title: Reperfusion hemorrhage following acute myocardial infarction: assessment with T2* mapping and effect on measuring the area at risk.
abstract: Research ethics committee approval and informed consent were obtained. The purpose of this study was to assess the feasibility of multiecho T2* mapping of the heart for detecting reperfusion hemorrhage following percutaneous primary coronary intervention (PPCI) for acute myocardial infarction, and to measure the effect of hemorrhage on quantifying the ischemic area at risk (IAR) on T2-weighted magnetic resonance images. Fifteen patients (mean age, 59 years; 13 men, two women) were imaged a mean of 3.2 days following PPCI. The mean area of hemorrhage, indicated by a T2* decay constant of less than 20 msec, was 5.0% +/- 4.9 (standard deviation) at the level of the infarct and this correlated with the infarct (r(2) = 0.76, P < .01) and microvascular obstruction (r(2) = 0.75, P < .01) volumes. When 5% or less hemorrhage was present, the IAR was underestimated by 50% at a standard deviation threshold level of five, compared with a boundary detection tool (21.8% vs 44.0%, P < .05). T2* mapping is feasible for quantifying post-reperfusion hemorrhage and boundary detection is required to accurately assess the IAR when hemorrhage is present.
authors.affiliation: Medical Research Council Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, England. declan.oregan@csc.mrc.ac.uk
authors.forename: Declan P
authors.initials: DP
authors.lastname: O'Regan
authors.forename: Rizwan
authors.initials: R
authors.lastname: Ahmed
authors.forename: Narayan
authors.initials: N
authors.lastname: Karunanithy
authors.forename: Clare
authors.initials: C
authors.lastname: Neuwirth
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Tan
authors.forename: Giuliana
authors.initials: G
authors.lastname: Durighel
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Hajnal
authors.forename: Imad
authors.initials: I
authors.lastname: Nadra
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Corbett
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Cook
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006470:Hemorrhage / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis*; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000209:etiology*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity