Research Of Twin Gradient MRI Imaging Parameters And Clinicial Application

ObjectiveCompare imaging quality of ZOOM and WHOLE gradient mode in twin gradient MRI, and Investigate the influence of numbers of diffusion gradient direction on derived quanlity from diffusion tensor imaging in normal adult brain.Materials and methods1. Scan all kind of test plane of Magphan? phantom in ZOOM and WHOLE mode using twinspeed 1.5T MRI. Measure or calculate SNR, slice thickness, slice gap, spatial resolution and geometry distortion of test imaging plane.2.The routine MRI and DTl were performed on 27 healthy volunteers. DTl are performed with 6,15 and 25 diffusion gradient directions.ADC, FA, RA,1-VR and eigenvalues(λl,λ2,λ3) and Trace, gemometer index, Cp,Cs are measured or calculated at 10 ROIs of all volvnteers image in DtiStudio 2.4 software .Statistical analysis was obtained.Results1. Imaging quality in ZOOM gradient mode is better than in WHOLE gradient mode.2.ADC value is not affected by diffudion gradient direction (p>0.05).3.As all subjects and all ROIs a uint, parameters eigenvalues (λl,λ2,λ3) and linear index Cl are not affected by diffusion gradient direction (p>0.05) ,but as a single ROI, they are affected by diffusion gradient direction(p<0.05).FA, VA,1-VR, Cp, Cs are affected by diffusion gradient direction (p<0.05).Conclusions1. we should use ZOOM gradient mode imaging in clinical application.2.Measuring ADC value can be using all sorts of diffusion gradient direction in DTI.3.It is desirable to use the same diffusion gradient direction for anisotropy parameters when comparing between different subjects and ROIs.