In:
Acta Radiologica, SAGE Publications, Vol. 54, No. 4 ( 2013-05), p. 401-411
Abstract:
Perfusion magnetic resonance imaging (MRI) and delayed contrast-enhanced MRI (DE-MRI) serve as tools for tissue characterization. Purpose To assess and compare semi-quantitative parameters of myocardial infarct (MI) in the subacute and chronic phase, and to correlate these parameters with qualitative enhancement analysis. Material and Methods Perfusion MRI at rest and DE-MRI were performed in 63 patients with anterior wall MI at 2–3 weeks after revascularization and repeated after 6 months. Descriptive enhancement parameters of contrast arrival time, initial upslope, enhancement at normal tissue peak (TTP n ) and wash-out slope, and kinetic tissue parameters rBF, K trans , k ep and v e were calculated. Subacute infarct tissue was compared to normal myocardium and chronic infarct tissue. Patients were stratified at baseline according to a qualitative grading of hypoenhancement based on first-pass enhancement and presence of microvascular obstruction (MO) at perfusion MRI and on persistent MO at DE-MRI. The qualitative grade was correlated to semi-quantitative perfusion MRI parameters. Results Initial upslope, enhancement at TTPn, rBF, and k ep were decreased and wash-out slope and v e were increased in infarct tissue ( P 〈 0.001 for all analyses). Infarct tissue v e decreased from baseline to 6 months ( P = 0.045). At baseline infarct tissue with persistent MO revealed decreased K trans and delayed contrast arrival, and more pronounced decrease of enhancement at TTPn, rBF and k ep compared to other enhancement groups ( P 〈 0.008 for pairwise analyses). Conclusion Perfusion is decreased in subacute reperfused infarct tissue compared to normal tissue. K trans is not decreased, consistent with increased surface area of the vascular bed of the subacute infarct. Infarct tissue v e is increased, and decreases with scarring. The presence of persistent MO correlates to more pronounced perfusion reduction and results in delayed contrast arrival, indicating microvascular collateral circulation.
Type of Medium:
Online Resource
ISSN:
0284-1851
,
1600-0455
DOI:
10.1177/0284185113475605
Language:
English
Publisher:
SAGE Publications
Publication Date:
2013
detail.hit.zdb_id:
2024579-8
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