188Re-tin-colloid as a new therapeutic agent for rheumatoid arthritis

Radiation synovectomy is a useful treatment modality in patients with refractory synovitis. We have developed a 188Re-tin-colloid as a new radiopharmaceutical agent and investigated its efficacy and safety in patients with rheumatoid arthritis. Radiation synovectomy was performed using 188Re-tin-colloid in 22 knees from 21 rheumatoid arthritis patients refractory to intra-articular corticosteroid injection. The efficacy and safety of administration of 370-1110 MBq of 188Re-tin-colloid were evaluated after 1, 3, 6, 9 and 12 months. Pain intensity on a visual analogue scale decreased significantly 12 months after therapy (mean+/-SD: 68.0+/-26.1 mm vs. 25.1+/-23.4 mm; P=0.0001 by the paired t-test). Pain decreased in 19 cases (86.3%), joint tenderness improved in 14 cases (63.6%) and joint swelling was reduced in all cases (100%). 188Re-tin-colloid was safe. The residual activity of 188Re in the blood was 0.077%+/-0.25% of the injected dose. The radioactivity of 188Re in the urine was 0.14%+/-0.13% of the injected dose. Transient reactive synovitis was observed in 18 cases (81.8%). No clinical side-effects or abnormalities in leucocyte count, platelet count, liver function tests or urine analysis were observed in any patient. In conclusion, in this first study of radiation synovectomy using 188Re-tin-colloid for patients with rheumatoid arthritis, the treatment resulted in the improvement of arthritis and was well tolerated.     

Influence of radiation synovectomy on articular cartilage, synovial thickness and enhancement as evidenced by MRI in patients with chronic synovitis.

Radiation synovectomy is a safe and effective treatment for chronic synovitis that is refractory to the repetitive, intra-articular application of glucocorticosteroids in patients with rheumatoid or seronegative arthritis. Short-term and long-term effects of radiation synovectomy on articular cartilage, synovial enhancement and thickness were assessed in a prospective, clinical trial by MRI. METHODS: Thirteen patients (mean age 39+/-13 y) were treated with a median activity of 8.4 GBq 165Dy ferric hydroxide, a radionuclide with favorable physical properties and a well-documented clinical safety and efficacy profile. MRI was performed on a 1.5-T MR unit using a circular polarized knee coil. RESULTS: After a mean observation period of 13 mo, a marked reduction in synovial enhancement was observed in 10 patients. The mean reduction in baseline synovial thickness (mean 7.6+/-3.0 mm) was 24% (P = 0.03) at 1 wk and 42% (P = 0.01) about 1 y after treatment, respectively. Clinically, 9 of 13 patients (69%) exhibited persistent response to radiation synovectomy. The local clinical score, as defined by the reduction in pain, pannus, joint effusion and by the increase in the range of motion, improved significantly (P = 0.01), from a median of 7 (range 4-10) to a median of 2 (range 0-9). One year after treatment, changes in the local clinical score were related to the decrease in synovial enhancement in MRI (r = 0.7, P = 0.008, n = 12). There were no persistent adverse effects, nor was there evidence for any severe radiation-induced damage to the articular cartilage. On later follow-up images, the structure of the articular cartilage remained unaltered in all but 3 patients, who had new, superficial erosions most likely attributed to an active disease with persistence of inflammation. CONCLUSION: This study suggests that radiation synovectomy with 165Dy-ferric hydroxide is effective in terms of reducing chronic synovitis without causing detectable harm to the articular cartilage, as shown by MRI.     

A phase I/IIa study on intra-articular injection of holmium-166-chitosan complex for the treatment of knee synovitis of rheumatoid arthritis

Previous animal studies have established that the intra-articular injection of holmium-166-chitosan complex (DW-166HC) causes effective necrosis of the inflamed synovium with litle leakage of radioactivity from the injected joint. Based on these findings, we conducted a phase I/IIa study to examine the biodistribution of DW-166HC and to assess the safety of DW-166HC for the treatment of knee synovitis in patients with rheumatoid arthritis (RA). A total of 16 patients [1 man, 15 women; median age 49 (range 36-65) years] who had RA knee synovitis refractory to disease-modifying anti-rheumatic drug treatments of > 3 months' duration were randomly assigned to three treatment groups with different radiation doses of DW-166HC: 370 MBq (n = 6), 555 MBq (n = 5) and 740 MBq (n = 5). In each treatment group, blood and urine radioactivity were analysed by beta counter and biodistribution of the injected DW-166HC was evaluated using a gamma scan camera. Clinical assessment was done according to three variables (evaluation method): knee joint pain (visual analogue scale), range of motion (goniometry) and joint swelling (circumference of knee joint). The duration of follow-up observation was 3 months. Following the intra-articular injection of DW-166HC, the blood radioactivity was little changed from the baseline measurement and the accumulated radioactivity excreted in urine was minimal. Gamma scan study indicated that most of the injected radiochemical was localized within the injected joint cavity, and the extra-articular leakage was negligible at 24 h after the injection: brain, 0.3%; lung, 0.6%; abdomen, 0.7%; and pelvis, 0.8%. Major adverse events were transient post-injection knee joint pain and swelling. These results suggest that DW-166HC might be a safe agent for radiation synovectomy, particularly for the treatment of knee synovitis of RA, and further trials in a larger patient population are warranted to evaluate the therapeutic efficacy of DW-166HC.     

A phase I/IIa study on intra-articular injection of holmium-166-chitosan complex for the treatment of knee synovitis of rheumatoid arthritis

Previous animal studies have established that the intra-articular injection of holmium-166-chitosan complex (DW-166HC) causes effective necrosis of the inflamed synovium with little leakage of radioactivity from the injected joint. Based on these findings, we conducted a phase I/IIa study to examine the biodistribution of DW-166HC and to assess the safety of DW-166HC for the treatment of knee synovitis in patients with rheumatoid arthritis (RA). A total of 16 patients [1 man, 15 women; median age 49 (range 36-65) years] who had RA knee synovitis refractory to disease-modifying antirheumatic drug treatments of >3 months' duration were randomly assigned to three treatment groups with different radiation doses of DW-166HC: 370 MBq (n=6), 555 MBq (n=5) and 740 MBq (n=5). In each treatment group, blood and urine radioactivity were analysed by beta counter and biodistribution of the injected DW-166HC was evaluated using a gamma scan camera. Clinical assessment was done according to three variables (evaluation method): knee joint pain (visual analogue scale), range of motion (goniometry) and joint swelling (circumference of knee joint). The duration of follow-up observation was 3 months. Following the intra-articular injection of DW-166HC, the blood radioactivity was little changed from the baseline measurement and the accumulated radioactivity excreted in urine was minimal. Gamma scan study indicated that most of the injected radiochemical was localized within the injected joint cavity, and the extra-articular leakage was negligible at 24 h after the injection: brain, 0.3%; lung, 0.6%; abdomen, 0.7%; and pelvis, 0.8%. Major adverse events were transient post-injection knee joint pain and swelling. These results suggest that DW-166HC might be a safe agent for radiation synovectomy, particularly for the treatment of knee synovitis of RA, and further trials in a larger patient population are warranted to evaluate the therapeutic efficacy of DW-166HC.     

MR Evaluation of Radiation Synovectomy of the Knee by Means of Intra-articular Injection of Holmium-166-Chitosan Complex in Patients with Rheumatoid Arthritis: Results at 4-month Follow-up

Objective

To determine whether MRI is able to demonstrate the effect of radiation synovectomy after the intra-articular injection of holmium-166-chitosan complex for the treatment of rheumatoid arthritis of the knee.

Materials and Methods

Fourteen patients aged 36-59 years were treated with 10-20 mCi of holmium-166-chitosan complex. A criterion for inclusion in this study was the absence of observable improvement after 3- or more months of treatment of the knee with disease-modifying anti-rheumatic drugs. MR images were acquired both prior to and 4-months after treatment. Clinical evaluation included the use of visual analog scales to assess pain, and the circumference of the knee and its range of motion were also determined. MR evaluation included measurement of the volume of synovial enhancement and wall thickness, the amount of joint effusion, and quantifiable scoring of bone erosion, bone edema and lymph nodes.

Results

Visual analog scale readings decreased significantly after radiation synovectomy (p < 0.05). MRI showed that joint effusion decreased significantly (p < 0.05), and that the volume of synovial enhancement tended to decrease, but to an insignificant extent (p = 0.107).

Conclusion

The decreased joint effusion noted at 4-month follow-up resulted from radiation synovectomy of the rheumatoid knee by means of intra-articular injection of holmium-166-chitosan complex.     

Long-term results of radiation synovectomy: a clinical follow-up study

Radiation synovectomy by intra-articular injection of beta-emitting radionuclides is a reliable and easy-to-perform therapy without harmful side effects for the treatment of inflammatory rheumatoid as well as degenerative joint diseases. The indication for radiation synovectomy is based on both clinical symptoms and on proven hyperperfusion, with active synovitis being seen on a pre-therapeutic three-phase bone scan. In this study, the clinical response after 6-18 months, evaluated by a standardized questionnaire, was compared with the reduction of synovitis seen on three-phase bone scintigraphy after treatment of 475 joints in 151 patients. The best clinical results were obtained in cases of true rheumatoid arthritis (73.4%), with less in other kinds of arthritis (48.8%) such as psoriatic or reactive arthritis. Because of the inflamed synovium being the main target tissue, clinical results in osteoarthritis with severe bone destruction are poorer (33.9%). However, synovitis can be markedly reduced (in approximately 70%), regardless of the underlying diagnosis, as shown by post-therapeutic three-phase bone scanning. Radiation synovectomy can be recommended in all kinds of arthritis. It should also be considered in cases of osteoarthritis as a last therapeutic option prior to joint replacement.     

Measurement of synovial inflammation in rheumatoid arthritis with technetium 99m labelled human polyclonal immunoglobulin G

The ability of technetium 99m labelled nonspecific, polyclonal human immunoglobulin G (99mTc-IgG) scintigraphy to depict and quantify synovial inflammation was studied in patients with rheumatoid arthritis (RA). Eight patients with clinically active synovitis were injected with 350 MBq 99mTc-IgG, and imaging took place 4 h later. This resulted in excellent images of inflamed synovium. Significant correlations were observed between individual joint uptake on the scan and scores for joint pain (n = 316, p less than 0.001), joint swelling (n = 300, p less than 0.001) or the average of pain and swelling (n = 300, p less than 0.001). These results suggest that 99mTc-IgG scintigraphy may provide an objective, non-invasive test to detect and measure synovitis.     

Clinical efficacy of radiation synovectomy in digital joint osteoarthritis

Purpose Radiation synovectomy was developed for local treatment of rheumatoid arthritis. In this study, the long-term efficacy of radiation synovectomy was retrospectively evaluated in patients with osteoarthritis (activated arthrosis) of the digital joints using an algofunctional score.Methods Fifty-three digital joints in 29 patients (mean age 64.8 years) were treated by intra-articular injection of ¹⁶⁹Er citrate. All joints were painful despite pharmacotherapy and showed an elevated blood pool pattern in a pretherapeutic three-phase bone scan, indicative for local synovitis. The patients were asked to classify their complaints with respect to different daily manual activities on a ten-step pain scale from 1 (total disability) to 10 (lack of any impairment) prior to and after treatment, with a mean follow-up of 41 months. Local signs of osteoarthritis such as joint swelling or pain were additionally evaluated and were scored from progression of complaints to excellent improvement based on patient self-evaluation.Results All patients reported a pronounced improvement in their manual activities. The mean total score of 4.73±0.58 for all activities prior to treatment increased significantly to 6.79±0.47 after radiation synovectomy (p<0.05). The best results were obtained in the thumb base joints, whereas distal interphalangeal joints were frequently resistant to therapy.Conclusion Radiation synovectomy is highly effective in digital joint osteoarthritis with concomitant local synovitis.     

The results of 394 consecutive cases of knee joint radiation synovectomy (radiosynoviorthesis) using 90 Y

The aim of this study was to assess the treatment results of 90Y radiation synovectomy for chronic exudative synovitis of knee joints. The retrospective data consist of 394 consecutive knee radiation synovectomies performed using 6 mCi (222 MBq) of 90Y. The assessment included 3-point custom pain and joint mobility scale, evaluation of joint’s circumference, binary joint’s temperature evaluation, patellar ballottement test, indications for puncture and its volume in applicable cases. 21 cases had to be forfeited due to missing data regarding follow-up. The final analysis of 373 treatment procedures performed in 253 patients yielded following results—at 6 months after treatment, 80.9% of the patients reported at least partial pain relief (including 33.3% with complete pain relief), which increased to 86.7% at one year. The pain intensity decreased over time, however, the outcomes were worse in older patients. The probability of pain recurrence was 15% at 6 months, and 28% at one year. It was highest in post-traumatic synovitis, and lowest in pigmented villonodular synovitis. The circumference of the treated knee joints decreased over the course of follow-up, however, the decrease was significantly lower in older patients. The fraction of patients with full knee joint mobility increased from 34.6 to 40.6% at 6 months and 49.2% at one year. The percentage of patients that required articular puncture decreased from 62.8% at baseline to about 35.6% at 6 months, and 32.8% at one year. Positive patellar ballottement was found in 68.5% before treatment and remained at about 40–50% during the course of follow-up. The increased temperature of the joint was reported in 51.2% at baseline and decreased to 33% at 6 months and 28.3% at one year. (1) Radiation synovectomy is a safe and effective method of treatment in patients with exudative synovitis, however, the pain recurrence rate is significantly higher in post-traumatic exudative synovitis compared to pigmented villonodular, undifferentiated, and rheumatoid arthritis. (2) Our results suggest that older patients have worse treatment results with radiation synovectomy compared to younger patients.     

Utility of Tc-99m human polyclonal immunoglobulin G scintigraphy for assessing the efficacy of yttrium-90 silicate therapy in rheumatoid knee synovitis

PURPOSE: The aim of this study was to determine the utility of Tc-99m human polyclonal immunoglobulin G (HIG) scintigraphy for evaluating the efficacy of yttrium-90 (Y-90) silicate therapy in rheumatoid knee synovitis. MATERIALS AND METHODS: Fifteen patients (13 women, 2 men; mean age, 53.5 +/- 8.4 years) with rheumatoid arthritis had radionuclide synovectomy using 185 MBq (5 mCi) Y-90 silicate to evaluate 24 knee joints with chronic persistent synovitis. Radiologic and clinical evaluations and Tc-99m HIG scans were performed in each patient before radionuclide synovectomy. Each patient was reassessed 3, 6, 9, and 12 months after therapy using clinical examination and Tc-99m HIG scintigraphy. RESULTS: In 14 of 24 knee joints (4 Larsen stage I, 10 Larsen stage II) that had excellent or good clinical responses to Y-90 silicate therapy, the Tc-99m HIG index values 3 months after treatment were significantly lower than the pretreatment index values (P < 0.001). In 13 of these 14 joints, these low index values and clinical results remained constant throughout the 1 year of follow-up. One patient (1 of the 14 knee joints) experienced severe pain and swelling as a result of recurrent arthritis at 9 months, and the Tc-99m HIG index value increased at 9 months and remained high 12 months after therapy. In 10 of 24 knee joints (4 Larsen stage II, 6 Larsen stage III) that had a fair or poor clinical response, Tc-99m HIG index values were statistically similar before and after radionuclide therapy. CONCLUSIONS: Quantitative Tc-99m HIG scintigraphy is a valuable method for assessing the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.     

Synovectomy of the knee with 90Y

In 33 patients with chronic arthritis of the knee, 48 knees were treated with an intra-articular injection of 5 mCi yttrium silicate (90Y). There were 27 patients with rheumatoid arthritis (RA) and 6 with osteoarthrosis (OA); the mean follow-up period was 33 months. At clinical investigation after 1 year, no signs of pain or swelling were found in 15 knees. In most cases, pain and swelling improved subjectively, with a mean duration of 11 months; in 20 knees, the improvement lasted more than 22 months. When radiographs showed severe destruction, 90Y treatment was unsuccessful, but an important new finding was that most patients with mild or moderate radiological abnormalities appeared to have a long-lasting improvement. The result did not correlate with erythrocyte sedimentation rate (ESR), haemoglobin or Rose titre at the time of injection or at follow up, suggesting that the result of the treatment is more dependent on local factors than on the disease activity. The results of 90Y treatment in 6 OA knees with persistent swelling were promising regarding swelling, even in patients with moderate radiological abnormalities. The main side-effect was a sometimes painful swelling of the knee, which was always successfully treated with an intraarticular corticosteroid injection. In 90Y-treated knees, the incidence of unstable joints was not significantly higher than in non-treated knees. In conclusion, 90Y synovectomy may be a successful treatment for patients older than 50 years with chronic arthritis of the knee due to RA and probably also OA, even when moderate radiological abnormalities are present.     

The relationship between limited MRI section analyses and volumetric assessment of synovitis in knee osteoarthritis

AIM: To assess whether simple, limited section analysis can replace detailed volumetric assessment of synovitis in patients with osteoarthritis (OA) of the knee using contrast-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-five patients with clinical and radiographic OA of the knee were assessed for synovitis using gadolinium-enhanced MRI. The volume of enhancing synovium was quantitatively assessed in four anatomical sites (the medial and lateral parapatellar recesses, the intercondylar notch and the suprapatellar pouch) by summing the volumes of synovitis in consecutive sections. Four different combinations of section analysis were evaluated for their ability to predict total synovial volume. RESULTS: A total of 114 intra-articular sites were assessed. Simple linear regression demonstrated that the best predictor of total synovial volume was the analysis containing the inferior, mid and superior sections of each of the intra-articular sites, which predicted between 40-80% (r(2) = 0.396, p < 0.001 for notch; r(2) = 0.818, p < 0.001 for medial parapatellar recess) of the total volume assessment. CONCLUSIONS: The results suggest that a three-section analysis on axial post-gadolinium sequences provides a simple surrogate measure of synovial volume in OA knees.     

Knee in early juvenile rheumatoid arthritis: MR imaging findings

PURPOSE: To determine the magnetic resonance (MR) imaging findings in the knee in early juvenile rheumatoid arthritis. MATERIALS AND METHODS: MR imaging (1.5 T) was performed in the more symptomatic knee in 30 children with juvenile rheumatoid arthritis with a symptom duration 1 year or less. Conventional, fast spin-echo, three-dimensional gradient-echo, and gadolinium-enhanced T1-weighted images were assessed. Two radiologists independently read the images, and a third resolved disagreements. These images were compared with knee radiographs in 27 children. RESULTS: Mean maximal synovial thickness was 4.8 mm +/- 2.4 (SD). Mean synovial volume was 15.4 mL +/- 10.8. Suprapatellar joint effusions were seen in 26 (87%) of 30 knees, meniscal hypoplasia in 11 (37%) of 30 knees, and abnormal epiphyseal marrow in eight (27%) of 30 knees. Three knees had articular cartilage contour irregularity, fissures, and/or thinning. One knee had a bone erosion. Knee radiographs showed suprapatellar fullness in 78% of the knees, joint space narrowing in one knee, and no bone abnormalities. CONCLUSION: Synovial hypertrophy and joint effusions are the most frequent MR imaging findings of knees in early juvenile rheumatoid arthritis. Early in the disease, radiographically occult cartilage and bone erosions are uncommonly seen at MR imaging. The potential relationship of synovitis to cartilage abnormalities deserves further study.     

Gallium 67 scanning in rheumatoid arthritis

Gallium 67 scans were performed on both knees of 38 patients with rheumatoid arthritis. There was a significantly higher level of 67Ga accumulation in those knees with clinically active synovitis (p less than 0.001). Synovial white cell concentration was also elevated in the group with active synovitis. The white cell concentration correlated with the 67Ga knee/femoral ratio at the p less than 0.001 level. 67Ga activity in the synovial fluid was predominantly in the supinate and activity was also present in the synovium. The findings indicate that 67Ga uptake occurs in rheumatoid joints and reflects the degree of synovial inflammation.     

Measurement of synovial inflammation in rheumatoid arthritis with technetium 99m labelled human polyclonal immunoglobulin G

The ability of technetium 99m labelled nonspecific, polyclonal human immunoglobulin G (^99mTc-IgG) scintigraphy to depict and quantify synovial inflammation was studied in patients with rheumatoid arthritis (RA). Eight patients with clinically active synovitis were injected with 350 MBq ^99mTc-IgG, and imaging took place 4 h later. This resulted in excellent images of inflamed synovium. Significant correlations were observed between individual joint uptake on the scan and scores for joint pain (n=316, p<0.001), joint swelling (n = 300, p < 0.001) or the average of pain and swelling (n = 300, p < 0.001). These results suggest that ^99mTc-IgG scintigraphy may provide an objective, non-invasive test to detect and measure synovitis. Offprint requests to: P.A.H.M. van der Lubbe     

Cutaneous radiation necrosis as a complication of yttrium-90 synovectomy

Radiation synovectomy is an effective method of treatment of chronic synovitis in patients with conditions such as rheumatoid arthritis, haemophilic synovitis and pigmented villonodular synovitis. This case demonstrates one of the potential complications of this procedure in a 46 year old man treated with bilateral radiation synovectomy for haemophilic synovitis. Cutaneous radiation necrosis is a known but rare complication of this procedure and this case is reported to demonstrate this known complication and to highlight that appropriate technique is required to avoid this.     

18F-FDG PET imaging of rheumatoid knee synovitis correlates with dynamic magnetic resonance and sonographic assessments as well as with the serum level of metalloproteinase-3

Purpose The aim of this study was to assess rheumatoid arthritis (RA) synovitis with positron emission tomography (PET) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in comparison with dynamic magnetic resonance imaging (MRI) and ultrasonography (US).Methods Sixteen knees in 16 patients with active RA were assessed with PET, MRI and US at baseline and 4 weeks after initiation of anti-TNF- treatment. All studies were performed within 4 days. Visual and semi-quantitative (standardised uptake value, SUV) analyses of the synovial uptake of FDG were performed. The dynamic enhancement rate and the static enhancement were measured after i.v. gadolinium injection and the synovial thickness was measured in the medial, lateral patellar and suprapatellar recesses by US. Serum levels of C-reactive protein (CRP) and metalloproteinase-3 (MMP-3) were also measured.Results PET was positive in 69% of knees while MRI and US were positive in 69% and 75%. Positivity on one imaging technique was strongly associated with positivity on the other two. PET-positive knees exhibited significantly higher SUVs, higher MRI parameters and greater synovial thickness compared with PET-negative knees, whereas serum CRP and MMP-3 levels were not significantly different. SUVs were significantly correlated with all MRI parameters, with synovial thickness and with serum CRP and MMP-3 levels at baseline. Changes in SUVs after 4 weeks were also correlated with changes in MRI parameters and in serum CRP and MMP-3 levels, but not with changes in synovial thickness.Conclusion ¹⁸F-FDG PET is a unique imaging technique for assessing the metabolic activity of synovitis. The PET findings are correlated with MRI and US assessments of the pannus in RA, as well as with the classical serum parameter of inflammation, CRP, and the synovium-derived parameter, serum MMP-3. Further studies are warranted to establish the place of metabolic imaging of synovitis in RA.     

Contrast enhanced gray-scale sonography in assessment of joint vascularity in rheumatoid arthritis: results from the IACUS study group

The purpose of this study way to assess the value of contrast enhanced gray-scale ultrasound (CEUS) in detection of vascularity in joints of patients with rheumatoid arthritis (RA) in a multicenter study of the International Arthritis Contrast Ultrasound (IACUS) study group. We assessed 113 joints in 113 patients (44 men, 69 women; mean age 51±14 years) with clinical diagnosis of RA. Gray-scale ultrasound (US), power Doppler US (PDUS) and CEUS, using a low mechanical index US technique, was performed. CEUS was done by bolus administration of the contrast agent SonoVue (Bracco, Milan, Italy) with a dosage of 4.8-ml SonoVue flushed with 10 ml saline. Detection of joint vascularity was performed for differentiation of active synovitis from inactive intra-articular thickening (synovitis/effusion). With the use of US and PDUS, active synovitis could be differentiated from inactive intra-articular thickening in 68/113 joints (60.1%), whereas CEUS enabled differentiation in 110/113 (97.3%) joints (p<0.0001). Thickness measurement of active synovitis was significantly improved after contrast administration (p=0.008). In conclusion, CEUS improves the differentiation of active synovitis from inactive intra-articular thickening. Since CEUS has shown an ability to improve assessment of vascularized synovial proliferation in RA affected joints, this technique may have further potential in monitoring therapy.     

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.     

Rheumatoid arthritis of the knee: value of gadopentetate dimeglumine-enhanced MR imaging

In an attempt to differentiate among joint effusion, synovitis, pannus, and subchondral sclerosis in patients with clinically proved chronic rheumatoid arthritis, we used gadopentetate dimeglumine-enhanced MR imaging to examine 23 patients with acute knee symptoms. All patients had had rheumatoid arthritis for more than 6 months and satisfied four or more of the criteria of the American Rheumatism Association for rheumatoid arthritis. MR imaging was performed on a 1.5-T machine by using unenhanced T1-weighted spin-echo imaging, unenhanced T2*-weighted gradient-echo imaging, and unenhanced and enhanced T1-weighted gradient-echo imaging. Signal intensities of the synovium and bone marrow were measured with the region-of-interest technique on unenhanced and enhanced T1-weighted gradient-echo scans. Conventional radiographs were available for each patient. Joint effusion, synovitis, intraarticular pannus, subchondral sclerosis, and subchondral pannus had the same signal intensities on unenhanced T1-weighted spin-echo, unenhanced T1-weighted gradient-echo, and unenhanced T2*-weighted gradient-echo MR images, and could not be differentiated from one another. On enhanced T1-weighted gradient-echo sequences, pannus and synovitis showed marked enhancement in 15 patients, whereas joint effusion and sclerosis did not. Synovitis was diagnosed if the synovial membrane showed high enhancement; pannus was diagnosed if enhancing masses were seen within the joint space or in the subchondral area. In eight of the 23 joints, there was no enhancement of the synovium or intraarticular or subchondral tissue. We conclude that gadopentetate dimeglumine-enhanced MR imaging allows differentiation between synovitis and joint effusion and between subchondral pannus and subchondral sclerosis. Enhancement of the synovium and pannus indicates acute inflammation of the joint.