Magnetic Resonance (MR) is a well known diagnostic technique today widely used especially for cardiac and neurological applications. MR has an excellent spatial resolution and a good temporal resolution and it allows obtaining high quality clinical images often essential to diagnosis or monitoring of several diseases. Moreover, MR is considered a safe technology since it has just the ability to change the position of atoms, but not to alter their structure, composition, and properties, as the ionizing radiations do attempts. In fact, the electromagnetic radiations involved in a MR procedure (see Fig. 1) have no enough energy to detach electrons from atoms or molecules, such as other higher energetic radiations can do (X-rays, radiations used in nuclear medicine etc). However, as in any sanitary interventions, even in a MR diagnostic procedure there are intrinsic hazards that must be understood, acknowledged and taken into consideration: for this reason, the analysis of the interaction between the magnetic fields and the biological tissues underwent to a MR procedure, is essential. These interactions are caused from different physical phenomena which, on the hand, are responsible to the signal generation that contribute to the final image but, on the other hand, can cause dangerous biological effects for the patient or signal artefacts. The study of these interactions has been become more important in the last years due to the growing interest for high static magnetic field MR scanners which assure a higher signal to noise ratio (SNR), and hence a better quality for the final images, but imply heavier risks for patients and occupational workers. Although the radiation used is not ionizing, there are several effects to consider for safety assurance and engineering aspects relative to MR signal and image generation. The knowledge of these phenomena is important not only for the design of transmission/reception coils and acquisition sequences but also for the choice of acquisition parameters for each diagnostic exam.
Risk of the Magnetic Resonance: the safety - biological effects". In "Magnetic Resonance Imaging Handbook-Image Principles, Neck, and the Brain
Valentina Hartwig
2016
Abstract
Magnetic Resonance (MR) is a well known diagnostic technique today widely used especially for cardiac and neurological applications. MR has an excellent spatial resolution and a good temporal resolution and it allows obtaining high quality clinical images often essential to diagnosis or monitoring of several diseases. Moreover, MR is considered a safe technology since it has just the ability to change the position of atoms, but not to alter their structure, composition, and properties, as the ionizing radiations do attempts. In fact, the electromagnetic radiations involved in a MR procedure (see Fig. 1) have no enough energy to detach electrons from atoms or molecules, such as other higher energetic radiations can do (X-rays, radiations used in nuclear medicine etc). However, as in any sanitary interventions, even in a MR diagnostic procedure there are intrinsic hazards that must be understood, acknowledged and taken into consideration: for this reason, the analysis of the interaction between the magnetic fields and the biological tissues underwent to a MR procedure, is essential. These interactions are caused from different physical phenomena which, on the hand, are responsible to the signal generation that contribute to the final image but, on the other hand, can cause dangerous biological effects for the patient or signal artefacts. The study of these interactions has been become more important in the last years due to the growing interest for high static magnetic field MR scanners which assure a higher signal to noise ratio (SNR), and hence a better quality for the final images, but imply heavier risks for patients and occupational workers. Although the radiation used is not ionizing, there are several effects to consider for safety assurance and engineering aspects relative to MR signal and image generation. The knowledge of these phenomena is important not only for the design of transmission/reception coils and acquisition sequences but also for the choice of acquisition parameters for each diagnostic exam.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
