A microhemorrhage can be completely invisible on a standard T2 or FLAIR image and light up clearly on GRE or susceptibility weighted imaging.
So here is the uncomfortable truth. If a reader never opens those sequences, the bleed did not disappear. It was simply never looked for.
I have reviewed studies called clean where the answer was sitting on a series the first reader never pulled up. Same scan. Same patient. Different level of effort.
A thorough read is not about staring harder at one image. It is about honoring every sequence the magnet gave you.