Opriessnig P, Mangge H, Stollberger R, Deutschmann H, Reishofer G. In vivo cardiovascular magnetic resonance of 2D vessel wall diffusion anisotropy in carotid arteries.
J Cardiovasc Magn Reson 2016;
18:81. [PMID:
27876066 PMCID:
PMC5120527 DOI:
10.1186/s12968-016-0304-8]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/02/2016] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND
Diffusion weighted (DW) cardiovascular magnetic resonance (CMR) has shown great potential to discriminate between healthy and diseased vessel tissue by evaluating the apparent diffusion coefficient (ADC) along the arterial axis. Recently, ex vivo studies on porcine arteries utilizing diffusion tensor imaging (DTI) revealed a circumferential fiber orientation rather than an organization in axial direction, suggesting dominant diffusion perpendicular to the slice direction. In the present study, we propose a method to access tangential and radial diffusion of carotids in vivo by utilizing a pulse sequence that enables high resolution DW imaging in combination with a two-dimensional (2D) diffusion gradient direction sampling scheme perpendicular to the longitudinal axis of the artery.
METHODS
High resolution DTI of 12 healthy male volunteers (age: 25-60 years) was performed on one selected axial slice using a read-out segmented EPI (rs-EPI) sequence on a 3T MR scanner.
RESULTS
It was found consistently for all 12 volunteers, that the tangential component as the principle direction of diffusion. Mean vessel wall fractional anisotropy (FA) values ranged from 0.7 for the youngest to 0.56 for the oldest participant. Linear regression analysis between the FA values and volunteers age revealed a highly significant (P < 0.01) linear relationship with an adjusted R2 of 0.52. In addition, a linear trend (P < 0.1) could be observed between radial diffusivity (RD) and age.
CONCLUSION
These results point to FA being a sensitive parameter able to capture changes in the vascular architecture with age. In detail, the data demonstrate a decrease in FA with advancing age indicating possible alterations of tissue microstructural integrity. Moreover, analyzing 2D diffusion tensor directions is sufficient and applicable in a clinical setup concerning the overall scan time.
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