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Mapping of arterial transit time by intravascular signal selection
Author(s) -
Mildner Toralf,
Müller Karsten,
Hetzer Stefan,
Trampel Robert,
Driesel Wolfgang,
Möller Harald E.
Publication year - 2014
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.3098
Subject(s) - circle of willis , human brain , carotid bifurcation , signal (programming language) , transit time , sensitivity (control systems) , arterial spin labeling , amplitude , perfusion , biomedical engineering , nuclear magnetic resonance , computer science , physics , anatomy , cardiology , medicine , biology , neuroscience , carotid arteries , optics , electronic engineering , transport engineering , engineering , programming language
The arterial transit time ( δ a ) is a potentially important physiological parameter which may provide valuable information for the characterization of cerebrovascular diseases. The present study shows that δ a can be measured by arterial spin labeling (ASL) applied quasi‐continuously in an amplitude‐modulated fashion at the human neck. Imaging was performed using short repetition times and excitation flip angles of 90°, which resulted in the selection of an ASL signal of mostly intravascular origin. Model‐independent estimates of δ a were obtained directly from the temporal shift of the ASL time series. An extended two‐compartment perfusion model was developed in order to simulate the basic features of the proposed method and to validate the evaluation procedure. Vascular structures found in human δ a maps, such as the circle of Willis or cerebral border zones, hint at the sensitivity of the method to most sizes of arterial vessels. Group‐averaged values of δ a measured from the carotid bifurcation to the tissue of interest in selected regions of the human brain ranged from 925 ms in the insular cortex to 2000 ms in the thalamic region. Copyright © 2014 John Wiley & Sons, Ltd.