Table IV.
SVM classification results
| Local weights | Grey matter | White matter | ||
|---|---|---|---|---|
| No | Yes | No | Yes | |
| IPS vs. controls | ||||
| Accuracy (P value) | 39.53% (NS) | 39.53% (NS) | 41.86% (NS) | 37.31% (NS) |
| Sensitivity | 28.57% | 33.33% | 38.10% | 28.57% |
| Specificity | 50.00% | 45.45% | 45.45% | 45.45% |
| MSA‐P vs. IPS | ||||
| Accuracy (P value) | 62.50% (NS) | 71.87% (0.010) | 65.63% (NS) | 65.63% (NS) |
| Sensitivity | 27.27% | 36.36% | 27.27% | 27.27% |
| Specificity | 80.95% | 90.48% | 85.71% | 85.71% |
| PSP vs. IPS | ||||
| Accuracy (P value) | 87.10% (<0.001) | 87.10% (<0.001) | 90.32% (<0.001) | 96.77% (<0.001) |
| Sensitivity | 60.00% | 70.00% | 80.00% | 90.00% |
| Specificity | 100.00% | 95.24% | 95.24% | 100.00% |
| MSA‐P vs. PSP | ||||
| Accuracy (P value) | 38.10% (NS) | 33.33% (NS) | 61.9% (NS) | 76.19% (0.013) |
| MSA‐P vs. controls | ||||
| Accuracy (P value) | 69.70% (0.017) | 63.63% (NS) | 78.78% (<0.001) | 51.52% (NS) |
| Sensitivity | 27.27% | 27.27% | 54.55% | 18.18% |
| Specificity | 90.91% | 81.82% | 90.91% | 68.18% |
| PSP vs. controls | ||||
| Accuracy (P value) | 71.88% (0.010) | 65.63% (NS) | 84.37% (<0.001) | 93.75% (<0.001) |
| Sensitivity | 40.00% | 20.00% | 70.00% | 90.00% |
| Specificity | 86.36% | 86.36% | 90.91% | 95.45% |
Overall accuracy, sensitivity, and specificity of the SVM classification based on grey and white matter maps and with/without local weights are shown (leave‐one‐out design). Accuracy P value is given when the likelihood of achieving this binominal distribution by chance is <0.05.
NS, not significant; IPS, idiopathic Parkinson syndrome; MSA‐P, multiple systems atrophy (parkinsonian variant); PSP, progressive supranuclear palsy.