Fig 1.
Primary MRI sequences of the brain.
(a) T1C exhibiting enhanced tumor structure and boundary (Red), (b) T2 associated with edema or swelling (Yellow), and (c) FLAIR demonstrating both the edema (Yellow) and enhanced solid core (Red).
Fig 2.
Sample images, of four categories, from BRATS.
(a) HG, (b) LG, (c) SimHG, and (d) SimLG.
Fig 3.
Six pseudo-colored brain MR sequences.
(a) FLAIR—T2—T1C, (b) FLAIR—T1C—T2 (c) T2—FLAIR—T1C(d) T2—T1C—FLAIR(e) T1C—FLAIR—T2, and (f) T1C—T2—FLAIR, as mapped to the RGB plane.
Fig 4.
Six pseudo-colored (L* a* b*) converted brain MR image sequences, corresponding to the six pseudo-colored (RGB) MR sequences of Fig 3.
Fig 5.
3-D color cubes showing the color distributions of the L* a* b* converted images of Fig 4.
Fig 6.
Saliency map generation for a low-grade glioma.
MRI sequences (a) T1C, (b) T2, and (c) FLAIR. (d) Ground truth superimposed on the FLAIR image. Saliency maps (e) without spatial distance, and (f) with spatial distance component.
Fig 7.
Saliency map of pseudo-colored MR image of the whole tumor region of Fig 4(a) at different scales.
Patch sizes of (a) 4 × 4, (b) 8 × 8, (c) 16 × 16, and (d) 32 × 32.
Fig 8.
Superimposed saliency map corresponding to Fig 7 and (b) its final smoothened version.
Table 1.
Comparison of mean AUC scores with considered saliency models.
Fig 9.
Comparative study of averaged precision-recall values, with varying thresholds [0—255] on saliency map for four groups of MR images.
(a) HG, (b) LG, (c) SimHG, and (d) SimLG.
Fig 10.
Comparative study of ROC curves for averaged TPR-FPR values, with varying thresholds [0—255] on saliency map for four groups of MR image.
(a) HG, (b) LG, (c) SimHG, and (d) SimLG.
Fig 11.
MR images of five High-Grade Glioma cases.
(a) T1C, (b) T2, (c) FLAIR, (d) pseudo RGB, and (e) L* a* b*, (f) Saliency map, (g) color coded saliency map, with extracted (h) proto-object, and (i) corresponding ground truth.
Fig 12.
MR images of five Low-Grade Glioma cases.
(a) T1C, (b) T2, (c) FLAIR, (d) pseudo RGB, and (e) L* a* b*, (f) Saliency map, (g) color coded saliency map, with extracted (h) proto-object, and (i) corresponding ground truth.
Fig 13.
MR images of five Simulated High-Grade Glioma cases.
(a) T1C, (b) T2, (c) FLAIR, (d) pseudo RGB, and (e) L* a* b*, (f) Saliency map, (g) color coded saliency map, with extracted (h) proto-object, and (i) corresponding ground truth.
Fig 14.
MR images of five Simulated Low-Grade Glioma cases.
(a) T1C, (b) T2, (c) FLAIR, (d) pseudo RGB, and (e) L* a* b*, (f) Saliency map, (g) color coded saliency map, with extracted (h) proto-object, and (i) corresponding ground truth.