Noise measurement from magnitude MRI using local estimates of variance and skewness.

In this note, we address the estimation of the noise level in magnitude magnetic resonance (MR) images in the absence of background data. Most of the methods proposed earlier exploit the Rayleigh distributed background region in MR images to estimate the noise level. These methods, however, cannot be used for images where no background information is available.

Machine learning study of several classifiers trained with texture analysis features to differentiate benign from malignant soft-tissue tumors in T1-MRI images.

Purpose: To study, from a machine learning perspective, the performance of several machine learning classifiers that use texture analysis features extracted from soft-tissue tumors in nonenhanced T1-MRI images to discriminate between malignant and benign tumors.

Materials And Methods: Texture analysis features were extracted from the tumor regions from T1-MRI images of clinically proven cases of 49 malignant and 86 benign soft-tissue tumors. Three conventional machine learning classifiers were trained and tested.