Radiologic assessment of maxillofacial, mandibular, and skull base trauma

Cranio-maxillofacial injuries affect a significant proportion of trauma patients either in isolation or concurring with other serious injuries. Contrary to maxillofacial injuries that result from a direct impact, central skull base and lateral skull base (petrous bone) fractures usually are caused by a lateral or sagittal directed force to the skull and therefore are indirect fractures. The traditional strong role of conventional images in patients with isolated trauma to the viscerocranium is decreasing. Spiral multislice CT is progressively replacing the panoramic radiograph, Waters view, and axial films for maxillofacial trauma, and is increasingly being performed in addition to conventional films to detail and classify trauma to the mandible as well. Imaging thus contributes to accurately categorizing mandibular fractures based on location, into alveolar, mandibular proper, and condylar fractures—the last are subdivided into intracapsular and extracapsular fractures. In the midface, CT facilitates attribution of trauma to the categories central, lateral, or combined centrolateral fractures. The last frequently encompass orbital trauma as well. CT is the imaging technique of choice to display the multiplicity of fragments, the degree of dislocation and rotation, or skull base involvement. Transsphenoid skull base fractures are classified into transverse and oblique types; lateral base (temporal bone) trauma is subdivided into longitudinal and transverse fractures. Supplementary MR examinations are required when a cranial nerve palsy occurs in order to recognize neural compression. Early and late complications of trauma related to the orbit, anterior cranial fossa, or lateral skull base due to infection, brain concussion, or herniation require CT to visualize the osseous prerequisites of complications, and MR to define the adjacent brain and soft tissue involvement.     

CT of soft tissue injury and orbital fractures

Complex orbital rim and fractures of the internal orbital skeleton (orbital walls) are best analyzed by high-resolution axial CT. Optic canal fractures are optimally visualized with thin 1-mm section high-resolution CT scanning. Spiral CT may be used in the acutely injured patient because of its rapid scan technique. This spiral technique provides smooth data sets for three-dimensional reformations and may demonstrate foreign bodies in more than one plane. Another advantage of spiral CT is the capability of CT angiography. MR imaging usually is not the initial modality for the assessment of orbital trauma, but it is helpful in evaluating vascular injuries such as carotid-cavernous sinus fistulas or post-traumatic pseudoaneurysms. In general, CT with contrast injection is not necessary except when traumatic vascular anomalies, such as carotid cavernous, dural fistulas, or thrombosis of the superior ophthalmic vein, are considered in the differential diagnosis.     

Brain trauma in head injuries presenting with and without concurrent skull fractures

Head injuries and skull fractures may be problematic in cause and manner of death. Over a 10-year period, 54 cases showing head injuries were studied. Of thsese, 34 had skull fractures and 20 had no skull fractures. Virtually all decedents with skull fractures had brain injuries. The most common injury in both groups was motor vehicle accidents (MVA), in which 50% had skull fractures. In cases of skull fracture, brain lacerations, hemorrhages, and cerebral edema were common. Of 20 decedents with head injury but no skull fracture, most were accidents, and all but 3 cases had brain injury, although often relatively minor, except for atlanto-occiptital dislocation. There were significant differences between the two groups. Decedents with skull fractures tended to by younger (mean 35 years) compared to those with head injury only (mean 52 years) (p = 0.0021). The use of drugs or alcohol was more likely in decedents with skull fractures than in those with head trauma only (p = 0.0431). Mean abbreviated injury scale scores were higher for the face and head/neck of decedents with skull fractures, while significantly lower for chest and extremities, compared to decedents without skull fractures. Brain injury of some kind occurred in 90% of cases of head trauma, so a high level of suspicion should be placed in seeking skull fractures or brain injury.     

Orbital fractures in sport: a review

Orbital fractures represent a small proportion of sports-related injuries in the US and abroad. However, the significant functional and cosmetic sequelae of such fractures warrant a comprehensive evaluation of any athlete sustaining facial trauma. Initial evaluation is directed at excluding neurological impairment or the presence of vision-threatening injury. Subsequent examination should ascertain the presence of signs and symptoms consistent with orbital fracture. These include gross bony deformity, limitation of gaze, diplopia and malposition of the globe. The presence of any of the aforementioned symptoms should prompt further investigation using computed tomography to corroborate or refute clinical suspicion. Orbital fracture mandates referral to an ophthalmologist or oculoplastic surgeon; initial management is dictated by the severity of functional symptoms, and may necessitate early surgical intervention. Those patients who are managed conservatively should return for frequent follow-up, as progressive diplopia, enophthalmos, or gaze limitation are indications for late operative repair. The majority of patients who sustain orbital fractures are able to return to sport, however, persistent diplopia is not uncommon, and may persist despite optimal treatment.     

Pontomedullary lacerations in pedestrians: an autopsy study

It is common that injuries to the head are among the most frequent injuries found in pedestrian accidents, and can constitute a serious, if not fatal, threat. Brainstem lesions have only occasionally been reported in pedestrian injuries. The aim of this study has been to determine the frequency of brainstem pontomedullary lacerations (PMLs) among fatally injured pedestrians, the frequency of concomitant cranial, facial and cervical spine injuries in such cases, as well as to establish their possible underlying mechanism. In this work, PML was present in a significant number of fatally injured pedestrians from a sample of 50 out of 360 cases with head injuries (14%). When observed alone, the most frequent head impact areas were the chin, lateral and frontal (χ(2) = 14.200, df = 4, P = 0.007) in the subgroup with PML. Hinge fractures were most often seen in this subgroup (25 cases), followed by the absence of skull base fractures (χ(2) = 26.320, df = 3, P < 0.01). There are several possible mechanisms of PML in these cases. Impact to the chin, with or without a skull base fracture, could lead to this fatal injury due to impact force transmission. Additionally, lateral head impacts, the most frequent in pedestrians, with subsequent hinge fractures, PML and fronto-posterior hyperextension of the head that is associated with upper-spine fractures, may be possible mechanisms of brainstem injury in fatally injured pedestrians.     

Imaging in spinal trauma

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.     

Basic principles of nuclear medicine techniques for detection and evaluation of trauma and sports medicine injuries

Nuclear medicine skeletal imaging is a very sensitive technique for evaluating bone and muscle abnormalities because it can detect minor changes in metabolism and blood flow. The specificity of bone imaging, however, depends on the ability of the nuclear medicine physician to make a differential diagnosis. To aid in making a specific diagnosis, this article describes the various patterns of abnormality in stress fractures, tibial stress syndrome (shin splints), compartment syndrome, enthesopathy, and traumatic fractures. The characteristic scintigraphic appearance of joint injuries, muscle injuries (rhabdomyolysis), and radionuclide arthrography is discussed and the way the scan patterns change with time in these various disorders is described. A brief summary of the basic anatomy and physiology of bone and muscle in normal and injured tissue is presented and the basic mechanisms which cause the various abnormal scan patterns is postulated. In addition, a staging system for stress fractures is presented to help direct the referring physician toward the proper management of the injured patient. In most cases, nuclear medicine skeletal imaging can be used to differentiate between acute muscle injury, tibial stress syndrome, skeletal injury (periosteal reaction, stress fracture, and traumatic fracture) or an abnormality that is entirely associated with the joint or connective tissue. This differential diagnosis is easier if the nuclear medicine procedure is performed within a few days after the onset of injury.     

Covered Stent-Graft Treatment of Traumatic Internal Carotid Artery Pseudoaneurysms: A Review

Objective To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures. Method We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case. Results We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totally occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure. Conclusion Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.     

Imaging of paranasal sinus trauma

The role of imaging in the management of maxillofacial trauma is to describe anatomical lesions and to detect complications and associated injuries. Plain films are still useful for minimal trauma, but CT-scan is the gold standard for complex trauma. Helical CT and multidetector row CT simplify the emergency imaging of horizontal struts (skull base, orbital floor, alveolar ridge and palate). The diagnosis, and sometimes the treatment of complications may require CT cisternography, MRI and angiography. Learning objectives: review mechanisms and classification of paranasal sinuses trauma; present the imaging techniques with special emphasis on CT; describe paranasal sinuses trauma features and pseudo-fracture patterns; describe complications and associated injuries.     

Case report: lethal fetal head injury and placental abruption in a pregnant trauma patient

Fetal trauma in blunt abdominal trauma is uncommon, but traumatic fetal head injury is almost universally fatal to the fetus. Placental abruption is the most common injury to the gravid uterus in trauma, and when the mother survives, it is the most common cause of fetal death. The imaging diagnosis of these conditions may be difficult since there are only three cases reported in the literature of intrauterine skull fractures on plain films [3, 8, 10], ultrasound is in sensitive in the diagnosis of placental abruption [24], and the most sensitive test to diagnose placental abruption is external fetal monitoring with devices that measure uterine tone and contractility and fetal heart rate [23]. The diagnosis of fetal trauma and placental abruption may be made on contrast enhanced CT performed through the abdomen and pelvis of pregnant trauma patients. For these reasons, it is useful for the radiologist interpreting the CT scan to recognize fetal head injuries and placental abruption in pregnant trauma patients.Fig. 7 Axial scans through the bony pelvis demonstrate an unstable pelvic fracture with posterior pelvic ring disruption.There is a zone 2 fracture of the left sacrum and a fracture of the left obturator ring (arrowheads)     

The spectrum of facial fractures in motor vehicle accidents: an MDCT study of 374 patients

Road traffic accidents are a major health problem worldwide resulting frequently in maxillofacial injuries. The purpose of the study was to assess the incidence and spectrum of facial fractures in patients involved in a motor vehicle accident (MVA). Using picture archiving and communication system, all requests for suspected facial trauma were retrieved during a 62-month period; 374 met the inclusion criteria. Two researchers interpreted the multidetector computed tomography images by consensus. The motor vehicles involved were divided into two groups: those involving a passenger car or a larger vehicle and those involving a motorized two-wheeler. Furthermore, the motor vehicle accidents were divided into collisions and run-off-road accidents. Of the 374 patients (aged 15–80, mean 34), 271 (72 %) were male and 103 (28 %) female. Of all patients, 262 (70 %) had a facial or skull base fracture; of these, multiple separate fractures were present in 56 %. Nasal fractures were the most common fractures followed by orbital, skull base, and maxillary fractures. Frontal bone, LeFort, and zygomatic arch fractures were always accompanied by other fractures. Fractures were more frequent in the group of collisions compared with run-off-road accidents. In the two-wheeled group, only 15 % did not have facial or skull base fractures. Fractures often occur in multitudes as 39 % of all patients have multiple facial or skull bone fractures, and thus, emergency radiologists should be familiar with the complexity of the injuries. Negative clear sinus sign and low-energy sentinel injuries should be trusted as indications of undetected injuries in MVA victims.     

Tectorial membrane injury: frequently overlooked in pediatric traumatic head injury

REHs and tectorial membrane injuries are rare complications of pediatric head and neck injuries. We aim to describe the neuroimaging findings in pediatric REHs, to summarize the mechanism of injury, and to correlate the imaging findings with the clinical presentation. We retrospectively evaluated CT and/or MR imaging studies of 10 children with traumatic REH. Most patients were involved in MVAs. The tectorial membrane was injured in 70% of patients, and REHs were medium to large in 80%. None of the patients had a focal spinal cord or brain stem injury, craniocervical junction dislocation, or vertebral fractures. Tectorial membrane disruption was diagnosed in most patients without craniocervical junction-related symptoms. Tectorial membrane lesions and REHs were seen in young children who sustained high-speed head and neck injuries. Clinical symptoms may be minimal or misleading. The radiologist should be aware of these injuries in children. MR imaging appears to be more sensitive than CT.     

CT and MR imaging of the pediatric orbit.

Orbital abnormalities encountered in the pediatric population differ substantially from those found in adult patients. Retinoblastoma, the most serious intraocular tumor, is often difficult to diagnose, but use of computed tomography (CT) (which reveals the characteristic focal calcification) and magnetic resonance (MR) imaging allows this tumor to be differentiated from pseudogliomas, such as Coats disease, and retrolental fibroplasia. CT and MR imaging help in the differentiation of orbital cellulitis from preseptal, lacrimal, and eyelid infectious processes and of orbital pseudotumor from Graves disease. In cases of orbital trauma, CT is excellent for detecting orbital fractures and metallic foreign bodies; MR imaging is better for depicting ocular and optic nerve injuries. Both modalities allow the differentiation of rhabdomyosarcoma from dermoid, cavernous hemangioma, and lymphangioma and provide helpful information for the diagnosis of many other tumors. Since CT and MR imaging have widely expanded the capabilities of orbital imaging, it is more important than ever before for radiologists to understand pediatric orbital disease.     

Head injuries in falls from a standing height: Do fractures of the orbital roof matter? A prospective autopsy study

Purpose

The aim of this study was to analyze the occurrence and characteristics of orbital roof fractures, periorbital hematoma, conjunctival hemorrhage, orbital roof discoloration, and concomitant head injuries in falls from a standing height.

Methods

A prospective autopsy study was performed over a 4-year period (from 2010 to 2013). Subjects who had died due to traumatic brain injury caused by falls from a standing height were included in the study.

Results

Fifty cases of ground level falls were recorded. This group consisted of 39 men and 11 women, with an average age of 67.3 ± 13.6 years, and median age of 70 years. Skull fractures originating in the proximity of impact site were found in 47 of 50 individuals, and 22 had isolated orbital roof fractures not connected to the fracture line. Bluish discoloration of the orbital roof was noted in 19 subjects, 14 had periorbital hematomas, and 12 had blotchy or purpura-like conjunctival hemorrhages.

Conclusions

Isolated orbital roof fractures in falls from a standing height are easily detected using a standard autopsy technique, with special regard to careful removal of the dura in the anterior cranial fossa. Our study shows that orbital roof fractures can occur in accidental falls from a standing height and may not be associated with concomitant skull fractures and brain injuries.     

The role of the radiologist in the management of politrauma patients

The management of trauma patients has become a very relevant issue and one of the major challenges in the western countries. In the assessment of politrauma patients, since the last 2 decades, radiological imaging methods have been increasingly used in order to provide a quick and thorough survey of craniocerebral, cervical, abdominal, pelvic and limb traumatic injuries. Among imaging methods, conventional radiographs (CR) have precise but limited indications. In most European hospitals, UltraSonography (US) represents the method of choice for patients referred following blunt abdominal trauma, whereas multislice computed tomography (MSCT) remains a second-line method of investigation, although it provides a fully comprehensive assessment of their injuries and allows for their categorization according to the severity of traumatic injuries. In fact, injury prevalence, radiation dose exposure, and costs represent important considerations in all of the emergency departments, where a growing number of patients seeking medical attention is seen. The radiologist's task is to decide which imaging method is mostly appropriate after initial patient presentation. In the severe politrauma patient, the diagnostic endpoint is to identify the nature and extent of the various injuries in order to execute a more tailored therapeutic approach: this is the patient in whom a total-body MSCT has to be performed in order to provide rapid and accurate information for a correct management. In the large majority of our patients, who do not show the need for a formal hospital admission, after the physical examination has revealed the clinical suspicion of minimal single-organ injury, US provides an adequate assessment of abdominal traumatic injuries and triage those few who are subsequently to be evaluated by means of MSCT. In the majority of this patients category, with low to very-low grade of potential injuries, CR can detect all types of skeletal fractures (except for the skull and the hips). Overall, the role of the emergency radiologist has become of primary importance in the management of trauma patients, and this all the more so since development of interventional radiology affords therapeutic procedures alternative to surgery.     

CT and MR imaging of primary cerebrovascular complications in pediatric head trauma

The incidence of severe traumatic head injury in children has constantly increased over the last years. Diagnostic imaging has become an unrenounceable tool for the documentation and follow-up of intracranial lesions. The use of magnetic resonance imaging (MRI) in the early posttraumatic phase has led to a more thorough understanding of intracranial injuries. We retrospectively analyzed the cranial computed tomography (CCT) and magnetic resonance (MR)-studies of patients with traumatic head injuries for primary cerebrovascular complications. In 64 children (45 male, 19 female) with traumatic head injuries, CCT and MR examinations were available for analysis. The children's age ranged from 3 months to 15 years with a median age of 7 years. All patients had initial CCT on admission to the hospital with follow-up examinations depending on clinical state and initial imaging findings. All patients had at least one MR examination between 0 to 120 days after the trauma with a median time interval of 17 days. In five of 64 (7.8%) patients, cerebrovascular complications were found on imaging studies. Initial imaging within the first 24 h after the trauma detected a complete middle cerebral artery infarction in one patient and extensive sinus thrombosis after a complex skull fracture in another. In two patients, thrombosis of the transverse sinus appeared on MRI 4 to 6 days after the trauma. In another patient with open-skull injury, a posttraumatic aneurysm of the pericallosal artery was diagnosed on MRI 30 days after the trauma. Our study shows that, although primary cerebrovascular lesions after traumatic head injuries in children are rare, the radiologist should be aware of the characteristic injury patterns and the time appearance of imaging findings on CT and MRI.     

Investigation of injuries sustained from falls down stairs

Interpretation of injuries sustained from fatal falls involving stairs is a challenge encountered by death investigation teams regularly. The high incidence of this occurrence is because stairs are a common entity in society. Without a medical evaluation of an individual's injuries, it is difficult to determine whether a fall from stairs contributed to how the individual died. The purpose of this study is to characterize the injuries of individuals that were sustained from a confirmed fatal fall involving stairs within our jurisdiction (Ontario, Canada) during 2014–2020. In a retrospective cross-sectional observation study, we examined 159 cases using both postmortem imaging and routine autopsy approaches. Our findings showed the head was the most common anatomical region injured. The most common injuries observed in the head included skull fracture(s) (most commonly the temporal, parietal and occipital bones), subarachnoid hemorrhages, and brain contusions. Anatomical regions less commonly injured included the extremities, thorax, and pelvis. This study identified an association between the presence of intracranial hemorrhage and those 65-years-old and younger; brain injury in the absence of pre-existing medical conditions; and brain injury for individuals that had a blood alcohol concentration between 0 and 80mg/100 mL. Extracranial skeletal trauma, as defined by skeletal trauma apart from the head region, was observed in 62% of cases. Extracranial skeletal trauma was also found to be strongly associated with individuals over 65-years-old. Overall, our study affirms that traumatic head injury is the primary cause of death from falls down stairs. Also, we provide information on rare injuries from falls down stairs, and indirectly, identify which body locations appear protected from injury during falls. These findings may aid in the interpretation of whether injuries in this setting are compatible with accidental or non-accidental trauma.     

Orbital complications of functional endoscopic sinus surgery: MR and CT findings

AIM: To describe the radiological findings of ophthalmic complications during functional endoscopic sinus surgery (FESS) and correlate them with the clinical manifestations and mechanisms of injury. METHODS: This was a retrospective review of the clinical and cross-sectional imaging findings of 9 patients with orbital complications during FESS. RESULTS: The most common site of entry into the orbit during FESS was the lower medial orbital wall (7 of 9), followed by the inferior orbital wall, resulting in injury to the medial rectus (4 of 9) and, less frequently, the inferior rectus (2 of 9) or superior oblique muscles (1 of 9). Extensive scarring on imaging (3 of 9) was associated with global ocular motility dysfunction. In contrast, localized scarring (3 of 9) or extraocular muscle trauma (6 of 9) resulted in disturbance of eye movement in the direction of gaze from the injured site. CONCLUSIONS: Orbital magnetic resonance and computed tomography findings correlate very well with the abnormal eye movements clinically observed, and can assist in clarifying the cause of injury and guide surgical corrective management of patients suffering orbital complications from FESS. Radiologists should be familiar with the recent developments in FESS instrumentation as well as with the most commonly injured structures within the orbit.     

Traumatic neuropathies: spectrum of imaging findings and postoperative assessment

Traumatic injury to peripheral nerves is a significant cause of morbidity and disability. Until reinnervation occurs, electrodiagnostic studies cannot differentiate severe axonotmetic lesions (Sunderland class 4) from complete nerve transection or neurotmesis (Sunderland class 5). This limitation is relevant clinically because in cases of neurotmesis an improved outcome may be achieved with an early surgical repair (within 1 week after trauma). High-resolution ultrasound (US) is an efficient modality to visualize injured nerves and is becoming increasingly important among radiologists and surgeons. Magnetic resonance (MR) imaging is complementary to high-resolution US, especially in evaluating deep-seated and proximal nerve segments. This article describes the imaging features of traumatic peripheral nerve lesions. The role of diagnostic imaging in stretching injuries, contusion trauma, penetrating wounds, and after surgery is discussed. A multimodality diagnostic approach including physical examination, electrophysiology, and US and MR imaging allows an accurate evaluation of most peripheral nerves. Imaging assessment of peripheral nerves trauma is useful for the diagnosis, follow-up, and postoperative evaluation.