Accuracy of Visual Assessment in the Detection and Quantification of Myocardial Scar by Delayed Enhancement Magnetic Resonance Imaging
Rungroj Krittayaphong MD*, Pairash Saiviroonporn PhD**, Thananya Boonyasirinant MD*, Supaporn Nakyen RT***, Prajak Thanapiboonpol RT***, Suthipol Udompunturak MS****
Affiliation : * Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Bangkok ** Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok *** Her Majesty Cardiac Center, Faculty of Medicine Siriraj Hospital, Bangkok **** Office for Research and Development, Faculty of Medicine Siriraj Hospital, Bangkok
Background : Delayed-enhancement magnetic resonance imaging (DE-MRI) is now a standard for the detec-
tion 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.
Materials and 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 calcula-
tion 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 athirty
two myocardial segments were analyzed. Visual detection of myocardial scar has an excellent level of agree-
ment 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 com-
pared 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 correla-
tion coefficient = 0.934).
Conclusion : Visual assessment of myocardial scar is accurate for the detection and quantification of scar.
Keywords : Magnetic resonance imaging, Delayed enhancement, Myocardial scar, Visual assessment
