Table 4.
Grading of each measurement in conventional radiographs.
| Grades | CG | Stage B1 | Stage B2 | Stage C | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OB1 | OB2 | OB3 | OB1 | OB2 | OB3 | OB1 | OB2 | OB3 | OB1 | OB2 | OB3 | ||
| VHS | 1 | 17 | 21 | 40 | 22 | 25 | 42 | 23 | 24 | 45 | 13 | 16 | 40 |
| 2 | 23 | 18 | 5 | 19 | 14 | 6 | 19 | 17 | 3 | 24 | 19 | 5 | |
| 3 | 4 | - | 3 | 4 | 2 | 1 | 5 | 1 | 1 | 4 | 1 | 2 | |
| 4 | 2 | 1 | 1 | 3 | 1 | - | 2 | - | 1 | 3 | 1 | 2 | |
| 5 | 4 | 10 | 1 | 2 | 8 | 1 | 1 | 8 | - | 6 | 13 | 1 | |
| RLAD | 1 | 2 | 3 | 3 | 3 | 4 | 6 | 7 | 3 | 10 | 2 | 3 | 21 |
| 2 | 7 | 8 | 14 | 11 | 13 | 14 | 14 | 10 | 15 | 18 | 13 | 13 | |
| 3 | 11 | 3 | 2 | 13 | 3 | 5 | 12 | 2 | 1 | 10 | 3 | 3 | |
| 4 | 7 | 7 | 17 | 7 | 6 | 15 | 7 | 9 | 19 | 6 | 1 | 7 | |
| 5 | 23 | 29 | 14 | 16 | 24 | 10 | 10 | 26 | 5 | 14 | 30 | 6 | |
| LAWidth | 1 | 12 | 17 | 34 | 16 | 20 | 35 | 22 | 19 | 43 | 8 | 15 | 39 |
| 2 | 20 | 16 | 10 | 20 | 11 | 11 | 19 | 18 | 3 | 29 | 21 | 4 | |
| 3 | 6 | 1 | 3 | 5 | 5 | - | 5 | 1 | 2 | 2 | - | 2 | |
| 4 | 6 | - | 1 | 4 | 3 | 3 | 2 | 2 | 2 | 5 | 3 | 5 | |
| 5 | 6 | 16 | 2 | 5 | 11 | 1 | 2 | 10 | - | 6 | 11 | - | |
| VLAS | 1 | 27 | 23 | 35 | 26 | 23 | 36 | 35 | 29 | 44 | 31 | 30 | 44 |
| 2 | 11 | 17 | 11 | 15 | 19 | 10 | 10 | 13 | 3 | 10 | 10 | - | |
| 3 | - | 1 | 1 | 1 | - | - | 1 | - | 1 | - | - | 2 | |
| 4 | 12 | 4 | 2 | 7 | 5 | 3 | 4 | 2 | 2 | 7 | 7 | 4 | |
| 5 | - | 5 | 1 | 1 | 3 | 1 | - | 6 | - | 2 | 3 | - | |
Summarized observers’ confidence in the radiographic measurements. Three veterinarians with different levels of experience level (recently graduated veterinarian, experienced veterinarian, and specialized veterinarian) performed the grading. Grades represented the difficulty in recognizing the anatomical landmarks and defining the radiographic measurements. Staging according to the latest consensus statement of the American Colleague of Veterinary Internal Medicine (ACVIM). CG—Control group; LAWidth—Left Atrial Width; OB1—recently graduated veterinarian; OB2—experienced veterinarian; OB3—specialized veterinarian; RLAD—Radiographic Left Atrial Dimension; VHS—Vertebral Heart Size; VLAS—Vertebral Atrial Size.