High-resolution MRI to noninvasively characterize drainage around the carotid artery into the cervical lymph nodes

Zafer Keser; Garrett Smith; Emin Cagil; Fatih Tufan; Onder Albayram; Mehmet Sait Albayram

doi:10.1111/jon.13056

High-resolution MRI to noninvasively characterize drainage around the carotid artery into the cervical lymph nodes

J Neuroimaging. 2023 Jan;33(1):102-108. doi: 10.1111/jon.13056. Epub 2022 Oct 2.

Authors

Zafer Keser¹, Garrett Smith², Emin Cagil³, Fatih Tufan⁴, Onder Albayram^{5

6}, Mehmet Sait Albayram²

Affiliations

¹ Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
² Department of Radiology, College of Medicine, University of Florida, Gainesville, Florida, USA.
³ Department of Neurosurgery, Ankara Numune Training and Research Hospital, Ankara, Turkey.
⁴ Geriatrician (PP), Silivrikapi Mh. Hisaralti Cd, Istanbul, Turkey.
⁵ Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.
⁶ Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA.

PMID: 36184887
DOI: 10.1111/jon.13056

Abstract

Background and purpose: Previous studies have proposed multiple parallel channels for waste clearance from the brain, though many gaps remain in our understanding of these systems. In this study, we examined periarterial fluid drainage around intracranial and extracranial segments of the internal carotid arteries (ICAs) from the brain into the cervical lymph nodes using a noninvasive and clinical-based method.

Methods: Eighty-one subjects (45 females, aged 15-80 years old) with nonlesioned epilepsy underwent high-resolution 3-dimensional T2-weighted fluid-attenuated inversion recovery (FLAIR) MRI. We utilized a noninvasive and clinical-based method with a manual semiautomated approach to characterize the periarterial lymphatic system's maximum thickness and signal intensities along the ICAs using high-resolution 3-dimensional FLAIR imaging. We conducted group comparisons and correlation analyses to investigate sex- and age-based trends. Results were corrected with Bonferroni's test for multiple comparisons, and we performed power analysis for sample size calculations.

Results: Using high-resolution FLAIR images, we show evidence that fluid drainage emerges around the ICA petrous segment and joins lymphatic flow from cranial nerves in the upper neck, with this flow ultimately draining into the cervical lymph nodes bilaterally. Lymphatic signal at the petrous segment level was significantly thinner in females compared to males bilaterally (w = 413, p = .0001 on the right, w = 356, p < .0001 on the left). Lymphatic drainage around the petrous segments of the ICAs bilaterally was thicker with age in males but not in females.

Conclusions: We describe the in vivo high-resolution imaging characteristics of periarterial fluid drainage along the vessel walls of ICAs. This represents a potentially major channel for brain waste clearance. We also report interesting sex- and age-based trends in these structures within our cohort.

Keywords: brain; glymphatics; lymphatics; periarterial drainage.

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Brain
Carotid Artery, Common
Female
Humans
Lymph Nodes*
Magnetic Resonance Imaging* / methods
Male
Middle Aged
Young Adult