The parameters acquired from time intensity curve (TIC) (i.e. arrival time, mean transit time, time to peak, basal intensity, peak intensity, area under curve, slope rate of ascending and descending curves), the date acquired from spectral Doppler ultrasound (i.e. restive index, pulsatility index) and Values of shear wave velocities of the several regions of interest acquired from Sonoelastography will be analyzed to find statistical significance in assessment of allograft nephropathy such as acute rejection or chronic allograft nephropathy.