Estimation of the Number of Pores and Capillary Wall Thickness using Diffusion and Perfusion MRI

In theory, diffusion and perfusion information in MRI maps can be combined to yield morphological information such as mean radius, volume and possibly capillary plasma velocity. This manuscript suggests a new model, pseudo-liquid drop model, along with appropriate quantitative physiological purposes for determination of capillary wall thickness and the number of pores in normal regions using diffusion and perfusion MRI. This model has been used as an essential way in transportation of blood from inner to outer parts of the capillary. In order to calculate these quantities, it has been utilized from cerebral blood volume (CBV), apparent diffusion coefficient (ADC), and values. To verify the proposed theory, aspecial protocol was designed and tested on normal regions of a male Wistar rat using obtained functions. Capillary wall thickness and the number of pores in the normal regions were calculated to be 0.492 micron and 72540 on the capillary with the length of 234 microns, respectively. The size of the pores is suggested to be 8 nanometers. Finally, mean radius of capillary will increase with increasing the number of openings on the capillary wall.

Keywords:

Capillary , Radius , Thickness , Pores , MRI