Noise removal for multi-echo MR images using global enhancement

Magnetic Resonance Images are corrupted by random noise which affects the accuracy of the quantitative measurements when acquiring the data. This paper proposes an effective noise removal method for multiple-echo MR images using global enhancement. Applying inverse histogram equalization to the mean image, not only the noise is removed from the MRI but also the noise-free image can be reconstructed. Firstly, the background is segmented using morphological operations and curve fitting based on histogram equalization is performed to normalize the noise signal. Then, the average filtering is applied to the segmented MR images in order to remove the noise. Next, the noise-removed multi-echo MR images are reconstructed using the inverse histogram equalization. The experimental results demonstrate that the proposed method can eliminate not only anisotropic noises but also the flow artifacts in multi-echo MR Images.