title: Long-term visibility of primary intracerebral hemorrhage on magnetic resonance imaging.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Department of Clinical Neurosciences, Western General Hospital, Edinburgh, United Kingdom.
authors: Marion
authors: M
authors: Dimigen
authors: Sarah
authors: S
authors: Keir
authors: Martin
authors: M
authors: Dennis
authors: Joanna
authors: J
authors: Wardlaw