Imaging evaluation of adult spinal injuries: emphasis on multidetector CT in cervical spine trauma

Computed Tomographic Scan for Head Injury Patients: Any Justification for Adapting Routine Cranio-Cervical Examination Irrespective of Clinical Severity?

Background and Objective

This study aimed to assess the prevalence of concomitant cervical spine and head injury at our University Teaching Hospital in Nigeria and attempted to justify examining patients' head and cervical spine using computed tomography (CT) scan at presentation irrespective of the head injury severity by clinical assessment using Glasgow Coma Scale (GCS).

Patients and Methods

All eligible patients, 1-80 years of age who presented with head injuries in the accident and emergency (A&E) unit during the study period, were included if they satisfied the inclusion criteria. Post-resuscitation GCS was assessed clinically, and head and cervical spine injury (CSI) were observed radiologically on cranio-cervical CT scan for all patients. The presence of cervical spine fractures, subluxation or dislocation was considered a confirmation of CSI.

Results

There were 143 patients with head injuries studied; 90.2% of them were males. The mean age of the patients was 28.87 ± 15.93 years. The most common cause of injury was road traffic accidents in 110 (76.90%). The prevalence of CSI was 11.2%. Majority of the patients with CSI in this study (56.25%) had a mild head injury, 25% had a moderate head injury, and 18.75% had a severe head injury. The lower cervical spine was the most frequently injured segment in this study, involving 10 patients. Multi-level cervical vertebral body fractures of C3 to C6 were the most common form of CSI in this segment.

Conclusion

The prevalence of concomitant cervical spine and head injury was significant in this study. This was confirmed among study subjects with a clinical diagnosis of mild-to-moderate head injury as compared with moderate-to-severe head injury. Therefore, all patients who sustained a head injury irrespective of severity are required to have a complete and rapid evaluation of the cervical spine.

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.

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.

Variation in global treatment for subaxial cervical spine isolated unilateral facet fractures

PURPOSE

To determine the variation in the global treatment practices for subaxial unilateral cervical spine facet fractures based on surgeon experience, practice setting, and surgical subspecialty.

METHODS

A survey was sent to 272 members of the AO Spine Subaxial Injury Classification System Validation Group worldwide. Questions surveyed surgeon preferences with regard to diagnostic work-up and treatment of fracture types F1-F3, according to the AO Spine Subaxial Cervical Spine Injury Classification System, with various associated neurologic injuries.

RESULTS

A total of 161 responses were received. Academic surgeons use the facet portion of the AO Spine classification system less frequently (61.6%) compared to hospital-employed and private practice surgeons (81.1% and 81.8%, respectively) (p = 0.029). The overall consensus was in favor of operative treatment for any facet fracture with radicular symptoms (N2) and for any fractures categorized as F2N2 and above. For F3N0 fractures, significantly less surgeons from Africa/Asia/Middle East (49%) and Europe (59.2%) chose operative treatment than from North/Latin/South America (74.1%) (p = 0.025). For F3N1 fractures, significantly less surgeons from Africa/Asia/Middle East (52%) and Europe (63.3%) recommended operative treatment than from North/Latin/South America (84.5%) (p = 0.001). More than 95% of surgeons included CT in their work-up of facet fractures, regardless of the type. No statistically significant differences were seen in the need for MRI to decide treatment.

CONCLUSION

Considerable agreement exists between surgeon preferences with regard to unilateral facet fracture management with few exceptions. F2N2 fracture subtypes and subtypes with radiculopathy (N2) appear to be the threshold for operative treatment.

Occult Disco-Ligamentous Lesions of the Subaxial c-Spine-A Comparison of Preoperative Imaging Findings and Intraoperative Site Inspection

Despite the general acceptance of magnetic resonance imaging (MRI) as the gold standard for diagnostics of traumatic disco-ligamentous injuries in the subaxial cervical spine, clinical experience shows cases where no lesion is detected in MRI exams but obtained during surgery. The aim of this study was to compare intraoperative site inspection to preoperative imaging findings and to identify radiological features of patients having a risk for under- or over-estimating disco-ligamentous lesions. We performed a retrospective analysis of our clinical database, considering all patients who underwent surgical treatment of the cervical spine via an anterior approach after trauma between June 2008 and April 2018. Only patients with availability of immediate preoperative computed tomography (CT), 3-Tesla MRI scans, and information about intraoperative findings were considered. Results of preoperative imaging were set in context to intraoperative findings, and receiver operator characteristics (ROC) were calculated. Out of 144 patients receiving anterior cervical surgery after trauma, 83 patients (mean age: 59.4 ± 20.5 years, age range: 12–94 years, 63.9% males) were included in this study. Included patients underwent surgical treatment via anterior cervical discectomy and fusion (ACDF; 79 patients) or anterior cervical corpectomy and fusion (4 patients) with ventral plating. Comparing preoperative imaging findings to intraoperative site inspection, a discrepancy between imaging and surgical findings was revealed in 14 patients, leading to an overall specificity/sensitivity of preoperative imaging to identify disco-ligamentous lesions of the cervical spine of 100%/77.4%. Yet, adding the existence of prevertebral hematoma and/or vertebral fractures according to preoperative imaging improved the sensitivity to 95.2%. Lack of sensitivity was most likely related to severe cervical spondylosis, rendering correct radiological reporting difficult. Thus, the risk of missing a traumatic disco-ligamentous injury of the cervical spine in imaging seems to be a particular threat in patients with preexisting degenerative cervical spondylosis. In conclusion, incorporating the existence of prevertebral hematoma and/or vertebral fractures can significantly improve diagnostic yield.

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.

Feasibility of sub-milliSievert CT of the cervical spine: Initial results in fresh human cadavers

PURPOSE

To investigate the feasibility of sub-milliSievert CT of the cervical spine in fresh human cadavers using a standard-dose (SD) and four different reduced-dose (RD) protocols reconstructed with filtered back projection (FBP) and iterative reconstruction (IR).

METHODS

The cervical spine of 29 cadavers was examined using different RDCT protocols with decreasing reference tube currents (RDCT-1:70 mAs; RDCT-2:50 mAs; RDCT-3:30 mAs; RDCT-4:10 mAs) at 140 kV. A clinical SDCT (160 mAs, 120 kV) served as reference. Raw data were reconstructed using FBP and two increasing levels of IR (IRL4&6). Images of the upper (C1-4) and lower (C5-7) cervical spine were evaluated for image quality, diagnostic acceptability and visibility of anatomical structures according to a 5-point-scale.

RESULTS

Image quality of the upper cervical spine was diagnostically acceptable for all protocols using FBP and IR except for RDCT-4 with FBP. Image quality of the lower cervical spine was rated as non-diagnostic in RDCT-3 with FBP and RDCT-4 with FBP and IR. RDCT-3 with IR was the most reduced dose CT protocol allowing diagnostically acceptable image quality for both upper and lower cervical spine in all cadavers. RDCT protocols achieved significantly reduced effective radiation doses (SDCT: 1.5 ± 0.7 mSv; RDCT-1:1 ± 0.6 mSv; RDCT-2:0.7 ± 0.4 mSv; RDCT-3:0.4 ± 0.2 mSv; RDCT-4:0.2 ± 0.1 mSv; p < 0.001).

CONCLUSION

Diagnostically acceptable sub-milliSievert CT of the cervical spine is feasible with a low reference tube current at 140 kV using iterative reconstruction and could be suitable for isolated cervical trauma in cooperative patients.

Cervical Disc and Ligamentous Injury in Hyperextension Trauma: MRI and Intraoperative Correlation

BACKGROUND AND PURPOSE

To identify and evaluate diagnostic magnetic resonance imaging (MRI) features in patients with suspicion of discoligamentous cervical injury after hyperextension trauma of the cervical spine.

METHODS

MR images with a standard protocol (1.5 T, including sagittal T2‐weighted images and short tau inversion recovery [STIR]) in 21 patients without any sign of fracture or instability on multidetector computed tomography of the cervical spine were assessed. Among other structures we evaluated the following: prevertebral hematoma, anterior longitudinal ligament (ALL), intervertebral disc, and spinal cord. Presence and the anatomic level of injury were identified and recorded. Results were then compared with intraoperative findings as a reference standard. Simple descriptive statistical analysis, agreement coefficients (given by calculating the percent agreement), and the determination of Gwet's AC1 coefficient were used to analyze our results.

RESULTS

The overall percent agreement between STIR and intraoperative findings was 90.9% (AC1 = .881) and for T2 69.7% (AC1 = .498). For the ALL, the overall agreement was 87.9% (AC1 = .808) and for the intervertebral disc 78.8% (AC1 = .673), in which STIR always showed a higher agreement. Prevertebral hematoma was found in 20 of 21 patients with the maximum thickness at the same anatomic level as the intraoperatively proven lesion in 12 of 18 patients (67%). Edema and/or hemorrhage of the spinal cord was shown in 16 of 21 being at the same anatomic level as the intraoperatively confirmed pathology in 16 of 16 patients (100%).

CONCLUSIONS

MRI is a reliable tool for the evaluation of discoligamentous injuries in the cervical spine, with ancillary features proven as helpful information.

MRI has limited agreement with CT in the evaluation of vertebral fractures of the canine trauma patient

Complete assessment of vertebral trauma in dogs currently requires CT and MRI for evaluation of the osseous and soft tissue structures that contribute to vertebral stability. Some studies in people have suggested that MRI may be sensitive and specific at detecting vertebral fractures making this potentially a single modality that could be used in spinal trauma evaluation. This study aimed to assess the ability for observers to evaluate vertebral fractures using MRI when compared to CT, which was used as the reference standard. Twenty-nine dogs with previously diagnosed acute vertebral fractures and four dogs with no vertebral fracture that had undergone sequential CT and MRI were included into the study. One hundred twenty-eight vertebrae were evaluated for the presence of fractures. Imaging studies were read by two observers blinded to the history. While both observers had similarly high sensitivity and specificity for simple detection of any fractured vertebrae, interobserver agreement was only moderate (κ = 0.584). When evaluations were specifically limited to detection of structurally unstable fractured vertebrae both observers showed improved specificity and interobserver agreement became substantial (κ = 0.650). Complete agreement for exact fracture location between MRI and CT results was only achieved in 14.3-32.6% of fractured vertebra with up to 79% of fractures being missed in some vertebral structures. This suggests that although MRI may be able to detect the presence of fractured vertebrae, it is not able to replace CT for the complete evaluation of the traumatized spine and documentation of fracture morphology.

Preprocessing of Medical Image Data for Three-Dimensional Bioprinted Customized-Neural-Scaffolds

IMPACT STATEMENT

Nerve damage, which can be devastating, triggers several biological cascades, which result in the insufficiencies of the human nervous system to provide complete nerve repair and regain of function. Since no therapeutic strategy exists to provide immediate attention and intervention to patients with newly acquired nerve damage, we propose a strategy in which accelerated medical image processing through graphical processing unit implementation and three-dimensional printing are combined to produce a time-efficient, patient-specific (custom-neural-scaffold) solution to nerve damage. This work aims to beneficially shorten the time required for medical decision-making so that improved patient outcomes are achieved.

Pattern Recognition: A Mechanism-based Approach to Injury Detection after Motor Vehicle Collisions

Motor vehicle collisions cause substantial mortality, morbidity, and expense worldwide. Certain types of injuries are more likely to result from frontal versus side-impact collisions, and knowledge of these specific patterns and why they occur aids in accurate and efficient diagnosis of traumatic injuries. Although the proper use of seat belts decreases crash-related mortality during frontal impact, certain injury patterns to the torso are directly attributed to restraint use. The spectrum of seat belt-related injuries ranges from mild skin and soft-tissue contusions to traumatic bowel injuries and unstable spine injuries that require surgery. Impact with the steering wheel or windshield during a frontal crash can cause characteristic injuries to the head, neck, torso, and distal upper extremity. Steering wheel deformity is an independent predictor of serious thoracic and abdominal injury among front-seat passengers. Impact of a flexed knee with the dashboard during a frontal collision can cause knee, thigh, and hip injuries. Distal lower extremity injuries are encountered frequently when the floorboard is driven into the foot. Lateral impact crashes often result in traumatic brain, thoracic, abdominal, and pelvic injuries, which are more often fatal to occupants on the side of the impact. The specific mechanism-based injury patterns are reviewed to establish a structured systematic search pattern that enables the radiologist to identify traumatic injuries with greater accuracy and speed, thereby improving the care of patients who experience acute trauma. ^©RSNA, 2019 See discussion on this article by Ballard and Mellnick .

Imaging of the spine: Where do we stand?

The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leaps for diagnostic imaging modalities, including those exploited for imaging the spine. These developments improved our diagnostic capabilities in different spinal pathologies, especially with multi-detector computed tomography and magnetic resonance imaging, via both hardware and software improvisations. Nowadays, imaging may depict subtle spinal instability caused by various osseous and ligamentous failures, and could elucidate dynamic instabilities. Consequently, recent diagnostic modalities can discern clinically relevant spinal canal stenosis. Likewise, improvement in diagnostic imaging capabilities revolutionized our understanding of spinal degenerative diseases via quantitative biomarkers rather than mere subjective perspectives. Furthermore, prognostication of spinal cord injury has become feasible, and this is expected to be translated into better effective patient tailoring to management plans with better clinical outcomes. Meanwhile, our confidence in diagnosing spinal infections and assessing the different spinal instrumentation has greatly improved over the past few last decades. Overall, revolutions in diagnostic imaging over the past few decades have upgraded spinal imaging from simple subjective and qualitative indices into a more sophisticated yet precise era of objective metrics via deploying quantitative imaging biomarkers.

Spectrum of diagnostic errors in cervical spine trauma imaging and their clinical significance

PURPOSE

To describe and categorize diagnostic errors in cervical spine CT (CsCT) interpretation performed for trauma and to assess their clinical significance.

METHODS

All CsCTs performed for trauma with diagnostic errors that came to our attention based on clinical or imaging follow-up or quality assurance peer review from 2004 to 2017 were included. The number of CsCTs performed at our institution during the same time interval was calculated. Errors were categorized as spinal/extraspinal, involving osseous/soft tissue structures, by anatomical site and level. Images were reviewed by a radiologist and two spine surgeons. For each error, the need for surgery, immobilization, CT angiogram of the neck, and MRI was assessed; if any of these were needed, the error was considered clinically significant.

RESULTS

Of an approximate total 59,000 CsCTs, 56 reports containing diagnostic errors were included. Twelve were extraspinal, and 44 were spinal (26 fractures, 15 intervertebral disc protrusions, two subluxations, one lytic bone lesion). The most common sites of spinal fractures were vertebral body (n = 10) and transverse process (n = 8); the most common levels were C5 (n = 8) and C7 (n = 6). All (n = 26) fractures and two atlantooccipital subluxations were considered clinically significant, including three patients who would have required urgent surgical stabilization (two subluxations and one facet fracture). Two transverse processes fractures did not alter the need for surgical intervention/surgical approach, immobilization, or MRI.

CONCLUSIONS

In our study, 66% of spinal diagnostic errors on CsCT were considered clinically significant, potentially altering clinical management. Transverse process and vertebral body fractures were commonly missed.

[Modern radiological diagnostics in spine surgery]

BACKGROUND

Radiological imaging is important in the preoperative diagnosis of many forms of spinal pathology and plays a fundamental role in the assessment of p.o. effects, which can be verified on the spinal column as well as on the surrounding soft tissues, depending on the imaging method used.

AIM

The article provides an overview of the current status and possibilities of radiological diagnostic methods for the verification of possibly recommended spine surgery in the context of degenerative, inflammatory-infectious, post-traumatic or p.o. pathologies and changes in the spine: X‑rays, computed tomography (CT), magnetic resonance imaging (MRI). The supplementary nuclear medicine procedures (scintigraphy, PET[-CT], SPECT, etc.) which may be required for special questions are not discussed.

MATERIAL AND METHODS

The merits and limitations of the techniques used in the investigation of advanced degenerative spinal pathologies and post-traumatic conditions are discussed, with multidetector CT being the focus of attention in spinal clearance for traumatic injuries. In most cases of spinal infection, MRI images, as a central diagnostic tool, show typical findings such as destruction of adjacent endplates, bone marrow and intervertebral disc abnormalities, and paravertebral or epidural abscesses. However, it is not always easy to diagnose a spinal infection, especially if atypical MR patterns of infectious spondylitis are present. Knowledge of them means misdiagnosis and improper treatment can be avoided.

RESULTS

It is shown that high-quality modern radiological examinations are essential for diagnosis and p.o. management, as these provide answers to the main questions in the treatment: Is the entity/injury stable or unstable, acute or old, benign or malign; is there a myelopathy or p.o. complication?

DISCUSSION

The main indications for p.o. diagnostic imaging, difficulties such as metal artefact formation, and potential pitfalls are analyzed. Entity-specific radiological image patterns, imaging algorithms and differential diagnostic peculiarities are presented and discussed based on current literature and selected case studies.

The Role of CT and MRI in Suspected Acute Cervical Spine Trauma

Objective

To evaluate the accuracy of computed tomography (CT) in evaluation of patients with acute cervical spinal injury.

Design

Retrospective case series.

Setting

Three major public emergency departments in the southern hemisphere.

Methods

We performed a retrospective review of patients with neck injury aged at least 16, with CT cervical spine examinations performed for blunt trauma over a 6 month period (1 January 2011 to 30 June 2011) and magnetic resonance imaging (MRI) cervical spine performed for same indications over two and a half years (12 January 2010 to 22 June 2012).

Results

Acute cervical spine trauma was present on CT in 35 of 783 patients (4.5%) and on MRI in 98 of 206 patients (48%). Eleven of the 35 patients (31%) with CT confirmed trauma did not meet the Hanson criteria; the majority were at least 60 years of age and none had unstable injuries. CT is 100% sensitive in excluding an unstable injury if there is no soft tissue abnormality or fracture (with MRI as gold standard). An abnormal CT (including subtle paravertebral fat stranding) is often non-specific and often cannot reliably confirm an unstable ligamentous injury. Close attention to soft tissue axial and sagittal soft tissue CT reconstructions is important, as abnormalities can be subtle.

Conclusions

An unstable injury can often be excluded if CT is completely normal, without the need for MRI. (Hong Kong j.emerg.med. 2014;21:368-372)

Cord Topographical Anatomy and its Role in Evaluating Intramedullary Lesions

Intramedullary spinal lesions present a wide differential diagnosis including infectious, inflammatory, traumatic, ischemic, benign, or malignant neoplastic etiologies. Using knowledge of anatomy and physiology within the spinal cord, many similar appearing entities can be parsed into a prioritized differential. The purpose of this article is to review anatomy and pathophysiology of the spinal cord, with subsequent discussion of how this knowledge can be used to differentiate several similar appearing intramedullary pathologic processes. Discussion includes the pathophysiology, imaging findings, and clinical pearls of several intramural lesions including infarct, demyelinating lesions, traumatic injury, neoplasm, vascular malformation, and metabolic processes such as subacute combined degeneration.

Imaging investigations in Spine Trauma: The value of commonly used imaging modalities and emerging imaging modalities

Traumatic spine injuries can be devastating for patients affected and for health care professionals if preventable neurological deterioration occurs. This review discusses the imaging options for the diagnosis of spinal trauma. It lays out when imaging is appropriate and when it is not. It discusses strength and weakness of available imaging modalities. Advanced techniques for spinal injury imaging will be explored. The review concludes with a review of imaging protocols adjusted to clinical circumstances.

Effectiveness of second-opinion radiology consultations to reassess the cervical spine CT scans: a study on trauma patients referred to a tertiary-care hospital

PURPOSE

A second opinion is a valuable resource in confirming proper medical diagnosis and treatment. This study evaluates the effectiveness of second-opinion radiology consultations to reassess the cervical spine computed tomography (CT) scans of the trauma patients referred to our hospital.

METHODS

Cervical spine CT scans of 301 consecutive adult trauma patients, who were referred to our hospital from outside institutions, were analyzed. The emergency radiologists at our institution completed the over-read reports on the CT images obtained at the outside facilities. A single radiologist compared the outside- and over-read reports and determined the discrepancy of the radiologic reports.

RESULTS

Based on the outside reports, 31% of the CT scans had cervical traumatic injury. In 92% of patients, the first-read and the over-read reports had consistent radiologic findings. About 90% of the positive, and 93% of the negative radiologic findings, were reported consistently in the over-read reports. Our analysis showed that the over-read reporting resulted in reassurance of negative findings in 63%; confirmation of positive findings in 29%; clearing a false diagnosis in 3%; and detection of a missed diagnosis in 5%. A rescan was done in 80% of patients with inconsistent and 20% of patients with consistent findings (P < 0.05). The most common missed radiologic findings in the first-reports were transverse and spinous process fractures and the most common misdiagnoses were dens fractures.

CONCLUSION

For a service offering second-opinion consultations on cervical spine trauma, review of outside CT studies improves diagnosis and benefits patient care.

Assessment of MRI as a Modality for Evaluation of Soft Tissue Injuries of the Spine as Compared to Intraoperative Assessment

INTRODUCTION

Traumatic injuries of the spine and spinal cord are potentially devastating as they may lead to significant neurological damage as the clinical and prognostic spectrum of the effects of spinal injuries is vast. Timely imaging studies can help mitigate these possibly life threatening complications. There is a dearth of studies that directly compare MR imaging findings to surgical findings.

AIM

Hence, this study was undertaken to assess the sensitivity of MRI in identifying injuries to the soft tissue structures of the spine.

MATERIALS AND METHODS

MRI scans were performed on 31 cases of acute spinal injuries that presented within 72 hours of the trauma and underwent surgical fixation by either an anterior or posterior approach. The non-osseous structures namely; Anterior Longitudinal Ligament (ALL), Posterior Longitudinal Ligament (PLL), Intervertebral Disc, Ligamentum Flavum, Interspinous Ligament (ISP) and the Spinal Cord were evaluated. They were classified as 'True Positive' if an injury was found to correlate with intraoperative findings and as 'False Negative' when diagnosed falsely as normal. The statistical sensitivity of MRI in diagnosing injuries to the non-osseous structures of the spine were thus calculated.

RESULTS

Of the 31 patients, in 51.6% of patients the site of injury was to the cervical spine (n=16), thoracic spine was the next highest in occurrence of 39% (n=12) and lumbar spine accounted for the least. In correlating the imaging findings to the intraoperative findings, MRI was highly sensitive in detecting injuries to the Posterior Longitudinal Ligament (94.4%) and the Spinal cord (93%) and fairly high in detecting injuries to the Intervertebral disc. However coming to the ligamentum flavum and interspinous ligaments, the sensitivity of the MRI dropped to 62.5% and 63.6% respectively.

CONCLUSION

MRI was found to be highly sensitive in detecting injuries to the spinal cord and the posterior longitudinal ligament and moderately sensitive for detection of disc injuries. Though concerning the Anterior Longitudinal Ligament, Ligamentum Flavum and the Interspinous Ligaments MRI performed ineffectively with higher number of false negative interpretations.

Pediatric Cervical Spine and Spinal Cord Injury: A National Database Study

STUDY DESIGN

A retrospective administrative database analysis.

OBJECTIVE

The aim of this study was to investigate the incidence and characteristics of pediatric cervical spine injury (PCSI) utilizing the Kids' Inpatient Database (KID).

SUMMARY OF BACKGROUND DATA

PCSI is debilitating, but comprehensive analyses have been difficult due to its rarity. There have been a few database studies on PCSI; however, the studies employed databases that suffer from selection bias.

METHODS

The triennial KID was queried from years 2000 to 2012 using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Pediatric admissions were divided into five age groups reflecting different developmental stages. PCSI was analyzed in terms of trend, demographics, injury characteristics, hospital characteristics, comorbidities, and outcomes variables. Multivariate logistic regression analyses were used to identify independent risk factors for PCSI among trauma admissions and to identify independent risk factors for mortality among PCSI admissions.

RESULTS

Over the past decade, the overall prevalence of traumatic PCSI was 2.07%, and the mortality rate was 4.87%. Most frequent cause of PCSI was transportation accidents, accounting for 57.51%. Upper cervical spine injury (C1-C4), cervical fracture with spinal cord injury, spinal cord injury without radiographic abnormality (SCIWORA), and dislocation showed a decreasing trend with age. Some comorbidities, including, but not limited to, fluid and electrolyte disorders, and paralysis were common across all age groups, while substance abuse showed a bimodal distribution. Independent risk factors for PCSI after trauma were older cohorts, non-Northeast region, and transportation accidents. For mortality after PCSI, independent risk factors were younger cohorts, transportation accidents, upper cervical spine injury, dislocation, and spinal cord injuries. Median length of stay and cost were 3.84 days and $14 742.

CONCLUSION

Pediatric patients are highly heterogeneous, constantly undergoing behavioral, environmental, and anatomical changes. PCSI after trauma is more common among older cohorts; however, mortality after sustaining PCSI is higher among younger patients.

LEVEL OF EVIDENCE

4.

Diagnostic Value of Serum Levels of GFAP, pNF-H, and NSE Compared With Clinical Findings in Severity Assessment of Human Traumatic Spinal Cord Injury

STUDY DESIGN

An analytical cohort study.

OBJECTIVE

This study aimed to evaluate severity of traumatic spinal cord injury (SCI) based on the serum levels of phosphorylated form of heavy subunit of neurofilament (pNF-H), neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP), which are axonal, neural cell body, and glial cell injury markers, respectively.

SUMMARY OF BACKGROUND DATA

Prior studies have reported elevated serum levels of pNF-H, NSE, and GFAP as biomarkers for the detection of traumatic SCI in animals. However, in this study, these biomarkers were studied in humans and with an extended level of timing.

METHODS

The study included 35 patients with SCI with a mean age of 36.5 years. All patients were evaluated using the American Spinal Injury Association Impairment Scale, followed by examinations including radiography and spinal computed tomography for determining the injury level. Serum levels of NSE, pNF-H, and GFAP were determined using enzyme-linked immunosorbent assay.

RESULTS

The mean serum level of GFAP was significantly higher in patients with SCI than in the control group. Mean serum levels of pNF-H and NSE were significantly higher during 24 and 48 hours after injury in patients with SCI than in the control group. The serum level of GFAP was appropriate for estimating the severity of SCI in the first 24 hours after injury.

CONCLUSION

Our findings suggest that increased serum levels of GFAP, NSE, and pNF-H can be used for the diagnosis and degree of SCI severity in trauma patients. During 48 hours after injury, estimation of serum levels of pNF-H, NSE, and GFAP, combined with neurological testing, could predict the presence of SCI and severity prior to spinal computed tomography and surgical or conservative interventions.

LEVEL OF EVIDENCE

2.

Aneurysmal bone cyst involving the c2 vertebra

A 9-year-old boy presented with a 3-month history of cervical pain, limited range of motion, and a palpable "bump" in his posterior neck. After treatment with antibiotics for presumptive adenopathy and progression of the palpable finding, radiographs were obtained.

Low-dose multidetector computed tomography of the cervical spine: optimization of iterative reconstruction strength levels

BACKGROUND

Iterative reconstruction (IR) techniques reduce image noise in multidetector computed tomography (MDCT) imaging. They can therefore be used to reduce radiation dose while maintaining diagnostic image quality nearly constant. However, CT manufacturers offer several strength levels of IR to choose from.

PURPOSE

To determine the optimal strength level of IR in low-dose MDCT of the cervical spine.

MATERIAL AND METHODS

Thirty consecutive patients investigated by low-dose cervical spine MDCT were prospectively studied. Raw data were reconstructed using filtered back-projection and sinogram-affirmed IR (SAFIRE, strength levels 1 to 5) techniques. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at C3-C4 and C6-C7 levels. Two radiologists independently and blindly evaluated various anatomical structures (both dense and soft tissues) using a 4-point scale. They also rated the overall diagnostic image quality using a 10-point scale.

RESULTS

As IR strength levels increased, image noise decreased linearly, while SNR and CNR both increased linearly at C3-C4 and C6-C7 levels (P < 0.001). For the intervertebral discs, the content of neural foramina and dural sac, and for the ligaments, subjective image quality scores increased linearly with increasing IR strength level (P ≤ 0.03). Conversely, for the soft tissues and trabecular bone, the scores decreased linearly with increasing IR strength level (P < 0.001). Finally, the overall diagnostic image quality scores increased linearly with increasing IR strength level (P < 0.001).

CONCLUSION

The optimal strength level of IR in low-dose cervical spine MDCT depends on the anatomical structure to be analyzed. For the intervertebral discs and the content of neural foramina, high strength levels of IR are recommended.

The prevalence and clinical importance of incidental soft-tissue findings in cervical CT scans of trauma population

OBJECTIVES

To define the age-related prevalence of incidental soft-tissue findings in cervical CT scans of a trauma population and to investigate their clinical importance.

METHODS

The original diagnostic radiology reports and the CT images of the 357 patients with cervical trauma were retrospectively evaluated. Incidental soft-tissue findings were investigated. All findings were grouped according to age. The findings were classified based on their clinical importance into three categories: Category 1: no clinical importance, Category 2: possible clinical importance requiring further investigation and Category 3: obvious clinical importance. In addition, the medical records of the patients were investigated. The follow-up ratio of the pathologies mentioned in the original radiology report was recorded.

RESULTS

The most frequently encountered findings in Categories 2 and 3 were carotid artery calcification (n = 89, 24.9%) and tonsillolith (n = 115, 32.2%), respectively. The reporting ratio in the original reports of Categories 1, 2 and 3 findings was 1.1% (n = 4), 9% (n = 27) and 34.5% (n = 64), respectively. No further investigations and follow-up was accomplished for Category 1 lesions, whereas 11.1% of Category 2 and 35.9% of Category 3 lesions were subjected to further investigations and follow-up.

CONCLUSIONS

The cervical CT scans of trauma patients reveal many clinically important soft-tissue incidental findings. Cervical region incidental findings may be followed up on an outpatient basis, rarely being of life-threatening value. The ratio of reporting and follow-up of incidental findings increases parallel to the clinical importance of the lesions.

Clinical applicability of magnetic resonance imaging in acute spinal cord trauma

PURPOSE

To assess the clinical application of magnetic resonance imaging (MRI) in patients with acute spinal cord trauma (SCT) according to the type, extension, and severity of injury and the clinical-radiological correlation.

METHODS

Diagnostic imaging [computed tomography (CT) and MRI] tests of 98 patients with acute SCT were analyzed to assess their clinical diagnostic value. The following radiological findings of SCT were investigated: vertebral compression fractures, bursts and dislocations, posterior element fractures, C1 and C2 lesions, vertebral listhesis, bone swelling, spinal canal compression, disk herniation, extradural hematoma, spinal cord contusions, spinal cord swelling, and posterior ligamentous complex (PLC) injuries.

RESULTS

The radiological findings were better visualized using MRI, except for the posterior elements (p = 0.001), which were better identified with CT. A total of 271 lesions were diagnosed as follows: 217 using MRI, 154 using CT, and 100 (36.9 %) using both MRI and CT. MRI detected 117 more lesions than CT.

CONCLUSION

MRI was significantly superior to CT in the diagnosis of bone swelling, PLC injury, disk herniation, spinal canal compression, spinal cord contusion and swelling present in SCT. MRI detected a larger number of lesions than CT and is highly useful for the diagnosis of soft tissue and intrathecal injuries.