Improving the Visual Quality in Radially Acquired Real-Time MR Images

Real-time MRI using highly undersampled radial acquisition can be used for dynamic assessments of the heart. The main challenges, however, are the presence of severe undersampling artifacts in the periphery of the images. In this study, to improve the visual quality of the final real-time images, a new method for the acquisition of successive frames based on a radial trajectory with the turned arrangement is presented. Accordingly, by combining the information obtained from successive frames, it is possible to reconstruct images with high and low spatial resolution. In the proposed method, specifically due to the use of the Polar Fourier Transform reconstruction method, reconstructed images with two different resolutions can be combined to reduce the visual effects of undersampling artifacts. In this paper, the proposed method has been used especially for the real-time radially tagged images to increase the efficiency and accuracy of measuring left ventricular rotation motion. According to the simulation results, the structural similarity measure is improved from 0.6 to 0.8. Real-time imaging with a time resolution of 46 ms of healthy individuals also shows that while the temporal resolution of the rotational information is well preserved, the visual quality of images is improved.