In paediatric imaging, the anteroposterior supine chest x-ray is beneficial for imaging unconscious or uncooperative patients. This view is preferred in infant and neonate imaging, whilst AP erect and PA erect views are ideal for children able to co-operate in sitting or standing 1.
As radiation protection is necessary for paediatric patients, it is essential to image the chest properly and avoid unnecessary repeats. If the paediatric patient can only manage a supine view, this is more ideal than performing a poor erect view.
- patient is supine
- detector is placed underneath the patient, or the patient is placed on top of the detector
- head is straight and chin ideally out of the field of view
- arms are placed by the patients’ side outside of the field of view or above the head; either method is equally effective 2
- anteriorposterior projection
- observe breathing by watching the patient's stomach
- the level of the 7th thoracic vertebra; on or above the level of the nipple
- a 10 degree caudal angle can be used to degrees the patient’s lordosis
- superior to the 3rd cervical vertebrae
- inferior to the thoracolumbar junction
- lateral to the skin margins
- it is advised not to collimate too tightly at the apices as breathing may cause the apices to move superiorly
- 24 cm x 30 cm or 35 cm x 43 cm depending on the patient’s size
- 55-65 kVp
- 1-2 mAs
- 110 cm
Image technical evaluation
- entire lung fields should be visible; post-processing collimation is not advisable in paediatric imaging (if it is exposed it should be examined). This is particularly important if the clinical indications query a foreign body as demonstrating the abdomen will also be useful in diagnosis
- 6 anterior ribs must be visible to ensure full inspiration
- the clavicles lie on the same horizontal plane
- measuring the medial ends of the clavicle to the spinous process is not advised due to ossification centres and superior positioning of the shoulder girdle 2
- measure the distances from the 4th ribs lateral border to the centre of the spine (upper)
- measure the distances from the 8th ribs lateral border to the centre of the spine (lower)
In order to streamline workflow, preparing the room beforehand (set up the detector and prepare lead gowns) will be extremely useful in paediatric chest imaging. Placing a pillowcase over the detector will also increase patient comfort.
Ensuring appropriate inspiration and no motion may also require specialised communication techniques to gain co-operation from the child. Examples include:
- “you have to breathe in like you are about to blow out a birthday candle!”
- “take a big sniff now”
- “lets play dead fish!”
Some children will maintain their position for the examination, others will not. Research regarding the most effective method of immobilisation is lacking. Immobilisation methods will range from radiographers holding the child to the utilisation of multiple Velcro straps, some departments may consider the latter 'restraint' it is important to clarify with local guidelines.
Family members may assist in distracting or holding the child. It is important to give the parents a focussed task; particularly when they are feeling anxious for their children. It is suggested to avoid physical holding due to the scattered radiation given to the parent or holder 6.
- 1. Leonard E. Swischuk. Imaging of the Newborn, Infant, and Young Child. (2015) ISBN: 9781469875743
- 2. Pedersen Christina Carøe Ejlskov, Maryann Hardy and Anne Dorte Blankholm. "An Evaluation of Image Acquisition Techniques, Radiographic Practice, and Technical Quality in Neonatal Chest Radiography". Journal of Medical Imaging and Radiation Sciences 49, no. 3 (2018): 257-264. . doi:10.1016/j.jmir.2018.05.006.
- 3. Kohn M. M. European guidelines on quality criteria for diagnostic radiographic images in paediatrics, 1996.
- 4. Knight SP. A paediatric X-ray exposure chart. (2014) Journal of medical radiation sciences. 61 (3): 191-201. doi:10.1002/jmrs.56 - Pubmed
- 5. Hardy Maryann and Beverly Snaith,. "Improving neonatal chest radiography: an evaluation of image acquisition techniques, dose and technical quality". In UK Radiological Congress. Manchester, 2014.
- 6. Ng Jessica Hui Shi and Edel Doyle. "Keeping Children Still in Medical Imaging Examinations- Immobilisation or Restraint: A Literature Review". Journal of Medical Imaging and Radiation Sciences (2018). . doi:10.1016/j.jmir.2018.09.008.
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