CASE REPORT Is the skull x-ray a useful tool in paediatric blunt head injury and are we familiar with an abnormal finding? S Andronikou MBChB, FCRadDiag (SA), FRCR (London) eWelman MBChB E Kader MBChB J Venter MBChB T Kilborn MBChB Department of Paedlatrfc Radiology, University of Gape Town and Institute of Child Health, Red Cross War Memorial Children's Hospital, Rondebosch, Cape Town Corresponding aut lIar SAndronlkou Department of Paediatric Radiology, Red Cross war Memorial Children's Hospital, Gape Town, 7700 Tel: (021) 658-5422. Fax: (021) 658-5101. E-mail: docsav@mweb.co.za Abstract Skull X-ray (SXR) has been, and sti II is, used in some institutions to detect skull fractures in paediatric head injuries. When no clinical/neurological indication for computed tomography (CT) scanning exists, the presence of a sku II fracture may be used as an indication for this. This case report demonstrates an unusual SXR finding of oval lucencies in a neurologically normal child who had sustai ned a head injury. The subsequent CT scan demonstrated a subacute subdural haemorrhage with ai r pockets, highlighting the need to recognise 45 SAJOURNAL OF RADIOLOGY· February2001 intracranial air. The Iiterature is reviewed regarding the usefulness of SXR in childhood head injury. Keywords Computerised tomography/ skull fracture/ subdural haem orrh age/ pneumocranium Introduction Some institutions have previously used and continue to use a skull x- ray (SXR) in the protocol for investi- gation of blunt head injury.' Compu- terised tomography (CT) is recom- mended as the imaging modality of choice for investigating blunt head trauma and, when normal in a patient with an isolated head injury, allows the clinician to discharge the patient.': 4 It is in mildly injured patients where there are no positive neurological findings or a Glasgow coma scale (GCS) between 13 and 15 that con- troversy exists on whether a CT scan is routinely indicated.1,2,4,s In an environment where costs and the availability of CT scanning are primary considerations, there is a dif- ficult choice between - 1. discharging patients based on negative clinical/neurological findings and running the potential risks of missing an intracranial abnormality; 2. admitting patients for observation without CT scanning, which has been shown by certain authors to be more expensive than the following option 3; 3. subjecting all patients to routine CT scanning. The place of skull radiography is considered controversial,' but detect- ing a skull fracture is considered an in- dication for CT scanning in institutions----- topage46 mailto:docsav@mweb.co.za Is the skull x-ray a useful tool in paediatric blunt head injury and are we farriil iar with an abnornlal finding? from page 45 where SXR is still performed. Recog- nising the skull fracture per se has lit- tle clinical benefit, as it has little to do with management or outcome.' It is also well known that in children severe intracranial injury can occur in the ab- sence of skull fractures.' A study from Alder Hey in Liver- pool states that SXR is not a reliable predictor of intracranial injury and is indicated only- • in penetrating head injury; • when non-accidental injury (NAI) is suspected, especially in children less than two years of age; • to confirm/ excl ude suspected depressed skull fracture.' The sensitivity for predicting in- tracranial injury based on neurologi- cal abnormalities was 91 %, while the sensitivity of SXR for predicting in- tracranial injury was 65%.] Other authors have calculated that in a fully conscious child with a skull fracture, the risk of intracranial hae- matoma was 80 times higher than in a child without a fracture."These are two typical conflicting views on the value of SXR. Lloyd et al noted that significant injury was not seen in the ab- sence of neurological signs and symptoms, but brain injury is com- monly seen in the ab- sence of a skull frac- ture.' The number of skull fractures detected was also very low at 2,7%. Another feature to note is that intracra- nial haem atom as sus- tained from mild head injuries are associated with neither an abnor- mal skull X -ray nor ab- normal neurological findings in up to 16-20% of cases.' As yet unpublished data from our institution showed that no drainable collection found on CT over a five-year period in patients with mild head injury was present without an associated skull fracture. Case report We present a case of a four-year- old boy who presented five days after having sustained a blunt head injury from falling off a bed. There was no history of loss of consciousness, but the patient had complained of head- aches for the past week and had vom- ited twice. The Glasgow coma scale was 15/15 and no neurological abnor- malities were detected on clinical ex- amination. A CT scan was not indi- cated according to the existing pro- tocol, but a skull X -ray was performed and called normal, resulting in the patient being discharged. When the radiologist reviewed the films the following day, he noted nu- merous lucencies on the lateral skull film (Figure 1), which were puzzling, Figure 1: Numerous ovallucencies are seen over the temporal and parietal bones on lateral SXR (open arrow) and a faint linear fracture that was missed initially is visible on careful inspection (closed arrow) 46 SA JOURNAL OF RADIOLOGY. February 2001 and recalled the patient for a CT scan. The CT scan demonstrated a large right subdural haemorrhage contain- ing air pockets and low densities in keeping with clot evolution (Figures 2 and 3). Review of the skull X-ray showed a fine vertical fracture line traversing the lucencies. Figure 2: Axial CT of the brain on bone window setting clearly demonstrates the air pockets (open arrow), explaining the ovallucencies seen on plain film underlying the right parietal bone Figure 3: Axial CT of the brain on soft tissue/ "brain" window setting demonstrates a significant right-sided subacute subdural haemorrhage (open arrow) that has undergone evolution and the air pockets at the non-dependent portion of the surface col/eclion topage47 Is the skull x-ray a useful tool in paediatric blunt head injury and are vye familiar vvith an abnormal finding? frompage46 I Head injury I ----------- ---------No neurological findings Positive neurological findings Skull X-ray Skull fracture or other abnormality Computed tomography of the head If normal and no other injury, then discharge home Conclusion Current imaging protocol for paediatric blunt head injury used at the Red Cross Children's Hospital This case highlights numerous is- sues: 1. A child may present with a normal Glasgow coma scale and no neurological findings, but still have a significant intracranial bleed that needs surgical intervention. 2. If skull X -rays are to be performed, then we should be aware of features other than skull fractures, such as pockets of air, that are also an indication for CT scanning. 3. Assessment of an SXR by non- radiological staff is a drawback of performing routine SXR, as fractures and more confusing findings may be missed. 4. Institutions without direct CT access may need to evaluate patients clinically and possibly using skull X- rays alone as predictors of intracranial haemorrhage. In such institutions it should be remembered that the neurological findings have a better predictive value than skull X -rays, but if skull X -rays are to be used, then any 47 SA JOURNAL OF RADIOLOGY· February 2001 abnormality should urge the clinician to request a CT scan from a tertiary institution. Acknowledgements We would like to thank the Red Cross Children's Hospital radiogra- phers Dawn Skippers, Jessica Bertelsman, Sylvia Paverd and Nasrin Lahri for their contribution toward this paper. References 1. Lloyd DA, Carty H, Patterson M, Butcher CK, Roe D. Predictive value of skull radiography for intracranial injury in children with blunt head injury. Lancet 1997; 349: 821-824. 2. Davis RL, Mullen N, Makela M, Taylor JA, Cohen W, Rivara FP. Cranial computed tomography scans in children after minimal head injury with loss of consciousness. Ann Emerg Med 1994; 24: 640-645. 3. Davis RL, Hughes M, Gubler KO, Waller PL, Rivara FP. The use of cranial CT scans in triage of paediatric patients with mild head injury. Paediatrics 1995; 95 (3): 345-349. 4. Baker SR, Gaylord GM, Lantos G, Tabadder K, Gallagher EJ. Emergen y skull radiography: The effect of restrictive crit ria on skull radiography and CT use. Radiology 1985; 156: 409-413. 5. Stein SC, O'Malley KF, Ross SE. Is routine computer tomography scanning too expensive for mild head injury? Ann Emerg Med 1991; 20: 1286-1289. 6. Teasdale G M, Murray G, Anderson E et al. Risks of acute traumatic intracranial haematoma in children and adults: Implications for managing head injuries. BMI 1990; 300: 363-67