introduction:  image  distortion  is  one  of  the  major  problems  of  magnetic  resonance  imaging  (mri) for use in 3dmri, velocity mri, fmri and radiotherapy treatment planning (rttp). it is  widely known that the most obvious effect of the inhomogenity of the magnetic fields and the  nonlinearity  of  the  gradient  is  the  geometric  distortion  of  mr  tomograms.  in  this  study,  the...

introduction: one of the major causes of image non-uniformity in mri is due to the existence of  non-homogeneity in rf receive and transmit. this can be the most effective source of error in  quantitative  studies  in  mri  imaging.  part  of  this  non-homogeneity  demonstrates  the  characteristics of rf coil and part of it is due to the interaction of rf field with the material being  imaged...

recent advances in nanotechnology have rapidly developed new therapeutic and diagnostic concepts in all aspects of medicine. magnetic nanoparticles (mnps) can be simultaneously functionalized and guided by a magnetic field, thus providing promising tools for several biomedical applications. mnps contrast agents at low concentrations offer the potential to significantly improve existing methods o...

MRI is one of the most powerful techniques to study the internal structure of the body. MRI image quality is affected by various noises. Noises in MRI are usually thermal and mainly due to the motion of charged particles in the coil. Noise in MRI images also cause a limitation in the study of visual images as well as computer analysis of the images. In this paper, first, it is proved that proba...

Background Transfusion-induced iron overload leads to many complications in patients with β-thalassemia major. This study aimed to compare the level of iron stored in the liver and heart measured by MRI T2 * with ferritin levels in these patients. Materials and Methods This study was done on 52 patients with β-thalassemia major aged 7 to 29 years. Serum ferritin level was checked and heart and ...

Background: Polymer gel dosimeters combined with magnetic resonance imaging (MRI) can be used for dose verification of advanced radiation therapy techniques. However, the uncertainty of dose map measured by gel dosimeter should be known. The purpose of this study is to investigate the uncertainty related to calibration curve and MRI protocol for MAGIC (Methacrylic and Ascorbic acid in Gelatin I...