Accuracy of visual assessment in the detection and quantification of myocardial scar by delayed enhancement magnetic resonance imaging.
BACKGROUND
Delayed-enhancement magnetic resonance imaging (DE-MRI) is now a standard for the detection of myocardial scar and viability. Standard analysis needs expensive software.


OBJECTIVE
To determine the accuracy of visual assessment in the detection and quantification of myocardial scar by DE-MRI technique.


METHODS
The authors enrolled 32 patients with coronary artery disease (CAD) as documented by coronary angiography (CAG) and left ventricular dysfunction. All patients underwent cardiac magnetic resonance imaging for the assessment of global and regional myocardial function and DE-MRI. The presence and amount of scar in each myocardial segment was assessed by standard method. Visual assessment was performed by two methods: 1) visual drawing of the boundary of the hyperenhancement region and calculation of percentages of scar in an individual segment; 2) visual estimation of grading of hyperenhancement area from 0 (no scar) to 4 (> 75% scar). The agreement for scar detection and correlation of scar quantification for individual segments were evaluated.


RESULTS
Thirty-one of 32 patients in the present study had myocardial scar. One thousand four hundred and thirty two myocardial segments were analyzed. Visual detection of myocardial scar has an excellent level of agreement with standard method of scar (Kappa = 0.963 and 0.952, p<0.001 for visual method I and II). Visual method I and II has an accuracy of 98.2% and 97.6% respectively in the detection of myocardial scar compared to standard method. Percentages of myocardial scar in each myocardial segment by visual method I correlate very well with standard method (Intraclass Correlation Coefficient = 0.885). Visual grading of amount of myocardial scar also has an excellent correlation with standard method (Spearman rank correlation coefficient = 0.934).


CONCLUSIONS
Visual assessment of myocardial scar is accurate for the detection and quantification of scar.
Krittayaphong
Rungroj
R
Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand. sirkt@mahidol.ac.th
Saiviroonporn
Pairash
P
Boonyasirinant
Thananya
T
Nakyen
Supaporn
S
Thanapiboonpol
Prajak
P
Udompunturak
Suthipol
S
D009202:Cardiomyopathies / Q000175:diagnosis / Q000473:pathology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D012680:Sensitivity and Specificity; D012984:Software; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000473:pathology