Retrotracheal Soft Tissues
1
(Lateral radiographs of the neck)
| Age(yrs) | Maximum (mm) |
| 0-1 | 1.5 x C5* |
| 1-3 | 0.5 x C5 |
| 3-6 | 0.4 x C5 |
| 6-14 | 0.3 x C5 |
Retrotracheal Soft Tissues
1
(Lateral radiographs of the neck)
|
|
Maximum (mm) |
| 0-1 | 2.0 x C5* |
| 1-2 | 1.5 x C5 |
| 2-3 | 1.2 x C5 |
| 3-6 | 1.2 x C5 |
| 6-14 | 1.2 x C5 |
*measurement made at mid-portion of C5 vertebral body on lateral radiograph
Note: expiratory phase and flexion of neck increases apparent thickness of tissues artifactually
Rule of 7's:
no greater than 7 mm for retropharyngeal soft tissues
no greater than 14 mm for retrotracheal soft tissues2
References:
1. Hay PD, Jr. The Neck: A roentgenological study
of the soft tissues: Consideration of the normal and pathological.
III. Normal necks (infants and children). Ann Roentgenol Vol
9. New York: Hoever, 1930, p22-8
2. Redman HC, Purdy PD, Miller GL, Rollins NK. Emergency
Radiology. Cervical Spine. W.B. Saunders 1993. p 183-186.