RÉSUMÉ
Objectives:To analyze the consistency of evaluating left ventricular hemodynamics (HDF) based on single plane and multi plane cine sequences of magnetic resonance mitral valve orifice.Methods:A prospective study was conducted on 48 healthy adults, and two methods were used to measure the mitral valve diameter and calculate HDF parameters. The first method was to measure the diameter of the mitral valve opening in the left ventricular three chamber cine sequence; The second method is to measure the mitral valve diameter using cine sequences of two chamber, three chamber, and four chamber hearts, and then take the average value. Paired t-tests were used to compare the differences in HDF measured by two methods, and Pearson correlation coefficient ( r), intra group correlation coefficient ( ICC), and Bland-Altman analysis were used to test the consistency and reproducibility of the two methods. Results:The root mean square (RMS) of longitudinal HDF calculated using single plane and multi plane mitral valve diameters were [(17.28±4.41)% vs (17.21±4.61)%] ( P=0.379) for the entire cardiac cycle, [(21.45±5.54)% vs (21.49±5.68)%] ( P=0.646) for systolic phase, and [(12.78±4.10)% vs (12.54±4.24)%] ( P=0.106) for diastolic phase, respectively. The difference in the calculation results of HDF parameters related to ventricular function was not statistically significant (all P>0.05), and there was good consistency ( r=0.924-0.996, ICC=0.924-0.995). The two HDF parameters related to atrial function were sensitive to the measurement method of mitral valve orifice diameter [RMS of longitudinal HDF during active atrial emptying: (3.26±1.51)% vs (3.32±1.55)%, P=0.006; longitudinal HDF pulse during active atrial emptying: (-2.60±1.28)% vs (-2.76±1.30)%, P<0.001]. Conclusions:The ventricular function related HDF parameters obtained from the analysis of mitral valve orifice diameter using single plane and multi plane methods have good consistency, and can be evaluated using relatively simple single plane methods for left ventricular HDF.
RÉSUMÉ
Five kinds of trace elements (Cu, Zn, Fe, Mn, Pb) in the hair of unknown causal hypophrenic children and normal children in the cretinism area (Cailiang Township, Ankang County, Shaanxi Province) were determined. The results indicate that the content of Mn Pb and the ratio of Cu to Zn in hypophrenic children's hair are both higher than those in the normal children's hair. It is suggested by this experiment that the main causation of hypophrenia in this area may be a lower content of zine, higher content of M auganese and higher Cu/Zn ratio.