Vittorio Semeraro MD, Abstract Co-Author: Nothing to Disclose

Carmela Napolitano MD, Abstract Co-Author: Nothing to Disclose

Agostino Meduri MD, Abstract Co-Author: Nothing to Disclose

Riccardo Marano MD, Abstract Co-Author: Nothing to Disclose

Luigi Natale MD, Presenter: Nothing to Disclose

Lorenzo Bonomo MD, Abstract Co-Author: Nothing to Disclose

Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) is the gold standard for evaluation of infarct size (IS) and microvascular obstruction (MVO). Current guidelines recommend assessment of LGE as a percentage of wall thickness, scored in quintiles from 0-4. We aimed to compare this score to the quantitative computed volumetric assessment of IS for accuracy and reproducibility.

CMR studies (GE 1.5T) for clinical assessment of infarct size after acute myocardial infarction were retrospectively reviewed. IS and extent of MVO were scored as per guidelines by two separate, blinded independent viewers, and infarct size calculated as the sum of the score divided by maximum score in 16 segments. Infarct volume was separately and blindly calculated using threshold signal >2SD (ReportCard v4.04), and expressed in grams and %LV mass. A16-segment model was used as the quantitative planimetry short axis imaging does not measure the apical cap. Regression analysis was performed, and intra- and inter-observer variability calculated.

1344 myocardial segments were analyzed in 84 patients who underwent CMR with LGE. IS by semi-quantitatative and volumetric quantitation were highly correlated, with r-square 0.96. Reproducibility of semi-quantitative scoring was similar to that of volumetric analysis. MVO, present in 29 patients (35%) also showed good accuracy between both methods (r=0.83).

The semi-quantitative score accurately predicts infarct size and degree of MVO when compared to volumetric computed quantitative methods, with similar reproducibility. Infarct size score vs quantitatiation.

Semiquantitative scoring correlates with quantitative scoring, with similar reproducibility, and is appropriate for clinical daily practice.

Semeraro, V, Napolitano, C, Meduri, A, Marano, R, Natale, L, Bonomo, L, Assessment of Infarct Size and Microvascular Obstruction: A Direct Comparison of Semi-quantitative and Volumetric Methods by Cardiovascular Magnetic Resonance.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034512.html