Accuracy of myocardial viability imaging by cardiac MRI and PET depending on left ventricular function

Table 1 Scoring system for evaluation of myocardial viability in cardiac magnetic resonance imaging and positron emission tomography

Score	CMR	PET
1	No enhancement	Normal FDG uptake
2	Enhancement < 50% of wall thickness	Reduced FDG uptake, ≥ 50% of maximum
3	Enhancement ≥ 50% of wall thickness	Reduced FDG uptake, < 50% of maximum
4	Transmural enhancement	No FDG uptake

Based on the data by Kim et al[22], score 1 and 2 represent viable myocardium, while score 3 and 4 are regarded as non-viable tissue (“scar”) in view of expected functional improvement after revascularization. Per definition, reduced or completely missing viability encompassed decreased or no FDG-uptake. CMR: Cardiac magnetic resonance imaging; PET: Positron emission tomography; FDG: Fluorodeoxyglucose.

Table 2 Myocardial scar detection by cardiac magnetic resonance imaging (contingency table)

	Sensitivity	Specificity	PPV	NPV	Accuracy
All patients	69%	71%	62%	77%	70%
EF< 30%	79%	66%	66%	79%	72%
EF 30%-50%	64%	69%	58%	74%	67%
EF > 50%	25%	89%	41%	79%	74%

Detection of myocardial scar (score 2-4) by cardiac magnetic resonance imaging (CMR) as test parameter compared to positron emission tomography (PET). Analysis was done for the whole patient collective as well as in the three patient subgroups with different ejection fraction (EF). In patients with moderately or severely compromised EF CMR outperformed PET. NPV: Negative predictive value; PPV: Positive predictive value.

Table 3 Functional recovery as detected by cardiac magnetic resonance imaging shown as contingency table

	Sensitivity	Specificity	PPV	NPV	Accuracy
All patients	72%	83%	51%	92%	81%
EF < 30%	74%	79%	55%	90%	78%
EF 30%-50%	73%	82%	50%	93%	81%
EF > 50%	30%	92%	19%	95%	89%

The contingency table shows the detection of tissue with potential functional recovery (score 1 and 2) by cardiac magnetic resonance imaging (CMR) as test variable compared to positron emission tomography (PET). Calculation was performed for the whole patient collective as well as separately for the three patient subgroups with different EF. Except for patients with not compromised left ventricular function sensitivity, specificity, PPV, NPV and accuracy were higher in CMR. EF: Ejection fraction; NPV: Negative predictive value; PPV: Positive predictive value.