Fluid-attenuated inversion recovery (FLAIR) is an inversion-recovery pulse sequence used to nullify the signal from fluids. For example, it can be used in brain imaging to suppress cerebrospinal fluid so as to bring out periventricular hyperintense lesions, such as multiple sclerosis plaques. By carefully choosing the inversion time TI (the time between the inversion and excitation pulses), the signal from any particular tissue can be suppressed.