Rethinking cervical spine clearance in obtunded trauma patients: An updated systematic review and meta-analysis

BACKGROUND

Cervical spine injuries (CSI) are often challenging to diagnose in obtunded adult patients with blunt trauma and the optimal imaging modality remains uncertain. This study systematically synthesized the last decade of evidence to determine the type of imaging required to clear the c-spine in obtunded patients with blunt trauma.

METHODS

A systematic review with meta-analysis was conducted and reported using PRISMA 2020 guidelines. The protocol was registered on June 22, 2022 (PROSPERO CRD42022341386). MEDLINE (Ovid), EMBASE, and Cochrane Library were searched for studies published between January 1, 2012, and October 17, 2023. Studies comparing CT alone to CT combined with MRI for c-spine clearance were included. Two independent reviewers screened articles for eligibility in duplicate. Meta-analysis was conducted using a random-effect model. Risk of bias and quality assessment were performed using the ROBINS-I and QUADAS-2. The certainty of evidence was assessed using the GRADE methodology.

RESULTS

744 obtunded trauma patients from six included studies were included. Among the 584 that had a negative CT scan, the pooled missed rate of clinically significant CSI using CT scans alone was 6 % (95 % CI: 0.02 to 0.17), and the pooled missed rate of CSI requiring treatment was 7 % (95 % CI: 0.02 to 0.18). High heterogeneity was observed among included studies (I² > 84 %). The overall risk of bias was moderate, and the quality of evidence was low due to the retrospective nature of the included studies and high heterogeneity.

CONCLUSIONS

Limited evidence published in the last decade found that CT scans alone may not be sufficient for detecting clinically significant CSI and injuries requiring treatment in obtunded adult patients with blunt trauma.

IMPLICATIONS OF KEY FINDINGS

Clinicians should be aware of the limitations of CT scans and consider using MRI when appropriate. Future research should focus on prospective studies with standardized outcome measures and uniform reporting.

Utilization of a two-material decomposition from a single-source, dual-energy CT in acute traumatic vertebral fractures

Purpose

The purpose of this study is to utilize a two-material decomposition to quantify bone marrow edema on a dual-energy computed tomography (DECT) scanner at the cervical, thoracic, and lumbar spine acute fractures in correlation with short tau inversion recovery (STIR) hyperintensity on magnetic resonance imaging (MRI) in comparison with the normal bone marrow.

Materials and methods

This retrospective institutional review board-approved study gathered patients over 18 years old who had acute cervical, thoracic, or lumbar spinal fractures scanned on a DECT scanner. Those who had a spinal MRI done with bone marrow STIR hyperintensity within 3 weeks of the DECT were included. The water (calcium) and fat (calcium) density (mg/cm3) measurements of the region of interest of the bone marrow were obtained at a normal anatomic equivalent site and at the fracture site where STIR hyperintensity was noted on MRI. A statistical analysis was performed using the paired t-test and Wilcoxon signed rank test (p > 0.05).

Results

A total of 20 patients met the inclusion criteria (males n = 17 males, females n = 3). A total of 32 fractures were analyzed: 19 cervical and 13 thoracolumbar. There were statistically significant differences in the water (43 ± 24 mg/cm3) and fat (36 ± 31 mg/cm3) density (mg/cm3) at the acute thoracic and lumbar spine fractures in correlation with edema on STIR images (both paired t-test <0.001, both Wilcoxon signed ranked test p < 0.01). There were no significant differences in the water (-10 ± 46 mg/cm3) or fat (+7 ± 50 mg/cm3) density (mg/cm3) at the cervical spine fractures.

Conclusion

The DECT two-material decomposition using water (calcium) and fat (calcium) analyses has the ability to quantify a bone marrow edema at the acute fracture site in the thoracic and lumbar spine.

Cervical spine trauma

Cervical spine trauma encompasses a wide of injuries, ranging from stable, minor lesions to unstable, complex lesions that can lead to neurologic sequelae or vascular involvement. The Canadian C-Spine Rule and the NEXUS criteria aim to identify individuals with a low risk of cervical spine trauma who can safely forgo imaging tests. In high-risk patients, an imaging test is indicated. In adult patients the imaging test of choice is multidetector computed tomography. Complementary imaging tests such as CT angiography of the supra-aortic vessels and/or magnetic resonance imaging are occasionally necessary. It can be challenging for radiologists to diagnose and classify these lesions, because some of them can be subtle and difficult to detect. This paper aims to describe the most important imaging findings and the most widely used classification systems.

Cervical spine injury: clinical and medico-legal overview

Spinal trauma is an important cause of disability worldwide. Injury to the cervical spine (CS) occurs frequently after major trauma. 5-10% of patients with blunt trauma have a cervical spine injury. The cervical spine accounts for ~ 50% of all spinal injuries. Determination of CS stability is a common challenge in the acute care setting of patients with trauma. Several issues, indeed, are of particular concern: who needs CS imaging; what imaging should be obtained; when should computed tomography (CT), magnetic resonance imaging (MRI), or flexion/extension (F/E) radiographs be obtained; and how is significant ligamentous injury excluded in the comatose patient. CT and MRI both have roles to play. This article aims to present the different imaging to frame techniques to be used with greater precision in the acute event also for the purpose of planning the next therapeutic process. An overview of the applicability of the same methods in forensic pathology is also provided highlighting possible future biomarker to ease in diagnosis of acute TBI.

Thoracic Inlet in Cervical Spine CT of Blunt Trauma Patients: Prevalence of Pathologies and Importance of CT Interpretation

BACKGROUND

The thoracic inlet of blunt trauma patients may have pathologies that can be diagnosed on cervical spine computed tomography (CT) but that are not evident on concurrent portable chest radiography (pCXR). This retrospective investigation aimed to identify the prevalence of thoracic inlet pathologies on cervical spine CT and their importance by measuring the diagnostic performance of pCXR and the predictive factors of such abnormalities.

METHODS

This investigation was performed at a level-1 trauma center and included CT and concurrent pCXR of 385 consecutive adult patients (280 men, mean age of 47.6 years) who presented with suspected cervical spine injury. CT and pCXR findings were independently re-reviewed, and CT was considered the reference standard.

RESULTS

Traumatic, significant nontraumatic and nonsignificant pathologies were present at 23.4%, 23.6% and 58.2%, respectively. The most common traumatic diagnoses were pneumothorax (12.7%) and pulmonary contusion (10.4%). The most common significant nontraumatic findings were pulmonary nodules (8.1%), micronodules (6.8%) and septal thickening (4.2%). The prevalence of active tuberculosis was 3.4%. The sensitivity and positive predictive value of pCXR was 56.67% and 49.51% in diagnosing traumatic and 8.89% and 50% in significant nontraumatic pathologies. No demographic or pre-admission clinical factors could predict these abnormalities.

CONCLUSIONS

Several significant pathologies of the thoracic inlet were visualized on trauma cervical spine CT. Since a concurrent pCXR was not sensitive and no demographic or clinical factors could predict these abnormalities, a liberal use of chest CT is suggested, particularly among those experiencing high-energy trauma with significant injuries of the thoracic inlet. If chest CT is not available, a meticulous evaluation of the thoracic inlet in the cervical spine CT of blunt trauma patients is important.

Feasibility analysis of high pitch cervical spine CT in uncooperative patients with acute cervical spine trauma: An initial experience

Cervical computed tomography (CT) often suffers from examination failure in uncooperative patients with acute cervical spinal trauma. Therefore, this study aimed to evaluate the feasibility of using high-pitch cervical CT (HP-CT) in such populations. A total of 95 patients with acute neck/head-neck trauma who underwent HP-CT (n = 29) or standard cervical CT (SD-CT, n = 66) from October 2020 to June 2021 were included in this study. Differences in patient characteristics between the HP-CT group and the SD-CT group were firstly compared. Then, the objective image quality based on the mean score of the signal-to-noise ratio (SNR)/contrast noise ratio (CNR) was evaluated, while double-blind five-point scoring was adopted for the subjective evaluation. Finally, radiation doses in HP-CT and SD-CT were compared. Furthermore, the Student t test and/or Mann-Whitney U test were performed to analyze differences in patient characteristics, image quality, and radiation dose between the two regimes. A total of 17 cases of cervical spine fractures were found in 95 patients, including 6 cases in the HP-CT group and 11 cases in the SD-CT group. The average age of patients who received HP-CT was higher than that of those who received SD-CT, and the scan time using HP-CT was shorter than that SD-CT. The differences were statistically significant (both, P < .05). In addition, there was no significant difference between HP-CT and SD-CT in terms of sex, body mass index, field of view (FOV), and scan length (all P > .05). The SNR/CNR at the middle and upper neck was not significantly different between HP-CT and SD-CT (all P > .05). However, the SNR/CNR at the lower neck in HP-CT was lower than that in SD-CT (all P < .05). There was no significant difference in the subjective scores between HP-CT and SD-CT images in both the soft tissue and bone window (P = .129 and 0.649, respectively). The radiation dose in HP-CT was lower than that in SD-CT (all P < .05). With a scan time reduction of 73%, radiation dose reduction of 10%, and similar image quality, high-pitch cervical CT was of feasibility to evaluate cervical spine injury in uncooperative patients with acute cervical spine trauma.

Diagnostic accuracy of deep learning for evaluation of C-spine injury from lateral neck radiographs

Background

Materials and methods

Results

Conclusion

Intraoperative color-coded duplex ultrasound for safe surgical reduction of displaced hangman fractures in patients with atypical course of the vertebral artery: A case report of two patients

An atypical course of the vertebral artery can be medically relevant in displaced Hangman fractures, especially if the artery course runs within the fracture gap of the C2 isthmus. During surgical reduction, the artery can be occluded inside the fracture, potentially leading to ischemic conditions of the brain. The aim of this study was to report two cases according to the CARE (case reporting) guidelines, in which intraoperative color-coded duplex-ultrasound was performed to secure safe surgical reduction of hangman fractures in two patients with an atypical course of the vertebral artery. Two patients with displaced hangman fractures (Effendi-Levine type II) were diagnosed with an atypical course of the vertebral artery running inside the fracture gap. This endangered safe surgical management with the risk of iatrogenic occlusion or injury during reduction through entrapment of the vessel inside the fracture gap. Therefore, an intraoperative color-coded duplex-ultrasound of the vertebral artery was conducted before and after reduction of the fracture, as well as at the end of the surgery. The surgical treatment in both cases included posterior unilateral spondylodesis, followed by anterior cervical discectomy and fusion (ACDF). In both patients, a safe reduction of the fracture was performed. Neither occlusion nor dissection of the vertebral artery occurred. The duplex ultrasound before and after reduction, and at the end of the procedure showed normal blood flow and morphology of both vertebral arteries. At follow-up examinations, the patients showed a favorable clinical outcome, radiographic signs of fusion, and no irregularity of the vertebral arteries. This case report serves as proof-of-concept, demonstrating the feasibility of this regimen to minimize the risk of entrapment or occlusion of the vertebral artery in the surgical management of displaced Hangman fractures with atypical course of the vertebral artery running inside the fracture gap.

Accuracy and Clinical Utility of Reports from Outside Hospitals for CT of the Cervical Spine in Blunt Trauma

BACKGROUND AND PURPOSE

Multidetector CT is the workhorse for detecting blunt cervical spine injury. There is no standard of care for re-interpretation of radiology images for patients with blunt trauma transferred to a higher level of care. The clinical impact of discrepancies of cervical spine CT reads remains unclear. We evaluated the discordance between primary (from referring hospitals) and secondary radiology interpretations (from a receiving level I tertiary trauma center) of cervical spine CT scans in patients with blunt trauma and assessed the clinical implications of missed cervical spine fractures.

MATERIALS AND METHODS

Medical records of patients with blunt trauma transferred to our institution between 2008 and 2015 were reviewed. Primary and secondary interpretations were compared and categorized as concordant and discordant. Two senior neuroradiologists adjudicated discordant reports. The benefit of re-interpretation was determined. For discordant cases, outcomes at discharge, injury severity pattern, treatment, and arrival in a cervical collar were assessed.

RESULTS

Six hundred fifty patients were included; 608 (94%) presented with concordant reports: 401 (61.7%) with fractures and 207 (31.8%) with no fractures. There were 42 (6.5%) discordant reports; 18 (2.8%) were cervical spine injuries undetected on the primary interpretation. Following adjudication, the secondary interpretation improved the sensitivity (99.3% versus 95.7%) and specificity (99.1% versus 91.7%) in detecting cervical spine fractures compared with the primary interpretation alone (P < .001).

CONCLUSIONS

There was an overall 6.5% discordance rate between primary and secondary interpretations of cervical spine CT scans. The secondary interpretation of the cervical spine CT increased the sensitivity and specificity of detecting cervical spine fractures in patients with blunt trauma transferred to higher-level care.

Cervical spine trauma: impact of different imaging classification systems in the clinical decision-making

Background and aim:

Considering the high rate of mortality and permanent disability related to vertebral traumas, an early and detailed diagnosis of the trauma and subsequently an immediate and effective intervention are crucial. Cervical vertebral injury classifications guide treatment choice through a severity grade based on radiological information. The purpose of the present study was to define which imaging classification system could provide the best morphological and clinical-surgical correlations for cervical spine traumas.

Methods:

We retrospectively analyzed patients evaluated for cervical spine trauma at our Institution in the period 2015-2020. Information regarding the morphological examination (using CT and MRI), the neurological evaluation, and the therapeutic management were collected. C3-C7 fractures were classified according to the SLIC and AOSpine criteria; axial lesions were classified according to the modified AOSpine for the C1-C2 compartment and through the Roy-Camille and the Anderson D’Alonzo system for the odontoid process of the axis.

Results:

29 patients were included in the final study population. Nine patients with axial spine trauma and 21 with subaxial cervical spine trauma. A conservative approach was applied in 16 patients while nine patients underwent neurosurgery. Considering the therapeutical indications provided by the SLIC system, a 76.9% accordance was found for patients with a <4 score, while a 100% concordance was calculated for patients with a >4 score undergoing neurosurgery. Regarding the AOSspine classification, a 28.6% concordance was observed for patients classified group B being treated with a posterior neurosurgical approach, while for patients belonging to subgroup C, considered for anterior neurosurgical approach, a 66.7% accordance was calculated.

Conclusions:

The study demonstrated a better morphological correlation for the AOSpine classification in subaxial trauma and the AOSpine and Anderson D’Alonzo in axial trauma. The therapeutic indication found a better correlation in the SLIC classification for subaxial trauma and the Anderson D’Alonzo for axial ones. (www.actabiomedica.it)

Traumatic cervical spine fracture patterns on CT: a retrospective analysis at a level 1 trauma center

PURPOSE

The purpose of our study was to determine common acute traumatic cervical spine fracture patterns on CT cervical spine (CTCS).

METHODS

We retrospectively reviewed 1091 CTCS positive for traumatic fractures performed over a 10-year period at a level 1 trauma center. Fractures were classified by vertebral level, laterality, and anatomic location (anterior/posterior arch, body, odontoid, pedicle, facet, lateral mass, lamina, spinous process, transverse foramina, and transverse processes).

RESULTS

C2 was the most commonly fractured vertebra (38% of all studies), followed by C7 (32.4%). 48.7% of studies had upper cervical spine (C1 and/or C2) fractures. 39.7% of positive studies involved > 1 vertebral level. Conditioned on fractures at one cervical level, the probability of fracture was greatest at adjacent levels with a 50% chance of sustaining a C7 fracture with C6 fracture. However, 31.3% (136) of studies with multi-level fractures had non-contiguous fractures. The most common isolated vertebral process fracture was of the transverse process, seen in 89 (8.2%) studies at a single level, 27 (2.5%) studies at multiple levels. Subaxial spine vertebral process fractures outnumbered body fractures with progressive dominance of vertebral process fracture down the spine.

CONCLUSION

C2 was the most commonly fractured vertebral level. Multi-level traumatic cervical spine fractures constituted 40% of our cohort, most commonly at C6/C7 and C1/C2. Although the conditional probability of concurrent fracture in studies with multi-level fractures was greatest in contiguous levels, nearly one-third of multi-level fractures involved non-contiguous fractures.

Spine trauma: Radiological approach and new concepts

The spine is the main stabilizer and load bearer of the axial skeleton. It is also important for the protection of neural structures, such as the spinal cord, nerve roots, and cauda equina. In the healthy skeleton, most injuries are a consequence of high-energy trauma and can lead to severe dysfunction, such as tetraplegia or paraplegia. In order to avoid such disabilities, it is important to recognize details that will guide treatment, and that will determine the necessity or not to have surgery. Familiarity with radiography, CT, and MRI in evaluating spine trauma is necessary, as, in some cases, all three methods will be useful in determining management and surgical planning. The most important factor in determining management in the thoracolumbar spine is the posterior ligamentous complex (PLC). Therefore, familiarity with its anatomy, primary and secondary signs of its injuries, is essential for radiologists in the emergency setting. Spine fractures are a very heterogeneous group of disorders. Management can be both conservative and surgical. It is important for radiologists to be aware of classifications and patterns for these injuries.

Skull Base-related Lesions at Routine Head CT from the Emergency Department: Pearls, Pitfalls, and Lessons Learned

Routine non-contrast material-enhanced head CT is one of the most frequently ordered studies in the emergency department. Skull base-related pathologic entities, often depicted on the first or last images of a routine head CT study, can be easily overlooked in the emergency setting if not incorporated in the interpreting radiologist's search pattern, as the findings can be incompletely imaged. Delayed diagnosis, misdiagnosis, or lack of recognition of skull base pathologic entities can negatively impact patient care. This article reviews and illustrates the essential skull base anatomy and common blind spots that are important to radiologists who interpret nonenhanced head CT images in the acute setting. The imaging characteristics of important "do not miss" lesions are emphasized and categorized by their cause and location within the skull base, and the potential differential diagnoses are discussed. An interpretation checklist to improve diagnostic accuracy is provided. ^©RSNA, 2019.

Imaging of cranio-cervical junction traumas

The craniocervical junction (CCJ) or upper cervical spine (UCS) has anatomic features and a biomechanics completely different from the other spinal segment of the spine. Several ligaments and muscles control its motion and function and ensure the maximum mobility and the visual and auditory spatial exploration. UCS traumas represent approximately one-third of all cervical spine injuries. Most of UCS traumas results from blows to the head and sudden deceleration of the body. Thanks to the improvement of the Advanced Trauma Life Support protocols dissociative injuries of CCJ have become less lethal onsite. In other less severe but unstable injuries, patients are neurologically intact at presentation, but they may deteriorate during the stay in hospital, with important clinical and medico-legal consequences. Knowing the peculiarities of UCS is fundamental for the early detection of imaging findings that influences the patient management and outcome. The classification of UCS traumas is mechanistic. More than in any other spinal segment, fractures of CCJ bones can occur without generating instability; on the contrary highly unstable injuries may not be associated with bone fractures. An early and correct diagnosis of occipito-cervical instability may prevent secondary neurological injury. The goal of imaging is to identify which patients can benefit of surgical stabilization and prevent secondary neurologic damage. Actual helical multidetector-CT (MDCT) offers high sensitivity and specificity for bone lesions and displacements in cervical spine traumas, but magnetic resonance imaging (MRI) is increasingly being used to evaluate soft tissues and ligaments, and mainly to identify possible spinal cord injury.

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.

Significance of the absent vertebral artery T2 flow void on cervical spine MRI in atraumatic patients without acute neurological symptoms

PURPOSE

Loss of the T2 vertebral artery flow void can be an ominous sign in patients with trauma. However, the significance of an absent vertebral artery flow void is less clear when discovered incidentally in patients without trauma or acute neurological symptoms. The purpose of this study was to review retrospectively the results of additional imaging and clinical evaluation in atraumatic patients without acute neurological symptoms found to have an incidentally discovered absent vertebral artery flow void on magnetic resonance imaging.

MATERIALS AND METHODS

An imaging database was reviewed for absent vertebral artery flow voids in atraumatic cervical spine magnetic resonance images. Imaging and long-term clinical follow-up were recorded.

RESULTS

Fifty-four patients were included in the study. All patients had clinical follow-up and 22 patients (40% of cases) had vascular imaging follow-up. Nine patients had a hypoplastic but patent vertebral artery on follow-up vascular imaging, and no further action was taken. Ten patients had evidence of stenosis or occlusion of the vertebral artery on follow-up imaging, none with acute neurological symptoms or new symptoms/subsequent change in management during follow-up. Three additional patients had vertebral artery dissections on follow-up imaging, but all of them had acute neurological symptoms at the time of imaging and acute infarcts on current or subsequent magnetic resonance imaging. The other 32 patients had clinical follow-up and remained asymptomatic throughout the study period, without change in management.

CONCLUSION

In the absence of trauma or acute neurological symptoms an absent vertebral artery flow void has a low likelihood of altering patient management.

Traumatic Atlantoaxial and Fracture-Related Dislocation

Traumatic atlantoaxial dislocation due to ligamentous and combined osseous injuries rarely occurs in adults. There are only few cases published in the literature. In this level 4 study, a cohort of nine consecutive patients suffering from traumatic atlantoaxial dislocation has been analyzed regarding morphology of injury, trauma mechanism, and outcome since 2007. Three types of those injuries have been found regarding direction of dislocation indicating the underlying ligamentous injuries as well as the accompanying grade of instability. Firstly, there was rotatory dislocation, if the alar ligaments were injured. Secondly, there occurred horizontal dislocation, when transverse atlantal ligament was damaged additionally. Thirdly, excessive ligamentous injury led to distraction of the atlantoaxial complex resulting in dissociation of the atlas against the axis. Additionally fractures of the atlas as well as of the odontoid process (type II or III according to Anderson/D'Alonzo) were diagnosed frequently. Atlantoaxial dislocation injuries, especially distraction injuries, offer a high risk for accompanied neurovascular disorders deserving reduction followed by surgical fixation. Only rotatory injuries leading to ligamentous damage solitarily can safely be successfully treated conservatively. Understanding of the injuries' morphology is essential, in order to set the correct diagnosis and to implicate the most advantageous treatment regime.

[Cervical spine trauma]

CLINICAL/METHODICAL ISSUE

In the emergency department 65 % of spinal injuries and 2-5 % of blunt force injuries involve the cervical spine. Of these injuries approximately 50 % involve C5 and/or C6 and 30 % involve C2. Older patients tend to have higher spinal injuries and younger patients tend to have lower injuries. The anatomical and development-related characteristics of the pediatric spine as well as degenerative and comorbid pathological changes of the spine in the elderly can make the radiological evaluation of spinal injuries difficult with respect to possible trauma sequelae in young and old patients.

METHODICAL INNOVATIONS

Two different North American studies have investigated clinical criteria to rule out cervical spine injuries with sufficient certainty and without using imaging.

PRACTICAL RECOMMENDATIONS

Imaging of cervical trauma should be performed when injuries cannot be clinically excluded according to evidence-based criteria. Degenerative changes and anatomical differences have to be taken into account in the evaluation of imaging of elderly and pediatric patients.

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

Parsing the Utility of CT and MRI in the Subaxial Cervical Spine Injury Classification (SLIC) System: Is CT SLIC Enough?

OBJECTIVE

The aim of our blinded retrospective study was to evaluate the diagnostic performance of the Subaxial Cervical Spine Injury Classification (SLIC) System in predicting the need for surgical intervention after subaxial cervical spine injury; SLIC scores were determined using CT alone or both CT and MRI.

MATERIALS AND METHODS

Patients were included if they had injuries that were subaxial (C3-C7), if they had undergone CT and MRI within 48 hours of admission, if they were either treated surgically or had sufficient clinical documentation describing nonsurgical management (halo device or hard collar), and if the SLIC neurologic score could be determined from a documented neurologic examination. Two hundred two consecutive patients (139 surgical patients and 63 nonsurgical control subjects) from January 2010 through December 2013 met all criteria and were included in the study. Additionally, 40 patients were randomly selected from this group for the purpose of determining interrater agreement. Initially, readers gave a SLIC score (< 4 for nonsurgical, 4 = indeterminate, > 4 for surgical) based on neurologic status and CT only. After waiting 4 weeks to minimize recall bias, the readers repeated scoring with the addition of MRI. Diagnostic performance values-that is, sensitivity, specificity, AUC under the ROC curve, and interrater agreement (Cohen kappa)-for both trials were determined.

RESULTS

Using a SLIC score of 4 as the cutoff value for surgical intervention, we found that SLIC scoring based on CT and MRI had a sensitivity of 94.6%, specificity of 71.0%, and AUC of 0.87 with a kappa value of 0.28. SLIC scoring based on CT alone had a sensitivity of 86.2%, specificity of 77.3%, and AUC of 0.88 with a kappa value of 0.52.

CONCLUSION

SLIC scoring based on CT alone performs similarly to SLIC scoring based on CT and MRI but with improved interobserver agreement. Although MRI is useful for surgical planning, these results indicate that MRI may have limited added value in the initial triage of patients with subaxial cervical spine injury for conservative versus surgical management.

Diagnostic errors in examinations of the spine

The most common radiological error in examinations of the spine is the failure to diagnose fractures. This is the third most frequent reason for lawsuits brought against radiologists for negligence, after the failure to diagnose breast cancer and the failure to diagnose lung cancer. The thousands of radiological reports of spinal examinations done every year affect not only patients' health, but also their permission to be off work and their compensation. For this reason, it is our responsibility to know why errors are committed and how to detect them in order to avoid their repetition. In this article, we show the spectrum of the most common errors in our experience in double reading spinal examinations, and we try to determine what causes these errors.

Magnetic resonance imaging of traumatic injury to the craniovertebral junction: a case-based review

OBJECT

The craniovertebral junction (CVJ) is unique in the spinal column regarding the degree of multiplanar mobility allowed by its bony articulations. A network of ligamentous attachments provides stability to this junction. Although ligamentous injury can be inferred on CT scans through the utilization of craniometric measurements, the disruption of these ligaments can only be visualized directly with MRI. Here, the authors review the current literature on MRI evaluation of the CVJ following trauma and present several illustrative cases to highlight the utility and limitations of craniometric measures in the context of ligamentous injury at the CVJ.

METHODS

A retrospective case review was conducted to identify patients with cervical spine trauma who underwent cervical MRI and subsequently required occipitocervical or atlantoaxial fusion. Craniometric measurements were performed on the CT images in these cases. An extensive PubMed/MEDLINE literature search was conducted to identify publications regarding the use of MRI in the evaluation of patients with CVJ trauma.

RESULTS

The authors identified 8 cases in which cervical MRI was performed prior to operative stabilization of the CVJ. Craniometric measures did not reliably rule out ligamentous injury, and there was significant heterogeneity in the reliability of different craniometric measurements. A review of the literature revealed several case series and descriptive studies addressing MRI in CVJ trauma. Three papers reported the inadequacy of the historical Traynelis system for identifying atlantooccipital dislocation and presented 3 alternative classification schemes with emphasis on MRI findings.

CONCLUSIONS

Recognition of ligamentous instability at the CVJ is critical in directing clinical decision making regarding surgical stabilization. Craniometric measures appear unreliable, and CT alone is unable to provide direct visualization of ligamentous injury. Therefore, while the decision to obtain MR images in CVJ trauma is largely based on clinical judgment with craniometric measures used as an adjunct, a high degree of suspicion is warranted in the care of these patients as a missed ligamentous injury can have devastating consequences.