Quantification of vessel wall cyclic strain using cine phase contrast magnetic resonance imaging.

In vivo quantification of vessel wall cyclic strain has important applications in physiology and disease research and the design of intravascular devices. We describe a method to calculate vessel wall strain from cine PC-MRI velocity data. Forward-backward time integration is used to calculate displacement fields from the velocities, and cyclic Green-Lagrange strain is computed in segments defined by the displacements.

Measurement of vessel wall strain using cine phase contrast MRI.

Purpose: To determine the feasibility of using magnetic resonance imaging (MRI) to non-invasively measure strain in the aortic wall.

Materials And Methods: Cine phase contrast MRI was used to measure the velocity of the aortic wall and calculate changes in circumferential strain over the cardiac cycle. A deformable vessel phantom was used for initial testing and in vitro validation.

Noninvasive measurement of extraction fraction and single-kidney glomerular filtration rate with MR imaging in swine with surgically created renal arterial stenoses.

Purpose: To test whether magnetic resonance (MR) imaging enables accurate measurement of extraction fraction (EF) in swine with unilateral renal ischemia and to evaluate effects of renal arterial stenosis on EF and single-kidney glomerular filtration rate.

Materials And Methods: High-grade unilateral renal arterial stenoses were surgically created in eight pigs. Direct measurements of renal venous and arterial inulin concentration provided reference standard estimates of single-kidney EF.