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
Friedrich, J Am Coll Cardiol 2008
Abstract
Currently used diagnostic tools to assess patients with acute
Among the CMR techniques, several approaches can be
myocardial disease such as ECG, seromarkers and
combined to a comprehensive CMR exam, which provides
ventricular function studies are limited in their diagnostic
information not only on ventricular size morphology and
accuracy and scope. Thus, for informed therapeutic
function, but also on the stage, degree and extent of
decision-making, tissue characterization may serve as a
reversible and irreversible myocardial injury. Streamlined
very important source of information in these, initially
protocols allow such a CMR exam to be a time- and cost-
regional diseases.
efficient diagnostic tool, even in patients with acute disease.
Cardiovascular Magnetic Resonance (CMR) is becoming a
This paper reviews current CMR approaches for visualizing
more and more important tool for phenotyping cardiac
tissue pathology in vivo, presents examples and discusses
patients in vivo. Recent advances of CMR hardware and
the potential role of CMR tissue characterization in patients
software as well as protocols have allowed for accurately
with acute myocardial disease. The specific role of imaging
visualizing tissue changes in patients with acute myocardial
the extent and regional distribution of myocardial edema
diseases. This is of special interest for acute myocardial
and necrosis is discussed.
infarction and acute myocarditis, since these entities may
have a very similar clinical presentation and require
immediate therapeutic decision-making.
Friedrich, J Am Coll Cardiol 2008
Morphology
Function
Tissue
Metabolism
Echo
Nuclear
CT
CMR
Figure 1
Strengths of currently used cardiac imaging tools
Friedrich, J Am Coll Cardiol 2008
Table 2
Appearance of acute myocardial infarctions in CMR images
Friedrich, J Am Coll Cardiol 2008
Upper panel: Systolic frame
CMR of
in a short axis view.
acute,
non-transmural
infarction
Systolic frame
Lower
panel:
T2-weighted
(left) and post-contrast T1weighted
("late
enhancement")
showing
image
infarction-related
transmural edema, but only
subendocardial necrosis.
Edema
Necrosis
Figure 2
Friedrich, J Am Coll Cardiol 2008
Upper panel: Systolic frame
CMR of
in a short axis view with
acute,
hypokinesis (arrows).
transmural
infarction
Systolic frame
Lower panel: T2-weighted
(left) and post-contrast T1weighted ("late
enhancement") image
showing infarct-related
transmural edema with
Edema
Necrosis
Figure 3
transmural necrosis of the
same size.
Friedrich, J Am Coll Cardiol 2008
Upper panel: Systolic frame in a
CMR
of
acute,
transmural
infarction with noreflow
(late reperfusion)
short
axis
view
showing
preserved wall thickness of the
lateral
wall,
but
regional
akinesis of the anterolateral and
inferolateral segments (arrows).
Systolic frame
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, T2weighted and late enhancement
No-reflow/edema
No-reflow/necrosis
Figure 4
images show central no-reflow
(arrowheads).
Friedrich, J Am Coll Cardiol 2008
CMR of ischemic
cardiomyopathy
with chronic,
transmural inferior
infarction
Upper panel: Systolic frame
in a short axis view with
akinesis of the inferoseptal
and inferior segments
(arrows).
Systolic frame
Lower panel: T2-weighted
(left) and post-contrast T1weighted ("late
enhancement", right) images
showing no edema, but
transmural fibrosis (arrows)
Lack of edema
Scar
within the akinetic region.
Figure 5
Friedrich, J Am Coll Cardiol 2008
Upper panel: Systolic frame
CMR of acute
of a cine study showing
myocarditis
pericardial effusion (bright
signa, arrow) and largely
preserved systolic function.
Systolic frame
Lower panel: T2-weighted
(left) and post-contrast T1weighted ("late
enhancement", right) images
showing lateral edema
(arrows) and focal fibrosis
typical for the non-ischemic
Edema
Necrosis
Figure 6
injury pattern of myocarditis
(arrows).
Friedrich, J Am Coll Cardiol 2008
CMR of a patient with
acute myocarditis
Findings:
•Pathologic edema ratio
•Pathologic early
enhancement
Edema
•No definite late
enhancement
Systolic frame
Early enh./post contrast
No regional necrosis
Figure 7
Friedrich, J Am Coll Cardiol 2008
CMR of a patient with
acute myocarditis and
chronic scar
Findings:
•Focal edema
•Pathologic early
enhancement
Early enh./pre contrast
Edema
Early enh./post contrast
Lateral scar
•Focal late enhancement
Systolic frame
Figure8
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
Friedrich, J Am Coll Cardiol 2008
Tako-Tsubo - Admission
CMR of a patient with stress-induced
CMP (Tako-Tsubo) - admission
Findings:
•Apical ballooning
•Regional edema
•Atypical late enhancement
Edema
Systolic frame
Diffuse necrosis
Figure 10a
Friedrich, J Am Coll Cardiol 2008
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
Systolic frame
Edema
Diffuse necrosis
Figure 10 b
Friedrich, J Am Coll Cardiol 2008