Synopsis

Keywords: Image acquisition: Sequences

In this lecture, we will delve into the fascinating world of MR pulse sequences and how to optimize them, either for speed or to achieve a desired contrast weighting. We will introduce the basic concept of an MR pulse sequence, what elements it consists of, and which parameters determine a pulse sequence. The basic pulse sequences: gradient echo and spin echo will be introduced, as well as more efficient sequences such as steady state approaches or fast spin echo. More complex sequences that create a complex transient state signal evolution like MR Fingerprinting will also be briefly discussed.

In this lecture, we will delve into the fascinating world of MR pulse sequences and how to optimize them ether for speed or to achieve a desired contrast weighting.
We will begin by introducing the basic concept of an MR pulse sequence, what elements it consists of and which parameters determine a pulse sequence.
The basic pulse sequences: spin echo and gradient echo will be introduced, explaining the formation of the MR signal and the various factors that influence signal intensity and image contrast in these sequences. We will briefly touch on spatial encoding, which will be explained in more detail later in the course. We will then explore more complex pulse sequences, that apply multiple RF pulses shortly after each other and how this affects the signal evolution. We will discuss various techniques for optimizing pulse sequences, such as adjusting parameters like flip angle, repetition time or adding gradients to manipulate the spin system.
At the end we will also discuss more complex sequences, like the ones used in MR Fingerprinting (MRF) that rely on transient state signal evolution to encode multiple tissue properties at once. Besides the more rigorous simulations used to estimate the signal evolution in MRF, the high degree of freedom of selecting the sequence parameters also poses a very challenging sequence optimization problem. Although this is still a largely unsolved problem, some approaches for sequence optimization for MRF will also be discussed.
By the end of the lecture, participants will have a good overview of the basic concepts of MR pulse sequences and the tools to optimize them.

Acknowledgements

No acknowledgement found.