Comprehensive Review of Multidetector Computed Tomography (MDCT) in the Assessment of Blunt Cervical Spine Trauma in Adults

ABSTRACT

Since the release of 64-section computed tomographic (CT) scanners in 2004, there have been several new advancements in cervical spine imaging. A growing trend in polytrauma patients with obtain-dating is the use of multidetector CT as a stand-alone screening test to rule out cervical injuries. Spine surgeons are beginning to adopt the SLIC (Subaxial Injury Classification and Scoring) method for the cervical spine based on CT and MR imaging data. Multidetector CT is currently being used to reassess radiographic parameters that were previously established for the evaluation of craniocervical distraction injuries. Even while most blunt trauma patients are presently managed without surgery, procedures for management have changed to favor surgical intervention because of improved surgical techniques, hardware, and breakthroughs in our understanding of spinal stability. For this reason, radiologists need to be aware of this. Cervical spine imaging has significantly improved since the introduction of 64-section computed tomography (CT) scanners in 2004. MDCT has become a single imaging modality of significance in the evaluation of polytrauma patients, especially those who are obtunded to assess for cervical spine injury. The recent generation of Subaxial Injury Classification and Scoring (SLIC) based on CT and MRI is establishing itself among spine surgeons. Regarding craniocervical distraction injuries, the role of MDCT is also being rediscussed. Cervical spine injuries that are found in 5–10% of the cases of blunt trauma affect the spinal cord and require more demanding investigations because of a high rate of noncontiguous lesions. MDCT is increasingly used in cervical spine clearance because of the higher sensitivity compared with radiography in patients with other injuries that distract the cervical spine. Cervical spine CT is recommended in these cases by the American College of Radiology. The superiority of MR imaging in identifying disc and ligament abnormalities is counterbalanced by the higher false-positive study rates and modest effect on management; for this reason, MDCT remains preferable for screening purposes. CD as a form of ligamentous injury with neurological deficit as its component signifies the value of an MDCT scan in its early diagnosis. Occipital condyle injuries as a sign of high-tied trauma and atlas and axis fractures, highly stable and some of which require different treatment, also enable further improvement of MDCT detection. Current diagnostic imaging has replaced radiography mostly because of better visualization and sensitivity, especially among high-risk patient groups. In conclusion, MDCT can be advocated as the gold standard in the primary assessment of blunt cervical spine injury due to improved and sensitive diagnostic performance. At the same time, the radiation dose issue remains the current radiologist challenge.

INTRODUCTION

As part of whole-body CT procedures for the evaluation of blunt polytrauma, multidetector computed tomography (CT) is increasingly being employed as the initial screening test for high-risk patients suspected of having cervical spine trauma in major US trauma centers. In 5%–10% of patients with blunt polytrauma, there are lesions to the cervical spine. About 55% of the roughly 10,000 spinal cord injuries that are identified each year affect the cervical spinal cord. Treatment for quadriplegics is thought to cost the US economy roughly 5.6 billion dollars a year.[1] A significant degree of suspicion regarding a potentially harmful mechanism of injury or a neurological injury should present when a cervical spine appears normal on initial examination.[2] Since 10%–15% of patients involve noncontiguous lesions to the cervical spine, imaging of the full spinal axis should be initiated as soon as a cervical spine injury is detected.[3] It is critical to comprehend (a) the limitations and blind spots of multidetector CT, (b) the emergence of normal variations, and (c) the complementary function of magnetic resonance imaging (MR) in assessing the extent of injuries and surgical strategy. This article aims to clarify the use of multidetector CT in detecting and diagnosing adult cervical spine injuries. The procedure is discussed after elucidating the “clearance” of the cervical spine. The various cervical spine injury types—from the subaxial cervical spine to the craniocervical junction are then explained. Finally, the limits of multidetector CT, including normal variants and pitfalls, are covered.[4]

Until shown otherwise, the cervical spine after blunt trauma should be considered wounded; research indicates that the cervical spine needs to be “cleared” or effectively excluded from injury before the precautions can be safely withdrawn.[5] The study’s total sensitivity for conclusions derived from the clinical examination was 99 percent. Closed head injuries account for up to one-third of polytrauma patients, and this increases the risk of cervical spine injury by 8.5 percent. Others need analgesics or sedation, which might mask symptoms of neurological impairment. In these patients, the risk of subsequent brain damage increases tenfold with missing or delayed diagnoses. On the other hand, fewer problems, fewer days spent on mechanical breathing, and shorter stays in the critical care unit are associated with early termination of cervical spine precautions.[6]

Global communities face high death rates from blunt cervical spine trauma, which occurs most often in car crashes, falling injuries, and contact sports incidents. The fragile cervical spine design that protects the spinal cord needs quick and correct diagnosis because it controls head and neck movement. Finding spinal injuries too late or incorrect can cause lasting brain and head damage that makes death more likely.[7] For many years, healthcare providers started examinations of cervical spine trauma using standard X-rays since these tools are readily available at low cost. The technology has basic detection problems with hard-to-spot or intricate bone damage, so additional imaging solutions have become standard practice. During the past 20 years multidetector computed tomography became the preferred imaging tool to examine traumatic damage to the neck region. MDCT provides superior detection of bone injuries alongside the fast production of multi-layered images that show exam injuries clearly.[8] The rapid features and varying use of MDCT become essential in emergency trauma episodes when fast diagnoses matter for patients who need many imaging tests performed together. Trauma care systems now prioritize Medical Computerized Tomography (MDCT) because research shows this technology helps doctors find and treat injuries more effectively.[9]

REVIEW

Cervical spine clearance

Asymptomatic Patients: Interventions, including cervical spine immobilization and airway protection following blunt trauma, are the focus of the ATLS protocol. Thus, cervical spine protections must be lifted before removing additional safety precautions.[10] Polytrauma Patients with Obtundation According to recent research, patients with alert blunt trauma who are free of complaints and have significant distractions may not need imaging. The American College of Radiology advises cervical spine CT for patients with distracting injuries. It has been demonstrated that a patient’s clinical examination alone has a high sensitivity, yet the SE of subsequent neurologic injury is increased by overlooked or delayed diagnosis. Consequently, CT is required to rule out missing injuries since its greater sensitivity over traditional radiography makes up for its higher radiation dosage. Patients with obtundation may be in a touch-and-go situation regarding MR imaging for clearance.[11] Although there is a risk of false-positive outcomes, MR imaging seems more sensitive than CT in demonstrating disc and ligament injury. Although MR imaging is quite sensitive and does not always affect care, it is proposed as a clearing measure for obtunded patients with negative CT findings. The results of this study generally suggest that cervical spine CT should be stopped earlier than cervical spine precautionsin polytrauma patients with obtundation.[12]

Traumatic injuries of the craniocervical junction

Craniocervical dissociation

This severe ligamentous rupture and neurological consequences are part of the lister hall unstable injury, which is most commonly seen in traumatized youngsters but can also occur in adults. Despite the importance of these preventive actions, therapy often begins later than diagnosis. Although normal values may vary, the population’s evaluation criteria have been modified by CT measurement of the craniocervical.[13]

Occipital condyle injuries

Observed in 8–16% of injuries involving the craniocervical junction and indicate a high energy impact. They have a connection to other serious trauma types, and CT is probably a better way to assess the damage.[14]

Fractures of the atlas

Nervous injury is relatively seldom seen in atlas fractures, which are anatomically stable. Ligament state and loose connections with other bodily structures dictate surgical treatment. If the transverse ligament is also affected, Jefferson fractures that are axially stressed could require stabilization.[15]

Fractures of the axis

Of cervical spine fractures, 17–20% are caused by axial damage. Odontoid fractures, hangman fractures, and axis body fractures are the three kinds of injuries. Odontoid fractures, particularly type II ones, are common; proper care is necessary to prevent nonunion.[16]

MDCT in cervical spine

Sixty-three participants in one research study required a full cervical spine assessment compared to the particular locations. Road accidents, especially those involving motor vehicles, were the more common cause of the two. MDCT is helpful in patient populations with a high risk of fracture since it is effective in detecting not only fractures but also other abnormalities.[17]

Cervical spine clearance

Asymptomatic patients

The American College of Surgeons Committee on Trauma established the Advanced Trauma Life Support procedure, which starts with cervical spine immobilization and airway protection. The cervical spine following physical trauma should be regarded as damaged until demonstrated differently. The cervical spine must be effectively “cleared” from harm before the safeguards can be removed without risk.[18]

Polytrauma patients with obtundation

Recent data suggest that imaging may not be required to rule out cervical spine injuries in patients who have experienced acute blunt trauma and have significant distraction injuries but are asymptomatic. The American College of Radiology advises cervical spine CT for patients with distracting injuries or other favorable findings.[19]

A prospective cohort of 761 patients with severe trauma and a Glasgow Coma Scale score of 14 or higher revealed that findings from the clinical examination alone had a 99 percent overall sensitivity. Up to one-third of polytrauma patients have closed head injuries, which raises the risk of cervical spine injury by 8.5 percent.[20] On the other hand, early termination of cervical spine precautions is associated with fewer adverse events, fewer days spent on mechanical breathing, and shorter ICU stays. In a retrospective analysis of 800 patients with polytrauma, it was discovered that. In contrast, radiography has a high probability of missed injuries; CT had a sensitivity of 98.5 percent for identifying fractures, compared to 43 percent for radiography. Given a fictitious patient cohort of one million.[21]

Used a risk-benefit decision analysis model contrasting CT with radiography and discovered that, in both low- and high-risk individuals of all ages, the greater diagnostic accuracy of CT greatly surpassed the increased anticipated lifetime cancer risk and financial cost. These results support the American College of Radiology’s suggestion to use screening CT as soon as possible to screen individuals with polytrauma who have obtundation.[22]

MR imaging’s controversial role in Clea rance for patients with obtundation

Although MR imaging has a larger false-positive rate than CT imaging, it is more sensitive in assessing disc and ligament injury.[23] Although prevalent, isolated signal anomalies without bone damage or aberrant alignment are of questionable relevance and can, in certain situations, result in needless spinal immobilization.[24] It is still up for contention how much of a benefit MR imaging is regarding cervical spine clearance in patients with obtundation who have negative screening cervical spine CT findings. Many associations advise MR imaging as the preferred modality for patients who cannot be checked for longer than 24 to 48 hours due to its great sensitivity.[25] Found that CT had a negative predictive value of 100% for unstable cervical spine injury and 98.9% for ligament injury in a retrospective evaluation of 366 “unreliable” or obtunded individuals who had multidetector CT and MR imaging done in 2005 to rule out unstable cervical spine injury. Since the MR imaging results were considered unstable injuries, none needed to be treated. Because few individuals with negative CT results but positive MR imaging results need to change their course of treatment or show signs of delayed instability, the majority of the existing data, which includes data from multiple sizable investigations and a meta-analysis of 17 studies including 14,327 people[26] encourages the early termination of cervical spine precautions in patients with polytrauma and obtundation based only on CT scans.[27] Studies that support MR imaging for cervical spine clearance when CT findings are negative are small, rare, and vulnerable to verification bias because prolonged collar entrapment is often used as an outcome.[25]

Injuries of the craniocervical junction

Craniocervical dissociation

Traumatic atlantooccipital dissociation is more prevalent and more survivable in skeletally immature pediatric trauma patients; in a recent study, adults made up half of the presenting patients, yet only six of the 22 patients made it through the perioperative period.[25] An unstable injury type called atlanto-occipital dissociation is characterized by a significant disruption of the ligaments and a significant neurologic impairment. Associated closed head injuries and upper cervical spine injuries are the primary determinants of prognosis.[28] Craniocervical dissociation refers to both complete dislocations, which are frequently associated with fatal motor vehicle accidents, and subluxation or distraction injuries, which can be mild and perhaps survive.[29] An unstable injury known as atlanto-occipital dissociation is typified by significant disruption. Of the ligaments and substantial impairments in the nervous system. Associated closed head injuries and upper cervical spine injuries are the primary determinants of outcome.[30] The diagnosis of craniocervical distraction is often missed prospectively, irrespective of experience level, and is easy to miss on whole-body CT scans.[31] Findings can be subtle, and a qualitative assessment is often inadequate. In the last few years, several craniocervical measurements established using conventional radiography have been reassessed with CT.[32] While most aberrant readings are not specific, they are sensitive. While normal intervals effectively eliminate craniocervical distraction, some patients may exhibit normal values within the previously stated upper limits, while others may exhibit abnormalities.[33] In a recent cohort of 18 individuals with atlantooccipital dissociation, evidence of atlantooccipital capsular damage on MR imaging was consistently linked to some degree of articular displacement in the abnormal range. A cruciate ligament damage or other neurological comorbidities are typically absent when the isolated distraction of the C1-C2 lateral masses occurs.[34]

Occipital condyle injuries

With a 3% prevalence in patients with severe blunt cervical trauma, occipital condyle fractures can occur in as many as 16 percent of craniocervical injuries. They can be regarded as indicators of a high-energy mechanism of injury. The majority of occipital condyle fractures are connected to closed head injuries, even though a sizable fraction of patients with these fractures have Normal Glasgow Coma Scale scores. A CT scan can reveal fractures anywhere along the cervical spinal column, damage to the vertebrae and carotid arteries, and facial fractures.[14]

Fractures of the atlas

Atlas fractures cause twenty-five percent of craniocervical injuries. Axial fractures account for as many as 44% of atlas fractures. With some adjustments, the original Atlas fracture classification system was created by Jefferson and is still in use today Only[15] the posterior arches can have C1 fractures. Bilateral posterior arches fractures and burst fractures are the most frequent patterns. A comparatively rare consequence are isolated anterior arch fractures. Neurologic damage is a rare consequence of atlas fractures, which are typically mechanically stable. The integrity of the transverse ligament and related cervical spine fractures are the primary factors that determine whether surgical intervention is necessary in cases of atlas fractures.[35]

Jefferson fractures

Burst atlas fractures are hypothesized to be caused by axial loading. There are several variations in the unilateral or single midline fractures of the anterior and posterior arches. This is a rare Jefferson burst with unilateral anterior and posterior arch fractures. The fracture pattern causes the lateral masses to shift outward, suggesting a potential transverse ligament injury. In order to prevent atlantoaxial separation, surgical stabilizations for Jefferson fractures may be necessary if the transverse ligament is damaged or the anterior arch is severely displaced. According to radiography, a transverse ligament disruption was predicted by a total lateral mass displacement of 6.9 mm.[36] After that, Antonio et al. showed that 61 percent of fractures would have gone unnoticed if the Spence rule had been applied. This low performance could be explained by the absence of magnification during cross-sectional imaging, but as far as we know, a useful smaller cutoff value for CT has not been found.[37]

Fractures of the axis

Roughly 17–20% of cervical spine fractures involve the axis. The three primary categories of injury patterns are odontoid fractures, hangman fractures, and axis body fractures.[38]

Odontoid fractures

Odontoid fractures were found to be the most common type of axis fractures, making up approximately 59% of the cases in are search involving 340 cases. Odontoid fractures seem to be more common in the elderly, which may be because inflexible spondylotic spines transmit more force to the dens. Anderson and D’Alonzo devised a three-part classification system for odontoid fractures in 1974, gaining universal support. Obliquely directed fractures through the odontoid tip, most likely caused by avulsions in the alar ligament, are known as type I odontoid fractures. Hadley et colleagues observed that nonunion occurred in around 26% of patients with type II fractures treated nonsurgically in a study of 107 axis fractures. Nonunion incidence in type II odontoid fractures increased to 67 percent when the dens were displaced by 6 mm or more.[39]

MDCT in the cervical spine

In January–June 2004, 63 individuals were referred for CT scans of the cervical spine. Sixty-one instances (97%) were full cervical examinations, whereas just two cases (3%), at C1/2 levels, were level-specific scans. Of the 61 complete cervical spine tests, 26 were related to motor vehicle accidents, 14 to falls, 12 to slips or collapses, and 9 to bicycle incidents. The two cervical spine exams that were level-specific were associated with both collapse and MVA. Six (11%) of the 63 individuals (five full, one level-specific assessment) suffered cervical spine fractures. Two of the occurrences included falls, while four involved motor vehicle collisions. Three cases were apparent on radiographs, but the other three were not. The fracture kinds and healing mechanisms for the fracture cases with CT documentation. Forecasts for thyroid, lens, and breast dose were 75.8, 9.7, and 0.7 m, respectively, for full cervical spine exams with radiographs showing a strong indication or proof of cervical spine damage.[40]

Any one of the following six factors was considered to be in a high-risk group in a previous study by carrying a risk of cervical spine fracture greater than 5%: High-speed (>56 km/h) automobile accident victim; fatality at the scene of the incident; fall from a height (>3 m) cerebral bleeding is observed. When radiographs show insufficient cervical spine visibility or equivocal findings, individuals undergo a level-specific CT scan of the cervical spine, which scans one vertebral body above and below the area of concern. The Multidetector Computed Tomography helps identify diseases, bone fractures, and locations.[41] MDCT cervical spine, as shown in Figure 1.

Figure 1.

MDCT cervical spine

DISCUSSION

A cervical radiograph (frontal, lateral, and open mouth views) is the main tool used to assess patients with suspected cervical spinal injuries for cervical spine injuries. On the other hand, earlier research has emphasized radiography’s shortcomings. In 23–57 percent of patients, the cervicothoracic junction identified as fractured—was not visible in 63 percent of cases.[42] Consequently, for suspected patients with normal radiograph findings and fracture delineation, CT is a frequently used diagnostic technique. In addition to ruling out various noncervical traumas, CT scans are incredibly sensitive in identifying fractures (such as fracture skull base, fracture mandible, pneumothorax, etc). A level-specific CT scan is performed if a fracture is suspected or if C7 and T1 are not evident on radiographs even after obtaining Swimmer’s view. A total cervical spine CT examination is carried out in trauma patients who have changed mental status or who are not fully conscious.[43]

Multi-detector computed tomography (MDCT) and spiral CT are commonly employed to identify thoracic aortic conditions. A CT scan is quick, straightforward, and noninvasive. Administering contrast intravenously enhances the understanding of the extra-cardiac vasculature, the cardiovascular system, and thoracic connective tissues, including abnormalities in the trachea and esophagus.[44] MDCT monitoring has proven to be a reliable imaging method for identifying solid tumors, especially synchronous renal cell carcinoma. In the last 8 years, computed tomography (CT) technology has significantly advanced by incorporating multi-detector row CT (MDCT) scans into clinical radiology practice. The drive for superior technology continually pushes suppliers to create innovations in very short timeframes. Over the past decade, CT scanning has significantly increased due to a surge in newly developed applications. Since 1998, global sales of CT scanners have doubled, with projections exceeding 25,000 units worldwide. According to a recent survey, approximately 90 million CT examinations are conducted globally each year, resulting in a frequency of 16 per thousand people.[45]

CONCLUSION

Whatever the cause of the damage, more individuals seeking a comprehensive cervical spine examination than a level-specific examination were seen after the installation of MDCT (Multi-Detector Computed Tomography). As a result, the thyroid, lens, and breast all received much higher radiation. Our duty as radiologists is to try and keep the dose of a cervical spine examination as low as possible without compromising its accuracy. A multidetector CT scan is now the first screening test for evaluating direct cervical spine damage in individuals who do not meet clinical clearance requirements. In addition to being able to identify and explain the variety of injuries to the cervical subaxial spine and craniocervical junction that can be detected on multidetector CT.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.