Assessment of the effect of intensity standardization on the reliability of T1-weighted MRI radiomic features: experiment on a virtual phantom.

Abstract

The effect of time of repetition (TR) and time of echo (TE) on radiomic features was evaluated using a virtual phantom. Forty-two T1-weighted MRI images of the same virtual phantom were simulated with TR and TE in a range used in clinical practice. Fifty-eight radiomic features were considered for this analysis. Features were extracted from 3 different regions of interest (ROIs) from the original images and from images that underwent intensity standardization (linear intensity standardization, Z-score standardization and histogram matching). Intraclass correlation coefficient (ICC) was used to assess the reliability of the radiomic features and a threshold of 0.75 was used to discriminate features with good or bad reliability. The coefficient of determination R2 was used to quantify correlation between features and image acquisition parameters. The majority of radiomic features (76%) had good reliability (ICC>0.75) and 66% of the features were uncorrelated with TR and TE (R2<; 0.5). Intensity standardization (in particular histogram matching) significantly reduced the correlation. Intensity standardization also increased the reliability of FOS features, but histogram matching significantly reduced the reliability of GLCM features.