Exclusion of unstable cervical spine injury in obtunded patients with blunt trauma: is MR imaging needed when multi-detector row CT findings are normal?

PURPOSE: To retrospectively determine what information, if any, magnetic resonance (MR) imaging of the cervical spine in obtunded and/or "unreliable" patients with blunt trauma adds to multi-detector row computed tomography (CT) of the entire cervical spine (including routine multiplanar sagittal and coronal reformations) when the CT findings are normal. MATERIALS AND METHODS: The study was HIPAA compliant and institutional review board approved. Informed consent was not required. From April 2001 to November 2003, 1400 trauma patients underwent MR imaging of the cervical spine to evaluate potential cervical spine injuries. Multi-detector row CT of the cervical spine was performed with a four- or 16-detector row scanner. MR imaging of the cervical spine was performed with transverse gradient-echo, sagittal intermediate-weighted, sagittal short inversion time inversion-recovery, and sagittal T1- and T2-weighted fast spin-echo sequences. Many MR examinations were performed to exclude soft-tissue injuries in the cervical spine of obtunded patients with blunt trauma in whom cervical spine injury could not be excluded with physical examination. Complete cervical spine MR studies were obtained to evaluate soft-tissue injuries in 366 obtunded patients with blunt trauma (281 male and 85 female patients; age range, 13-92 years; mean age, 42.1 years). The patients had previously undergone total cervical spine multi-detector row CT with normal findings. The results obtained with these two modalities were compared. RESULTS: MR images were negative for acute injury in 354 of the 366 patients and negative for cervical spine ligamentous injury in 362. Seven of the 366 patients had cervical cord contusions, four patients had ligamentous injuries, three patients had intervertebral disk edema, and one patient had a cord contusion, a ligamentous injury, and an intervertebral disk injury. Four patients had ligamentous injuries; however, all of these patients had ligament injuries limited to only one of the three columns of cervical spine ligament support. Multi-detector row CT had negative predictive values of 98.9% (362 of 366 patients) for ligament injury and 100% (366 of 366 patients) for unstable cervical spine injury. CONCLUSION: A normal multi-detector row CT scan of the total cervical spine in obtunded and/or "unreliable" patients with blunt trauma enabled the authors to exclude unstable injuries on the basis of findings at follow-up cervical spine MR imaging.     

Comparison of MR and CT myelography in imaging the cervical and thoracic spine

MR imaging and CT myelography were compared in a retrospective study of 38 patients with suspected lesions of the cervical and thoracic spinal canal and cord. Twenty-eight abnormal cases were found, including spondylosis (9), tumors (8), intramedullary cavities (3), arachnoiditis (3), disk-space-centered infection or osteomyelitis (2), nonneoplastic cord swelling (2), and CSF-borne metastasis (1). MR was equal or superior to CT myelography in depicting cases of cord enlargement, cord compression, and cord atrophy, providing better tissue characterization, no shoulder artifact, and no limitation caused by CSF block. CT myelography was superior to MR in depicting cases of spondylosis and arachnoiditis. It showed superior spatial resolution, which was most pronounced when comparing axial images and hence particularly superior in detecting the lateral extent of disk herniation. Use of surface coils and thin imaging sections is essential for accurate and complete MR evaluation of the cervical and thoracic spine.     

MR imaging of the spine: trauma and degenerative disease

The purpose of this paper is to discuss the capabilities and drawbacks of MR imaging in patients with trauma to the spine and degenerative spinal conditions. In spinal trauma MR imaging is secondary to plain X-ray films and CT because of the greater availability and ease of performance of these techniques and their superior capability for detecting vertebral fractures. Magnetic resonance imaging is useful for detecting ligamentous ruptures and intraspinal mass lesions such as hematoma, and for assessing the state of the spinal cord and prognosis of a cord injury. In degenerative spinal disease the necessity is emphasized of critically evaluating the clinical relevance of any abnormal feature detected, as findings of degenerative pathology are common in individuals without symptoms. Magnetic resonance myelography permits rapid and accurate assessment of the state of the lumbar nerve roots (compressed or not). In the cervical region the quality of the myelographic picture is often degraded in patients with a narrow spinal canal.     

Surface coil MR of spinal trauma: preliminary experience

Nineteen fractured vertebral bodies involving the spine from C1 to L2 in 14 patients were imaged with a 0.6-T magnet using prototypical surface coils. Ten of these patients were studied within the first week of trauma. CT and plain films are superior to MR in detecting fractures and identifying the origin of displaced fragments in cases of extensive comminution. However, all body fractures and most posterior element fractures in the thoracolumbar spine were visible on MR. Fractures involving the cervical neural arch were difficult to detect on transverse section without CT correlation. Our results indicate that MR can probably replace CT in the thoracolumbar region. MR is superior to CT in demonstrating ligamentous injury and trauma to the disk. Unlike CT, MR shows the relation of the thecal sac and spinal cord to retropulsed fragments and epidural hematoma. MR also visualizes cord parenchyma; two cases of cord hemorrhage were not seen on CT. Even at this early stage of development, surface coil MR promises to become important in the evaluation of spinal trauma, not only in assessing the integrity of the spinal canal and cord, but in separating stable from unstable fractures on the basis of disruption of the posterior ligaments and elements. Additionally, the demonstration of rupture of specific ligaments may have an impact on surgical management.     

Degenerative diseases of the cervical spine: comparison of a multiecho data image combination sequence with a magnetisation transfer saturation pulse and cervical myelography and CT

Assessing degenerative disease in the cervical spine remains a challenge. There is much controversy about imaging the cervical spine using MRI. Our aim in this prospective study was to compare a T2*-weighted 2D spoiled gradient-echo multiecho sequence (MEDIC) with a magnetisation transfer saturation pulse with cervical myelography and postmyelographic CT. Using an assessment scale we looked at the vertebral bodies, intervertebral discs, neural foramina, anterior and posterior nerve roots, grey matter, ligamenta flava, oedema in the spinal cord and stenosis of the spinal canal. We also evaluated postmyelography CT and the MEDIC sequence for assessing narrowing of the neural foramina in a cadaver cervical spine. We examined 67 disc levels in 18 patients, showing 18 disc prolapses and 21 osteophytes narrowing the spinal canal or the neural foramina. All MRI studies showed these abnormalities findings equally well. Postmyelography CT was significantly better for showing the bony structures and the anterior and posterior nerve roots. The MEDIC sequence provided excellent demonstration of soft-tissue structures such as the intervertebral disc and ligamentum flavum. No statistical differences between the imaging modalities were found in the assessment of narrowing of the neural foramina or the extent of spinal stenosis. The cadaver measurements showed no overestimation of abnormalities using the MEDIC sequence.     

Imaging of the spine and spinal cord

Recent technologic advances in MR imaging of the spine and spinal cord have been aimed at shortening examination time and suppressing artifacts. Gradient-recalled fast T2-weighted imaging is advocated for evaluating cervical radiculopathy. Better signal-to-noise ratios are achieved with three-dimensional Fourier transform gradient-recalled T2-weighted imaging and with decreased bandwidth acquisition. Obtaining high-contrast images of the spine is often complicated by the appearance of truncation artifacts. In outpatient radiculography, both iopamidol and iohexol appear safe, but iohexol seems better tolerated. In trauma, MR imaging is definitive, and signal abnormalities can help in evaluating neurologic recovery. Intraoperative spinal sonography may be helpful in evaluating acute injury. Enhancement with gadolinium diethylenetriamine penta-acetic acid is useful in the evaluation of disk space infections, osteomyelitis, and epidural abscess and in the study of spinal cord sarcoidosis. In patients with the acquired immunodeficiency syndrome, MR imaging may show hyperintense spine on T2-weighted images. MR imaging with gadolinium diethylenetriamine penta-acetic acid or gadolinium tetra-azacyclododecane tetra-acetic acid enhancement can be useful in evaluating intramedullary and intradural extramedullary tumors and for determining the extent of spinal leptomeningeal metastases. MR imaging can also be used to differentiate benign from pathologic fractures.     

Spinal cord compression due to metastatic disease: diagnosis with MR imaging versus myelography

To determine the efficacy of magnetic resonance (MR) imaging and myelography for the diagnosis of spinal cord compression due to metastatic disease, the authors prospectively examined 70 patients who had known or suspected spinal involvement by malignancy. Most MR examinations consisted of T1-weighted sagittal imaging of the entire spine, with additional sequences as needed for clarification. Extradural masses were found in 46 patients, 25 of whom had cord compression. For extradural masses causing cord compression, the sensitivity and specificity of MR imaging was .92 and .90, respectively, compared with .95 and .88 for myelography. For extradural masses without cord compression the sensitivity and specificity of MR imaging was .73 and .90, versus .49 and .88 for myelography. MR imaging was much more sensitive for metastases to bone (.90 vs .49), as expected. MR imaging is an acceptable alternative to myelography for diagnosing spinal cord compression and is preferable as a first study because it is noninvasive and better tolerated.     

Cervical spine: postmortem assessment of accident injuries--comparison of radiographic, MR imaging, anatomic, and pathologic findings.

PURPOSE: To assess the ability of postmortem radiography and magnetic resonance (MR) imaging to depict occult cervical spine injuries as compared with anatomic and pathologic findings. MATERIALS AND METHODS: The cervical spines of 10 adult accident victims underwent radiography and MR imaging, with T1-weighted, fast spin-echo T2-weighted, and four gradient-echo pulse sequences. The frozen specimens were cut into 3-mm-thick slices (sagittal plane) and photographed, and microfocus radiographs were obtained. Imaging findings were compared with the anatomic and pathologic findings. RESULTS: Eight of the 10 specimens had 28 posttraumatic lesions: three fractures (two missed at the initial MR imaging reading), 10 facet joint capsule lesions with bleeding, five soft-tissue and ligament lesions, eight disk lesions, and two spinal cord lesions. Radiography depicted one lesion (4%). Two partial ruptures of the anterior annulus fibrosus were depicted at only MR imaging. Initially, 11 of 28 lesions were detected on MR images; retrospectively, 17 of 28 lesions were correlated with anatomic findings. CONCLUSION: Soft-tissue and intervertebral disk and ligament injuries account for 89% (25 of 28) of posttraumatic cervical spine lesions detected on postmortem images. Occult lesions, including apophyseal joint injuries, were found in clinically noninjured cervical spines. MR imaging was limited in the depiction of discrete lesions when T1-weighted non-fat-saturated, fast spin-echo T2-weighted, and gradient-echo pulse sequences were used.     

Spinal infection: evaluation with MR imaging and intraoperative US

Magnetic resonance (MR) images of the spine and/or intraoperative spinal ultrasound (US) in 24 patients with spinal infections were reviewed and correlated with clinical and pathologic data to determine their diagnostic value. In disk space infection with osteomyelitis and in retrospinal abscess, MR images showed characteristic findings, whereas in myelitis, MR images demonstrated nonspecific abnormalities. The appearance on MR images of epidural abscesses ranged from clearly identifiable extradural masses with high-intensity signal on spin-echo T2-weighted images to extensive inhomogeneous collections of mixed signal intensities, difficult to distinguish from adjacent meningitis. Myelography with high-resolution computed tomography (CT) and intraoperative spinal US was superior to MR imaging in demonstrating epidural abscesses when there was concomitant meningitis. With intraoperative spinal US, epidural abscesses could be located and their decompression monitored. MR imaging is recommended as the initial screening procedure in spinal infection; in those few patients with nondiagnostic MR images, myelography with high-resolution CT should be the supplementary study. If surgery is planned, intraoperative spinal US should be used.     

Spine trauma

Spinal fractures represent 3% to 6% of all skeletal injuries. Spine trauma is a complex diagnostic area in which the radiological assessment is crucial. Plain radiography is often used as the initial diagnostic modality. However, stabilization of the acutely injured spine is a primary concern. In this respect, computed tomography (CT) is vastly superior to plain film in terms of speed and accuracy. In many trauma centers, CT has replaced plain film as the primary modality for evaluation of spinal trauma. Magnetic resonance imaging is not indicated for all cases of spinal trauma but provides detailed information about soft tissue structures including the intervertebral disc, the ligaments, the epidural space, the blood vessels, and the spinal cord. MR imaging provides information on these structures not obtained from other modalities. Patients with spinal cord injury may suffer devastating long-term neurologic deficits, so prompt and efficient spinal imaging guidelines are necessary in all trauma centers.     

Acute cervical spine trauma: correlation of MR imaging findings with degree of neurologic deficit

A retrospective analysis of magnetic resonance (MR) imaging studies of 78 patients with acute cervical spinal cord injuries was undertaken to determine which observations related directly to the neurologic injury. All MR imaging studies were performed on a 1.5-T unit and assessed with respect to 14 parameters related to the bony spine, ligaments, prevertebral soft tissues, intervertebral disks, and spinal cord. Forty-eight patients also underwent non-contrast material-enhanced thin-section computed tomography (CT) of the cervical spine. MR imaging was the definitive modality in the assessment of soft-tissue injury, especially in the evaluation of the spinal cord and intervertebral disks. All patients with a neurologic deficit had abnormal spinal cords at MR imaging. Intramedullary hemorrhage was predictive of a complete lesion. The degree of associated bone and soft-tissue injury had no bearing on the extent of spinal cord injury or neurologic deficit. Patients with residual cord compression following reduction demonstrated greater neurologic compromise than those without compression.     

脊髓亚急性联合变性的MRI诊断要点分析

目的分析脊髓亚急性联合变性(SCD)的MRI诊断要点。资料与方法回顾性分析15例临床确诊SCD的病人临床及MRI资料,分析其脊髓MRI表现特点,统计分析SCD病人受累脊髓节段数与血清VB12水平、发病时间的相关性。结果 15例SCD病人均于横断面影像上显示颈胸段脊髓对称性等或长T1、长T2信号,13例病变主要位于颈胸段水平脊髓后索,2例同时累及后索、侧索及前索。但于横断面T2WI上颈段与胸段脊髓异常信号形态各具特点。颈段脊髓受累时于横断面T2WI上呈脊髓内"倒V"形或"反兔耳"形的对称性高信号。胸段脊髓受累时于横断面T2WI上呈脊髓内"哑铃"形的对称性高信号。统计学分析显示15例SCD病人脊髓受累节段数与血清VB12水平呈负相关,而与病程长短无相关性。结论脊髓MR成像对于SCD脊髓疾病的诊断有重要价值。     

Diffusion-weighted MR imaging offers no advantage over routine noncontrast MR imaging in the detection of vertebral metastases

BACKGROUND AND PURPOSE: Diffusion-weighted MR imaging of the spine has been used to differentiate benign from pathologic vertebral body compression fractures. We sought to determine the utility of diffusion-weighted MR imaging in the detection of vertebral metastases and to compare it with conventional noncontrast T1- and T2-weighted MR imaging. METHODS: Fifteen patients with metastases to the spine were studied using conventional MR imaging and diffusion-weighted imaging. Blinded review of all images was undertaken, and patients were categorized according to whether they had focal or multiple lesions. The signal intensity of the lesions was compared on T1-, T2- (fast spin-echo), and diffusion-weighted images. RESULTS: In five patients with focal disease, metastases were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 1), or hyperintense (n = 2) on T2-weighted images; and hypointense (n = 3) or hyperintense (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. In 10 patients with disease in multiple sites, all lesions were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 4), hyperintense (n = 2), or mixed (n = 2) on T2-weighted images; and hypointense (n = 5), hyperintense (n = 3), or mixed (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. CONCLUSION: As used in this study, diffusion-weighted MR imaging of the spine showed no advantage in the detection and characterization of vertebral metastases as compared with noncontrast T1-weighted imaging, but was considered superior to T2-weighted imaging.     

Spinal cord infarction: MR imaging and clinical features in 16 cases

Spinal cord infarctions are rare and due to heterogeneous etiologies. The aim of the study was to analyze the MR imaging findings and evaluate their correlations with clinical symptoms in ischemic spinal cord lesions. MR images and clinical features of 16 patients (11 male, 5 female) with typical sudden onset of neurological deficits caused by spinal cord ischemia were evaluated. MR imaging was performed within 2 h to 14 days after the initial neurological symptoms. Eight patients had follow-up examinations including contrast-enhanced MR imaging. MR abnormalities were best demonstrated on sagittal T2-weighted images, with "pencil-like" hyperintensities (16/16) and cord enlargement (9/16). Axial T2-weighted images showed bilateral (13/16) and unilateral (3/16) hyperintensities according, in 15 patients, to anterior spinal artery (ASA) territory, with three of them located particularly in the spinal sulcal artery territory. In one patient only the posterior spinal artery (PSA) territory was involved. Spinal cord was affected at the cervical level (especially C2-C3) in seven patients, at the upper thoracic level (T3-T5) in two patients and at the thoracolumbar region including the conus medullaris (T10-L1) in seven patients. Presumed etiologies were vascular surgery (3 patients), infrarenal aortic aneurysm (1 patient), bilateral vertebral artery dissection (1 patient), hypotension (1 patient), spine operation (1 patient), excessive cocaine misuse (1 patient) and cardioembolic vertebral artery occlusion (1 patient); six of seven patients with unclear etiologies had vascular risk factors such as hypertension, diabetes and cigarette smoking. MR imaging is therefore useful in detecting spinal cord infarction, with axial T2-weighted images showing hyperintensities in the ASA territory in 15 of 16 patients. Contrary to the presumed spinal cord watershed at the lower cervical and upper thoracic level, and despite numerous central arteries in the cervical cord, our data suggest a high ischemic vulnerability of the cervical spinal cord at level C2-C3.     

Cervical myelopathy: a comparison of magnetic resonance and myelography

Fifty-seven patients with a strong clinical suspicion of cervical myelopathy were studied with body coil magnetic resonance (MR) and conventional myelography or CT myelography. Eight patients were believed to have normal studies with both modalities. There were six patients with syringomyelia; four with an intramedullary tumor; one with an arteriovenous malformation; 19 with cervical spondylosis at multiple levels; eight with cervical spondylosis at a single level; four with extensive rheumatoid arthritis; four with extradural neoplasm; two with trauma; and one patient with an epidural abscess. In this study, body coil MR was the superior examination for the evaluation of an intramedullary process. It was as diagnostic as myelography in one case of an extramedullary intradural lesion. In patients with extradural disease, body coil MR was the superior study in 45%, equivalent to myelography in 37%, and, although still diagnostic, inferior to myelography in 17%. In 8% of the cases, body coil MR was at best equivocal, whereas myelography was diagnostic. It appears that in technically adequate studies, MR is at least equivalent to myelography in its ability to delineate disease. A superior MR study provides a better appraisal of the size and character of the spinal cord as well as the degree of both anterior and posterior defects on the subarachnoid space and neural structures. In addition, MR is as good as conventional myelography for the identification of extrinsic cervical cord lesions producing cervical myelopathy. Finally, an additional small group of 30 patients were studied with a prototype surface coil to determine its advantages relative to body coil imaging. Each patient had correlative myelography. As with body coil MR, imaging with the surface coil was believed to be more informative than conventional myelography in four patients with intramedullary lesions. The remaining 26 patients suffered from cervical spondylosis. Surface coil MR was believed to be more informative than myelography in six cases (23%), equivalent to myelography in 19 (73%), and less diagnostic than myelography in one (4%). The improved spatial resolution with the use of the surface coil was believed to increase the accuracy of MR.     

Central nervous system tumors in children: detection by magnetic resonance imaging

Fifty-one pediatric patients who were suspected of having central nervous system (CNS) tumors underwent magnetic resonance (MR) imaging using a 0.35 T Diasonics MT/S system. Pulse intervals (TR) ranged from 0.5 to 2.0 seconds with echo delays (TE) of 28 and 56 msec. The ability of MR and contrast-enhanced CT to detect focal lesions, determine lesion extent, and evaluate associated abnormalities was compared. In most patients in whom there was suspected spinal cord disease, comparison with myelography was made. Thirty-three intracranial lesions were detected with at least one imaging modality in 43 cranial examinations. MR was judged superior to CT in 14 of these cases and CT superior to MR in only one. Of eight spinal examinations, there were six that demonstrated abnormal findings. MR was superior to CT in all six cases and better than myelography in four of five cases where myelography was performed. Spin echo (SE) sequences with long pulse intervals were the most sensitive, but in some cases short pulse intervals permitted further characterization of the lesion. Patient motion was not a problem; sedation was routinely used in children younger than five years of age. MR imaging has rapidly become a valuable diagnostic modality in neuroradiology. The lack of ionizing radiation and the ability to evaluate the spinal cord noninvasively makes it particularly attractive in examination of children.     

Thoracic disc disease and stenosis

Disc herniation and stenosis in the thoracic spine are relatively uncommon compared with their occurrence in the cervical or lumbar spine. They are usually degenerative, although trauma may be an aggravating or initiating factor. The clinical presentation includes local and/or radicular pain with or without signs and symptoms of cord dysfunction. Radicular pain may be secondary to mechanical compression or vascular impingement. MR imaging is the best way to define the specific abnormality as well as the effect on the adjacent spinal cord. CT after myelography may be useful as well, especially in those patients in whom there is involvement of the posterior ligamentous and osseous structures of the thoracic spinal canal. MR imaging may finally reveal the true incidence of thoracic disc herniation.     

Cervical spine fractures in ankylosing spondylitis: MR findings

Purpose: The purpose of this study is to evaluate the MR findings in patients with long-term ankylosing spondylitis (AS) and acute cervical spine fractures. Materials and methods: The magnetic resonance imaging (MRI) studies of five patients with AS and acute cervical spine fractures were retrospectively reviewed for the presence of cervical spine instability, spinal cord compression, and epidural hematoma. Results: Spinal fractures were unstable in all five patients. Three patients had neurological symptoms and abnormal signal within the spinal cord. All patients with neurological deficits had epidural hematomas posterior to the dural sac. Conclusion: MRI is useful for assessment of the integrity of intervertebral disks and spinal ligaments and, therefore, of the instability of the spinal fracture. MRI is mandatory in patients with neurological symptoms, especially in those with a symptom-free interval and those with neurological deterioration after established spinal cord injury, when suspicion for epidural hematoma is high. Electronic Publication     

Calcium pyrophosphate dihydrate crystal deposition in and around the atlantoaxial joint: association with type 2 odontoid fractures in nine patients

PURPOSE: To investigate the histopathologic anatomy of calcium pyrophosphate dihydrate (CPPD) crystal deposition in and around the atlantoaxial joint and the association between CPPD crystal deposition and subchondral cysts, erosions, and fracture involving the odontoid process of the axis. MATERIALS AND METHODS: One adult cadaver demonstrating calcification in the retro-odontoid area at computed tomography (CT) was selected for further radiography, CT, and magnetic resonance (MR) imaging at the C1-2 level. Anatomic sectioning and histologic evaluations were performed in the specimen. For clinical study, radiographs (n = 5), CT scans (n = 8), and MR images (n = 6) in nine patients (mean age, 74.4 years) with odontoid process fractures and CPPD crystal deposits in and around the atlantoaxial joint were reviewed. RESULTS: In the cadaveric specimen, radiography and CT demonstrated calcifications in the transverse ligament; histologic evaluation confirmed that these calcifications were CPPD crystal deposits. In all nine patients, radiography (n = 5) and CT (n = 8) also showed calcification in areas adjacent to the odontoid process, which included the transverse ligament. T1- and T2-weighted MR imaging showed a retro-odontoid mass of low signal intensity that compressed the cervical cord in six patients. CT, MR imaging, or both demonstrated subchondral cysts, osseous erosions, or a type 2 odontoid fracture in all patients. CONCLUSION: CPPD crystal deposition disease involving the C1-C2 articulation can be a clinically important entity that may place affected patients at increased risk of pathologic fracture of the odontoid process.