Three-dimensional maximum principal strain using cardiac computed tomography for identification of myocardial infarction.

OBJECTIVES: To evaluate the feasibility of three-dimensional (3D) maximum principal strain (MP-strain) derived from cardiac computed tomography (CT) for detecting myocardial infarction (MI).

METHODS: Forty-three patients who underwent cardiac CT and magnetic resonance imaging (MRI) were retrospectively selected. Using the voxel tracking of motion coherence algorithm, the peak CT MP-strain was measured using the 16-segment model. With the trans-mural extent of late gadolinium enhancement (LGE) and the distance from MI, all segments were classified into four groups (infarcted, border, adjacent, and remote segments); infarcted and border segments were defined as MI with LGE positive. Diagnostic performance of MP-strain for detecting MI was compared with per cent systolic wall thickening (%SWT) assessed by MRI using receiver-operating characteristic curve analysis at a segment level.

RESULTS: Of 672 segments excluding16 segments influenced by artefacts, 193 were diagnosed as MI. Sensitivity and specificity of peak MP-strain to identify MI were 81 % [95 % confidence interval (95 % CI): 74-88 %] and 86 % (81-92 %) compared with %SWT: 76 % (60-95 %) and 68 % (48-84 %), respectively. The area under the curve of peak MP-strain was superior to %SWT [0.90 (0.87-0.93) vs. 0.80 (0.76-0.83), p < 0.05].

CONCLUSIONS: CT MP-strain has a potential to provide incremental value to coronary CT angiography for detecting MI.

KEY POINTS: • CT MP-strain allows for three-dimensional assessment of regional cardiac function. • CT-MP strain has high diagnostic accuracy for detecting myocardial infarction. • CT-MP strain may assist in tissue characterisation of myocardium assessed by LGE-MRI. • CT-MP strain provides incremental values to coronary CTA for detecting myocardial infarction.