1. Friedrich, J Am Coll Cardiol 2008 Tissue characterization of acute myocardial infarction and myocarditis by CMR Matthias G. Friedrich Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Inatitute of Alberta, Departments of Cardiac Scienes and Radiology, University of Calgary, Calgary, AB, Canada

2. Friedrich, J Am Coll Cardiol 2008 Abstract Currently used diagnostic tools to assess patients with acute myocardial disease such as ECG, seromarkers and ventricular function studies are limited in their diagnostic accuracy and scope. Thus, for informed therapeutic decision-making, tissue characterization may serve as a very important source of information in these, initially regional diseases. Cardiovascular Magnetic Resonance (CMR) is becoming a more and more important tool for phenotyping cardiac patients in vivo. Recent advances of CMR hardware and software as well as protocols have allowed for accurately visualizing tissue changes in patients with acute myocardial diseases. This is of special interest for acute myocardial infarction and acute myocarditis, since these entities may have a very similar clinical presentation and require immediate therapeutic decision-making. Among the CMR techniques, several approaches can be combined to a comprehensive CMR exam, which provides information not only on ventricular size morphology and function, but also on the stage, degree and extent of reversible and irreversible myocardial injury. Streamlined protocols allow such a CMR exam to be a time- and cost- efficient diagnostic tool, even in patients with acute disease. This paper reviews current CMR approaches for visualizing tissue pathology in vivo, presents examples and discusses the potential role of CMR tissue characterization in patients with acute myocardial disease. The specific role of imaging the extent and regional distribution of myocardial edema and necrosis is discussed.

3. Friedrich, J Am Coll Cardiol 2008 MorphologyFunctionTissueMetabolism Echo Nuclear CT CMR Figure 1Strengths of currently used cardiac imaging tools

4. Friedrich, J Am Coll Cardiol 2008 Table 2 Appearance of acute myocardial infarctions in CMR images

5. Friedrich, J Am Coll Cardiol 2008 Figure 2 EdemaEdemaNecrosisNecrosis Upper panel: Systolic frame in a short axis view. Lower panel: T2-weighted (left) and post-contrast T1- weighted ("late enhancement") image showing infarction-related transmural edema, but only subendocardial necrosis. CMR of acute, non-transmural infarction Systolic frame

6. Friedrich, J Am Coll Cardiol 2008 Figure 3 EdemaEdemaNecrosisNecrosis Upper panel: Systolic frame in a short axis view with hypokinesis (arrows). Lower panel: T2-weighted (left) and post-contrast T1- weighted ("late enhancement") image showing infarct-related transmural edema with transmural necrosis of the same size. CMR of acute, transmural infarction Systolic frame

7. Friedrich, J Am Coll Cardiol 2008 Figure 4 No-reflow/necrosisNo-reflow/necrosisNo-reflow/edemaNo-reflow/edema Upper panel: Systolic frame in a short axis view showing preserved wall thickness of the lateral wall, but regional akinesis of the anterolateral and inferolateral segments (arrows). Lower panel: T2-weighted (left) and post-contrast T1-weighted ("late enhancement") images with infarct-related transmural edema and matching necrosis in dysfunctional area. Both, T2- weighted and late enhancement images show central no-reflow (arrowheads). CMR of acute, transmural infarction with no- reflow (late reperfusion) Systolic frame

8. Friedrich, J Am Coll Cardiol 2008 Figure 5 ScarScar Lack of edema Upper panel: Systolic frame in a short axis view with akinesis of the inferoseptal and inferior segments (arrows). Lower panel: T 2 -weighted (left) and post-contrast T 1 - weighted ("late enhancement", right) images showing no edema, but transmural fibrosis (arrows) within the akinetic region. CMR of ischemic cardiomyopathy with chronic, transmural inferior infarction Systolic frame

9. Friedrich, J Am Coll Cardiol 2008 Figure 6 EdemaEdemaNecrosisNecrosis Upper panel: Systolic frame of a cine study showing pericardial effusion (bright signa, arrow) and largely preserved systolic function. Lower panel: T2-weighted (left) and post-contrast T1- weighted ("late enhancement", right) images showing lateral edema (arrows) and focal fibrosis typical for the non-ischemic injury pattern of myocarditis (arrows). CMR of acute myocarditis Systolic frame

10. Friedrich, J Am Coll Cardiol 2008 Figure 7 EdemaEdema No regional necrosis Early enh./post contrast CMR of a patient with acute myocarditis Findings: Pathologic edema ratio Pathologic early enhancement No definite late enhancement Systolic frame

11. Friedrich, J Am Coll Cardiol 2008 Figure8 Systolic frame EdemaEdema Lateral scar Early enh./post contrast Early enh./pre contrast CMR of a patient with acute myocarditis and chronic scar Findings: Focal edema Pathologic early enhancement Focal late enhancement

12. Friedrich, J Am Coll Cardiol 2008 CMR of a patient with remote myocarditis Chronic multifocal, partially subendocardial scarring (T1-weighted "late enhancement" image) Figure 9

13. Friedrich, J Am Coll Cardiol 2008 Figure 10a Systolic frame EdemaEdema Diffuse necrosis Tako-Tsubo - Admission CMR of a patient with stress-induced CMP (Tako-Tsubo) - admission Findings: Apical ballooning Regional edema Atypical late enhancement

14. Friedrich, J Am Coll Cardiol 2008 Figure 10 b Systolic frame EdemaEdema Diffuse necrosis Tako-Tsubo - Follow-up CMR of a patient with stress-induced CMP (Tako-Tsubo) – follow-up/4 wk Findings: Normalizatioon of function No edema Some persisting late enhancement