Magnetic resonance images are obtained by a combination of different radiofrequency pulses and gradient waveforms applied to the subject inside a magnetic field. There are multiple pulse sequences used in clinical and preclinical studies adjusted to whatever physician or researches want to analyze, from basic anatomic images to accurate diagnostic techniques as diffusion, perfusion, or functional imaging. In this chapter, we present the most used radiofrequency pulse combinations of the two groups of sequences available in magnetic resonance imaging: spin-echo and gradient-echo sequences.
Keywords: Gradient echo; Magnetic resonance imaging; Pulse sequences; Spin echo.