Spectrum of critical imaging findings in complex facial skeletal trauma

Imaging of Maxillofacial Injuries

This article reviews the system of facial buttresses and discusses the role of diagnostic imaging in the evaluation of the patient with maxillofacial trauma.

[Orbital trauma]

Orbital trauma can occur independently or in conjunction with other craniofacial trauma and can cause damage to bony and neurovascular structures as well as soft tissues. Appropriate interdisciplinary treatment of patients is essential to prevent long-term damage such as blindness or muscle dysfunction. Even complex fractures and soft tissue damage can be visualized using modern thin-layer computed tomography (CT), which is necessary for proper treatment.

Facial fractures: The "bottom-up" approach

Given the demands of a busy high-volume trauma center, trauma radiologists are expected to evaluate an enormous number of images covering a multitude of facial bones in a short period of time in severely traumatized patients. Therefore, a comprehensive checklist, search pattern, and practical approach become indispensable for evaluation. Moreover, fracture complex classification conveys abundant information in a succinct shorthand fashion, which can be a large asset in a busy high-volume trauma center: reliably helping clinicians communicate urgent findings, make early treatment decisions, and effectively plan surgical approaches. Traditionally, radiologists' approach the CT axial dataset in top-down fashion: navigating their descent craniocaudal. However, a bottom-up approach may be advantageous, especially when it comes to facial fracture complex classification. Four key anatomic landmarks of the face, when evaluated sequentially in bottom-up fashion, are favorable to rapid single-sweep facial fracture characterization: the mandible, the pterygoid plates, the zygoma, and the bony orbits. That is, when done in succession: 1. Clearing the mandible rules out a panfacial smash fracture. 2. Clearing the pterygoid plates effectively rules out a Le Fort I, II, and III fracture. 3. Clearing the zygoma effectively rules out a zygomaticomaxillary complex (ZMC) type fracture. 4. Clearing the bony orbits effectively rules out a naso-orbital-ethmoid (NOE) fracture. Following this process of exclusion and elimination; as one ascends through the face, fracture characterization becomes more manageable and straightforward. Besides identifying all of the fractures and using the appropriate classification system, the radiologist also needs to recognize key clinically relevant soft tissue injuries that may be associated with facial fractures and thus should address these in the report.

Head Computed Tomography Versus Maxillofacial Computed Tomography: An Evaluation of the Efficacy of Facial Imaging in the Detection of Facial Fractures

BACKGROUND

In an initial trauma evaluation, computed tomography of the head (CTH) is performed to assess for life-threatening intracranial injury. Given the high incidence of concomitant facial injuries, many facial fractures are diagnosed incidentally during this evaluation. Although maxillofacial CT (CTMF) is widely accepted as the most sensitive method for evaluating facial fractures, it is often excluded from the initial survey. Failure to obtain dedicated imaging can lead to increased costs related to a missed or delayed facial fracture diagnosis. Our study investigates the location and type of missed facial fractures on CTH by reviewing imaging data from patients who presented at a level 1 trauma center and underwent both CTH and CTMF.

METHODS

A retrospective review of all facial fractures diagnosed at a single institution from 2002 through 2016 was conducted. Inclusion criteria included adults aged 18 years or older who received CTH and then subsequent CTMF. Patients who had either CTH or CTMF only or combined CTH/CTMF were excluded. The facial fractures were further subdivided by location.

RESULTS

There were 501 patients with 1743 total facial fractures. CTH successfully identified 788 (45.21%) fractures, versus 1743 (100%) for CTMF. The most common fractures, in both cohorts, were nasal bone (15.7%) and orbital floor (12.8%) fractures. Using CTMF to identify missed fractures on CTH, significant differences were noted in the following locations: anterior table frontal sinus, medial/lateral pterygoid, maxillary sinus, lateral orbital wall, zygomatic arch, palate, and all types of mandible fractures excluding the mandibular condyle.

CONCLUSIONS

CTH for initial trauma evaluation often misses facial fractures. CTH alone was only sufficient in detecting posterior frontal sinus, orbital (excluding lateral wall), and mandibular condyle fractures. In patients with suspected facial injury, dedicated imaging should be performed to detect the location and extent of injury because CTH inadequately identifies most facial fractures.

ACR Appropriateness Criteria® Imaging of Facial Trauma Following Primary Survey

Maxillofacial trauma patients comprise a significant subset of patients presenting to emergency departments. Before evaluating for facial trauma, an emergency or trauma physician must perform a primary survey to ensure patient stabilization. Following this primary survey, this document discusses the following clinical scenarios for facial trauma: tenderness to palpation or contusion or edema over frontal bone (suspected frontal bone injury); pain with upper jaw manipulation or pain overlying zygoma or zygomatic deformity or facial elongation or malocclusion or infraorbital nerve paresthesia (suspected midface injury); visible nasal deformity or palpable nasal deformity or tenderness to palpation of the nose or epistaxis (suspected nasal bone injury); and trismus or malocclusion or gingival hemorrhage or mucosal hemorrhage or loose teeth or fractured teeth or displaced teeth (suspected mandibular injury). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Computed tomography in traumatic orbital emergencies: a pictorial essay-imaging findings, tips, and report flowchart

Computed tomography (CT) is considered the gold standard technique for the assessment of trauma patients with suspected involvement of the eye and orbit. These traumas can result in dramatic consequences to visual function, ocular motility, and aesthetics. CT is a quick and widely available imaging modality, which provides a detailed evaluation of the orbital bony and soft tissue structures, an accurate assessment of the globes, and is used to guide the patients’ treatment planning. For a timely and accurate diagnosis, radiologists should be aware of fracture patterns and possible associated complications, ocular detachments and hemorrhages, and different appearances of intraorbital foreign bodies. This educational review aims to describe all post-traumatic orbital abnormalities that can be identified on CT, providing a list of tips and a diagnostic flowchart to help radiologists deal with this complex condition.

A Prediction Model for Selective Use of Facial Computed Tomography in Blunt Head Trauma Patients

BACKGROUND

Head trauma patients may have concomitant facial fractures, which are usually underdetected by head computed tomography alone. This study aimed to identify the clinical indicators of facial fractures and to develop a risk-prediction model to guide the discriminative use of additional facial computed tomography in head trauma.

METHODS

The authors retrospectively reviewed head trauma patients undergoing simultaneous head and facial computed tomography at a Level II trauma center from 2015 to 2018. Multivariate logistic regression analysis was used to evaluate independent risk factors for concomitant facial fractures in head trauma patients using data collected from 2015 to 2017, and a risk-prediction model was created accordingly. Model performance was validated with data from 2018.

RESULTS

In total, 5045 blunt head trauma patients (development cohort, 3534 patients, 2015 to 2017; validation cohort, 1511 patients, 2018) were enrolled. Concomitant facial fractures occurred in 723 head trauma patients (14.3 percent). Ten clinical and head computed tomographic variables were identified as predictors, including age, male sex, falls from elevation, motorcycle collisions, Glasgow Coma Scale scores less than 14, epistaxis, tooth rupture, facial lesions, intracranial hemorrhage, and skull fracture. In the development cohort, the model showed good discrimination (area under the receiver operating characteristic curve = 0.891), calibration (Hosmer-Lemeshow C test, p = 0.691), and precision (Brier score = 0.066). In the validation cohort, the model demonstrated excellent discrimination (area under the receiver operating characteristic curve = 0.907), good calibration (Hosmer-Lemeshow C test, p = 0.652), and good precision (Brier score = 0.083). With this model, 77.1 percent of unnecessary facial computed tomography could be avoided.

CONCLUSION

This model could guide the discriminative use of additional facial computed tomography to detect concomitant facial fractures in blunt head trauma.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Retrospective Cohort Study of Frequency and Patterns of Orbital Injuries on Whole-Body CT with Maxillofacial Multi-Slice CT

Background: High-impact trauma frequently leads to injuries of the orbit, but literature focusing on the viscerocranium rather than the neurocranium is underrepresented. Methods: Retrospective cohort study (2006–2014) at an urban level 1 trauma center assessing the frequency and typical patterns of orbital injuries on whole-body computed tomography (WBCT) with maxillofacial multi-slice CT (MSCT) after severe trauma. (1) Screening of consecutive WBCT cases for dedicated maxillofacial MSCT. (2) Examination by two independent experts’ radiologists for (peri-/)orbital injuries. (3) Case review for trauma mechanisms. Results: 1061 WBCT were included revealing 250 (23.6%) patients with orbital injuries. Less than one-quarter (23.3%) of patients showed osseous and 9.5% showed soft tissue injuries. Combined osseous and soft tissue lesions were present in 39.2% of orbital injuries, isolated soft tissue injuries were rare. Single- or two-wall fractures of the orbit were prevalent, and the orbital floor was affected in 67% of fractures. Dislocated extraocular muscles (44.6%), deformation of the ocular globe (23.8%), and elongation of the optic nerve (12.9%) were the most frequently soft tissue findings. Vascular trauma was suspected in 15.8% of patients. Conclusions: Orbital trauma was confirmed in 23.6% of cases with suspected facial injuries after severe trauma. Concomitant soft tissue injuries should be excluded explicitly in cases with orbital fractures to prevent loss of vision or ocular motility.

Rubber Bullet Induced Traumatic Brain Injury

ABSTRACT

Rubber bullets have long been known to cause, on rare occasions, traumatic brain injury (TBI). However, neurosurgical literature on this occurrence is limited, and no focused review of this injury pattern has been conducted. The authors present the case of a 28-year-old male struck by a rubber bullet in the left periorbital region, causing TBI in addition to complete left visual loss and complex facial fractures. After developing a cerebrospinal fluid (CSF) leak, the patient was taken to the operating room for combined neurosurgical-craniofacial intervention. Utilizing frameless intraoperative computation tomography navigation assistance, a successful repair was made of both the patient's CSF leak and complex craniofacial injuries. TBI due to a rubber bullet is a rare but severe occurrence. Unfortunately, much of the limited literature on this topic is bereft of demographic, clinical course, injury pattern, and imaging data. Presented here is the first operative case report of TBI due to a rubber bullet. Volume rendered imaging is provided to demonstrate the extent of trauma incurred. Additionally, a methodology for frameless intraoperative computation tomography navigation assistance is shared for consideration, as it served as a helpful adjunct for a combined intracranial-craniofacial surgical repair. The experience of treating the patient's traumatic CSF leak in the context of severe craniofacial and ophthalmologic injuries highlights the need for a multidisciplinary surgical approach that may arise when treating patients with TBI due to a rubber bullet.

Immediate Prosthetic Rehabilitation of Marginal Mandibulectomy Post Radiation Case by Single-Piece Implant - A Case Report

Prosthetic rehabilitation post resection and radiotherapy demand a thorough understanding of the biomechanics of the jaw, its associated structures, and their post radiation changes at the bone level. Restoring lost structures can often pose a challenge, especially with regard to the dentition. Due to inadequate hard- and soft-tissue structures as well as their demand for “biologic osseointegration,” it is difficult to conduct immediate loading as a treatment option on conventional implants. Alternatives are today available. Since piece smooth surface cortical implants transmit occlusal forces at cortical bone/buttress by engaging them, with or without reliance on the alveolar bone, it can be considered as an option. Here, we report a case of immediate loading with single-piece smooth surface implants in a male patient who had undergone a marginal mandibulectomy 3 years back for the removal of an oral squamous cell carcinoma of the retromolar trigone area that was closed by an anastomosed radial forearm flap, followed by radiation therapy. The dentition was restored successfully using a single piece smooth surface cortically anchored implant and reported favorable success and survival rate with high patient acceptance. Single piece corticobasal implant technology is one of the most predictable methods for the functional and sociopsychological correction, with minimal invasive immediate functional loading protocol restoring function and post resection surgical deformation of the jaw, thus improving lifestyle and survival.

Facial and Dental Trauma

Dental and facial trauma are very common in a daily routine radiology practice. Knowledge of the functional anatomy of the mandibulofacial and maxillofacial regions forms the cornerstone of a thorough full radiologic evaluation of the patient with a dental and/or facial trauma. Cone beam computed tomography and multidetector computed tomography are currently considered the imaging modalities of choice. There are several patterns and classification systems for the various subtypes of mandibulofacial and maxillofacial fractures. They are discussed separately in this article with special attention to the types of dental trauma and orbital trauma.

Imaging in trauma of the facial skeleton and soft tissues of the neck

Trauma to the face and neck is a frequent reason for emergency department attendance. Imaging is invaluable in the characterisation of such injuries, enabling delineation of fracture patterns as well as identification of vascular and other soft tissue injuries. It may also be used to prevent long-term mortality and morbidity and provide a roadmap for surgical intervention so that form and function may be restored. This article gives a pictorial review of the imaging of craniofacial trauma, stratified according to the thirds of the face, followed by a review of blunt and penetrating trauma of the neck. It discusses appropriate imaging modalities for each trauma category, describes major patterns of craniofacial trauma on cross-sectional imaging and identifies clinically relevant imaging features that should trigger subspecialist review or be of relevance to pre-surgical planning. It starts with the upper third comprising frontal sinus fractures before describing the component fractures of the middle third (including nasal, zygomaticomaxillary and orbital fractures) and then focusing on the lower third (specifically mandibular and dentoalveolar fractures). The article concludes with a review of soft tissue injuries of the neck, particularly penetrating, blunt and laryngeal trauma.

Facial fractures: classification and highlights for a useful report

In patients with facial trauma, multidetector computed tomography is the first-choice imaging test because it can detect and characterize even small fractures and their associated complications quickly and accurately. It has helped clinical management and surgical planning, so radiologists must communicate their findings to surgeons effectively. In Le Fort fractures, there is a breach between the pterygoid plates and the posterior maxilla. These fractures are classified in three basic patterns that can be combined and associated with various complications. Conceptualized when low-speed trauma was predominant, the Le Fort classification system has become less relevant giving more importance on maxillary occlusion-bearing segments. The classification of naso-orbito-ethmoid depends on the extent of injury to the attachment of the medial canthal tendon, with possible complications like nasofrontal duct disruption. Displaced fractures of the zygomaticomaxillary complex often widen the angle of the lateral orbital wall, resulting in increased orbital volume and sometimes in enophthalmos. Severe comminution or angulation can lead to wide surgical exposure. In orbital fractures, entrapment of the inferior rectus muscles can lead to diplopia, so it is important to assess its positioning and morphology. Orbital fractures can also result in injuries to the globe or infraorbital nerve. Frontal sinus fractures that extend through the posterior sinus wall can create a communication with the anterior cranial fossa resulting in leakage of cerebrospinal fluid, intracranial bleeding. It is essential to categorize fracture patterns and highlight features that may affect fracture management in radiology reports of facial trauma.

Dynamic changes of facial skeletal fractures with time

To investigate the characteristics of imaging changes with time of facial fractures, patients with facial fractures who had computed tomographic scan were enrolled including 500 patients who were divided into six groups based on the time of scanning: super early (<3 d), early (4–7 d), early-to-medium (8–14 d), medium (15–21d), medium-to-late (22d–2 months) and late stage (>2 months). The data were compared and analyzed. Forty two patients with frontal bone fractures had high-energy impact as the reason of fractures. The fracture line was clear and sharp within one week but blunt and sclerotic due to bone absorption at 2–3 weeks, and might exist for a long time. All patients had soft tissue swelling and paranasal sinus effusion at 1–2 weeks after injury. Air might gather in the adjacent soft tissues and/or intracranially within 3 days of injury if the fracture involved the frontal or other sinuses. Twelve of the 42 patients (28.6%) had intracranial hematoma, and five (11.9%) had epidural effusion. Subarachnoid hemorrhage was mostly absorbed within one week while epidural hematoma was completely absorbed over 3 weeks. Significant changes (P < 0.05) in the fracture lines, effusion of paranasal sinuses, soft tissue swelling and pneumocephalus were observed during the study period. For patients with medial orbital wall fractures, the fracture line was sharp and clear at early stages with concurrent sphenoid sinus effusion, and the fracture line became depressed 3 weeks later with disappearance of sphenoid sinus effusion. Significant changes (P < 0.05) were observed in the sharp fracture line, soft tissue swelling, sphenoid sinus effusion and smooth depression at fracture sites. For nasal fractures, the fracture line was sharp and clear at early stages with concurrent soft tissue swelling which disappeared one week later. The fracture line became smooth three weeks later. A significant (P < 0.05) difference was demonstrated in the changes of fracture line and soft tissue swelling with time. In conclusion, facial fractures have some dynamic alterations with time and identification of these characteristics may help reaching a correct clinical diagnosis with regard to fracture severity and time.

Evaluation of Concomitant Orbital Floor Fractures in Patients with Head Trauma Using Conventional Head CT Scan: A Retrospective Study at a Level II Trauma Center

BACKGROUND

Patients with head trauma may have concomitant orbital floor fractures (OFFs). The objective of our study was to determine the specific CT findings and investigate the diagnostic performance of head CT in detecting OFFs.

METHODS

We analyzed 3534 head trauma patients undergoing simultaneous head and facial CT over a 3-year period. The clinical data and specific head CT findings between patients with and without OFFs were compared.

RESULTS

In our cohort, 198 patients (5.6%) had OFFs visible on CT. On head CT, orbital floor discontinuity, gas bubbles entrapped between floor fragments, inferior extraconal emphysema, and maxillary hemosinus (MHS) were more commonly observed among patients with OFFs (p < 0.001). The absence of MHS had a high negative predictive value (99.7%) for excluding OFFs. Among the different types of MHS, the pattern showing high-attenuation opacity mixed with mottled gas had the highest positive predictive value (69.5%) for OFFs and was the only independent predictor of OFFs after adjusting for the other CT variables in all patients with MHS.

CONCLUSION

Head CT may serve as a first-line screening tool to detect OFFs in head trauma patients. Hence, unnecessary facial CT and additional radiation exposure may be reduced.

A Comprehensive Review of Cross-Sectional Imaging of the Nasolacrimal Drainage Apparatus: What Radiologists Need to Know

OBJECTIVE. The purpose of this study is to provide a comprehensive review of the radiographic anatomy and cross-sectional imaging findings of the full gamut of nasolacrimal drainage apparatus diseases, highlighting imaging findings from the different nasolacrimal drainage apparatus surgeries, posttreatment complications, and potential imaging pitfalls. CONCLUSION. Radiologists play a critical role in guiding the management of nasolacrimal drainage apparatus diseases and should be familiar with the anatomy and characteristic imaging findings of commonly encountered nasolacrimal drainage apparatus abnormalities and surgeries.

Three-dimensional evaluation of mandibular volume in patients with cleft lip and palate during the deciduous dentition period

OBJECTIVES

To examine the relationship between mandibular volume and craniofacial morphology in patients with cleft lip and palate using cone beam computed tomography (CBCT) and to compare these findings with control (noncleft) patients undergoing CBCT for other purposes during the deciduous dentition period.

MATERIALS AND METHODS

Eighty-four patients were categorized into the unilateral cleft lip and alveolus (UCLA) group (n = 25; mean age, 4.60 ± 0.40 years), unilateral cleft lip and palate (UCLP) group (n = 23; mean age, 4.52 ± 0.39 years), bilateral cleft lip and palate (BCLP) group (n = 22; mean age, 4.54 ± 0.37 years), and control group without cleft (n = 14; mean age, 5.19 ± 0.52 years). Mandibular volume and craniofacial cephalometric measurements were obtained using CBCT. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests.

RESULTS

ANCOVA revealed no statistically significant differences in mandibular volume among the groups. SNA° and ANB° were significantly larger in the UCLA and BCLP groups than in the control group. SN-MP° was smallest in the UCLA group. Co-A in the UCLP group was shorter than in the UCLA and BCLP groups. Go-Gn was shortest in the UCLP and BCLP groups compared with the control group.

CONCLUSIONS

Three-dimensional evaluation of craniofacial morphology using CBCT can provide valuable information on malocclusion and other dentoskeletal problems among patients with CLP.

Dose reduction in CT imaging for facial bone trauma in adults: A narrative literature review

Trauma to the facial area accounts for a significant number of admissions to the emergency department. Diagnostic imaging is almost always required, and is critical in determining patient management. Multi‐detector computed tomography (MDCT) appears consistently in the literature as the gold‐standard imaging modality for facial bones, but results in a high radiation dose to the patient. This makes the application and advancement of dose reduction and dose optimisation methods vital. This narrative review presents a critical analysis of the literature concerning diagnostic imaging of facial bone trauma, with an emphasis on dose reduction methods for MDCT. Databases including Pubmed, Medline, Web of Science and Scopus were used to investigate this topic, with the key words: facial bone trauma, computed tomography (CT) imaging and dose reduction. Exclusion criteria included studies on nasal bone fracturing, dental imaging, elective surgeries and paediatric imaging. The literature shows overwhelming support for MDCT, given its accuracy, efficiency and ease of operation. Noise reducing reconstruction algorithms show promise as a successful method of dose reduction in facial bone imaging. Investigations of more innovative techniques also appear within the literature, including diagnostic cone‐beam CT (CBCT), intraoperative CBCT and dual‐source CT (DSCT), but further research is required to confirm their clinical value.

Diagnostic reliability of low dose multidetector CT and cone beam CT in maxillofacial trauma-an experimental blinded and randomized study

OBJECTIVES

To assess the diagnostic reliability of low dose multidetector CT (MDCT) and cone beam CT (CBCT) for zygomaticomaxillary fracture diagnosis.

METHODS

Unilateral zygomaticomaxillary fractures were inflicted on four out of six fresh frozen human cadaver head specimens. All specimens were scanned using four MDCT and two CBCT imaging protocols of which the radiation exposure was systematically reduced. A blinded diagnostic routine was simulated at which 16 radiologists and 8 oral and maxillofacial (OMF) surgeons performed randomized image assessments. We considered the findings during an open operative approach of the zygomatic region as the gold standard.

RESULTS

Zygomaticomaxillary fractures were correctly diagnosed in 90.3% (n = 130) of the image assessments. The zygomatic arch was most often correctly diagnosed (91.0%). The zygomatic alveolar crest showed the lowest degree of correct diagnosis (65.3%). Dose reduction did not significantly affect the objective visualization of fractures of the zygomaticomaxillary complex. The sensitivity and specificity also remained consistent among the low dose scan protocols. Dose reduction did not decrease the ability to assess dislocation, comminution, orbital volume, volume rendering and soft tissues. OMF surgeons considered the low dose protocols sufficient for treatment planning.

CONCLUSIONS

Dose reduction did not decrease the diagnostic reliability of MDCT and CBCT for the diagnosis of zygomaticomaxillary fractures.

Postoperative CT of the Midfacial Skeleton After Trauma: Review of Normal Appearances and Common Complications

OBJECTIVE

The objective of this article is to describe the CT appearance of the midfacial skeleton after surgical repair of posttraumatic Le Fort, nasoorbitoethmoidal (NOE), and frontal sinus fractures. Several of the more commonly encountered complications will also be described.

CONCLUSION

Surgery after midfacial trauma is aimed at restoring both form and function. Knowledge of the principal tenets of Le Fort, NOE, and frontal sinus fracture repair is vital for radiologists to accurately assess the adequacy of treatment on postoperative CT and provide meaningful reports for the surgeon.

Simultaneous head and facial computed tomography scans for assessing facial fractures in patients with traumatic brain injury

INTRODUCTION

Patients with traumatic brain injury (TBI) may have concomitant facial fractures. While most head injury patients receive head computed tomography (CT) scans for initial evaluation, the objective of our study was to investigate the value of simultaneous facial CT scans in assessing facial fractures in patients with TBI.

METHODS

From January 1, 2015 to December 31, 2015, 1649 consecutive patients presenting to our emergency department (ED) with a TBI who received CT scans using the protocol for head and facial bones were enrolled. The clinical data and CT images were reviewed via a standardized format.

RESULTS

In our cohort, 200 patients (12.1%) had at least one facial fracture shown on the CT scans. Patients with facial fractures were more likely to have initial loss of consciousness (ILOC; p<0.001), a Glasgow coma scale of 8 or less (p<0.001), moderate or severe degrees of head injury severity scale (p<0.001), positive physical examination findings (p<0.001), and positive CT cranial abnormalities (p<0.001). A total of 166 (83.0%) patients with facial fractures required further facial CT scans instead of conventional head CT scans alone. Surgical intervention was mandatory in 73 (44.0%) of the 166 patients, who more frequently exhibited fractures of the lower third of the face (p<0.001) and orbital fractures (p=0.019).

CONCLUSIONS

TBI patients with risk factors may have a higher probability of concomitant facial fractures. Fractures of the lower third of the face and orbit are easily overlooked in routine head CT scans but often require surgical intervention. Therefore, simultaneous head and facial CT scans are suggested in selected TBI patients.

Defining current facial fracture patterns in a quaternary institution following high-velocity blunt trauma

Background: In the early 20th century, René Le Fort studied facial fractures resulting from blunt trauma and devised a classification system still in common use today. This classification, however, was based on low-velocity trauma. In modern practice, in a quaternary-level referral hospital, patients are often admitted following high-velocity injuries that mostly result from motor vehicle collisions.Objectives: A retrospective study to define facial bone fractures occurring subsequent to highvelocity trauma.Method: A retrospective study comprising the review of CT scans of 52 patients with highvelocity facial fractures was performed between April 2007 and March 2013. Injuries were classified using the Le Fort classification system. Deviations from the true Le Fort types, which are often depicted in the literature as occurring bilaterally and symmetrically, were documented; these included unilaterality, occurrence of several Le Fort fractures on one side of the face, occurrence of several Le Fort fractures on different levels and on different sides of the face, and occurrence of other fractures in addition to Le Fort fractures.Results: Of the 52 cases, 12 (23%) had Le Fort injuries, with true Le Fort fractures occurring in only 1, and 11 deviating from the classic description. Nine patients had Le Fort fractures and additional fractures. Mandibular and zygomatic bone fractures were found to be common associations with Le Fort injuries, occurring in 58% and 33% of the cases respectively.Conclusion: Fractures occurring in modern practice often deviate from the traditional Le Fort classification. Precise recognition of these deviations and recognition of additional associated fractures is pivotal in their management, assisting the surgeon in determining the treatment plan, such as the surgical approach and the order in which to fix the various fractured components.

Fractures of the posterolateral maxillary sinus: a masticator space blowout injury?

BACKGROUND AND PURPOSE

Segmental, depressed fractures of the posterolateral maxillary sinus may occur as a result of trauma to the masticator space, previously described in association with mandibular fractures. The authors hypothesize that the fracture is due to a transient increase in pressure in the masticator space (blow out) and therefore should be seen in association with other regional fractures.

MATERIALS AND METHODS

Injuries of the masticator space were retrospectively identified by searching the imaging database from January 2014 to November 2014 for keywords that would identify regional trauma. The images were reviewed for segmental depressed fractures in the posterolateral aspect of the maxillary sinus accompanied by herniation of a variable amount of masticator space fat and/or muscle into the adjacent sinus. Three neuroradiologists reviewed the images and agreed by consensus on the presence or absence of a masticator space blowout fracture.

RESULTS

Forty-three zygomaticomaxillary complex (ZMC) fractures, 89 mandibular fractures, and 49 isolated zygomatic arch fractures were identified. While all of the ZMC fractures had a maxillary component, 3 of 43 (7.0 %) additional fractures met our fracture definition. Five of 89 (5.6 %) of the mandibular fractures and 6 of 49 (12.2 %) zygomatic arch fractures had an associated posterolateral maxillary fracture.

CONCLUSIONS

Segmental depressed fracture of the posterolateral maxillary sinus is relatively common, occurring in conjunction with other regional injuries. The authors hypothesize that it is due to a transient increase in pressure in the masticator space and is a separate entity from other fractures of the region that may occur concurrently.

Reevaluating the Utility of Maxillary Sinus Opacification as a Screening Tool for Facial Bone Fracture a Decade After Its Original Analysis

In 1997, Lambert and colleagues demonstrated that the absence of sinus fluid on head CT essentially excludes a fracture involving the sinus walls. Our purpose is to reevaluate this association utilizing the current standard of imaging technology. With improved image resolution, we aim to reassess whether the sensitivity and specificity of the “clear sinus sign” are improved or worsened. Furthermore, the current standard of care is to obtain a CT of the facial bones along with a head CT when facial trauma is suspected, so we also analyzed the association of the "clear sinus sign" with nasal bone and mandible fractures. We identified 629 facial bone CT scans performed on adult patients in the emergency department between July 2012 and May 2013. They were retrospectively analyzed by three reviewers for the presence of facial bone fracture and/or fluid opacification of at least one paranasal sinus (as defined by either complete sinus opacification or an air-fluid level - circumferential mucosal thickening was considered the absence of fluid). We found that sinus opacification was 98.8% specific for facial bone fracture but only 44.7% sensitive. However, for complex facial fractures, such as zygomaticomaxillary complex, orbital, and sinus fractures, the lack of sinus fluid is significantly more sensitive at 91%. Therefore, our results for complex facial fractures are congruent with those of the previous studies conducted by Lambert, et al. and Lewandowski, et al. However, we also demonstrate that sinus opacification is not specific for nasal bone or mandibular fractures.  

Neuroimaging in adult penetrating brain injury: a guide for radiographers

Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

Emergency radiology: Maxillofacial and skull-base trauma

Craniofacial trauma is common following road-traffic accidents, assaults and falls and may occur in isolation or associated with other body injuries. Due to the complexity of the maxillofacial and skull-base region, initial diagnosis may be inaccurate or delayed, leading to significant morbidity. Multidetector computed tomography is the modality of choice following high-energy blunt or penetrating trauma. It allows accurate evaluation of the fracture patterns and associated soft tissue complications and aids the appropriate medical and surgical treatment. In this article, we review and classify the most common traumatic injuries to the maxillofacial and skull-base region and outline the role of imaging in establishing complications and prognosis.

Head computed tomography in the emergency department: a collection of easily missed findings that are life-threatening or life-changing

BACKGROUND

The use of noncontrast head computed tomography (CT) has become commonplace in the emergency department (ED) as a means of screening for a wide variety of pathologies. Approximately 1 in 14 ED patients receives a head CT scan, and analyzing and interpreting this high volume of images in a timely manner is a daily challenge.

OBJECTIVES

Minimizing interpretation error is of paramount importance in the context of life-threatening and time-sensitive diagnoses. Therefore, it is prudent for the physician to recognize particular pitfalls in head CT interpretation and establish search patterns and practices that minimize such errors. In this article, we discuss a collection of common ED cases with easily missed findings, and identify time-effective practices and patterns to minimize interpretation error.

DISCUSSION

There are numerous reasons for false-negative interpretations, including, but not limited to, incomplete or misleading clinical history, failure to review prior studies, suboptimal windowing and leveling, and failure to utilize multiple anatomic views via multi-planar reconstructions and scout views. We illustrate this in four specific clinical scenarios: stroke, trauma, headache, and altered mental status.

CONCLUSION

Accurate and timely interpretation in the emergent setting is a daily challenge for emergency physicians. Knowledge of easily overlooked yet critical findings is a first step in minimizing interpretation error.

A systematic approach to CT evaluation of orbital trauma

Computed tomography (CT) is widely used in the initial evaluation of patients with craniofacial trauma. Due to anatomical proximity, craniofacial trauma often involves concomitant injury to the eye and orbit. These injuries may have devastating consequences to vision, ocular motility, and cosmesis. CT imaging provides a rapid and detailed evaluation of bony structures and soft tissues of the orbit, is sensitive in detection of orbital foreign bodies, and often guides clinical and surgical management decisions in orbital trauma. For this reason, radiologists should be prepared to rapidly recognize common orbital fracture patterns, accurately describe soft tissue injuries of the orbit, detect and localize retained foreign bodies within the globe and orbit, and recognize abnormalities of the contents and integrity of the globe. In this review, we present a systematic approach to assist radiologists in the rapid evaluation of orbital trauma using the "BALPINE" mnemonic-bones, anterior chamber, lens, posterior globe structures, intraconal orbit, neurovascular structures, and extraocular muscles/extraconal orbit. Using this approach, we describe common traumatic findings within each of these spaces, and present common postsurgical appearances that can mimic findings of acute trauma.

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.