Table 4.

Bone density and texture variables from X-ray images with minimal post-processing in the elastic net model to discriminate subjects without (n = 82) and with medial tibial bone marrow lesion (n = 23).

Variable	Coefficient
Intercept	− 1.752
GVmmAl in ROI7	0.220
FDVer,0.44mm in medial SB	0.396
FDVer,0.74mm in medial SB	0.004
FDVer,0.30mm in ROI7	0.260
FDVer,0.30mm in ROI12	0.127
FDVer,0.30mm in ROI15	0.393
FDVer,0.59mm in ROI7	0.197
FDVer,0.74mm in ROI4	− 0.092
FDVer,0.74mm in ROI6	− 0.126
FDHor,0.59mm in ROI2	− 0.012
FDHor,0.59mm in ROI3	− 0.644
FDHor,0.59mm in ROI13	− 0.091
FDHor,0.74mm in ROI1	− 0.351
FDHor,0.74mm in ROI2	− 0.012
FDHor,0.74mm in ROI5	− 0.313
FDHor,0.74mm in ROI7	− 0.213
FDHor,0.74mm in ROI8	− 0.443
FDHor,0.74mm in ROI12	− 0.243

SB subchondral bone, ROI region of interest, GV_mmAl mean grayscale value calibrated with aluminum step wedge, FD fractal dimension of vertical (Ver) or horizontal (Hor) structures