Helical computed tomography alone compared with plain radiographs with adjunct computed tomography to evaluate the cervical spine after high-energy trauma

BACKGROUND: Current literature supports the use of the three-view plain-radiograph series supplemented, when necessary, with helical computed tomography to evaluate the cervical spine in patients who have sustained trauma injury. The purpose of this study was to determine if helical computed tomography alone can be used to evaluate the cervical spine for acute osseous injury following high-energy trauma, thus eliminating the need to make radiographs. METHODS: Patients were prospectively evaluated with helical computed tomography scanning of the cervical spine and standard three-view plain radiography. At a later date, the plain radiographs and computed tomography scans were independently reviewed by two radiologists who were blinded to both the initial interpretation and the interpretation of the corresponding study. The radiologists documented whether the plain radiographs were adequate and whether they showed an acute process. The findings in the study were compared with the initial findings and, when necessary, with the discharge summaries to determine if an injury had been identified. The accuracy of the plain radiographs, of the plain radiographs that had been deemed adequate, and of helical computed tomography used alone was ascertained. RESULTS: Plain radiographs and helical computed tomography scans were made for 407 patients, and traumatic injuries were identified in fifty-eight of them. Plain radiographs alone were adequate for 194 (48%) of the 407 patients. Plain radiographs had a sensitivity of 45%, a specificity of 97%, a positive predictive value of 74%, and a negative predictive value of 91%. Adequate plain radiographs had a sensitivity of 52%, a specificity of 98%, a positive predictive value of 81%, and a negative predictive value of 93%. Helical computed tomography had a sensitivity and specificity of 98%, a positive predictive value of 89%, and a negative predictive value of >99%. The sensitivity, positive predictive value, and negative predictive value of adequate plain radiographs differed significantly from those of helical computed tomography alone (p < 0.001). Twelve (48%) of twenty-five adequate plain radiographs of patients in whom an injury had been identified on computed tomography missed that injury. Helical computed tomography alone missed one (2%) of the fifty-eight injuries. CONCLUSIONS: Although helical computed tomography has a limited ability to detect pure ligamentous injury, it can be safely used without plain radiographs to evaluate the cervical spine for osseous abnormalities such as fractures and dislocations after high-energy trauma.     

Variability in computed tomography and magnetic resonance imaging in patients with cervical spine injuries

OBJECTIVE: The purpose of this study was to describe the performance of adjunctive radiologic imaging in patients with cervical spine injury. METHODS: All patients undergoing cervical spine radiography were prospectively enrolled at 16 diverse emergency departments. We recorded the imaging modalities and radiographic interpretations rendered by unblinded faculty radiologists at each center. Only patients with cervical spine injury were included in this analysis. Findings revealed by individual modalities were compared with the final diagnosis (after all evaluations) in each patient. RESULTS: Six hundred eighty-eight patients with 1,302 separate cervical spine injuries were enrolled. Four hundred seventy-six (69%) patients had magnetic resonance imaging (MRI) and/or computed tomography (CT) of the cervical spine. MRI identified the following injuries among 124 imaged patients: osseous fractures, 85 of 154 (55%); spinal cord injury, 69 of 69 (100%); vertebral subluxation/dislocation, 37 of 43 (86%); ligamentous injury, 38 of 38 (100%); and unilateral/bilateral locked facets, 14 of 18 (78%). Among 418 patients undergoing CT, the following injuries were identified: osseous fractures, 721 of 740 (97%); spinal cord injury, 0 of 30 (0%); vertebral subluxation/dislocation, 76 of 88 (86%); ligamentous injury, 9 of 36 (25%); and unilateral/bilateral locked facets, 34 of 35 (97%). CT identified 29 patients with fractures who had normal plain radiographs. Cervical myelograms were obtained in two patients and cervical tomograms in seven patients. CONCLUSION: The majority of patients with cervical spine injury undergo MRI and/or CT imaging. In clinical practice, MRI is superior at identifying soft tissue injuries, whereas CT performs better in identifying bony injuries. Cervical myelograms and tomograms are rarely obtained.     

Safe cervical spine clearance in adult obtunded blunt trauma patients on the basis of a normal multidetector CT scan—A meta-analysis and cohort study

Background

A true gold standard to rule out a significant cervical spine injury in subset of blunt trauma patients with altered sensorium is still to be agreed upon. The objective of this study is to determine whether in obtunded adult patients with blunt trauma, a clinically significant injury to the cervical spine be ruled out on the basis of a normal multidetector cervical spine computed tomography.

Methods

Comprehensive database search was conducted to include all the prospective and retrospective studies on blunt trauma patients with altered sensorium undergoing cervical spine multidetector CT scan as core imaging modality to “clear” the cervical spine. The studies used two main gold standards, magnetic resonance imaging of the cervical spine and/or prolonged clinical follow-up. The data was extracted to report true positive, true negatives, false positives and false negatives. Meta-analysis of sensitivity, specificity, negative and positive predictive values was performed using Meta Analyst Beta 3.13 software.We also performed a retrospective investigation comparing a robust clinical follow-up and/or cervical spine MR findings in 53 obtunded blunt trauma patients, who previously had undergone a normal multidetector CT scan of the cervical spine reported by a radiologist.

Results

A total of 10 studies involving 1850 obtunded blunt trauma patients with initial cervical spine CT scan reported as normal were included in the final meta-analysis. The cumulative negative predictive value and specificity of cervical spine CT of the ten studies was 99.7% (99.4–99.9%, 95% confidence interval). The positive predictive value and sensitivity was 93.7% (84.0–97.7%, 95% confidence interval).In the retrospective review of our obtunded blunt trauma patients, none was later diagnosed to have significant cervical spine injury that required a change in clinical management.

Conclusion

In a blunt trauma patient with altered sensorium, a normal cervical spine CT scan is conclusive to safely rule out a clinically significant cervical spine injury. The results of this meta-analysis strongly support the removal of cervical precautions in obtunded blunt trauma patient after normal cervical spine computed tomography. Any further imaging like magnetic resonance imaging of the cervical spine should be performed on case-to-case basis.     

Detection of vertebral artery injury after cervical spine trauma using magnetic resonance angiography

BACKGROUND: We prospectively describe the incidence, magnetic resonance-based diagnosis, and treatment of vertebral artery (VA) injury resulting from closed cervical spine trauma. METHODS: Patients with fracture or dislocation on plain radiographic studies underwent computed tomography. Among these patients, the subset with computed tomographic evidence of foramen transversarium (FT) fracture underwent magnetic resonance angiography as early as possible. RESULTS: During a 16-month period, 38 patients with closed cervical trauma were treated. Twelve patients demonstrated fracture extension through at least one FT by computed tomography. Among these patients, four showed unilateral VA injury by magnetic resonance angiography, all ipsilateral to the fractured FT. Three cases of VA occlusion and one of focal narrowing were demonstrated. All four patients were initially treated with aspirin, and two were systemically anticoagulated. None developed irreversible neurologic deficits from the VA compromise. CONCLUSION: Our data suggest that the incidence of VA injury in closed cervical spine trauma is significant and that FT fractures warrant flow-sensitive magnetic resonance imaging.     

Bilateral multiple cervical root avulsions without skeletal or ligamentous damage resulting from blast injury: case report

OBJECTIVE AND IMPORTANCE: We describe a unique case of multiple bilateral cervical root injuries without ligamentous or bony injury secondary to a sandblast accident. CLINICAL PRESENTATION: A 19-year-old man sustained a sandblast injury to his face, neck, chest, and upper extremities, with immediate loss of motor and sensory function occurring in both of his upper extremities. Cervical spine x-rays, computed tomography, and magnetic resonance imaging demonstrated no fracture, soft tissue abnormality, or malalignment. The restriction of deficits to the patient's upper extremities suggested a central cervical spinal cord injury, bilateral brachial injuries, or a conversion disorder. INTERVENTION: Cervical computed tomographic myelography revealed multiple bilateral nerve root injuries. CONCLUSION: This case report is unique in the literature in that it describes a patient with multiple cervical nerve root injuries secondary to sandblast injury without ligamentous or bony injury. Although magnetic resonance imaging remains the diagnostic modality of choice in patients with acute spinal cord injury, it is deficient in demonstrating cervical root injury in the acute setting. In this setting, computed tomographic myelography is superior.     

Are five-view plain films of the cervical spine unreliable? A prospective evaluation in blunt trauma patients with altered mental status

OBJECTIVES: Clearing the cervical spine in a time-sensitive fashion is difficult. We hypothesized that admission computed tomographic scan of the occiput to T1 (CTS) with multiplanar reformatted images will replace five-view (odontoid, anteroposterior, lateral, and oblique) plain films of the cervical spine (CSX) in the initial evaluation of blunt trauma patients with altered mental status. METHODS: Between January and July 2001, all patients aged 16 years or older with altered mental status undergoing both CTS and CSX were prospectively entered into the study group. Attending physician interpretation defined the presence of cervical spine injury. Unstable fractures were defined as requiring surgical or halo stabilization. RESULTS: One thousand six patients met study criteria. One hundred sixteen patients had 172 cervical spine injuries (CSIs) (fracture and subluxation). CSX missed 90 of 172 (52.3%) CSIs in 65 of 172 (56.0%) patients. Anatomically, CSX failed to identify 14 of 15 occipital fractures (93.3%), 17 of 36 (47.2%) C1-3 fractures, and 59 of 121 (48.8%) C4-T1 CSIs. CSX failed to identify 5 of 29 (17.2%) patients with unstable CSIs. CTS failed to diagnose 3 of 172 (1.7%) CSIs that were stable (spinous process fractures at C6-7). Two patients exhibited spinal cord injury without radiologic abnormality missed by both modalities. CTS had a sensitivity of 97.4%, a specificity of 100%, a prevalence of 11.5%, a positive predictive value of 100%, and a negative predictive value of 99.7%. CSX had a sensitivity of 44.0%, a specificity of 100%, a prevalence of 11.5%, a positive predictive value of 100%, and a negative predictive value of 93.2%. CONCLUSION: CTS outperformed five-view CSX in a group of patients with altered mental status or distracting injuries. Five-view CSX failed to diagnose 52.3% of cervical spine fractures identified by CTS. Five-view CSX failed to diagnose five patients with unstable cervical fractures and failed to identify 93.3% of patients with occipital condyle fractures.     

下颈椎前纵韧带与后纵韧带损伤的MRI诊断

目的:探讨MRI对下颈椎前纵韧带与后纵韧带损伤的诊断标准、诊断价值,以指导临床诊断与治疗。方法:2010年8月～2011年7月87例下颈椎损伤但椎体无骨折脱位患者行前路手术,术前均行颈椎X线、CT及MRI检查。两位诊断医师分别以MRI T1加权像低信号带连续中断(T1D)、T2加权像纵形高信号(T2L)、T2加权像横形高或中等信号(T2T)作为标准诊断前纵韧带、后纵韧带损伤。术中仔细探查韧带损伤(韧带完全或部分断裂)情况,并将不同MRI标准的诊断结果与术中所见进行比较。诊断者间的一致性采用Kappa检验。以术中所见作为金标准,计算不同MRI标准诊断前纵韧带、后纵韧带损伤的敏感性、特异性、准确性、阳性预测值及阴性预测值。结果:以T1D为标准判断前、后纵韧带损伤时,两诊断者间一致程度差(Kappa值分别为0.152、0.238),敏感性(57.4%～67.2%、64.7%～64.7%)、特异性(43.3%～60.8%、56.5%～59.7%)、准确性(48.7%～63.3%、58.2%～60.8%)、阳性预测值(38.9%～51.9%、29.0%～30.6%)及阴性预测值(61.8%～74.7%、81.4%～86.1%)均较低。以T2L为标准诊断前、后纵韧带损伤时,两诊断者间一致程度较好(Kappa值分别为0.657、0.607),特异性也较高(78.4%～80.4%、88.7%～90.4%),但敏感性较低(54.1%～65.8%、29.4%～50%),准确性(70.3%～73.4%、75.9%～84.8%)、阳性预测值(63.5%～65.8%、41.7%～70.8%)及阴性预测值(73.6%～78.4%、82.1%～87.3%)也较低。以T2T为标准诊断前、后纵韧带损伤时,两诊断者间一致程度非常好(Kappa值分别为0.837、0.799),且有较高的敏感性(83.6%～86.9%、82.4%～88.2%)、特异性(91.8%～95.9%、90.3%～91.9%)、准确性(89.9%～91.1%、89.9%～89.9%)、阳性预测值(86.9%～92.7%、71.4%～73.7%)及阴性预测值(90.3%～91.8%、95.0%～96.6%)。结论:以MRI的T2T为标准诊断下颈椎前、后纵韧带完全或部分断裂较准确可靠,有助于评价下颈椎的稳定性。     

Poor surgical technique in cervical plating leading to vertebral artery injury and brain stem infarction--case report

BACKGROUND: Lateral mass plating is a safe fixating system for lower cervical fractures. Brain stem infarction after cervical lateral mass screw plating has not been reported in previous literature. We report a case of poor surgical technique leading to vertebral artery injury and brain stem infarction after cervical lateral mass plating. CASE DESCRIPTION: A 41-year-old male patient was transferred to our hospital because of hemiparesis and dysarthria immediately after lateral mass plating for fracture and dislocation of the fifth and sixth cervical vertebrae. Brain magnetic resonance imaging showed infarction of the left posterior inferior cerebellar artery territory, and the vertebral artery angiography showed complete occlusion of the left vertebral artery. The cervical computed tomography revealed a left screw of the fifth and sixth cervical vertebrae penetrating the central portion of the transverse foramen. The patient was managed with anticoagulant and supportive therapy only, with subsequent improvement of hemiparesis and dysarthria. CONCLUSIONS: Poor surgical technique of lateral mass plating in the cervical spine could lead to vertebral artery injury and even brain stem infarction. Postoperative brain infarction in cervical fusion could be a complication of the usually safe lateral mass plating of the cervical spine.     

Cervical spine clearance in blunt trauma: evaluation of a computed tomography-based protocol

BACKGROUND: Prompt identification of cervical spine injuries has been a critical issue in trauma management. In 1998, the authors developed a new protocol to evaluate cervical spines in blunt trauma. This protocol relies on clinical clearance for appropriate patients and helical computed tomography instead of plain radiographs for patients who cannot be clinically cleared. The authors then prospectively collected data on all cervical spine evaluations to assess the sensitivity and specificity of their approach. METHODS: Any patient without clinical evidence of neurologic injury, alcohol or drug intoxication, or distracting injury underwent cervical spine evaluation by clinical examination. Patients who did not meet these criteria underwent helical computed tomographic scanning of the entire cervical spine. For patients who had neurologic deficits, a magnetic resonance image was obtained. If the patient was not evaluable secondary to coma, the computed tomographic scan was without abnormality, and the patient was moving all four extremities at arrival in the emergency department, the cervical spine was cleared, and spinal precautions were removed. Data were collected for all patients admitted to Santa Barbara Cottage Hospital trauma service between 1999 and 2002. The authors selected for analysis patients with blunt trauma and further identified those with closed head injuries (Glasgow Coma Scale score < 15 and loss of consciousness). In addition, all blunt cervical spine injuries were reviewed. RESULTS: During the period of study, 2,854 trauma patients were admitted, of whom 2,603 (91%) had blunt trauma. Of these, 1,462 (56%) had closed head injuries. One hundred patients (7% of patients admitted for blunt trauma) had cervical spine or spinal cord injuries, of which 99 were identified by the authors' protocol. Only one injury was not appreciated in a patient with syringomyelia. Fifteen percent of patients with spinal cord injury had no radiographic abnormality; all of these patients presented with neurologic deficits. The sensitivity for detecting cervical spine injury was thus 99%, and the specificity was 100%. The risk of missing a cervical spine injury in these blunt trauma patients was 0.04%. The authors missed no spine injuries in patients with head injuries. CONCLUSION: The use of the authors' protocol resulted in excellent sensitivity and specificity in detecting cervical spine injuries. In addition, it allowed early removal of spinal precautions.     

Comparison of computed tomography myelography and magnetic resonance imaging in the evaluation of cervical spondylotic myelopathy and radiculopathy.

STUDY DESIGN: A cross-sectional retrospective radiologic study. OBJECTIVES: To establish concordance rates between interpretations of computed tomography myelography and magnetic resonance imaging in patients with degenerative cervical spine disease. SUMMARY OF BACKGROUND DATA: Observed discrepancies in interpretation of computed tomography myelography and magnetic resonance imaging question the reliability of comparisons between these two methods. METHODS: This study blindly and randomly evaluated cervical computed tomography myelography and magnetic resonance imaging in 20 patients referred for clinically diagnosed cervical spondylotic radiculopathy, myelopathy, or both. The discovertebral joints, facet joints, lateral recesses, cord size, spinal canal, and neural foramina also were evaluated with graded scales. All results were subjected to the kappa statistic for strength of agreement. RESULTS: Agreement for interpretation of the discovertebral junction occurred in 144 of 240 sites (60%), indicating only moderately good intermethod concordance (kappa = 0.44). Intermethod agreement on the characterization of facet joint disease was only moderately good (143 of 160 sites; 89.4%; kappa = 0.52), and on characterization of lateral recess disease was poor (125 of 160 sites; 78.1%; kappa = 0.20). On degree of spinal canal compromise, there was agreement within one grade in 199 of 240 sites (82.9%; kappa = 0.42). Intermethod agreement on neural foraminal encroachment and cord size was only moderately good (kappa = 0.42 and 0.46, respectively). Computed tomography myelography tended to upgrade the spinal canal narrowing and neural foraminal encroachment. CONCLUSIONS: For most parameters of interpretation, the degree of concordance between computed tomography myelography and magnetic resonance imaging is only moderately good, with discrepancies noted especially in the differentiation of disc and bony pathology. These methods should be viewed as complementary studies.     

The early work-up for isolated ligamentous injury of the cervical spine: does computed tomography scan have a role?

BACKGROUND: Helical computed tomography (HCT) scan is the preferred modality for diagnosing fractures of the cervical spine in blunt trauma. We hypothesize that HCT can be used as a screening tool for isolated ligamentous injury (LI) in blunt trauma. METHODS: A prospective, consecutive series study design was used to include patients that could not have their cervical spine cleared clinically. All patients underwent HCT (occiput-T1) and plain radiographs (PR) with five views of the cervical spine. Patients with clinical or radiographic abnormalities without fracture underwent cervical magnetic resonance imaging (MRI). Demographic and outcome data were collected. The attending radiologist's interpretation was used for clinical management. Three neuroradiologists in a blinded fashion re-reviewed the studies (HCT, PR, and MRI) of the MRI subgroup. RESULTS: One thousand five hundred seventy-seven patients met the study criteria. Two hundred seventy-eight had 416 cervical spine fractures. PR failed to identify 299 of 416 (72%) cervical spine fractures in 208 of 278 (74.8%) patients. Of the 1,299 (82%) patients who had no fracture, 85 (6.5%) required an MRI. The mean time from admission to MRI was 3 days for the LI subgroup. Of these, 21 of 85 (25%) had LI by MRI. Seven of 21 (33.3%) patients had an abnormal HCT versus 3 of 21 (14.3%) patients who had an abnormal PR. Four of 85 (4.7%) patients had spinal cord injury without radiographic abnormality. One (1.2%) patient required surgical stabilization of LI, as seen on all studies performed (PR, HCT, and MRI). Sensitivities for PR and HCT for LI were 16% and 32%, respectively. Negative predictive values for PR and HCT for LI were 74% and 78%, respectively. Measurements of interrater reliability for MRI, HCT, and PR had kappa values of 0.60, 0.14, and 0.41, respectively. CONCLUSION: HCT is the most sensitive, specific, and cost-effective modality for screening the cervical spine bony injuries, but it is not an effective modality for screening for cervical LI. MRI is clearly superior to HCT for LI. The indications for MRI include abnormalities on HCT, neurologic deficits, cervical pain or tenderness on examination, or the inability to clear the cervical spine in the obtunded patient. With the current state of the art technology, we have redefined the definition of spinal cord injury without radiographic abnormality to include spinal cord injuries without boney injuries or LI.     

Magnetic resonance imaging of posttraumatic spinal ligament injury

We evaluated the role of magnetic resonance imaging (MRI) in the detection of ligament injury in 37 patients after acute traumatic spinal injury. Thirty-five patients had fractures, one had neurologic deficit with normal x-rays, and one had evidence of cervical instability on flexion/extension plain films. MRI examinations were performed acutely (average 10.8 d after injury) using T1- and T2-weighted multiplanar imaging. Two radiologists blindly evaluated all MRI examinations. Subsequently, 35 plain films, 16 tomograms, and 30 computed tomography (CT) scans were also evaluated. Nineteen patients were considered to have torn posterior ligaments on the basis of their clinical, radiographic and surgical findings. MRI detected ligament damage in 17. All patients considered to have intact posterior ligament complexes clinically and radiographically had no evidence of ligament damage on MRI. T2-weighted sequences were essential for detection of ligament injury. We conclude that MRI is an accurate method for assessment of the integrity of spinal ligaments after acute trauma.     

False-negative plain cervical spine x-rays in blunt trauma

Although considered very accurate, false-negative plain cervical radiographs of blunt trauma patients will occur with potentially devastating complications. We sought to define the population of patients who fall into this category and the overall accuracy of adequate three-view cervical spine radiography in the blunt trauma population. A retrospective search was carried out of blunt trauma patients entered into our trauma registry. All patients with the ICD-9 codes indicating cervical spine injury with a negative three-view cervical spine radiograph reading had their charts and radiographs reviewed. Institutional statistics for blunt cervical trauma evaluation and injury were obtained from the trauma registry. Fifty-eight of 936 blunt trauma patients (6.2%) were diagnosed with cervical spine injury over the 9-month study period. Of 649 patients with adequate three-view plain radiographs, three patients were identified with negative plain radiographs and significant cervical spine injury, a false-negative rate of 0.5 per cent. Sensitivity was 90.3 per cent, specificity was 96.3 per cent, positive predictive value was 54.9 per cent, and negative predictive value was 99.5 per cent. Three-view plain radiograph series of the cervical spine remains a highly sensitive and specific test for cervical spine injury following blunt trauma. However, the fact that we identified three patients with significant fractures after negative plain radiographs suggests that serious consideration of computed tomography must be applied in treating symptomatic, high-risk blunt trauma patients when plain radiographs do not reveal an injury.     

Standard radiographs and computed tomographic scan underestimating pediatric acetabular fracture after traumatic hip dislocation: report of 2 cases

Posterior wall acetabular fractures are rare in the pediatric patient but require proper management to prevent significant complications. Plain radiographs and computed tomography scans are standard diagnostic imaging used with clinical examination of hip stability to determine if the injury requires open reduction and internal fixation. Two cases are presented of adolescent traumatic hip dislocations and posterior wall fractures in which radiography underestimated the extent of the posterior wall fracture. In one case, a magnetic resonance imaging study more clearly characterized the injury. Because the ossification of the posterior wall occurs throughout adolescence, magnetic resonance imaging may be a useful tool in characterizing these fractures and assisting with surgical planning.     

The optimal radiologic method for assessing spinal canal compromise and cord compression in patients with cervical spinal cord injury. Part II: Results of a multicenter study

STUDY DESIGN: A multicenter, retrospective study using computed tomographic and magnetic resonance imaging data to establish quantitative, reliable criteria of canal compromise and cord compression in patients with cervical spinal cord injury. OBJECTIVES: To develop and validate a radiologic assessment tool of spinal canal compromise and cord compression in cervical spinal cord injury for use in clinical trials. SUMMARY OF BACKGROUND DATA: There are few quantitative, reliable criteria for radiologic measurement of cervical spinal canal compromise or cord compression after acute spinal cord injury. METHODS: The study included 71 patients (55 men, 16 women; mean age, 39.7 +/- 18.7 years) with acute cervical spinal cord injury. Causes of spinal cord injury included motor vehicle accidents (n = 36), falls (n = 20), water-related injuries (n = 8), sports (n = 5), assault (n = 1), and farm accidents (n = 1). Canal compromise was measured on computed tomographic scan and T1- and T2-weighted magnetic resonance imaging, and cord compression at the level of maximum injury was measured on T1- and T2-weighted magnetic resonance imaging. All films were assessed by two independent observers. RESULTS: There was a strong correlation of canal compromise and/or cord compression measurements between axial and midsagittal computed tomography, and between axial and midsagittal T2-weighted magnetic resonance imaging. Spinal canal compromise assessed by computed tomography showed a significant although moderate correlation with spinal cord compression assessed by T1- and T2-weighted magnetic resonance imaging. Virtually all patients with canal compromise of 25% or more on computed tomographic scan had evidence of some degree of cord compression on magnetic resonance imaging, but a large number of patients with less than 25% canal compromise on computed tomographic scan also had evidence on magnetic resonance imaging of cord compression. CONCLUSIONS: In patients with cervical spinal cord injury, the midsagittal T1- and T2-weighted magnetic resonance imaging provides an objective, quantifiable, and reliable assessment of spinal cord compression that cannot be adequately assessed by computed tomography alone.     

The role of positron emission tomography in the evaluation of the N-positive neck.

BACKGROUND: A major prognostic indicator in patients with squamous cell carcinoma of the upper aerodigestive tract is the presence or absence of cervical metastasis. Nodal involvement at different levels affects treatment. Thus identification of the degree of nodal involvement is important. Evaluation of the neck by conventional imaging modalities (computed tomography or magnetic resonance imaging) is not completely accurate. Positron emission tomography (PET) scanning as a dynamic functional assessment may allow detection of multiple metastatic nodes at different levels. PURPOSE: We sought to compare the effectiveness of PET with pathologic examination for: presence, location, and number of cervical metastases in the clinically N-positive neck. SETTING: Tertiary care academic facility.Materials and methods From 1994 to 1997, 15 patients with clinically N-positive necks who had preoperative PET scans underwent 23 neck dissections. PET scans were correlated with the pathologic findings of the neck dissections in determining the ability to correctly identify the number and level(s) of nodal disease. RESULTS: When determining identification of the level of disease, PET demonstrated sensitivity of 81%; specificity, 99%; positive predictive value, 97%; negative predictive value, 90%; and accuracy, 92%. When evaluating the ability to correctly predict neck stage, PET demonstrated sensitivity of 86%, positive predictive value of 100%, and accuracy of 80% compared with clinical examination with sensitivity of 53% and accuracy of 53%. CONCLUSION: PET accurately identified disease in the N-positive neck. Its ability to identify multiple level disease may allow it to help predict the selectivity of neck dissection in the therapeutic protocol.     

Management of thoracolumbar spine trauma: An overview

Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Controversies exist regarding the appropriate radiological investigations, the indications for surgical management and the timing, approach and type of surgery. This review provides an overview of the epidemiology, biomechanical principles, radiological and clinical evaluation, classification and management principles. Literature review of all relevant articles published in PubMed covering thoracolumbar spine fractures with or without neurologic deficit was performed. The search terms used were thoracolumbar, thoracic, lumbar, fracture, trauma and management. All relevant articles and abstracts covering thoracolumbar spine fractures with and without neurologic deficit were reviewed. Biomechanically the thoracolumbar spine is predisposed to a higher incidence of spinal injuries. Computed tomography provides adequate bony detail for assessing spinal stability while magnetic resonance imaging shows injuries to soft tissues (posterior ligamentous complex [PLC]) and neurological structures. Different classification systems exist and the most recent is the AO spine knowledge forum classification of thoracolumbar trauma. Treatment includes both nonoperative and operative methods and selected based on the degree of bony injury, neurological involvement, presence of associated injuries and the integrity of the PLC. Significant advances in imaging have helped in the better understanding of thoracolumbar fractures, including information on canal morphology and injury to soft tissue structures. The ideal classification that is simple, comprehensive and guides management is still elusive. Involvement of three columns, progressive neurological deficit, significant kyphosis and canal compromise with neurological deficit are accepted indications for surgical stabilization through anterior, posterior or combined approaches.     

Helical computed tomographic scanning for the evaluation of the cervical spine in the unconscious, intubated trauma patient

BACKGROUND: Assessment of the spine in the unconscious trauma patient is limited by an inadequate clinical examination. The potential of a missed unstable disc or ligamentous injury results in many patients remaining immobilized in critical care units for prolonged periods. METHODS: This study evaluates helical computed tomographic (CT) scanning of the whole cervical spine as part of a spinal assessment and clearance protocol. RESULTS: Four hundred thirty-seven unconscious, intubated, blunt trauma patients underwent CT scanning of the cervical spine. Sixty-one patients had a cervical spine injury and 31 (7.0%) were unstable. CT scanning had a sensitivity of 98.1%, a specificity of 98.8%, and a negative predictive value of 99.7%. There were no missed unstable injuries. In contrast, an adequate lateral cervical spine film detected only 24 injuries (14 unstable), with a sensitivity of 53.3%. CONCLUSION: Helical CT scanning of the cervical spine allows rapid and safe evaluation of the cervical spine in the unconscious, intubated trauma patient.     

Cervical spine trauma

Traumatic injuries to the cervical spine are often difficult to detect and are associated with substantial morbidity and mortality. Along with standard trauma radiographs, a thorough physical examination and meticulous documentation are of the utmost importance because many neurologic injuries evolve over time. Although many injuries to the cervical spine can be treated nonoperatively, any injuries with neurologic deficits, instability, or ligamentous injury require instrumentation and fusion. It is crucial to recognize injuries to the cervical spine and the different treatment options. Computed tomography can be very helpful in defining the bony injury and evaluating the spinal canal, whereas magnetic resonance imaging can better evaluate the spinal cord and assess ligamentous injury.     

A prospective analysis of intraoperative electromyographic monitoring of posterior cervical screw fixation

OBJECTIVE: This is a prospective study of 26 patients undergoing posterior cervical spine instrumentation with lateral mass or pedicle screws to determine the correlation between intraoperative screw stimulation thresholds and the position of posterior cervical lateral mass and pedicle screws. METHODS: One hundred forty-seven posterior cervical screws (122 lateral mass screws and 25 C7 pedicle screws) in 26 patients were electrically stimulated intraoperatively and stimulation thresholds recorded. Computed tomography (CT) scans were taken postoperatively and were evaluated independently to assess screw position. Electromyographic (EMG) thresholds and CT data were compared to assess the accuracy of the EMG screw stimulation technique in detecting screw malposition. RESULTS: Intraoperative electrical stimulation was accurate in verifying screw position. A stimulation threshold of 15 mA provided a 99% positive predictive value (89% sensitivity, 87% specificity) that the screw was within the lateral mass or pedicle. Stimulation values of 10-15 mA provided a 13% predictive value (66% sensitivity, 90% specificity) that the screw was within the lateral mass or pedicle. A stimulation value of <10 mA provided a 100% predictive value that the screw was malpositioned (70% sensitivity, 100% specificity). CONCLUSIONS: Intraoperative evoked EMG monitoring is a valuable tool in posterior cervical instrumentation using lateral mass and pedicle screws. Stimulation thresholds in this study correlated with screw position. Stimulation values of >15 mA reliably predict acceptable screw position. Values between 10 and 15 mA are generally associated with acceptable screw position, although exploration is recommended. Values below 10 mA are associated with screw malposition and warrant exploration, repositioning, and possible removal.