Comparison of semi-automated methods to quantify infarct size and area at risk by cardiovascular magnetic resonance imaging at 1.5T and 3.0T field strengths

Table 3 Infarct size (IS) results at 3.0T by quantification method and corresponding reproducibilities

*3 T*	IS (FWHM)	IS (5SD)	IS (6SD)	IS (7SD)	IS (8SD)	IS (OAT)	IS (MANUAL)
Mean IS (%LVM)	10.8 ± 8.2	17.0 ± 11.2^b	14.77 ± 10.4^b	13.0 ± 9.7^a	11.4 ± 9.0	21.6 ± 9.8^b	11.5 ± 9.0
ICC v Manual	0.964	0.780	0.874	0.937	0.966	0.505
Mean bias v Manual (±1.96SD LoA)	+0.22 (+5.09, −4.65)	+6.42 (+14.93, −2.09)	+4.17 (+11.05, −2.71)	+2.38 (+7.92, −3.16)	+0.81 (+5.62, −4.01)	+11.03 (+22.20, −0.15)
Interobserver ICC	0.990	0.957	0.937	0.916	0.888	0.977	0.913
Interobserver mean bias (±1.96SD LoA)	−0.49 (+1.74, −2.72)	+0.44 (+7.23, −6.35)	+1.14 (+8.51, −6.23)	+1.40 (+9.25, −6.44)	+1.50 (+9.99, −6.98)	−0.05 (+4.35, −4.44)	+1.97 (+9.48, −5.54)
Intraobserver ICC	0.988	0.992	0.992	0.993	0.993	0.986	0.972
Intraobserver mean bias (±1.96SD LoA)	+0.20 (+1.49, −1.10)	+0.43 (+2.90, −2.03)	−0.04 (+2.42, −2.50)	+0.10 (+2.19, −1.98)	+0.32 (+2.08, −1.45)	+0.15 (+3.50, −3.21)	+1.14 (+4.35, −2.07)

IS expressed as mean ± standard deviation. FWHM = full-width half maximum, 5-8SD = >5-8 standard deviation, OAT = Otsu’s Automated Thresholding, LVM = Left Ventricular Mass, ICC = Intraclass Correlation Coefficient, LoA = Limits of Agreement (Bland-Altman).
^a - p < 0.05 vs. manually quantified IS. ^b – p < 0.01 vs. manually quantified IS.

ISSN: 1756-0500