Magnification of the mediastinum 1 and 2 SD above the mean*
| x ray cassette placement | ||||
|---|---|---|---|---|
| FFD (cm) | Beneath patient | Beneath spinal board | Beneath shallow trolley | Beneath deep trolley |
| *Mediastinum located at the average AP depth within the chest. | ||||
| 100 | 8.67,9.83 | 9.18,10.40 | 10.05,11.39 | 10.94,12.40 |
| 140 | 8.22,9.32 | 8.54,9.68 | 9.08,10.29 | 9.56,10.84 |
| 180 | 8.0,9.07 | 8.67,9.32 | 8.60,9.75 | 8.94,10.14 |