Contrast-enhanced magnetic resonance imaging assessment of scar size in patients with chronic myocardial infarction.
BACKGROUND
In the assessment of myocardial infarction (MI) mass, contrast-enhanced magnetic resonance imaging (CE-MRI) is comparable to single-photon emission computed tomography (SPECT). The aim of the present study was to determine whether the MI area, as assessed at CE-MRI and SPECT, is comparable to mass evaluation. We also compared CE-MRI and SPECT estimates of the MI area with functional evaluations made at echocardiography and kinetic MRI (cine-MRI).


METHODS
We used a 1.0 Tesla MRI scanner and an inversion-recovery turboFLASH sequence, a tomographic gamma-camera and second-harmonic ultrasound systems. Two blinded operators assessed the extent of scarring, expressed as a percentage of the whole left ventricle (LV), using a 16-segment model. We studied 55 consecutive patients with a clinically stable healed MI (50 Q wave, 5 non-Q wave).


RESULTS
The scar mass was 19+/-23% of the LV at CE-MRI and 21+/-25% at SPECT; the scar area was 29+/-23% of the LV at CE-MRI, 41+/-28% at SPECT, 29+/-31% at cine-MRI, and 32+/-29% at echocardiography. The Bland-Altman bias between CE-MRI and SPECT mass estimations was -2% of the LV with a+/-23% limit of agreement (LOA), while the bias between the area assessments was -12% with a+/-42% LOA. Bias between CE-MRI and functional evaluation by cine-MRI and echocardiography was 0% with a+/-39% LOA and -3% with a+/-36% LOA respectively. Comparing SPECT with cine-MRI and echocardiography the bias was 12% with a+/-52% LOA and 9% with a+/-56% LOA respectively.


CONCLUSIONS
CE-MRI has proved to be comparable to SPECT in the assessment of the healed MI mass. Conversely, a high systematic error (high bias and LOA) renders CE-MRI and SPECT assessments of the MI area incomparable. Similarly (high bias and/or LOA) CE-MRI and SPECT estimations of the MI area cannot be compared with functional evaluation by echocardiography or cine-MRI.
Catalano
Oronzo
O
IRCCS S Maugeri Foundation, Pavia, Italy. ocatalano@fsm.it
Antonaci
Serena
S
Moro
Guido
G
Cannizzaro
Giorgio
G
Mingrone
Renato
R
Opasich
Cristina
C
Frascaroli
Mauro
M
Rognone
Felice
F
Baldi
Maurizia
M
Tramarin
Roberto
R
D000368:Aged; D002908:Chronic Disease; D002921:Cicatrix / Q000000981:diagnostic imaging / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology*; D013673:Technology Assessment, Biomedical; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014463:Ultrasonography; D020257:Ventricular Remodeling
D003287:Contrast Media