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Dual echo vessel‐encoded ASL for simultaneous BOLD and CBF reactivity assessment in patients with ischemic cerebrovascular disease
Author(s) -
Faraco Carlos C.,
Strother Megan K.,
Dethrage Lindsey M.,
Jordan Lori,
Singer Robert,
Clemmons Paul F.,
Donahue Manus J.
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25268
Subject(s) - echo (communications protocol) , medicine , cardiology , magnetic resonance imaging , disease , radiology , computer science , computer network
Purpose Blood oxygenation level‐dependent (BOLD)‐weighted and vessel‐encoded arterial spin labeling (VE‐ASL) MRI provide complementary information and can be used in sequence to gauge hemodynamic contributions to cerebrovascular reactivity. Here, cerebrovascular reactivity is assessed using dual echo VE‐ASL MRI to understand how VE labeling preparations influence BOLD and ASL contrast in flow‐limited and healthy perfusion territories. Methods Patients ( n = 12; age = 55 +/– 14 years; 6F/6M) presenting with ischemic steno‐occlusive cerebrovascular disease underwent 3.0T angiographic imaging, T 1 ‐weighted structural, and planning‐free dual echo hypercarbic hyperoxic (i.e., carbogen) VE‐ASL MRI. Vasculopathy extent, timecourses, and cerebrovascular reactivity (signal change and Z‐statistic) for different VE‐ASL images were contrasted across flow territories and Bonferroni‐corrected P ‐values reported. Results BOLD cerebrovascular reactivity (i.e., long‐TE VE‐ASL) Z‐statistics were similarly sensitive to asymmetric disease ( P ≤ 0.002) regardless of labeling scenario. Cerebral blood flow reactivity correlated significantly with BOLD reactivity (Z‐statistic). However, BOLD signal changes did not differ significantly between labeling scenarios ( P > 0.003) or across territories ( P > 0.002), indicating BOLD signal changes in response to carbogen offer low sensitivity to lateralizing disease. Conclusion Dual echo VE‐ASL can provide simultaneous cerebral blood flow and qualitative BOLD contrast consistent with lateralizing disease severity in patients with asymmetric steno‐occlusive disease. The methodological strengths and limitations of composite BOLD and VE‐ASL measurements in the clinic are discussed. Magn Reson Med 73:1579–1592, 2015. © 2014 Wiley Periodicals, Inc.