MR imaging of the cervical spine in rheumatoid arthritis

The cervical spine was examined with MR imaging and conventional radiography in 23 patients with severe rheumatoid arthritis. All patients had neck pain and 17 also had neurologic symptoms. MR provided detailed information about soft-tissue lesions, vertebral dislocation, and narrowing of the spinal canal. Pannus surrounding the odontoid process was revealed in 14 patients, all with horizontal atlantoaxial subluxation. Compression of the medulla and/or spinal cord, caused by dislocated vertebrae and/or the soft-tissue mass around the odontoid process, was seen in 15 patients. When there was more than one dislocation the most important level could be determined. Posterior occipitocervical fusion had been performed in six of the patients, and in only two of these was adequate analysis of the upper cervical spine impossible because of artifacts from metal (stainless steel wires and pins). Sagittal MR in the neutral position combined with conventional radiography, including lateral views in flexion and extension, provided all the information necessary for further clinical management of rheumatoid arthritis of the cervical spine.     

Cervical rheumatoid arthritis: value of flexion and extension views in imaging

The magnetic resonance (MR) imaging findings in the cervical spines of eight patients with long-standing polyarticular rheumatoid arthritis were reviewed. Three pathologic conditions were readily demonstrated: anterior atlantoaxial subluxation (n = 6), atlantoaxial impaction (n = 6), and subaxial subluxation (n = 6). An abnormal soft-tissue signal was noted in the preodontoid space in six patients; this signal was thought to represent the associated inflammatory mass. MR imaging was useful not only for depicting the bony abnormalities in the cervical spine that are associated with rheumatoid arthritis, but also can directly show the effect of the disease process on the spinal cord and brain stem.     

Evaluation of flexion/extension of the upper cervical spine in patients with rheumatoid arthritis: an MRI study with a dedicated positioning device compared to conventional radiographs

PURPOSE: Using flexion/extension magnetic resonance imaging (MRI) with a dedicated positioning device, our purpose was to analyze pathologic cranio-vertebral joint anatomy and motion in patients with rheumatoid arthritis in comparison to normal patients, and to compare flexion/extension MRI with conventional radiographs (CRs) in patients with rheumatoid arthritis. MATERIAL AND METHODS: The 31 patients with rheumatoid arthritis and 20 healthy subjects included in the study were imaged in an open MRI scanner during flexion/extension. A dedicated positioning device was used. Additionally, we compared flexion/extension MRI with CRs in patients with rheumatoid arthritis. In MRI, the orientation and segmental motion of C0, C1, and C2 were assessed and structure of the dens and amount of pannus tissue were observed. Configuration of the cerebrospinal fluid space and the cord was evaluated in each position. In both MRI and CRs, anterior atlanto-axial subluxation and vertical dislocation were assessed and sagittal diameter of the dural sac was measured. RESULTS: In the neutral position, C1 of the patients was oriented in a more flexed position in relation to both C0 and C2 compared to that in healthy subjects. The patients had more extension in the upper cervical spine than did healthy subjects. In flexion, atlantoaxial subluxation was greater in CRs than in MRI. In MRI, the amount of vertical dislocation did not depend on position. In the patients, there was considerably more cord impingement in flexion than in other positions. CONCLUSION: Evaluation of the rheumatoid cervical spine is optimized using MR images in the neutral, flexed, and extended positions. Measurements and relationships between structures should be compared in all positions. CRs with flexion-extension views are recommended as the first imaging method.     

Are magnetic resonance flexion views useful in evaluating the cervical spine of patients with rheumatoid arthritis?

Objective. To determine whether MR imaging in flexion adds value relative to imaging in the neutral position with respect to displaying involvement of the subarachnoid space, brainstem and spinal cord. Design and patients. T1-weighted MR images of the cervical spine in 42 rheumatoid arthritis patients with cervical spine involvement were obtained and analyzed prospectively. We assessed changes between images obtained in the neutral position and following active flexion, especially horizontal atlantoaxial and subaxial motion, presence or absence of brainstem compression, subarachnoid space involvement at the atlantoaxial and subaxial level and the cervicomedullary angle. Vertical atlantoaxial subluxation and the amount of pannus were correlated with motion and change in subarachnoid space. Results. The flexion images showed horizontal atlantoaxial motion in 21 patients and subaxial motion in one patient. The flexion view displayed brainstem compression in only one patient. Involvement of the subarachnoid space increased at the atlantoaxial level in eight (19%) patients (P=0.004) and at the level below C2 in five (12%) patients (P=0.03). There were no patients with a normal subarachnoid space in neutral position and compression in the flexed position. The cervicomedullary angle changed significantly with flexion. Vertical atlantoaxial subluxation and the amount of pannus did not show a significant correlation with motion or subarachnoid space involvement. Conclusion. MR imaging in the flexed position shows a statistically significant narrowing of the subarachnoid space at the atlantoaxial level and below C2. Cord compression is only observed on flexion views if the subarachnoid space in neutral position is already decreased. MR imaging in the flexed position might be useful, since subarachnoid space involvement may be an indicator for the development of neurologic dysfunction. Received: 15 June 1999 Revision requested: 29 July 1999, 20 September 1999 Revision received: 2 October 1999 Accepted: 26 October 1999     

Ultra low field MR imaging of cervical spine involvement in rheumatoid arthritis.

In a study of 30 patients with longstanding rheumatoid arthritis the diagnostic usefulness of ultra low field MR equipment was analyzed in assessing lesions of the craniocervical junction. It was found that at 0.04 T all the examinations were diagnostic and that in combination with plain radiography the diagnostic information obtained was valuable in further planning of the treatment strategies. The neurologic findings were related to the degree and severity of atlantoaxial luxation, either horizontal or vertical, and to the periodontoid pannus formation. The correlation between the degree of cord compression shown with MR imaging and the clinical symptoms, especially long tract symptoms, was poor. The only correlating factor was the duration of the disease.     

Neurologic dysfunction in patients with rheumatoid arthritis of the cervical spine. Predictive value of clinical, radiographic and MR imaging parameters

The aim of this study was to evaluate if subjective symptoms, radiographic and especially MR parameters of cervical spine involvement, can predict neurologic dysfunction in patients with severe rheumatoid arthritis (RA). Sequential radiographs, MR imaging, and neurologic examination were performed yearly in 46 consecutive RA patients with symptoms indicative of cervical spine involvement. Radiographic parameters were erosions of the dens or intervertebral joints, disc-space narrowing, horizontal and vertical atlantoaxial subluxation, subluxations below C2, and the diameter of the spinal canal. The MR features evaluated were presence of dens and atlas erosion, brainstem compression, subarachnoid space encroachment, pannus around the dens, abnormal fat body caudal to the clivus, cervicomedullary angle, and distance of the dens to the line of McRae. Muscle weakness was associated with a tenfold increased risk of neurologic dysfunction. Radiographic parameters were not associated. On MR images atlas erosion and a decreased distance of the dens to the line of McRae showed a fivefold increased risk of neurologic dysfunction. Subarachnoid space encroachment was associated with a 12-fold increased risk. Rheumatoid arthritis patients with muscle weakness and subarachnoid space encroachment of the entire cervical spine have a highly increased risk of developing neurologic dysfunction. Received: 31 December 1999 Revised: 30 May 2000 Accepted: 5 June 2000     

The cervical spine in rheumatoid arthritis: relationship between neurologic signs and morphology on MR imaging and radiographs

 Objective. Comparison of clinically observed neurologic long tract signs in a heterogeneous group of patients with rheumatoid arthritis (RA), with morphologic abnormalities of the cervical spine as depicted on radiographs and magnetic resonance (MR) images. Design. The patients were prospectively assigned to one of three classes on the basis of their neurologic status. Lateral cervical spine radiographs and sagittal T1-weighted and gradient echo images were performed. The qualitative MR features evaluated were erosion of the dens and atlas, brain stem compression, subarachnoid space encroachment, pannus around the dens, appearance of the fat body caudal to the clivus, and the signal intensity of the pannus. The quantitative imaging parameters were the cervicomedullary angle and the distance of the dens to the line of McRae. Patients. Sixty-three consecutive patients with RA and subjective symptoms, especially neck or occipital pain, and/or clinical objective signs consistent with a compromised cervical cord were included in this study. Results and conclusions. Damage documented with radiographs and MR imaging in patients with RA is often severe, even in those without neurologic signs (class 1). None of the abnormalities confined to the atlantoaxial level correlated significantly with neurologic classification. Subarachnoid space encroachment anywhere in the entire cervical spine did correlate significantly with neurologic classification.     

MR imaging of atlantoaxial joint in early rheumatoid arthritis

Purpose

This study was done to assess the involvement of the atlantoaxial joint in patients with early rheumatoid arthritis and evaluate the role of magnetic resonance (MR) imaging in depicting this early joint involvement.

Materials and methods

Twenty patients (16 women and four men, mean age 55.0±12.9 years) with clinical and laboratory evidence of early rheumatoid arthritis (mean disease duration <12 months) were included in our study. MR imaging of the atlantoaxial joint was performed in all patients within 3 months from diagnosis. The MR features were correlated with clinical and biochemical variables.

Results

Five (25.0%) of the 20 patients exhibited enhancement of the periodontoid synovial spaces after gadolinium administration due to inflammatory synovitis. Compared with patients without cervical involvement, these five patients showed significantly higher values of erythrocyte sedimentation rate [median 77.0 mm/h (range 25th and 75th percentile 69.0–86.0) vs median 33.0 mm/h (range 25th and 75th percentile: 9.2–52) (p=0.007)]; significantly higher C-reactive protein values [median 53.6 mg/l (range 25th and 75th percentile 21.9–81.9) vs median 14.0 mg/l (range 25th and 75th percentile 0.8–20) (p=0.03)]; higher disease activity score [median 4.2 (range 25th and 75th percentile 3.9–5.4) vs median 3.2 (range 25th and 75th percentile 2.8–3.8) (p=0.03)]. Four (80%) of these five patients presented anti-citrulline antibodies (anti-CCP) and rheumatoid factor at laboratory testing. The latter was positive in 12 of the 20 patients (66%), and anti-CCP were positive in 15 (83%).

Conclusions

MR imaging showed an atlantoaxial inflammatory synovitis in 25% of patients with early rheumatoid arthritis. Our results indicate that patients with higher disease activity are likely to be at higher risk of presenting early involvement of the atlantoaxial joint. MR imaging of the cervical spine is an excellent tool for assessing the early manifestations of rheumatoid arthritis before any destructive changes occur. Therefore, MR imaging should be included in the diagnostic workup in order to provide reliable guidance for treatment choices.     

MRI of the cervical spine: rheumatoid arthritis compared with cervical spondylosis

This study is a comparison of the cervical spine MR images from 26 patients with rheumatoid arthritis of the cervical spine with those from an age and sex matched group suffering from cervical spondylosis. Erosion of bone and major atlanto-axial subluxation were confined to rheumatoid arthritis. Soft tissue changes revealed by MRI included distortion of normal ligaments and bursae around the dens, particularly in rheumatoid arthritis. Abnormal masses of soft tissue were found in both groups, but those suggesting acute inflammation were much more frequent in rheumatoid arthritis than in cervical spondylosis. Neural compression was well demonstrated, and in rheumatoid arthritis was usually caused by bony structures whereas in cervical spondylosis it was usually due to disc material. It is concluded that MRI should be used as the first investigation to follow plain films in rheumatoid arthritis of the cervical spine. Bone and soft tissue changes are clearly shown, but interpretation of the images requires the recognition that some observed abnormalities may be due to coincidental cervical spondylosis.     

Gd-DTPA-enhanced MR of suspected spinal multiple sclerosis

A prospective study was undertaken to evaluate the potential of Gd-DTPA-enhanced MR to differentiate active from inactive demyelinating lesions of the cervical spinal cord. Five patients with elongated high-signal-intensity lesions in the cervical cord on long TR/TE spin-echo MR images and a clinical suspicion of demyelinating disease had MR before and after IV Gd-DTPA. Delayed contrast enhancement (after 45-60 min) of the lesions was seen on short TR/TE images in two patients with clinically active disease, but no enhancement could be detected in three patients with stable disease. The patients with active disease underwent repeated MR examinations until the enhancement disappeared. The decrease in Gd-DTPA enhancement paralleled a decrease in clinical signs and symptoms of cervical myelopathy. MR is useful in evaluating patients suspected of having demyelinating disease. The MR finding of asymptomatic lesions in the brain lends support to the diagnosis of multiple sclerosis. Other possible causes of myelopathy, such as spinal cord compression and intramedullary tumor, can be excluded with the use of MR.     

MR imaging of the knee in acute rheumatoid arthritis: synovial uptake of gadolinium-DOTA

In patients with rheumatoid arthritis, the presence of acute synovial inflammation is an indication of the activity of the disease. It is an important finding because it often influences therapeutic decisions. However, acute synovitis may be difficult to detect by clinical examination, especially if a joint effusion also is present. As gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) can be expected to accumulate in areas of acute inflammation, we studied the value of Gd-DOTA-enhanced MR to determine the presence of acute synovitis. Nine patients with current knee symptoms underwent MR examination of the knee. Short and long TR/TE MR images were obtained with a 0.3-T magnet before and immediately after IV administration of Gd-DOTA. A 15-min delayed short TR/TE image also was obtained. Of eight patients with moderate to severe clinical evidence of acute synovitis, six had marked increase and two had moderate increase in signal intensity from synovial tissue on the short TR/TE image obtained immediately after administration of contrast material. In the ninth patient, who had minimal synovitis clinically, the signal from the synovium did not change after administration of contrast material. No difference was seen between the enhancement pattern on the immediate and the 15-min delayed images. These results suggest that Gd-DOTA is taken up by inflamed synovium and that Gd-DOTA-enhanced MR scans may be useful in detecting acute synovitis in patients with rheumatoid arthritis.     

Subluxation of the upper thoracic spine in rheumatoid arthritis

Only single cases with rheumatoid arthritis of the thoracic spine with vertebral subluxation have been reported to date. In a review of 100 patients with severe rheumatoid arthritis who had undergone occipitocervical fusion, arthritis of the upper thoracic spine with subluxation was discovered on conventional radiographs in four patients. Two additional patients were found elsewhere. Magnetic resonance imaging (MRI) was performed in three of the patients, confirming the diagnosis of subluxation of the upper thoracic vertebrae. In addition, MRI revealed encroachment on the anterior sub-arachnoid space and compression of the spinal cord.     

Atlantoaxial osteoarthritis in rheumatoid arthritis: FDG PET/CT findings

The cervical spine is a common focus of destruction in patients with rheumatoid arthritis, and the resultant instability and neural compression represent severe complications in these patients. Evaluation of disease activity at the level of the atlantoaxial joint is important in such cases. Here, we report a 47-year-old man with a 3-year history of rheumatoid arthritis. FDG PET/CT clearly demonstrated a hot spot in the atlantoaxial area, suggesting high metabolic activity of synovitis.     

Atlantoaxial subluxation. Radiography and magnetic resonance imaging correlated to myelopathy

Twenty-nine patients with atlantoaxial subluxation (18 with rheumatoid arthritis, 2 due to trauma, 4 with os odontoideum, and one each with polyarteritis nodosa, rheumatic fever. Klippel-Feil syndrome, achondroplasia, and cause unknown) were evaluated using a 0.22 tesla resistive MRI unit. Cord compression was classified into four grades according to the degree on magnetic resonance imaging. There were 7 patients with no thecal sac compression (grade 0). 10 with a minimal degree of subarachnoid space compression without cord compression (grade 1), 7 with mild cord compression (grade 2), and 5 with severe cord compression or cord atrophy (grade 3). Although the severity of myelopathy showed poor correlation with the atlantodental interval on conventional radiography, high correlation was observed between MR grading and the degree of myelopathy. The high signal intensity foci were observed in 7 of 12 patients with cord compression (grades 2 and 3) on T2 weighted images. Other frequently observed findings in rheumatoid arthritis included soft tissue masses of low to intermediate signal intensity in the paraodontoid space, erosions of the odontoid processes, and atlantoaxial impaction on T1 and T2 weighted images.     

Rheumatoid arthritis: epidural enhancement as an underestimated cause of subaxial cervical spinal stenosis

PURPOSE: To assess the frequency and site of subaxial spinal canal stenosis due to enhancing tissue in patients with rheumatoid arthritis. MATERIALS AND METHODS: Data from 33 consecutive patients with rheumatoid arthritis were evaluated; these patients had undergone 1.5-T magnetic resonance imaging following gadolinium chelate administration, in combination with a frequency selective fat-suppression technique. Stenosis and enhancement were scored for each of six cervical spinal levels and were compared with results in a control population consisting of 16 patients with degenerative disease. Enhancement was scored as superficial or deep on the anterior and posterior sides from the cervical spinal cord. Differences between patient groups were tested by using the chi(2) test for trend and the Fisher exact test. RESULTS: No significant difference was found in the frequency or severity of subaxial stenosis between rheumatoid arthritis and degenerative disease. Deep epidural enhancement was observed more often with rheumatoid arthritis than with degenerative disease both anterior (25 of 33 patients vs seven of 16 patients, respectively; P <.001) and posterior (24 of 33 patients vs two of 16 patients, respectively; P =.001) to the spinal cord. Enhancing stenosing tissue in rheumatoid arthritis frequently occurred anterior and posterior at the same time and at the same level, with segmental cufflike extension of enhancing tissue around the dural sac. Stenosing tissue enhanced more frequently with rheumatoid arthritis than with degenerative disease (22 of 33 vs four of 16 patients, respectively; P =.008). CONCLUSION: In patients with rheumatoid arthritis, subaxial stenosis is frequently caused by enhancing epidural tissue. This enhancing tissue presumably represents pannus.     

Orbit: initial experience with surface coil spin-echo MR imaging at 1.5 T

Fifty-nine cases in which surface coil MR imaging of the orbit was performed were reviewed. MR imaging was performed with spin-echo techniques at 1.5 T with both short repetition time/echo time (TR/TE) and long TR/TE sequences in all cases. In all patients short TR/TE images were obtained with small-diameter surface coils; long TR/TE images were usually obtained with a standard head coil. Surface coil MR appears to be an important adjunct in state-of-the-art orbital imaging. Orbital MR imaging may be most useful, providing information not available on computed tomography (CT), in identifying lesions in the orbital apex, superior orbital fissure, and optic canal; differentiating inflammatory pseudotumor from malignancy in clinically similar patients; characterizing lesions containing hemorrhage or other paramagnetic material; defining the posterior extent of optic pathway gliomas; and detecting abnormal flow in intraorbital vascular structures. CT seems to be superior to MR imaging in the evaluation of small perioptic meningiomas, especially those that are calcified.     

Low flip angle gradient echo magnetic resonance imaging of the cervical spine at 0.3 tesla

The influence of flip angle and TR on signal to noise ratio and contrast between cerebrospinal fluid (CSF) and cord was evaluated in cervical spine imaging in 5 volunteers, using gradient echo technique. All experiments were performed on a 0.3 tesla Fonar beta-3000 M scanner using solenoidal surface coils. The most useful sequence was considered to be TR/TE = 300/12 ms and 10 degrees flip angle. This sequence provided images with a 'myelographic appearance' with good delineation of cord, CSF and epidural space. The grey and white matter was also regularly visualized. The acquisition time was considerably shorter than would have been necessary if a long TR/TE spin echo sequence had been used to obtain the same contrast pattern and the sequence was not as sensitive to motion as was the spin echo sequence. The sequence was also evaluated in 10 patients with degenerative disease and in 5 with lesions in the cord. The gradient echo sequence was found to be equal to or better than short and long TR/TE spin echo sequences in demonstrating narrowing of the spinal canal and cord lesion. The drawback is the limited signal to noise ratio.     

Pseudoatrophy of the cervical portion of the spinal cord on MR images: a manifestation of the truncation artifact?

Routine evaluation of axial MR images of the cervical spine with high-intensity CSF (long TR/TE spin-echo or gradient-echo images) revealed apparent narrowing of the cord's anteroposterior diameter when these images were compared with corresponding postmyelography CT scans. This discrepancy was believed to be due to the truncation artifact at the CSF-cord boundary. To examine the truncation effect, we compared cord diameters in 12 patients on postmyelography CT scans and MR images and then compared these with MR scans of normal volunteers and of an agar-saline spine phantom. There was an artifactual diminution of the cord diameter in the 128-step phase-encoding axis of the 128 x 256-matrix MR scan as compared with the diameter of the cord in the patients' postiohexol CT scans and in the 256 phase-encoded axis MR scan in the volunteer study. A similar discrepancy was noted in the spine phantom study, in which the cord diameter in the 256-step phase-encoded MR scan, the CT scan, and direct measurement exceeded that in the 128-step phase-encoded axis MR scan. The range of differences between the measurements was as large as 2.3 mm (patients), 1.7 mm (volunteers), and 1.8 mm (phantom) for the three studies. In all three studies, varying the photographic window width and level produced variation in the apparent cord diameter of up to 1.5 mm. To eliminate this effect, the cord diameters in the phantom and the normal control subjects were measured at identical window levels. The truncation artifact, coupled with standard window settings used in photography, may lead to inaccurate display of the diameter of the cervical spinal cord.     

Correlation of MR imaging findings with intraoperative findings after cervical spine trauma

BACKGROUND AND PURPOSE: There are limited data correlating MR imaging and anatomic findings of ligamentous injury in cervical spine trauma. This study compares acute MR imaging with surgical observations of disk/ligamentous injury after blunt cervical trauma. MATERIALS AND METHODS: Consecutive patients with acute cervical spine trauma who underwent preoperative MR imaging and surgery from 1998 to 2001 were identified. MR imaging was obtained within 48 hours of injury for most patients. All scans included sagittal T1, T2 fat-saturated, and short tau inversion recovery sequences. At surgery, extent of injury at the operated level was recorded on a standardized form for either anterior or posterior structures or both depending upon the operative approach. MR examinations were separately evaluated by 2 readers blinded to the intraoperative findings. Radiologic and surgical findings were then correlated. RESULTS: Of 31 patients, an anterior surgical approach was chosen in 17 patients and a posterior approach in 13 patients. In one patient anterior and posterior approaches were utilized. Seventy-one percent of patients had spinal cord injury on MR imaging. MR imaging was highly sensitive for injury to disk (93%), posterior longitudinal ligament (93%), and interspinous soft tissues (100%), but it was less sensitive for injury to the anterior longitudinal ligament (71%) and ligamentum flavum (67%). For most ligamentous structures, there was limited agreement between specific MR imaging findings and injury at surgery. CONCLUSION: In acute cervical spine trauma, MR imaging has moderate to high sensitivity for injury to specific ligamentous structures but limited agreement between specific MR imaging findings and injury at surgery. MR imaging may overestimate the extent of disruptive injury when compared with intraoperative findings, with potential clinical consequences.     

Pseudoatrophy of the cervical portion of the spinal cord on MR images: a manifestation of the truncation artifact?

Routine evaluation of axial MR images of the cervical spine with high-intensity CSF (long TR/TE spin-echo or gradient-echo images) revealed apparent narrowing of the cord's anteroposterior diameter when these images were compared with corresponding postmyelography CT scans. This discrepancy was believed to be due to the truncation artifact at the CSF-cord boundary. To examine the truncation effect, we compared cord diameters in 12 patients on postmyelography CT scans and MR images and then compared these with MR scans of normal volunteers and of an agar-saline spine phantom. There was an artifactual diminution of the cord diameter in the 128-step phase-encoding axis of the 128 x 256-matrix MR scan as compared with the diameter of the cord in the patients' postiohexol CT scans and in the 256 phase-encoded axis MR scan in the volunteer study. A similar discrepancy was noted in the spine phantom study, in which the cord diameter in the 256-step phase-encoded MR scan, the CT scan, and direct measurement exceeded that in the 128-step phase-encoded axis MR scan. The range of differences between the measurements was as large as 2.3 mm (patients), 1.7 mm (volunteers), and 1.8 mm (phantom) for the three studies. In all three studies, varying the photographic window width and level produced variation in the apparent cord diameter of up to 1.5 mm. To eliminate this effect, the cord diameters in the phantom and the normal control subjects were measured at identical window levels. The truncation artifact, coupled with standard window settings used in photography, may lead to inaccurate display of the diameter of the cervical spinal cord.