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Three Part Question

In [a paediatric patient with blunt abdominal trauma] is [an ultrasound scan better at identifying intra-abdominal injury] than [a CT scan]?

Clinical Scenario

A 6 year old boy presents to the emergency department after falling out of a fast moving car. He is extremely distressed and appears to have sustained multiple injuries including a large laceration to his head, bruising and deformity to both forearms and his left lower leg. After initial assessment and stabilisation you decide to paralyse, intubate and ventilate him prior to performing a head CT. However you are also concerned about the possibility of an intra-abdominal injury. You wonder whether an ultrasound or CT would be better at identifying this.

Search Strategy

Medline 1966-07/02 using the OVID interface.
[exp abdominal injuries OR "abdominal injur$".mp OR "abdominal trauma$".mp] AND [exp tomography, x-ray computed OR "computed tomograph$".mp OR "computerised tomograph$".mp OR CT.mp] AND [exp ultrasonography OR ultrasonography.mp OR exp ultrasonics OR ultrasonics.mp Or ultrasound.mp] AND [exp adolescence OR exp child OR exp child of impaired parents OR exp child, abandoned OR exp child, exceptional OR exp child, hospitalised OR exp child, institutionalised OR exp child, preschool OR exp child, unwanted OR exp disabled children OR exp homeless youth/ OR exp infant OR exp only child OR child$.mp OR exp Pediatrics OR pediatric$.mp OR paediatric$.mp] LIMIT to human AND English.

Search Outcome

123 papers were found, of which 117 were irrelevant or of insufficient quality. The remaining 6 papers are shown in the table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Kaufmann RA et al, 1984, USA	95 children with suspected intra-abdominal injury Abdominal CT with contrast v abdominal ultrasound	Diagnostic test study	Intra-abdominal fluid or organ injury identified on initial CT or ultrasound	2 false negative and 6 false positive CT scans	No real gold standard
			Intra-abdominal injury identified at any stage by any means	18 false negative and 3 false positive ultrasound scans
Rossi D et al, 1993, Belgium	38 children with intra-abdominal injuries Abdominal CT with contrast v abdominal ultrasound	Diagnostic test study	Intra-abdominal fluid or organ injury identified on initial CT or ultrasound	CT identified 30 out of 31 cases with intra-abdominal fluid. Ultrasound identified 37 out of 38 cases with intra-abdominal fluid	Retrospective Not all patients had both tests No real gold standard
			Intra-abdominal injury identified at any stage by any means	CT identified organ injury in 33 out of 38 cases. Ultrasound identified organ injury in 14 out of 31 cases
Akgur FM et al, 1997, Turkey	60 children with blunt abdominal trauma who had abnormal findings on abdominal ultrasound Abdominal CT v abdominal ultrasound	Diagnostic test study	Intra-abdominal fluid or organ injury	CT identified the source of intra-abdominal fluid in 3 patients in whom ultrasound could not identify a source	Sample group selective No real gold standard
Richardson MC et al, 1997, UK	26 children with blunt abdominal trauma Abdominal CT with contrast v abdominal ultrasound	Diagnostic test study	Intra-abdominal fluid or organ injury identified on initial CT or ultrasound	CT missed 1 injury. Ultrasound missed 3 injuries	Retrospective No real gold standard
			Intra-abdominal injury identified at any stage by any means	CT diagnosed organ-specific injury in 22 out of 24 patients. Ultrasound diagnosed organ-specific injury in 12 out of 24 patients. Both correctly identified 2 cases of no injury
Partrick DA et al, 1998, USA	100 children who had abdominal CT and ultrasound performed as investigations for blunt abdominal trauma Abdominal CT v abdominal ultrasound performed by an emergency physician	Diagnostic test study	Intra-abdominal fluid. Organ injury	CT identified 7 intra-abdominal injuries not identified on ultrasound	Retrospective Sample group selective No real gold standard
Richards JR et al, 2002, USA	744 consecutive children undergoing ultrasonography for trauma	Prospective diagnostic cohort	Detection of haemoperitoneum	US 56% sensitivity, 97% specificity	Retrospective Sample group selective No real gold standard

Comment(s)

The studies do seem to indicate that CT is better than ultrasound at identifying intra-abdominal injury in children. However, as it is impossible to confirm most of the injuries identified on imaging, it is also difficult to compare the 2 imaging techniques with a definite gold standard. This also needs to be considered in the light of the clinical scenarios encountered by emergency physicians. Because of the need for transport and the time it takes to perform a CT, children with blunt abdominal trauma need to be stable and have no other injuries requiring urgent treatment. Most will also require sedation. Ultrasound can be performed in the resuscitation room, is much quicker and is much less distressing to a terrified child.

Clinical Bottom Line

CT is better than ultrasound at identifying intra-abdominal injury in children.

References

1. Kaufmann RA, Towbin R, Babcock DS, et al. Upper abdominal trauma in children: Imaging evaluation. Am J Roentgenol 1984;142:449-60.
2. Rossi D, de Ville de Goyet J, Clement de Clety S, et al. Management of intra-abdominal organ injury following blunt abdominal trauma in children. Intensive Care Med 1993;19:415-9.
3. Akgur FM, Aktug T, Olguner M, et al. Prospective study investigating routine usage of ultrasonography as the initial diagnostic modality for the evaluation of children sustaining blunt abdominal trauma. J Trauma 1997;42(4):626-8.
4. Richardson MC, Hollman AS, Davis CF. Comparison of computed tomography and ultrasonographic imaging in the assessment of blunt abdominal trauma in children. Br J Surg 1997;84:1144-6.
5. Partrick DA, Bensard DD, Moore EE, et al. Ultrasound is an effective triage tool to evaluate blunt abdominal trauma in the pediatric population. J Trauma 1998;45(1):57-63.
6. Richards JR, Knopf NA, Wang L, et al. Blunt abdominal trauma in children: evaluation with emergency US. Radiology 2002;222:749-54.