Physikalische Grundlagen bei 3Tesla

Basic Physical Effects: T1 relaxation times are increased and converge. T2/T2* relaxation times are reduced. The Signal-to-noise ratio (SNR) is increased. The specific absorption rate (SAR) is increased. RF focusing effects lead to inhomogeneous RF fields. The static field (B0) is inhomogeneous near air/tissue interfaces. Effects on Neuroimaging Techniques: General: The theoretical linear SNR increase is compromised by longer T1 and shorter T2/T2* values. Due to increased SAR, implants that are safe at 1.5 Tesla may constitute a risk at higher B0. Angiography: Time-of-flight (TOF) methods are based on magnetic l…