TY - JOUR
T1 - Non-invasive estimation of relative pressure in turbulent flow using virtual work-energy
AU - Marlevi, David
AU - Ha, Hojin
AU - Dillon-Murphy, Desmond
AU - Fernandes, Joao F.
AU - Fovargue, Daniel
AU - Colarieti-Tosti, Massimiliano
AU - Larsson, Matilda
AU - Lamata, Pablo
AU - Figueroa, C. Alberto
AU - Ebbers, Tino
AU - Nordsletten, David A.
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Vascular pressure differences are established risk markers for a number of cardiovascular diseases. Relative pressures are, however, often driven by turbulence-induced flow fluctuations, where conventional non-invasive methods may yield inaccurate results. Recently, we proposed a novel method for non-turbulent flows, νWERP, utilizing the concept of virtual work-energy to accurately probe relative pressure through complex branching vasculature. Here, we present an extension of this approach for turbulent flows: νWERP-t. We present a theoretical method derivation based on flow covariance, quantifying the impact of flow fluctuations on relative pressure. νWERP-t is tested on a set of in-vitro stenotic flow phantoms with data acquired by 4D flow MRI with six-directional flow encoding, as well as on a patient-specific in-silico model of an acute aortic dissection. Over all tests νWERP-t shows improved accuracy over alternative energy-based approaches, with excellent recovery of estimated relative pressures. In particular, the use of a guaranteed divergence-free virtual field improves accuracy in cases where turbulent flows skew the apparent divergence of the acquired field. With the original νWERP allowing for assessment of relative pressure into previously inaccessible vasculatures, the extended νWERP-t further enlarges the method's clinical scope, underlining its potential as a novel tool for assessing relative pressure in-vivo.
AB - Vascular pressure differences are established risk markers for a number of cardiovascular diseases. Relative pressures are, however, often driven by turbulence-induced flow fluctuations, where conventional non-invasive methods may yield inaccurate results. Recently, we proposed a novel method for non-turbulent flows, νWERP, utilizing the concept of virtual work-energy to accurately probe relative pressure through complex branching vasculature. Here, we present an extension of this approach for turbulent flows: νWERP-t. We present a theoretical method derivation based on flow covariance, quantifying the impact of flow fluctuations on relative pressure. νWERP-t is tested on a set of in-vitro stenotic flow phantoms with data acquired by 4D flow MRI with six-directional flow encoding, as well as on a patient-specific in-silico model of an acute aortic dissection. Over all tests νWERP-t shows improved accuracy over alternative energy-based approaches, with excellent recovery of estimated relative pressures. In particular, the use of a guaranteed divergence-free virtual field improves accuracy in cases where turbulent flows skew the apparent divergence of the acquired field. With the original νWERP allowing for assessment of relative pressure into previously inaccessible vasculatures, the extended νWERP-t further enlarges the method's clinical scope, underlining its potential as a novel tool for assessing relative pressure in-vivo.
KW - 4D flow MRI
KW - Fluid mechanics
KW - Relative pressure
KW - Turbulence
KW - Turbulent energy dissipation
KW - Virtual work-energy
U2 - 10.1016/j.media.2019.101627
DO - 10.1016/j.media.2019.101627
M3 - Article
AN - SCOPUS:85076673140
SN - 1361-8415
VL - 60
JO - Medical Image Analysis
JF - Medical Image Analysis
M1 - 101627
ER -
