Marco Francone MD, Presenter: Nothing to Disclose

Iacopo Carbone MD, Abstract Co-Author: Nothing to Disclose

Katia Lanciotti MD, Abstract Co-Author: Nothing to Disclose

Francesca Antonella Calabrese, Abstract Co-Author: Nothing to Disclose

Carlo Catalano MD, Abstract Co-Author: Nothing to Disclose

Roberto Passariello MD, Abstract Co-Author: Nothing to Disclose

Previous studies have shown that ME typically appears in the acute phase of MI after reperfusion and gradually resolves with infarct healing. The underlying patho-physiological mechanism leading to accumulation of water within the necrotic regions is related with the presence of osmotically active substances which enter infarcted regions trough collateral vessels. This suggests that if reperfusion is adequately performed, ME is further intensified and might overestimate real extension of necrosis. In the present study, we meant to investigate the feasibility of T2-weighted CMR to discriminate acute from chronic MIs and to correlate extension of ME with DE findings.

Forty-one patients with a previous history of MI were included in the study; 19 were studied in the acute phase ( 30days). In all patients a CMR protocol including T2-weighted black-blood and DE sequences was acquired using a 1.5-T CMR-system. According to the different DE patterns, infarcts were classified as reperfused (R), partially reperfused (p-R) and non-reperfused (non-R) In order to discriminate acute from chronic MIs, the presence of ME and DE was visually assessed by two blinded observers. When detected, the volume of edematous myocardium was correlated with extension and pattern of necrosis as shown by DE acquisitions.

After images analysis, ME was detected as a transmural area of hyperintense T2-weighted signal in 19/19 patients with acute MI and 3/22 chronic patients. The combined assessment of T2-weighted and DE images yielded a specificity of 91% to differentiate acute from chronic lesions. In R (n=11) and p-R (n=6) MIs, the volume of ME was significantly larger than necrosis in all cases (+18.6% p<0.05 and + 16.9% p<0.05) and a good correlation was found between edema and extension of MI (r =0.86 p<0.01). In non-R MIs (n=5), differences between edematous and infarcted myocardium was not statistically significant (+ 5.7% p=0.073).

Our study suggests that a combined approach of T2-weighted and DE CMR-sequences enables to differentiate acute from chronic MIs; extension of ME seems to be correlated with status of reperfusion.

Francone, M, Carbone, I, Lanciotti, K, Calabrese, F, Catalano, C, Passariello, R, Value of Myocardial Edema (ME) to Differentiate between Acute and Chronic Myocardial Infarctions (MIs) and Its Correlation with Different Patterns and Extension of Necrosis: A T2-weighted and Delayed Enhancement (DE) Cardiovascular-MR (CMR) Study.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4417569.html