Accuracy and reliability of the measurements of the first part of the anterior cerebral artery (A1) in cerebral CT angiography (CTA) scans
| Reliability (R) | Technical error of measurement (TEM) in mm | Relative TEM (rTEM) in % | |
| Repeat A1 measurement in axial CTA images (not adjusted*) | 0.93 | 0.24 | 11.00 |
| Repeat A1 measurement in axial CTA images (adjusted*) | 0.98 | 0.12 | 5.39 |
| Repeat A1 measurement in axial and coronal CTA images (adjusted*) | 0.98 | 0.10 | 4.77 |
| Repeat A1 measurement in coronal CTA images (not adjusted) | 0.94 | 0.22 | 10.45 |
| Repeat A1 measurement in coronal CTA images (adjusted*) | 0.96 | 0.14 | 6.55 |
The coefficients of variation of the measurements (rTEM) are presented. Reliability is the correlation among the previous first measurement done in coronal and axial CTA slices and the second measurement performed in axial and coronal cerebral CTA after 15 months of the initial measurement taken of the same artery, computed tomography = CT, A1=first part of anterior cerebral artery, n=30
*Adjustment made by excluding two outliers from the previous and the corresponding repeat measurements of right A1 (file supplied in online supplemental file 2).