the IJVs to the vertebral venous system. Upright head CT angiography can be useful for investigating physiological and pathophysiological hemodynamics of the venous system accompanying postural changes.

Cardiovascular Response to Posture Changes: Multiscale Modeling and in vivo Validation During Head-Up Tilt

“…Due to the low compliances of arteriolar, venular and capillary compartments, intracranial pressure was introduced only within cerebral veins, as illustrated in Figure 1 . This led to the maintenance of cerebral veins transmural pressure at negligible levels even at elevated tilt angles, agreeing with findings regarding the non-collapsibility of such vessels (Leggett and Williams, 1991 ; Hall and Hall, 2020 ; Kosugi et al, 2020 ), together with their non-deformable status enabled by the cranial box structure.…”

“…Almost no such pressure drop is registered at abdominal level ( Figure 7B ), since abdominal venous compartments have no dominant vertical dimension. Head veins ( Figure 7A ) experience negative intraluminal pressure after reaching 70° HUT, because of their position above the heart, although their tone does not vary significantly thanks to the peculiar extravascular condition (Blomqvist and Stone, 2011 ; Leggett and Williams, 1991 ; Holmlund et al, 2018 ; Hall and Hall, 2020 ; Kosugi et al, 2020 ).…”

Cerebral blood flow, cerebrovascular reactivity and their influence on ventilatory sensitivity

“…It should also be noted that in the supine position bilateral internal jugular veins collect most if not all cerebral drainage but this is almost completely abolished when upright (Manuel Valdueza et al., 2000; Kosugi et al., 2020) and that the jugular drainage is asymmetrical, often with pronounced right side dominance (Kosugi et al., 2020; Lichtenstein et al., 2001; Tartière et al., 2009) with intra‐individual variation in brain tissue region drainage and possibly also including extracranial anastomoses (Ferris et al., 1946; Gibbs et al., 1945; Himwich et al., 1947). These are both important experimental considerations which should be accounted for, for instance in studies assessing cerebral parameters indexed against jugular venous washout during postural changes.…”

Anticoagulation in the Treatment of Pulsatile Tinnitus Caused by Internal Jugular Vein Stenosis: A Rare Case Report

“…In addition, gravity affects cerebral venous system output. Studies indicate jugular vein collapse in an upright position, with cerebral venous drainage occurring through the vertebral venous system instead [7]. In this case, we report left jugular vein occlusion presenting as pulsatile tinnitus in the supine position.…”