Trauma of the Spine: CT and MRI
Interspinous and supraspinous ligament injuries are characterized by increased signal in the interspinous spaces and tip of the spinous processes, respectively, on STIR images. Partial tears or sprain of these ligaments are more common than complete tears.
Injuries to the facet joint capsule are seen as widening of the facet joint with increased fluid signal between the joint surfaces. Since ligaments are essential components of spinal columns, the presence of their injury can change a single column injury to a two column injury, thus upgrading a stable injury to an unstable injury [ 21 ]. Traumatic disc herniations are most commonly associated with vertebral fracture dislocations and hyperextension injuries of the spine, and are caused by injuries to annulus fibrosus with nucleus pulposus herniation.
On MRI, these can appear similar to non-traumatic disc herniations Fig. MRI is better than CT in evaluating the traumatic disc herniations due to excellent contrast between disc, vertebral body and cerebrospinal fluid on appropriate pulse sequences. Additionally, multiplanar MRI is very helpful in evaluating large disc extrusions and sequestrated disc fragments before closed reduction of spinal dislocations [ 24 ].
Undetected disc herniations can cause new or worsening cord injury with progressive neurological deficits. Disc injuries without herniations are characterized by asymmetric widening or narrowing of the disc with abnormal signal related to edema. Histologically, these changes may be related to rupture of annulus fibrosus with hematoma [ 25 ]. Axial gradient recalled echo GRE image a and sagittal T1 weighted image b show the presence of a small central disc herniation white arrows.
Also note the presence of paraspinal muscle edema black arrow , a. Extradural hematoma is the most common type of extra medullary collections in trauma patients. Subdural hematoma and subarachnoid hemorrhage are uncommon. Pseudomeningoceles and extradural fluid collections due to dural tear are other uncommon sequelae of spinal trauma. Epidural hematomas usually appear isointense to slightly hyperintense on T1W images and hyperintense on T2W images Fig. Entire craniocaudal extent of the hematoma can be easily evaluated on sagittal MRI.
Similar to epidural hematomas, subdural hematoma and subarachnoid hemorrhage show collections with varying signal intensities in the subdural Fig. Sagittal T1 weighted image a and axial gradient recalled echo GRE image b show the presence of epidural hematoma arrows , and axial T2 weighted image c shows subdural hematoma long arrow deep to the dura short arrow.greenufapas.tk
Major Trauma Guidelines & Education
Vascular injuries can be caused by both blunt and penetrating trauma. Although asymptomatic unilateral injuries are of less clinical significance, they can lead to cerebral and cerebellar infarctions, especially when bilateral [ 28 ]. The Denver screening criteria has been used to identify the patients at risk for vascular injuries and includes C1—C3 fractures, fracture of the cervical spine extending into a foramen transversarium, cervical spine subluxation, Le Fort II or III facial fractures, basilar skull base fractures involving the carotid canal, diffuse axonal injury, and expanding neck hematoma [ 29 ].
In case of thoracolumbar spine trauma, injuries to the aorta and its branches can occur. The imaging findings of vascular injuries include minimal intimal injury, visualization of intimal flap Fig.
Most of the vascular injuries can be seen as irregularity or loss of normal flow void on long TE sequences such as T2W images. Fat-suppressed T1W images are better to identify the high signal intensity intramural hematoma associated with dissection. In equivocal cases, CT angiography or catheter angiography can be used for further evaluation of vascular injuries [ 30 ]. Axial T2 weighted image a shows the presence of post traumatic vertebral artery dissection with double lumen arrow.
Subsequent CT angiogram of the neck b confirms of the finding of vertebral artery injury arrow. Follow-up angiography of the neck performed on the next day c shows the presence of pseudoaneurysm arrow. Most common MRI findings of cord trauma include abnormal hyperintense T2 signal suggesting cord edema Fig.
Although neurological function at the presentation remains the single best predictive factor for long term prognosis, presence of cord hemorrhage has been described as the most important findings associated with poor prognosis. Other findings of prognostic value include the extent of cord hematoma and cord edema, and spinal cord compression by extra-axial hematoma [ 35 ].
Acute traumatic central cord syndrome, which is characterized by disproportionately greater upper extremities motor function impairment than in the lower extremities with bladder dysfunction and sensory loss below the level of injury, has been reported more frequently in hyperextension injuries in older patients with degenerative changes in the spine. Due to narrowed spinal canal, osteophytes or buckled ligamentum flavum may result in injuries to the central grey matter including the central portions of corticospinal tracts of the cervical cord [ 36 — 38 ].
Sagittal T2 weighted image a and axial gradient recalled echo GRE image b show the presence of nonhemorrhagic contusion in the spinal cord arrows. Sagittal T2 weighted image a and axial gradient recalled echo GRE image b show the presence of hemorrhagic contusion arrow , a in the spinal cord characterized by susceptibility artifact on GRE image arrow , b. Osseous injuries with little apparent morphologic changes such as compression and cortical break are difficult to be diagnosed with CT.
MRI is very sensitive for detection of these occult osseous injuries by showing marrow edema and hemorrhage as hyperintense signal on fluid-sensitive sequences such as STIR Fig. Prevertebral soft tissue injuries can occur and may demonstrate abnormal thickening. This finding is usually related to edema and hemorrhage and is a sensitive indicator of other serious injury to the spine Fig.
This is usually seen in association with hyperextension injuries and vertebral body fractures, and may suggest underlying ALL injuries. Paraspinal muscles, nerves and other soft tissue injuries can also occur with trauma, either in isolation or associated with other injuries.
Usually, isolated muscle injuries are not clinically significant, but they can help to explain the cause of pain in the absence of other significant injuries. Sagittal CT image in the bone window a did not show any CT evidence for a fracture in this trauma patient. However, sagittal short tau inversion recovery STIR image b shows bone marrow edema in the superior aspect of multiple vertebrae arrows suggesting bone contusions.
Compression vertebral fractures are very common, especially in the elderly, and are usually osteoporotic in etiology.
Lumbar MRI scan: What can it diagnose and how is it done?
Spine radiographs and CT are usually the initial diagnostic modalities for detection of osteoporotic vertebral compression fractures. Although review of prior images, history of recent trauma combined with physical examination findings and presence of soft tissue hematoma can be helpful to differentiate acute from chronic fractures, it may not always be possible to differentiate between the two.
Soft tissue edema associated with acute compression fractures can also be an important differentiating clue. The chronic fractures will show fatty marrow as high signal on T1W and T2W images without marrow edema Fig. Sagittal T1 weighted image a and sagittal short tau inversion recovery STIR image b of a patient with an age-indeterminate fracture on CT showed bone marrow edema, suggestive of an acute vertebral body injury. Sagittal T1 weighted image c and sagittal STIR image d of a different patient with an age-indeterminate vertebral body fracture on CT showed no evidence of bone marrow edema, suggestive of a chronic injury.
Differentiating acute osteoporotic fractures from acute pathological fractures caused by metastases and other primary malignancies is a commonly encountered dilemma in the clinical practice. This is especially more important in deciding the appropriate treatment in patients with known primary tumor and no other known metastasis. MRI findings favoring acute osteoporotic compression fractures would include horizontal band of abnormal signal intensity separated by a straight line from the normal fatty marrow, relative lack of involvement of posterior elements, and angulated and concave appearance of the posterior vertebral margin Fig.
In contrast, pathological fractures due to malignancy on MRI are characterized by involvement of the entire vertebral body by abnormal bone marrow edema, extension into posterior elements, convex appearance of the posterior vertebral wall, involvement of the surrounding soft tissue, and the presence of other bony lesions Fig.
Diffusion weighted imaging also has been shown to be useful in differentiating these two by showing restricted diffusion in malignant pathological fractures. This has been attributed to the high cellularity and high nucleocytoplasmic ratio in rapidly dividing tumor cells. In patients at risk of having metastatic disease, limited follow-up MRI in 6—8 weeks is recommended to demonstrate partial or complete resolution of bone marrow edema in a situation where acute osteoporotic fractures are considered likely.
In comparison, malignant pathological compression fractures will remain unchanged or progress on follow-up examinations. Alternatively, biopsy can be performed in select cases for prompt and accurate treatment planning. Sagittal T1 weighted image a and sagittal T2 weighted image b show a compression fracture of L1 vertebral body with a horizontal band of bone marrow edema in the superior half of vertebra without associated soft tissue mass, suggesting a benign compression fracture. Sagittal T1 weighted image c and sagittal T2 weighted image d of a different patient with multiple metastases show compression fractures with diffuse involvement of vertebral body and associated epidural soft tissue mass.
Note abnormal bone marrow signal intensities also seen in other vertebral bodies, reflecting diffuse metastatic disease.
Computed Tomography (CT) - Spine
There are few limitations of MRI in the evaluation of spinal trauma. Susceptibility artifacts due to metallic hardware for spinal fusion and dental implants can degrade the image quality especially on GRE sequence Fig. Susceptibility artifacts can be reduced by using the spin echo sequences, short TE which allows less time for dephasing and reduces signal loss, large receiver bandwidth, STIR rather than chemically selective fat suppression, and swapping the phase-encode and frequency-encode directions [ 44 ].
Saturation pulses used in MRI can sometimes mask the prevertebral hematoma [ 15 ].
- No Benefit for MRI After Normal Cervical CT in Blunt Trauma - Neurology Advisor.
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Fluid in esophagus Fig. Prominent veins in the interspinous region demonstrating high signal on STIR images should not be confused with edema associated with interspinous injuries which appear as ill-defined area of high signal, while the veins appear as well-defined linear areas of high signal Fig. The sensitivity of MRI is also lower than CT for detecting fractures of the posterior elements due to minimal edema associated with avulsion injuries, and to injuries of the craniocervical junction [ 45 ].
Axial gradient recalled echo GRE image a shows marked susceptibility artifact arrow due to dental implants which partially obscures visualization of the prevertebral soft tissues.
Sagittal T2 weighted image b shows the presence of fluid in the esophagus arrow which may mimic prevertebral soft tissue edema. Sagittal short tau inversion recovery STIR image of cervical spine a shows the presence of blood vessels in the interspinous space which are seen as well defined high signal arrow.
This is in contrast to ill-defined high signal intensity arrow in the interspinous ligament on a sagittal STIR image b of a different patient who sustained acute interspinous ligament injury. In conclusion, MRI is more sensitive than other imaging modalities in the diagnosis of soft tissue and spinal cord injuries. While CT is considered adequate for determination of stable vs unstable spinal injuries, MRI can offer additional help due to its ability to better diagnose ligamentous injuries when compared with CT. Pitfalls in Musculoskeletal Radiology pp Cite as.
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Spinal trauma is a potentially devastating injury, and imaging is frequently required to assess its nature and extent. While computed tomography is often the primary imaging modality used, magnetic resonance imaging MRI is increasingly employed for imaging patients with acute spinal trauma, particularly if there is a need to assess the cord, soft tissues, or bone marrow. In most cases, the MRI diagnosis is usually straightforward, but there are a few normal variants, as well as some pathological entities, that can cause diagnostic confusion in interpretation.
Familiarity on the part of the radiologist with some of these diagnostic pitfalls will aid in the assessment and management of the patient with acute spinal trauma undergoing MRI evaluation. Skip to main content. Advertisement Hide. Chapter First Online: 12 August This is a preview of subscription content, log in to check access.
The same investigators now report the results of a cost-effectiveness analysis on this topic. Estimates of the likelihood and consequences of foreseeable outcomes were derived from the literature, and decision analytic techniques were used to calculate the costs and benefits of two follow-up strategies after normal CT findings: cervical spine MRI or no MRI.
This means MRI was both more costly and less beneficial. Nevertheless, considering the totality of evidence published to date, my opinion is that it is not necessary to obtain cervical spine MRI for trauma patients who have normal cervical spine CT scans, unless there are documented focal deficits. Depressed mental status and midline cervical spine tenderness should not be indications for cervical spine MRI. Xiao Wu BS et al. Cost-effectiveness of magnetic resonance imaging in cervical clearance of obtunded blunt trauma after a normal computed tomographic finding.