Correction and optimization of a T2-based approach to map blood oxygenation in small cerebral veins

Document Type

Article

Abstract

PURPOSE: Cerebral venous blood oxygenation (Yv ) is an important biomarker in brain physiology and function. The present study proposes a procedure to provide a quantitative map of the brain's intravascular Yv. THEORY AND METHODS: The method is based on a pulse sequence, T2 -Relaxation-Under-Phase-Contrast (TRU-PC) MRI, with postprocessing approaches to correct eddy-current effects. A complete scan protocol consists of four TRU-PC scans sensitized to large and small vessels with anterior-posterior and foot-head flow-encoding directions, and the data are analyzed conjunctively. Eddy-current correction was performed by fitting the tissue phase to a hyperplane, and then subtracting the eddy-current phase from the measured vessel phase. The reproducibility of the Yv-maps was examined in five participants. Sensitivity of the Yv map to a caffeine challenge was studied in another five participants. RESULTS: Removal of eddy-current induced artifact allowed for the correction of T2 measurements, as demonstrated in vivo and with simulation. A Yv-map depicting all vessels in the slice can be obtained with the proposed protocol. Test-retest variability of the Yv -map was 3.7 ± 1.2%. Yv reduction can be reliably detected (P < 0.001) following the caffeine ingestion. CONCLUSION: With the proposed TRU-PC protocol and eddy-current correction procedure, an accurate, vessel-specific Yv map of the human brain can be obtained.

Medical Subject Headings

Adult; Algorithms; Brain (blood supply); Cerebral Veins (physiology); Cerebrovascular Circulation (physiology); Female; Humans; Image Processing, Computer-Assisted (methods); Magnetic Resonance Imaging (methods); Male; Oxygen (blood, metabolism); Young Adult

Publication Date

3-1-2016

Publication Title

Magnetic resonance in medicine

E-ISSN

1522-2594

Volume

75

Issue

3

First Page

1100

Last Page

9

PubMed ID

25846113

Digital Object Identifier (DOI)

10.1002/mrm.25686

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