Preparing Bifidobacteria for Quantitative Detections

Objective To establish reference values for left ventricular (LV) myocardial strains in a cohort of healthy Chinese volunteers with feature tracking cardiac magnetic resonance imaging. Methods A total of 60 healthy volunteers were recruited, receiving a cardiac magnetic resonance imaging (CMR) examination at 3.0T scanner (Tim Trio, Magnetum, Siemens, Germany). A new feature tracking CMR software (Trufisp-strain, Siemens) was used to analyze left ventricular myocardial strain parameters, including radial, circumferential, longitudinal strain, systolic strain rate, and early diastolic strain rate. Results The image quality was sufficient to perform strain analysis.The reference values of global strain, global strain rate and segmental strains were obtained. A good inter- and intra-observer agreement was achieved in global strain analysis (except circumferential straininter-observer in apical level),with (37.7±9.6)% for LV global mean radial strain, (-18.4±3.3)% for circumferential strain and (-15.2±2.3%) for longitudinal strain, respectively.Age was positively correlated with global mean radial strain ( r=0.416, P r=-0.436, P r=-0.326, P=0.011; r=-0.273, P=0.035, respectively). Women showed higher circumferential and longituinal strain values and lower CM(155.3mmsystolic circumferential strain rate than men. The strain parameters were correlated with left ventricular ejection CM)