Simultaneous determination of exchange rate and concentration of paramagnetic contrast agent in magnetic resonance imaging using electromagnetic pulse width

Document Type : Research Paper


Biomedical Engineering Department, Hamedan University of Technology, Hamedan, Iran


Imaging of the chemical exchange phenomenon by magnetic resonance method using saturation transfer process has made it possible to non-invasively diagnose some diseases through image processing knowledge. Imaging pulses consisting of a rectangular electromagnetic saturating pulse with two adjustable parameters of amplitude and width are commonly used. Saturation transfer depends on parameters such as rest times, chemical exchange rate, contrast agent concentration, and saturation pulse properties. Among these, the exchange rate and concentration of the contrast agent are much more effective due to their dependence on some clinical indicators such as pH, temperature and glucose consumption, so studies have been performed to measure them. The title asymmetric magnetization transfer is quantified in accordance with paramagnetic factors in an analytical method using parametric data derived from body tissue and data from experimental experiments. The accuracy of the objective function is evaluated by measuring the relative error resulting from the square of the difference between the squares of the denoised data taken from the objective function and the actual data (approximately 2%). Using the optimal pulse width in the form of a closed relation and the maximum objective function, the exchange rate and the concentration of the contrast agent are determined simultaneously.