Is routine computed tomographic (CT) scanning necessary in suspected basal skull fractures?

[Basilar skull fractures]

CLINICAL ISSUE

Basilar skull fractures are fractures of the lower part of the skull. They make up about 20% of all skull fractures and are mainly caused by high-velocity blunt trauma and falls from high heights. Depending on their precise location, they can be divided into frontobasal, laterobasal and frontolateral fractures. Possible clinical signs are the presence of cerebrospinal fluid rhinorrhea or otorrhea, periorbital ecchymosis (raccoon eyes), retroauricular ecchymosis (battle sign) and cranial nerve injuries. Furthermore, fractures of the petrous bone can lead to a conductive hearing loss, sensorineural hearing loss as well as dizziness and nausea due to a failure of the labyrinth.

PRACTICAL RECOMMENDATIONS

If there are any clinical signs of a basilar skull fracture, neurological deficits or limited consciousness (GCS < 15), a CT should be performed to rule out a basilar skull fracture and accompanying pathologies. In addition, if vascular injury is suspected, a CT angiography should be performed. Treatment is usually interdisciplinary and depends mainly on the accompanying injuries and possible complications. A purely conservative approach with close controls (with imaging) is often sufficient. The surgical approach is primarily used to treat possible complications, for example intracerebral bleeding.

Application of a deep learning image reconstruction (DLIR) algorithm in head CT imaging for children to improve image quality and lesion detection

BACKGROUND

To evaluate the performance of a Deep Learning Image Reconstruction (DLIR) algorithm in pediatric head CT for improving image quality and lesion detection with 0.625 mm thin-slice images.

METHODS

Low-dose axial head CT scans of 50 children with 120 kV, 0.8 s rotation and age-dependent 150-220 mA tube current were selected. Images were reconstructed at 5 mm and 0.625 mm slice thickness using Filtered back projection (FBP), Adaptive statistical iterative reconstruction-v at 50% strength (50%ASIR-V) (as reference standard), 100%ASIR-V and DLIR-high (DL-H). The CT attenuation and standard deviation values of the gray and white matters in the basal ganglia were measured. The clarity of sulci/cisterns, boundary between white and gray matters, and overall image quality was subjectively evaluated. The number of lesions in each reconstruction group was counted.

RESULTS

The 5 mm FBP, 50%ASIR-V, 100%ASIR-V and DL-H images had a subjective score of 2.25 ± 0.44, 3.05 ± 0.23, 2.87 ± 0.39 and 3.64 ± 0.49 in a 5-point scale, respectively with DL-H having the lowest image noise of white matter at 2.00 ± 0.34 HU; For the 0.625 mm images, only DL-H images met the diagnostic requirement. The 0.625 mm DL-H images had similar image noise (3.11 ± 0.58 HU) of the white matter and overall image quality score (3.04 ± 0.33) as the 5 mm 50% ASIR-V images (3.16 ± 0.60 HU and 3.05 ± 0.23). Sixty-five lesions were recognized in 5 mm 50%ASIR-V images and 69 were detected in 0.625 mm DL-H images.

CONCLUSION

DL-H improves the head CT image quality for children compared with ASIR-V images. The 0.625 mm DL-H images improve lesion detection and produce similar image noise as the 5 mm 50%ASIR-V images, indicating a potential 85% dose reduction if current image quality and slice thickness are desired.

Prevalence and pattern of basal skull fracture in head injury patients in an academic hospital

Background

Basal skull fractures (BSFs) have been reported to be a major cause of morbidity and mortality in the literature, particularly in young male patients. However, there are limited data available on the aetiology, prevalence and patterns of such observed in South Africa.

Objectives

To evaluate the prevalence and pattern of BSF in head injury patients referred to Dr George Mukhari Academic Hospital, Gauteng, South Africa.

Methods

Patients of all ages with head injuries were considered for the study, and those who met the inclusion criteria were scanned using a 128-slice multidetector helical computed tomography (CT) machine after obtaining consent. Data were prospectively obtained over a 6-month period, interpreted on an advanced workstation by two readers and statistically analysed.

Results

The prevalence of BSF in this study was found to be 15.2%. The majority of patients (80.5%) were under 40 years old, with a male to female ratio of 3:1. The most common aetiology of BSF was assault, which accounted for 46% of cases. The middle cranial fossa was the most frequently fractured compartment, while the petrous bone was the most commonly fractured bone. There was a statistically significant association between head injury severity and BSF, and between the number of fracture lines and associated signs of BSF (p < 0.001). The sensitivity of clinical signs in predicting BSF was 31%, while specificity was 89.3% (p = 0.004).

Conclusion

The prevalence and pattern of BSF found were consistent with data from previously published studies, although, dissimilarly, assault was found to be the most common aetiology in this study.

Analysis and Clinical Importance of Skull Base Fractures in Adult Patients with Traumatic Brain Injury

Aims and Objectives:

Basal skull fracture (BSF) is rare in head injury (HI) patients and occasionally goes unnoticed which may lead to cerebrospinal fluid (CSF) fistula. With changing trends in HI, there is a need to reassess incidence and pattern of BSF pattern, CSF leak, meningitis, and management protocol, especially in this part of the world where detailed literature is lacking.

Subjects and Methods:

We closely followed adult patients admitted with BSF in our institute between January 2013 and December 2014. Associated clinical features were recorded. In case of CSF leak, detailed CSF study was done and patients were managed accordingly. Patients with persistent CSF leak were managed surgically.

Results:

During the study period, 194 of 5041 HI patients had evidence of BSF (3.85%). BSF was most commonly associated with moderate-to-severe HI (73.19%). About 81.44% patients were male and 29.9% were <30 years. Most common cause was road traffic accident (84.54%). Isolated anterior cranial fossa (ACF) fracture was most common (50%). About 63.92% patients had raccoon eyes. Forty-three patients had CSF leak with CSF rhinorrhea being more common. Culture of only 5 patients suggested bacterial meningitis. CSF leak lasted for more than 10 days in 8 patients, of which 4 patients required surgical repair.

Conclusions:

BSF is rare in victims of HI. It is more common in young adult males. ACF fractures are most common in our setup. Clinical signs of BSF are supportive but not definitive; high resolution computed tomography head is gold standard to detect BSF. CSF leak is rare and most of the cases can be managed conservatively. Leak persisting more than 7–10 days has high risk of developing meningitis and likely to need surgical intervention.

Comparative analysis of clinical and computed tomography features of basal skull fractures in head injury in southwestern Nigeria

BACKGROUND

Basal skull fractures (BSF) in head injury may be missed clinically. Early detection ensures prompt treatment and prevention of complications We compared the clinical and Computed Tomography (CT) features of basal skull fractures in head injured patients in a southwestern Nigerian hospital.

MATERIALS AND METHODS

Head injury patients who had cranial CT at a Southwestern Nigerian hospital were selected. CT images were acquired with a 64-slice Toshiba Aquillion CT scanner using a standard head protocol. The images were evaluated for evidence of skull fractures, and associated complications. The clinical data and CT findings were analyzed.

RESULTS

One hundred and thirty patients were evaluated, including 103 (79.2%) males. Their ages ranged between 7 months and 81 years, mean 35 years (SD, 20.3). In 59 patients (45.4%, 59/130) BSF was detected on CT, while 71 (54.6%) had no evidence BSF. Forty-two (71.2%) of the 59 patients detected on CT had clinical suspicion of BSF (P < 0.001) while the remaining 17 (28.8%) were not clinically diagnosed. This equaled a sensitivity of 71.2% and, specificity of 90.1% for clinical determination of BSF in this study. There was no statistically significant difference between clinical and CT diagnosis (P > 0.05). The commonest observed clinical feature in patients with confirmed BSF was otorrhagia (45.8%) and the petrous temporal bone (45.8%) was the most commonly fractured bone. The BSF was caused most commonly by motor bike accidents in 53 (40.8%). The most common associated intracranial injuries were intracerebral haemorrhage (34.6%) and subdural (17.3%).

CONCLUSION

It appears that neurosurgical evaluation is comparatively reliable in evaluating basal skull fractures in this study area even as they are consistently demonstrated by high resolution CT scanners. A clinical suspicion of BSF should warrant a closer detailed CT evaluation and reporting by radiologists.

The clinical features of periorbital ecchymosis in a series of trauma patients

INTRODUCTION

Periorbital ecchymosis (PE) is caused by blood tracking along tissue plains into periorbital tissues, causing discoloration in the upper and lower eyelids. This clinical feature is most commonly associated with basal skull fractures. Our objective is to present the first patient series describing the clinical features associated with traumatically induced PE.

METHODS

The authors retrospectively reviewed 36 consecutive cases of patients presenting to the emergency department with PE over a three-year period at St. Michael's Hospital in Toronto. Data were obtained using a standardised data acquisition template.

RESULTS

All patients presented to the emergency department with PE. The mean age in our series was 39 years (range 19-88 years), 31 patients were male. PE was associated with a variety of injuries including: 15 basal skull fractures, 9 soft tissue injuries without fractures, 8 convexity fractures, and 3 facial fractures. The other classic signs of basal skull fracture (Battle's sign, hemotympanum, cerebrospinal fluid otorrhea, cerebrospinal fluid rhinorrhea) were observed in 3, 7, 1, and 3 patients with PE, respectively. The most common clinical feature associated with PE was cranial nerve injury, observed in 10 patients. Surgical intervention was required in 8 patients. Five patients were discharged to a rehabilitation centre. No meningitis, cerebral abscess, encephalitis or deaths were observed.

CONCLUSION

Periorbital ecchymosis is a useful clinic sign that should alert the clinician to assess for skull fractures, intracranial haemorrhage, and cranial nerve injury. However, this series shows that PE can be associated with a variety of clinical features, is rarely accompanied by other classic signs of basal skull fracture, and most patients with PE do not have injuries severe enough to require surgical intervention or post-discharge rehabilitation.

A comparative study of cranial, blunt trauma fractures as seen at medicolegal autopsy and by computed tomography

Background

Computed Tomography (CT) has become a widely used supplement to medico legal autopsies at several forensic institutes. Amongst other things, it has proven to be very valuable in visualising fractures of the cranium. Also CT scan data are being used to create head models for biomechanical trauma analysis by Finite Element Analysis. If CT scan data are to be used for creating individual head models for retrograde trauma analysis in the future we need to ascertain how well cranial fractures are captured by CT scan. The purpose of this study was to compare the diagnostic agreement between CT and autopsy regarding cranial fractures and especially the precision with which cranial fractures are recorded.

Methods

The autopsy fracture diagnosis was compared to the diagnosis of two CT readings (reconstructed with Multiplanar and Maximum Intensity Projection reconstructions) by registering the fractures on schematic drawings. The extent of the fractures was quantified by merging 3-dimensional datasets from both the autopsy as input by 3D digitizer tracing and CT scan.

Results

The results showed a good diagnostic agreement regarding fractures localised in the posterior fossa, while the fracture diagnosis in the medial and anterior fossa was difficult at the first CT scan reading. The fracture diagnosis improved during the second CT scan reading. Thus using two different CT reconstructions improved diagnosis in the medial fossa and at the impact points in the cranial vault. However, fracture diagnosis in the anterior and medial fossa and of hairline fractures in general still remained difficult.

Conclusion

The study showed that the forensically important fracture systems to a large extent were diagnosed on CT images using Multiplanar and Maximum Intensity Projection reconstructions. Difficulties remained in the minute diagnosis of hairline fractures. These inconsistencies need to be resolved in order to use CT scan data of victims for individual head modelling and trauma analysis.

Epistaxis as the only initial symptom in pediatric naso-orbital-ethmoid fracture complicated with meningitis

Epistaxis is a frequent finding in patients with facial trauma. Herein, we report an unusual presentation of pediatric naso-orbital-ethmoid (NOE) fracture with epistaxis as the only initial symptom. The course of the patient's condition was later complicated by meningitis, related in part to the delay in diagnosis. A 3-year-old girl with preexisting upper respiratory symptoms was involved in a traffic accident, sustaining blunt trauma to the right side of her face. During the initial examination, only right-sided epistaxis was noted. Five days later, she developed febrile convulsion and was admitted to the intensive care unit with other signs of meningitis such as mental status change and neck stiffness. Her craniofacial computed tomographic scan showed a right-sided NOE fracture with minimal displacement and without dura tear. The cerebrospinal fluid culture grew Streptococcus pneumoniae, which may be due to ascending infection as a result of cribriform plate fracture. Intravenous antibiotic therapy was initiated with good response, and she was discharged from the hospital after 2 weeks. The presence of epistaxis and periorbital bruise, together with other symptoms and signs, helps in the identification of NOE and cribriform plate fracture. A high index of suspicion with repetitive computed tomographic scans is necessary to achieve correct early diagnosis. Parental antibiotic therapy is indicated if ascending cerebrospinal fluid infection develops.

Three-dimensional fracture visualisation of multidetector CT of the skull base in trauma patients: comparison of three reconstruction algorithms

The purpose of this study was to retrospectively assess the detection rate of skull-base fractures for three different three-dimensional (3D) reconstruction methods of cranial CT examinations in trauma patients. A total of 130 cranial CT examinations of patients with previous head trauma were subjected to 3D reconstruction of the skull base, using solid (SVR) and transparent (TVR) volume-rendering technique and maximum intensity projection (MIP). Three radiologists independently evaluated all reconstructions as well as standard high-resolution multiplanar reformations (HR-MPRs). Mean fracture detection rates for all readers reading rotating reconstructions were 39, 36, 61 and 64% for SVR, TVR, MIP and HR-MPR respectively. Although not significantly different from HR-MPR with respect to sensitivity (P = 0.9), MIP visualised 18% of fractures that were not reported in HR-MPR. Because of the relatively low detection rate using HR-MPRs alone, we recommend reading MIP reconstructions in addition to the obligatory HR-MPRs to improve fracture detection.

The contribution of high-resolution multiplanar reformats of the skull base to the detection of skull-base fractures

AIM

To investigate the contribution of routine review of submillimetric multiplanar reformats to the diagnosis of skull-base fractures.

METHODS

A prospective analysis was performed of 407 cases referred over a 6-month period for CT of the skull following cranial trauma. The reformatted 5-mm axial sections and subsequently the high-resolution multiplanar reformats (HRMPRs) were viewed on an ADW 4.1 workstation using bone windows and algorithm. All skull-base fractures and related features, recorded by the consensus of two radiologists, were classified as anatomically significant or non-significant on the basis of eight criteria. The clinical features of skull-base injury and any subsequent treatment were noted in all cases of skull-base fracture.

RESULTS

HRMPRs detected 80 separate skull-base fractures in 36/407 cases. Of these 80 fractures, 57 were visible on 5-mm axial sections. In 8 of the 36 cases, the significant anatomical features were only evident on review of the HRMPRs. In 6 of the 36 cases, none of the skull-base fractures was visible on 5-mm sections, but these individuals had only minor associated clinical features and no therapeutic requirements. Review of HRMPRs could have been confined to patients with skull-base fractures, abnormal intracranial and extracranial air collections or opacified mastoid air cells revealed by 5-mm axial sections. This policy would have led to the detection of 79/80 (99%) of skull-base fractures and all significant anatomical features.

CONCLUSION

The 5-mm axial sections demonstrated 71% of skull-base fractures and 78% of skull-base fractures with significant anatomical features, using HRMPRs as a gold standard. There were no significant clinical sequelae at short-term follow-up of those fractures only evident on HRMPRs.

'Raccoon eyes' (periorbital haematoma) as a sign of skull base fracture

This is a study of the relationship between skull base fracture and the raccoon eyes sign in a prospective study in cadavers. Fifty cadavers were analysed with cranio encephalic trauma and skull base fracture or the raccoon eyes sign. Both conditions were present in 24 (48.0%) cases. The association was significantly higher in cases with a frontal basal fracture and epidural haematoma. The raccoon eyes sign is easily recognised and can be associated with basal fractures.