Cardiovascular magnetic resonance ofacute myocardial infarction at a very early stage

Abstract

Contrast-enhanced magnetic resonance imaging detected infarct-related signal changes as early as 1 h after AMI in humans, whereas the sensitivity of edema-related signal changes was not sufficient during this very early stage.

Detecting Acute Myocardial Infarction by Diffusion-Weighted versus T2-Weighted Imaging and Myocardial Necrosis Markers

“…16 According to Nilsson and co-authors, 21 myocardial edema was greatest one week after the infarction and then gradually declined. Jeanette and associates 20 reported no relevant intramyocardial SI changes in T2WI within 1 hr after therapeutic septal artery embolization. These authors also found that no significant edema was detectable 7 hr after the intervention.…”

“…According to strong evidence, myocardial edema is predominantly intracellular early in the course of ischemic injury, and T2WI might be unable to detect bound water molecules in the case of intracellular edema. 20 The long T2 relaxation time of protons bound in free water indicates regional myocardial edema and is the primary cause of changes in T2WI signal intensity. 16 According to Nilsson and co-authors, 21 myocardial edema was greatest one week after the infarction and then gradually declined.…”

The role of non-invasive imaging in patients with suspected acute coronary syndrome

“…In studies performed following septal ablation for hypertrophic cardiomyopathy, LGE has been shown to demonstrate myocardial injury as early as 1 h after injury following the procedure [38]. There is evidence to suggest that LGE is useful in differentiating acute ischaemia from chronic irreversible myocardial injury and influencing further management of patients with ACS [39].…”

“…This myocardial oedema is a transient phenomenon and usually resolves at between 3 and 12 weeks. T 2 weighted imaging may help to visualise infract-related oedema without the use of contrast agent [38]. Since myocardial oedema occurs before irreversible damage, a single study using T 2 weighted imaging could be used to assess the area at risk and the eventual infarction size.…”

Myocardial Salvage

“…13,17 Also consistent with these interpretations is the reduction in T2 seen with successful treatment of myocardial edema with mannitol. 18 The increase in T2 observed with edema takes a minimum of 1 hour to be manifest in humans, 19 can be identified in dogs within 4 hours, 20 and only completely resolves some months later. 15 One question that has been raised regarding MI imaging by late-gadolinium-enhancement CMR is whether in the acute setting the gadolinium enhancement is confined to the necrotic area or whether extension occurs into the border zone of myocardial edema without necrosis, which might have increased interstitial space that could harbor gadolinium.…”