First and second year — the floor first, then every step
Children need selective, dose-conscious imaging: decision rules for the head (PECARN) and cervical spine, CT abdomen only when indicated, and awareness of the paediatric patterns — solid organ injury managed non-operatively, SCIWORA, and injuries that suggest abuse.
Orient first
Decision rules (PECARN head, NEXUS/Canadian not validated in young children — verify local pathway) reduce unnecessary CT.
FAST is less sensitive in children; a negative FAST does not exclude injury.
Weight-based low-dose protocols; single portal venous phase for the abdomen.
The manoeuvre
Portal venous phase: solid organ injury grade (AAST), active extravasation.
Hypovolaemic shock complex: flat IVC, bowel wall hyperenhancement, small aorta.
Pancreas and duodenum (bicycle handlebar injury).
Bone window: fractures inconsistent with the mechanism (abuse).
What confirms it
Injuries graded with a dose-appropriate study.
What licenses you to exclude it
A negative CT excludes significant solid organ injury at the time; hollow viscus injury may declare later.
The classic misread
Over-scanning low-risk children.
Reporting the injury
Classification to use
AAST organ injury scales apply; management in children is predominantly non-operative and follows physiology more than grade (verify pathway).
Measurements — and how to take them
Laceration depth in cm; IVC short axis in mm; haemoperitoneum extent.
What to report
Solid organ injuries with grade and active extravasation, the hypovolaemic shock complex, pancreatic and duodenal injury, fractures, and patterns suggesting abuse.
How to report it
CT: "Grade III liver laceration without active extravasation. Flat IVC and diffuse small-bowel hyperenhancement — hypovolaemic shock complex. Communicated to the trauma team."
What not to report
Do not overcall physiological pelvic fluid in girls.
Do not report injuries inconsistent with the mechanism without flagging the safeguarding concern.
Associated injuries to look for
Handlebar injury with pancreatic and duodenal injury; lap-belt injury with Chance fracture and bowel injury.
What changes management
Active extravasation with instability → angiography or surgery.
Suspected abuse → skeletal survey and safeguarding referral.