This International Standard specifies the description of PULSE SEQUENCES of MAGNETIC RESONANCE imaging. NOTE The classification in this standard is suitable for: – tender texts; – image annotation; – protocol definition; – technical publications. This International Standard does not apply to MAGNETIC RESONANCE spectroscopy. The classification does not focus on image contrast (T1, T2, proton density), as this is defined by PULSE SEQUENCE parameters (e.g. repetition time, echo time) and is not a property of the PULSE SEQUENCE alone. The PULSE SEQUENCE classification does not specify the K-SPACE acquisition scheme, reconstruction algorithm or post-processing.