Comparison of Known-Group Validity (Discrimination of 42 Patients with AD from 29 Control Subjects) with Other Linear CT-Based Measures of MTL Lobe Atrophy in CT Group
| Control Group | AD Group | Sensitivity (95% CI)* | ||
|---|---|---|---|---|
| Mean Crude Measure ± SD (mm) | Mean Crude Measure ± SD (mm) | Mean W-score ± SD | ||
| Radial width of the temporal horn | ||||
| Right | 2.9 ± 1.4 | 7.8 ± 3.0 | 3.6 ± 2.2 | 86% (71%–94%) |
| Left | 2.4 ± 1.3 | 7.8 ± 3.2 | 4.1 ± 2.4 | 83% (68%–92%) |
| Largest | 3.2 ± 1.2 | 9.1 ± 3.0 | 4.7 ± 2.4 | 93% (80%–98%) |
| Transverse width of the temporal horn | ||||
| Right | 1.0 ± 1.1 | 3.7 ± 1.9 | 2.2 ± 1.7 | 62% (46%–76%) |
| Left | 1.2 ± 1.3 | 4.3 ± 2.4 | 2.3 ± 1.9 | 57% (41%–72%) |
| Largest | 1.5 ± 1.3 | 4.7 ± 2.3 | 2.4 ± 1.9 | 64% (48%–78%) |
| Minimum thickness of the medial temporal lobe | ||||
| Right | 17.4 ± 2.3 | 10.9 ± 3.4 | −2.7 ± 1.4 | 74% (58%–86%) |
| Left | 17.0 ± 3.1 | 11.6 ± 3.6 | −1.9 ± 1.2 | 57% (41%–72%) |
| Smallest | 16.4 ± 2.8 | 10.2 ± 3.3 | −2.4 ± 1.2 | 74% (58%–86%) |
Note.—P < .001 for difference between groups on t test for all measures. W scores are age-standardized values; that is, the number of SD away from the age-specific atrophy value of control subjects (W scores in control subjects, 0.0 ± 1.0). Greater absolute values indicate greater atrophy.
* Values computed by modeling W scores of patients with AD and control subjects with specificity set at 95%.