@article {Turk111, author = {A.S. Turk and K.M. Johnson and D. Lum and D. Niemann and B. Aagaard-Kienitz and D. Consigny and J. Grinde and P. Turski and V. Haughton and C. Mistretta}, title = {Physiologic and Anatomic Assessment of a Canine Carotid Artery Stenosis Model Utilizing Phase Contrast with Vastly Undersampled Isotropic Projection Imaging}, volume = {28}, number = {1}, pages = {111--115}, year = {2007}, publisher = {American Journal of Neuroradiology}, abstract = {BACKGROUND AND PURPOSE: Noninvasive assessment of the hemodynamic significance of carotid stenosis is often performed with MR angiography and supplemented with carotid Doppler sonography. Phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR), a novel MR imaging technique, accelerates phase-contrast MR flow imaging and provides both images of the vessels and measurements of blood-flow velocities. For this study, we determined the accuracy of PC-VIPR blood-flow velocity measurements to determine pressure gradients across an experimental carotid stenosis.MATERIALS AND METHODS: A focal stenosis was surgically created in each common carotid artery of 6 canines. Digital subtraction angiography (DSA) was performed, and the degree of stenosis was determined using the North American Symptomatic Carotid Endarterectomy Trial methodology. A microcatheter was positioned in the carotid artery proximal and distal to the stenosis, and pressures were measured in the vessel through the catheter. PC-VIPR was then performed on a 1.5T MR imaging scanner with parameters producing 0.8-mm isotropic voxel resolution. From the velocity measurements, pressure gradients were calculated from the Navier-Stokes relationship to compare with the pressures measured by a catheter.RESULTS: Carotid stenoses in the 50\%{\textendash}85\% range were produced in the 12 arteries. Pressure gradients across the stenoses ranged from 6 to 26 mm Hg. The pressure gradient calculated from the PC-VIPR data correlated (r = 0.91, P \< .0001) with the actual pressure measurements.CONCLUSION: With PC-VIPR, a novel MR imaging technique, the hemodynamic effect of a stenosis on flow and pressure can be evaluated.}, issn = {0195-6108}, URL = {https://www.ajnr.org/content/28/1/111}, eprint = {https://www.ajnr.org/content/28/1/111.full.pdf}, journal = {American Journal of Neuroradiology} }