Diffusion parameters and volume of limbic connections
| Cingulum | Fornix | |||||
|---|---|---|---|---|---|---|
| Descending | Superior | Anterior | Crus | Body | Columns | |
| FA | ||||||
| Standard | 0.48 ± 0.02 | 0.66 ± 0.02 | 0.44 ± 0.02 | 0.49 ± 0.02 | 0.54 ± 0.05 | 0.52 ± 0.02 |
| FLAIR | 0.50 ± 0.02 | 0.65 ± 0.03 | 0.48 ± 0.03 | 0.53 ± 0.02 | 0.61 ± 0.03 | 0.54 ± 0.03 |
| Difference | 0.02 ± 0.01 | −0.01 ± 0.01 | 0.05 ± 0.03 | 0.03 ± 0.02 | 0.07 ± 0.05 | 0.01 ± 0.04 |
| P | .011 | .04 | .027 | .011 | .015 | .29 |
| Mean ADC (×10−3mm2/s) | ||||||
| Standard | 0.75 ± 0.03 | 0.71 ± 0.02 | 0.72 ± 0.03 | 0.96 ± 0.1 | 1.45 ± 0.1 | 0.99 ± 0.07 |
| FLAIR | 0.75 ± 0.02 | 0.72 ± 0.01 | 0.73 ± 0.03 | 0.89 ± 0.04 | 1.0 ± 0.04 | 0.95 ± 0.06 |
| Difference | 0 ± 0.02 | 0.01 ± 0.01 | 0.01 ± 0.01 | −0.06 ± 0.08 | −0.44 ± 0.13 | −0.04 ± 0.08 |
| P | 1.0 | .14 | .16 | .05 | .008 | .16 |
| Volume (mm3) | ||||||
| Standard | 504 ± 136 | 1196 ± 504 | 168 ± 30 | 244 ± 136 | 572 ± 96 | 174 ± 44 |
| FLAIR | 600 ± 196 | 1508 ± 492 | 260 ± 72 | 540 ± 130 | 724 ± 126 | 292 ± 110 |
| Difference | 110 ± 120 | 312 ± 391 | 120 ± 43 | 196 ± 87 | 150 ± 138 | 118 ± 81 |
| P | .123 | .036 | .018 | .008 | .015 | .011 |
Note.—FA indicates fractional anisotropy; ADC, apparent diffusion coefficient; FLAIR, fluid-attenuated inversion recovery.
FA, mean ADC, and volume (mean ± SD) are presented for 3 portions of the fornix and cingulum depicted with tractography derived from diffusion tensor imaging datasets with and without CSF suppression (FLAIR and Standard, respectively). Except for the superior portion of the cingulum, all structures showed no interhemispheric asymmetry and are therefore presented as collapsed data; that is (left + right)/2. FLAIR diffusion tensor imaging resulted in significant increases of fractional anisotropy in the descending and anterior portions of the cingulum, crus, and body of the fornix, as well as decreases of mean ADC in the crus and body of the fornix. A significant increase in tract volume with CSF suppression was also observed in 5 of 6 tract portions.