José Antonio Narváez

MR imaging of synovial tumors and tumor-like lesions.

The clinical diagnosis of synovial tumors and tumorlike lesions is difficult, and radiographic findings may establish a confident diagnosis only in some cases. MR imaging has become the modality of choice in evaluating these lesions, because with it a presumptive diagnosis can be made in most cases. Our goal is to review the MR features of pigmented villonodular synovitis, giant-cell tumor of the tendon sheath, synovial chondromatosis, synovial hemangioma, lipoma arborescens, synovial cysts and synovial sarcoma, emphasizing those findings that suggest a specific diagnosis.

Pancreatitis, Panniculitis, and Polyarthritis

BACKGROUND AND OBJECTIVE Lobular panniculitis, together with polyarthritis and intraosseous fat necrosis, may occasionally complicate pancreatic disease. This triad is known in the literature as the pancreatitis, panniculitis, and polyarthritis (PPP syndrome). We describe a case of the PPP syndrome and review the available literature to summarize the clinical characteristics of patients with this condition. METHODS A patient with the PPP syndrome, with evidence of extensive intraosseous fat necrosis in the joints involved revealed by magnetic resonance imaging, is described and the relevant literature based on a PubMed search from 1970 to February 2008 is reviewed. The keywords used were pancreatitis or pancreatic disease, panniculitis, arthritis, and intraosseous fat necrosis. RESULTS Including our case, 25 well-documented patients with the PPP syndrome have been reported. Our patient had few abdominal symptoms despite high serum levels of pancreatic enzymes. In our review of the literature, almost 2/3 of patients had absent or mild abdominal symptoms, leading to misdiagnosis. The delay in diagnosis and specific treatment of the underlying pancreatitis worsens the prognosis of this condition, which has a mortality rate as high as 24%. In nearly 45% of the patients, the arthritis follows a chronic course with a poor response to nonsteroidal anti-inflammatory drugs and corticosteroids, and the rapid development of radiographic joint damage. CONCLUSION Certain forms of pancreatic disease can very occasionally cause arthritis and panniculitis. Although uncommon, physicians should be alert to the possible presence of this syndrome for 2 reasons: first, unrecognized pancreatic disease can be fatal if not treated promptly; second, to avoid inappropriate and risky therapy to improve joint symptoms.

MR Imaging of Early Rheumatoid Arthritis

Early diagnosis and treatment have been recognized as essential for improving clinical outcomes in patients with early rheumatoid arthritis. However, diagnosis is somewhat difficult in the early stages of the disease because the diagnostic criteria were developed from data obtained in patients with established rheumatoid arthritis and therefore are not readily applicable. Magnetic resonance (MR) imaging is increasingly being used in the assessment of rheumatoid arthritis due to its capacity to help identify the key pathologic features of this disease entity at presentation. MR imaging has demonstrated greater sensitivity for the detection of synovitis and erosions than either clinical examination or conventional radiography and can help establish an early diagnosis of rheumatoid arthritis. It also allows the detection of bone marrow edema, which is thought to be a precursor for the development of erosions in early rheumatoid arthritis as well as a marker of active inflammation. In addition, MR imaging can help differentiate rheumatoid arthritis from some clinical subsets of peripheral spondyloarthropathies by allowing identification of inflammation at the insertions of ligaments and tendons (enthesitis).

Usefulness of Magnetic Resonance Imaging of the Hand versus Anticyclic Citrullinated Peptide Antibody Testing to Confirm the Diagnosis of Clinically Suspected Early Rheumatoid Arthritis in the Absence of Rheumatoid Factor and Radiographic Erosions

OBJECTIVE The diagnosis of rheumatoid arthritis (RA) is sometimes difficult to establish early in the disease process, particularly in the absence of its classic hallmarks. Our aim was to compare the practical usefulness of magnetic resonance imaging (MRI) of the hand versus anticyclic citrullinated peptide (anti-CCP) antibody testing to confirm the diagnosis of clinically suspected RA in the absence of rheumatoid factor (RF) and radiographic erosions. METHODS We prospectively included patients with early inflammatory arthritis and strong clinical suspicion of RA, in whom initial complementary tests (RF and radiographs of hands, wrists, and feet) did not provide unequivocal confirmation of the diagnosis. In all patients, anti-CCP antibodies were assessed and contrast-enhanced MRI of the most affected hand was performed according to a specifically designed protocol. The MRI criterion for the diagnosis of RA was either the presence of synovitis with bone erosions or bone marrow edema, which is currently considered to be a forerunner of erosions. RESULTS In the 40 patients (28 women), the mean age at diagnosis was 54 +/- 6 years and the median duration of symptoms was 4 +/- 2.6 months (range 1.5 to 12). Final diagnoses at 1-year follow-up were RA in 31 patients, undifferentiated arthritis in 7 (5 self-limiting), and psoriatic arthropathy (PsA) and antisynthetase syndrome in 1 patient each. Anti-CCP antibodies were positive only in 7 patients, all of whom were finally diagnosed with RA. The prevalence of anti-CCP positivity in our series of seronegative RA patients was thus 23% (7/31); in these patients the anti-CCP antibodies had a specificity of 100% (95% CI: 71.7 to 100) and sensitivity of 23% (95% CI: 9.6 to 41.1). Use of the MRI criterion led to the correct diagnosis in 100% of patients with RA and to false-positive results (1 with PsA and 1 with antisynthetase syndrome). The MRI criterion had a specificity of 78% (95% CI: 40.0 to 97.2) and sensitivity of 100% (95% CI: 90.8 to 100) for identification of seronegative RA. CONCLUSION Although the tests are not mutually exclusive, in our experience MRI is more helpful than anti-CCP antibody determination in confirming the diagnosis of clinically suspected early RA in patients in whom the diagnosis cannot be confirmed using conventional methods.

Changing Trends in the Epidemiology of Pyogenic Vertebral Osteomyelitis: The Impact of Cases with No Microbiologic Diagnosis

OBJECTIVES The observed higher incidence of pyogenic vertebral osteomyelitis (PVO) may entail an increasing number of patients with no microbiologic diagnosis. The true incidence of these cases, how exhaustive the etiologic diagnostic efforts must be, and the usefulness of an empirical antibiotic therapy are not well defined. METHODS Retrospective analysis of all cases of vertebral osteomyelitis in our center (1991-2009) and retrospective analysis of cases of PVO (2005-2009). Clinical data, diagnostic procedures, treatment, and outcome were reviewed. A comparative analysis between microbiologically confirmed PVO (MCPVO) and probable PVO (PPVO) was performed. RESULTS Increasing incidence of PVO (+0.047 episodes/100,000 inhabitants-year). During the last decade, there was an increase of PPVO (+0.059 episodes/100,000 inhabitants-year) with stable incidence of MCPVO. During 2005-2009, there were 72 patients [47 (65%) MCPVO and 25 (35%) PPVO]. 60% men; mean age was 66 years. Bacteremia was found in 59%. Computed tomographic guided vertebral biopsy, positive in 7/36 (19%), was more successful among patients with bacteremia. Among MCPVO, there was an increasing proportion of less virulent bacteria. Cases of MCPVO presented more frequently with sepsis, fever, and high acute-phase reactants, and PPVO cases were mostly treated with oral fluoroquinolones plus rifampin. No differences were found between both groups in outcome (93% success, 22% sequelae). CONCLUSIONS An epidemiologic change of PVO is suggested by a higher incidence of PPVO and the isolation of less virulent microorganisms among MCPVO. In this setting, the availability of an oral and effective empirical antibiotic therapy may challenge an exhaustive prosecution of the etiology.

Soft-tissue tumors update: MR imaging features according to the WHO classification

Soft-tissue tumors are a large and heterogeneous group of neoplasms. Hence, classification is often difficult. The most effective management decisions are made when a working group participates in the same diagnostic standard criteria in the evaluation of soft-tissue tumors. The purpose of this pictorial review is to highlight the new and the less well-known features on magnetic resonance (MR) imaging of soft-tissue tumors according to the World Health Organization (WHO) classification established in 2002. The article depicts the major changes of the WHO classification since it was established in 2002 and the most significant findings on MR imaging, thereby providing an update.

Can magnetic resonance imaging of the hand and wrist differentiate between rheumatoid arthritis and psoriatic arthritis in the early stages of the disease

OBJECTIVE To investigate whether rheumatoid arthritis (RA) and psoriatic arthritis (PsA) can be differentiated in the early stages of the disease (duration of symptoms ≤1 year) on the basis of magnetic resonance imaging (MRI) features of the hand and wrist. MATERIAL AND METHODS Twenty early RA and 17 early PsA patients with symptomatic involvement of the wrist and hand joints and inconclusive radiographic studies were examined prospectively with contrast-enhanced MRI. Images were evaluated in accordance with the Outcome Measures in Rheumatology Clinical Trials recommendations. RESULTS Certain MRI features, such as the presence of enthesitis or extensive diaphyseal bone marrow edema, were observed exclusively in PsA (P = 0.0001). These distinctive findings were present in nearly 71% (12/17) of PsA patients. Diffuse and, in some cases, pronounced soft-tissue edema spreading to the subcutis was also seen more frequently in patients with PsA (P = 0.002). There were no significant differences in the frequency of synovitis, bone erosions, subchondral bone edema, or tenosynovitis between the 2 groups. However, in RA extensor tendons were involved more often than the flexor tendons, whereas in PsA the opposite was observed (P = 0.014). With respect to the discriminatory power of the different MRI findings examined, only the presence of enthesitis or diaphyseal bone edema and, to a lesser extent, the pattern of hand tendon involvement and the presence of soft-tissue edema accurately differentiated PsA from RA (all these features achieved accuracies greater than 0.70). CONCLUSIONS We observed significant differences in the MRI findings of the hand and wrist that can help to distinguish between RA and PsA in the early stages of disease. This imaging method could help to assist in the differential diagnostic process in selected patients in whom diagnosis cannot be unequivocally established after conventional clinical, biochemical, and radiographic examinations.

Cervical spine involvement in rheumatoid arthritis: correlation between neurological manifestations and magnetic resonance imaging findings

OBJECTIVE To evaluate the correlation between neurological deficits indicative of compressive myelopathy and MRI findings in a series of patients with RA and symptomatic involvement of the cervical spine. METHODS Forty-one consecutive patients with RA were studied using cervical spine MRI. Unconditional logistic regression analysis was used to identify MRI parameters of cervical spine involvement associated with the development of neurological dysfunction. RESULTS The mean age of the 41 patients (33 women and 8 men) was 59 yrs (range 23-82 yrs), while the median disease duration was 18 +/- 9 yrs (range 4-40 yrs). According to Ranawats classification, 17 (42%) patients were in Class I, 21 (51%) in Class II and 3 (7%) in Class III. Thus, patients with clinical manifestations of compressive myelopathy (Ranawats Class II + III) represented 58% (24/41) of all cases. Among the different MRI parameters of cervical spine involvement analysed, only the presence of atlantoaxial spinal canal stenosis [odds ratio (OR) 4.55; 95% CI 1.14-18.15], atlantoaxial cervical cord compression (OR 9.6; 95% CI 1.08-85.16) and subaxial myelopathy changes (OR 11.43; 95% CI 1.3-100.81) were associated with a significantly increased risk for neurological dysfunction (Ranawats Class II or III). CONCLUSION In RA patients with symptomatic cervical spine involvement, there is a strong correlation between the development of neurological dysfunction and MRI identification of atlantoaxial spinal canal stenosis, especially in those cases with evidence of upper cervical cord or brainstem compression and subaxial myelopathy changes.

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.

Acral Myxoinflammatory Fibroblastic Sarcomas: MRI Findings in Four Cases

OBJECTIVE Acral myxoinflammatory fibroblastic sarcoma is a rare, recently described, low-grade sarcoma that involves mainly the distal extremities. The purpose of this study is to report the MRI findings in four cases of acral myxoinflammatory fibroblastic sarcoma. CONCLUSION Acral myxoinflammatory fibroblastic sarcomas may present with various MRI patterns that probably reflect their variable histologic composition. Differential diagnosis with other benign conditions, especially with ganglion cysts and giant cell tumors of the tendon sheath, may be difficult. We report tumoral invasion of the bone in one case, which to our knowledge has not been previously described.