Subaxial cervical spine involvement in symptomatic rheumatoid arthritis patients: Comparison with cervical spondylosis.

OBJECTIVE: To investigate the frequency, location, characteristics, and clinical significance of subaxial involvement (below C1-C2) in a series of patients with rheumatoid arthritis (RA) and symptomatic involvement of the cervical spine. METHODS: A total of 41 patients with RA were examined via cervical spine magnetic resonance imaging (MRI). A comparative analysis of the incidence of the different types of subaxial lesions was performed between these patients and 41 age- and sex-matched patients with symptomatic cervical spondylosis. RESULTS: Stenosis of the spinal canal was found at the subaxial level in 85% of RA patients, and at the atlantoaxial level in 44%. Comparative analysis between these patients and the cervical spondylosis patients revealed significant differences in the types and frequencies of subaxial lesions. For both conditions, signs of discopathy and end-plate osteophytosis were the most common abnormalities observed on magnetic resonance imaging (MRI). However, in the RA patients these abnormalities coincided with subchondral bone and ligamentous acute inflammatory changes and with secondary destruction (vertebral instability) or repair (vertebral ankyloses). Only evidence of subaxial myelopathy was significantly associated with an increased risk of neurological dysfunction among the RA patients [Ranawat class II or III; P = 0.01; odds ratio (OR) = 11.43], although subaxial cord compression tended toward a significant association with the risk of neurological dysfunction (P = 0.06; OR = 3.95). CONCLUSION: Subaxial stenosis seems to be the consequence of both the inflammatory process and mechanical-degenerative changes. Despite its frequency, it was not usually related to the occurrence of myelopathy symptoms, not even in cases with MRI evidence of spinal cord compression.

Multicentre evaluation of the INTERPRET decision support system 2.0 for brain tumour classification.

In a previous study, we have shown the added value of (1) H MRS for the neuroradiological characterisation of adult human brain tumours. In that study, several methods of MRS analysis were used, and a software program, the International Network for Pattern Recognition of Tumours Using Magnetic Resonance Decision Support System 1.0 (INTERPRET DSS 1.0), with a short-TE classifier, provided the best results. Since then, the DSS evolved into a version 2.0 that contains an additional long-TE classifier. This study has two objectives. First, to determine whether clinicians with no experience of spectroscopy are comparable with spectroscopists in the use of the system, when only minimum training in the use of the system was given. Second, to assess whether or not a version with another TE is better than the initial version. We undertook a second study with the same cases and nine evaluators to assess whether the diagnostic accuracy of DSS 2.0 was comparable with the values obtained with DSS 1.0. In the second study, the analysis protocol was flexible in comparison with the first one to mimic a clinical environment. In the present study, on average, each case required 5.4 min by neuroradiologists and 9 min by spectroscopists for evaluation. Most classes and superclasses of tumours gave the same results as with DSS 1.0, except for astrocytomas of World Health Organization (WHO) grade III, in which performance measured as the area under the curve (AUC) decreased: AUC = 0.87 (0.72-1.02) with DSS 1.0 and AUC = 0.62 (0.55-0.70) with DSS 2.0. When analysing the performance of radiologists and spectroscopists with respect to DSS 1.0, the results were the same for most classes. Having data with two TEs instead of one did not affect the results of the evaluation.

Prospective diagnostic performance evaluation of single-voxel 1H MRS for typing and grading of brain tumours.

The purpose of this study was to evaluate whether single-voxel (1)H MRS could add useful information to conventional MRI in the preoperative characterisation of the type and grade of brain tumours. MRI and MRS examinations from a prospective cohort of 40 consecutive patients were analysed double blind by radiologists and spectroscopists before the histological diagnosis was known. The spectroscopists had only the MR spectra, whereas the radiologists had both the MR images and basic clinical details (age, sex and presenting symptoms). Then, the radiologists and spectroscopists exchanged their predictions and re-evaluated their initial opinions, taking into account the new evidence. Spectroscopists used four different systems of analysis for (1)H MRS data, and the efficacy of each of these methods was also evaluated. Information extracted from (1)H MRS significantly improved the radiologists' MRI-based characterisation of grade IV tumours (glioblastomas, metastases, medulloblastomas and lymphomas) in the cohort [area under the curve (AUC) in the MRI re-evaluation 0.93 versus AUC in the MRI evaluation 0.85], and also of the less malignant glial tumours (AUC in the MRI re-evaluation 0.93 versus AUC in the MRI evaluation 0.81). One of the MRS analysis systems used, the INTERPRET (International Network for Pattern Recognition of Tumours Using Magnetic Resonance) decision support system, outperformed the others, as well as being better than the MRI evaluation for the characterisation of grade III astrocytomas. Thus, preoperative MRS data improve the radiologists' performance in diagnosing grade IV tumours and, for those of grade II-III, MRS data help them to recognise the glial lineage. Even in cases in which their diagnoses were not improved, the provision of MRS data to the radiologists had no negative influence on their predictions.

Bone marrow edema in the cervical spine of symptomatic rheumatoid arthritis patients.

OBJECTIVE: To investigate the frequency and clinical significance of bone marrow edema (BME) in a series of patients with rheumatoid arthritis (RA) and symptomatic involvement of the cervical spine. METHODS: We studied 19 consecutive RA patients with cervical spine magnetic resonance imaging (MRI) according to a specifically designed protocol that included short inversion time inversion recovery sequences. All cases had neck pain unresponsive to conventional treatment, neurological symptoms, or signs suggestive of cervical myelopathy, or cervical pain with evidence of atlantoaxial subluxation on radiographs. RESULTS: The mean age of the 19 patients (15 women and 4 men) at time of the study was 59 +/- 12 years (range, 23-82) and the median disease duration was 14 +/- 7.4 years (range, 4-30). BME was observed in 74% (14/19) of the patients: at the atlantoaxial level alone in 16% of the patients; subaxially alone in 16%; and at both levels in 42% of the patients. At the atlantoaxial level, BME was usually observed involving the odontoid process, whereas subaxially BME was limited to the vertebral plates and the interapophyseal joints. Patients with BME had higher erythrocyte sedimentation rate (ESR) values at the time of MRI examination (P = 0.014) and more severe atlantoaxial joint MRI synovitis scores (P = 0.05) compared with the remaining patients; the frequency of odontoid erosions was also greater in this group, but the difference did not reach statistical significance. Altogether, these data suggest a more severe inflammatory response in these patients. In this group a significant correlation was found between BME scores at atlantoaxial level and (1) ESR values (r = 0.854; P = 0.001) and (2) atlantoaxial joint MRI synovitis scores (r = 0.691; P = 0.001). CONCLUSION: BME is frequently observed in patients with established RA and symptomatic cervical spine involvement. Both atlantoaxial and subaxial levels are equally affected. The presence of BME seems related to the intensity of the inflammatory response and to the severity of the atlantoaxial joint synovitis.

Brain tumor classification by proton MR spectroscopy: comparison of diagnostic accuracy at short and long TE.

BACKGROUND AND PURPOSE: Different TE can be used for obtaining MR spectra of brain tumors. The purpose of this study was to determine the influence of the TE used in brain tumor classification by comparing the performance of spectra obtained at two different TE (30 ms and 136 ms). METHODS: One hundred fifty-one studies of patients with brain tumors (37 meningiomas, 12 low grade astrocytomas, 16 anaplastic astrocytomas, 54 glioblastomas, and 32 metastases) were retrospectively selected from a series of 378 consecutive examinations of brain masses. Single voxel proton MR spectroscopy at TE 30 ms and 136 ms was performed with point-resolved spectroscopy in all cases. Fitted areas of nine resonances of interest were normalized to water. Tumors were classified into four groups (meningioma, low grade astrocytoma, anaplastic astrocytoma, and glioblastoma-metastases) by means of linear discriminant analysis. The performance of linear discriminant analysis at each TE was assessed by using the leave-one-out method. RESULTS: Tumor classification was slightly better at short TE (123 [81%] of 151 cases correctly classified) than at long TE (118 [78%] of 151 cases correctly classified). Meningioma was the only group that showed higher sensitivity and specificity at long TE. Improved results were obtained when both TE were considered simultaneously: the suggested diagnosis was correct in 105 (94%) of 112 cases when both TE agreed, whereas the correct diagnosis was suggested by at least one TE in 136 (90%) of 151 cases. CONCLUSION: Short TE provides slightly better tumor classification, and results improve when both TE are considered simultaneously. Meningioma was the only tumor group in which long TE performed better than short TE.

Proton magnetic resonance spectroscopy ((1)H MRS) of human brain tumours: assessment of differences between tumour types and its applicability in brain tumour categorization.

Our objective was to evaluate the usefulness of proton magnetic resonance spectroscopy ((1)H MRS) in categorizing brain tumours. In vivo single-voxel (1)H MRS at an echo time of 136 ms was performed in 108 patients with brain neoplasms that included 29 meningiomas (MEN), 15 low-grade astrocytomas (LGA), 12 anaplastic astrocytomas (AA), 25 glioblastomas (GBM) and 27 metastases (MET). Time-domain fitted areas of nine resonances were evaluated in all spectra. Twenty-five additional tumours were prospectively included as independent test set. Differences in at least two resonances were found in all pairwise comparisons of tumour groups except in GBM vs MET. Large lipid resonance at 1.30 ppm was found to be characteristic of GBM and MET, and alanine was characteristic of MEN. Significant differences were found between LGA and AA in choline-containing compounds and total creatine resonances. When implemented in a stepwise algorithm, these findings correctly classified 84% (21 of 25) tumours in the independent test set. Some additional utility was found in glycine/myo-inositol at 3.55 ppm for bilateral differentiation between GBM and MET (9 of 11, 82% correct classification in the test set). (1)H MRS provides useful information to categorize the most common brain tumours that can be implemented in clinical practice with satisfactory results.

Adult primitive neuroectodermal tumor: proton MR spectroscopic findings with possible application for differential diagnosis.

PURPOSE: To assess the utility of proton magnetic resonance (MR) spectroscopy in the clinical categorization of primitive neuroectodermal tumors (PNETs) in adults. MATERIALS AND METHODS: In vivo proton MR spectroscopy was performed with an echo time of 136 msec in nine adults with PNET, and findings were retrospectively compared with spectroscopic findings of 22 meningiomas, 12 low-grade astrocytomas, eight anaplastic astrocytomas, 23 glioblastomas, and 21 metastases. Nine resonances were semiquantitatively evaluated. Statistical analysis was performed by using Kruskal-Wallis and Mann-Whitney U tests. The Hochberg correction was applied for multiple comparisons. Results were prospectively validated in 24 tumors of the six types included in the study. RESULTS: The resonances of choice for identifying PNET were alanine (P <.001) and glutamate and glutamine (P =.004), both decreased with respect to meningioma; choline increased with respect to low-grade (P <.001) and anaplastic astrocytoma (P =.055); and lipids at 1.30 ppm decreased and choline and other trimethyl-amine-containing compounds increased with respect to glioblastoma (P <.001 and P =.004, respectively) and metastasis (P <.001 and P =.021, respectively). We developed an algorithm for bilateral differential diagnosis between PNET and other tumor types. The leave-one-out method was used to test the five possible differential situations in the retrospective data set, with the following results: PNET versus meningioma, 31/23/5/3 (number of total/correct/unclassifiable/incorrect procedures); PNET versus low-grade astrocytoma, 21/19/2/0; PNET versus anaplastic astrocytoma, 17/6/9/2; PNET versus glioblastoma, 32/28/2/2; and PNET versus metastasis, 30/27/1/2. In total, 131 consecutive procedures produced 103 (79%) correct classifications and nine (7%) misclassifications. Twenty-five (78%) of 32 possible procedures in the prospective independent test set produced correct classifications and four (13%) produced incorrect classifications. CONCLUSION: In vivo proton MR spectroscopy provides useful information in clinical differentiation between PNETs and common brain tumors in adults.