Simulation of Capillary Hemodynamics and Comparison with Experimental Results of Microphantom Perfusion Weighted Imaging

J Biomed Phys Eng. 2020 Jun 1;10(3):291-298. doi: 10.31661/jbpe.v0i0.910. eCollection 2020 Jun.

Abstract

Background: Perfusion imaging, one of MRI's techniques, is widely used to test damaged tissues of the body. The parameters used in this technique include cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). The MRI scanner contains a device called a "phantom", which controls the accuracy of various imaging models.

Objective: Our goal is to design and produce a microphantom to control the perfusion-imaging model in MRI scanners.

Material and methods: Firstly, in an analytical study type, we designed the phantom based on Murray's minimum work rule using AutoCAD software. Next, the phantom was fabricated using lithography and then imaged using a Siemens Magnetom 3T Prisma MRI scanner at the National Brain Laboratory. Finally, the velocity and pressure in the capillary network was simulated using COMSOL software.

Results: CBF, CBV, and MTT curves for the capillary network were obtained at different times. In addition, the simulations showed that the velocity and pressure in the capillary network were between 0.0001 and 0.0005 m/s and between 5 and 25 mm/Hg, respectively.

Conclusion: The fabricated microphantom was used to simulate the movement of blood within tissues of the body. Different parameters of perfusion imaging were measured inside the phantom, and they in the phantom were similar to in the body.

Keywords: Capillary Hemodynamics; Cerebral Blood Volume; Contrast Media; Perfusion Imaging; Phantoms, Imaging.