Table 3.
Median Dice overlaps for 202 ADNI subjects using different approachesa
| Method | Left hippocampus | Right hippocampus | Whole hippocampus | Time |
|---|---|---|---|---|
| Patch-based | 0.848 | 0.842 | 0.844 | 10 min |
| SRCb | 0.873 | 0.869 | 0.871 | 40 min |
| DDLSb | 0.872 | 0.872 | 0.872 | 3–6 min |
| F-DDLSb | 0.865 | 0.859 | 0.864 | <1 min |
The numbers in bold represent the highest Dice overlaps among different methods. All three sparse coding methods (SRC, DDLS, and F-DDLS) outperform standard nonlocal patch-based classification. The sparse dictionary learning methods are also computationally efficient compared with conventional, nonsparse patch-based segmentation. Bold entries indicate the best-performing method.
Methodology utilizing sparsity.
Abbreviations: ADNI, Alzheimer’s Disease Neuroimaging Initiative; DDLS, discriminative dictionary learning for segmentation; F-DDLS, fixed DDLS; SRC, sparse representation classification.