Standardized assessment of global longitudinal and circumferential strain - a modality independent software approach

Mean GLS values were -16.2±5.3% and -17.3±5.3% for echocardiography and CMR, respectively. GLS did not differ significantly between the two imaging modalities, which showed strong correlation (r=0.86), a small bias (-1.1%) and narrow 95% limits of agreement (LOA, ±5.4%). Mean GCS values were -17.9±6.3% and -24.4 ±7.8% for echocardiography and CMR, respectively. GCS was significantly underestimated by echocardiography (p<0.001). A weaker correlation (r=0.73), a higher bias (-6.5%) and wider LOA (±10.5%) were observed for GCS. GLS showed a strong correlation (r=0.92) when image quality was good, while correlation dropped to r=0.82 with poor acoustic windows in echocardiography. GCS assessment revealed only a strong correlation (r=0.87) when echocardiographic image quality was good. No significant differences for GLS between two different echocardiographic vendors could be detected. Conclusions Quantitative assessment of GLS using a standardized software algorithm allows the direct comparison of values acquired irrespective of the imaging modality. GLS may therefore serve as a reliable parameter for the assessment of global left ventricular function in clinical routine besides standard evaluation of the ejection fraction.