Table 5.

Comparison of the radiomic features obtained using manual 2D ROIs by R1 versus R2 and, for R1, using manual versus circular 2D ROIs

For the main lesion of each patient, the RFs from R1 2D ROIs were compared to R2 2D ROIs and to the circular 2D ROIs (extROIs and intROIs). Mean relative discrepancy taking R1 values as reference is reported. Inter-reader variability was preponderant for nearly all RFs. As expected, RFs from extROIs and intROIs had a divergent behaviour in respect of R1 2D ROIs, whose characteristics were intermediate. The colour code refers to the absolute value of discrepancy

2D Two-dimensional, extROI Smallest circular segmentation including the whole lesion, GLCM Grey level co-occurrence matrix, GLNU Grey level non-uniformity, GLRLM Grey level run length matrix, HGLRE High grey level run emphasis, intROI Largest circular segmentation completely inside the lesion, LGLRE Low grey level run emphasis, LRE Long run emphasis, LRHGLE Long run high grey level emphasis, LRLGLE Long run low grey level emphasis, R1 Reader 1, R2 Reader 2, RFs Radiomic features, RLNU Run length non-uniformity, ROIs Region of interest, SRE Short run emphasis, SRHGLE Short run high grey level emphasis, SRLGLE Short run low grey level emphasis