EXPERIMENTAL STUDY OF FERROMAGNETIC OBJECTS HEATING DURING MAGNETIC RESONANCE IMAGING

• Main Authors: Y. A. Vasilev, M. Y. Marusina, D. S. Semenov, V. A. Yatseev, E. S. Akhmad, A. V. Petryaikin, Y. N. Vasileva
• Format: Article
• Language: English
• Published: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) 2019-05-01
• Series: Naučno-tehničeskij Vestnik Informacionnyh Tehnologij, Mehaniki i Optiki
• Subjects: magnetic resonance imaging; implants; ferromagnetic objects; heating; specific absorption coefficient
• Online Access: https://ntv.ifmo.ru/file/article/18423.pdf
• ISSN: 2226-1494; 2500-0373

Subject of study. Magnetic resonance imaging (MRI) is one of the most common and popular methods of medical imaging, based on the phenomenon of nuclear magnetic resonance. Despite the absence of ionizing radiation, there are some risk factors for the patient, one of which is the presence of metal structures in the patient's body. The thermal effect arising in the process of magnetic resonance study for patients with ferromagnetic objects is studied. Method. The study of metal objects surface heating was carried out using fiber optic sensors. A phantom was developed with the objects of different materials (steel, ferrite, brass, neodymium magnet) fixed on it. To obtain the maximum possible heating, the corresponding scanning conditions with the highest possible specific absorption coefficient were chosen. Main results. The results of materials heating measuring are presented. It is shown that the temperature of all objects increased in the range of 2.5 to 4.0 °C for total scan time of 90 minutes, while the temperature outside these objects did not change. In this case, heating exceeding the limit of 1 °C for 6 minutes was observed for none of the objects. Practical relevance. The study results can be applied in the development and identification of mathematical models of heat transfer within the framework of comprehensive patient safety in the MRI room. The study opens up the prospect of expanding indications in MRI studies for patients with metallic foreign bodies who need this type of diagnosis (without taking into account other risks: mechanical displacement and deterioration of visualization).