Long-term visibility of primary intracerebral hemorrhage on magnetic resonance imaging

Background: It is unclear whether primary intracerebral hemorrhage (PICH) remains detectable with magnetic resonance imaging (MRI) in the long term, or whether a gradient echo recalled (GRE) sequence is always necessary to detect it. Methods: In a prospectively collected cohort of patients with stroke, we identified survivors of PICH able to undergo MRI at least 3 months after the original PICH. We compared several MRI sequences (spin echo (SE) T2, fast SE (FSE) T2 and proton density, fluid-attenuated inversion recovery, GRE) in a blinded fashion. The number of PICHs visible on each MRI sequence, and the presence of infarcts and microhemorrhages, were determined. Results: In 26 patients imaged 3 years (median) after PICH, between 61% (fluid-attenuated inversion recovery) and 100% (GRE) of PICHs remained identifiable as definite PICH. On FSE T2, 3.4% of PICHs were missed. There were no specific patient features that determined which PICHs remained visible. A new PICH developed in 29% of patients between original presentation and the current study, and 38% had microhemorrhages. Conclusion: Although a FSE T2 sequence will identify most old PICHs, a GRE sequence is essential for definite identification. Recurrent PICH and microhemorrhages appear to be common.