Ultrasound and power Doppler evaluation of the hand and wrist in patients with psoriatic arthritis

Purpose: To evaluate the ability of high-resolution and power Doppler sonography in detecting joint and tendon abnormalities in patients with psoriatic arthritis (PsA) of the hands and wrists compared with clinical and radiological findings.

Material and Methods: Thirty-six patients with psoriatic arthritis of the hands and wrists and 10 healthy controls were examined with ultrasound (US). The degree of synovial proliferation, tenosynovitis, presence of joint effusion as well as the vascularity of synovial tissue was estimated. US findings were scored using a newly devised scoring system.

Results: Thirty-two patients had articular synovial proliferation and/or tenosynovitis/tendinitis or joint effusion in one or more joints according to US. Twenty-two patients had tendon changes; only five had joint effusion. The synovial, Doppler, and total articular-teno scores were all significantly correlated to the number of swollen joints. The scores, however, did not correlate to other clinical or laboratory measurements of disease activity.

Conclusion: US proved effective in demonstrating PsA involvement of the hands and wrists and was more sensitive than clinical examination in detecting pathology. Long-term follow-up studies are needed to evaluate whether this can change the traditional approach for assessing involvement of joints and tendons in PsA.     

The septic versus nonseptic inflamed joint: MRI characteristics

Objective. To differentiate the MR features of septic versus nonseptic inflamed joints. Design and patients. Thirty patients were referred for MRI with inflamed joints (19 were subsequently found to be septic and 11 nonseptic). At 1.5 T enhanced MRI five groups of signs related to joint space, synovium, cartilage, bone and peri-articular soft tissue respectively were assessed and compared between the septic and nonseptic groups. Results. The prevalence of MRI findings in septic versus nonseptic joints (respectively) was as follows: effusion (79% vs 82%), fluid outpouching (79% vs 73%), fluid heterogeneity (21% vs 27%), synovial thickening (68% vs 55%), synovial periedema (63% vs 55%), synovial enhancement (94% vs 88%), cartilage loss (53% vs 30%), bone erosions (79% vs 38%), bone erosions enhancement (77% vs 43%), bone marrow edema (74% vs 38%), bone marrow enhancement (67% vs 50%), soft tissue edema (63% vs 78%), soft tissue enhancement (67% vs 71%), periosteal edema (11% vs. 10%). The presence of bone erosions appeared to be an indicator for an infected joint (P=0.072); coexistence of bone marrow edema slightly improves the significance (0.068). A similar trend was obtained when combining bone erosions with either synovial thickening, synovial periedema, bone marrow enhancement or soft tissue edema (P=0.075). Conclusions. The combination of bone erosions with marrow edema is highly suggestive for a septic articulation; the additional coexistence of synovial thickening, synovial edema, soft tissue edema or bone marrow enhancement increases the above level of confidence. Similar to conventional radiography, the single sign that appeared to show a significant trend was the presence of bone erosions. However, no single sign or combination could either be considered pathognomonic or exclude the presence of a joint infection. Received: 18 February 1999 Revision requested: 6 April 1999 Revision received: 26 July 1999 Accepted: 26 July 1999     

Tuberculous arthritis of the appendicular skeleton: MR imaging appearances

Tuberculosis [TB] of the appendicular skeleton is an uncommon infection caused by the tuberculous bacilli and constitutes only 1-3% of all tuberculosis infections. MR imaging features of tuberculous arthritis include bone marrow oedema, cortical erosions, synovitis, joint effusion, tenosynovitis, soft tissue collections, and myositis. These imaging features are at times non-specific, but in the correct clinical context help in diagnosis of tuberculosis. We present the various pathological manifestations of TB arthritis involving the different joints of appendicular skeleton and discuss their MR imaging appearances.     

MR imaging features of foot involvement in patients with psoriasis

OBJECTIVE: To determine alterations of the soft tissues, tendons, cartilage, joint spaces, and bones of the foot using magnetic resonance (MR) imaging in patients with psoriasis. MATERIALS AND METHODS: Clinical and MR examination of the foot was performed in 26 consecutive patients (52ft) with psoriasis. As a control group, 10 healthy volunteers (20ft) were also studied. Joint effusion/synovitis, retrocalcaneal bursitis, retroachilles bursitis, Achilles tendonitis, soft-tissue edema, para-articular enthesophytes, bone marrow edema, sinus tarsi syndrome, enthesopathy at the Achilles attachment and at the plantar fascia attachment, plantar fasciitis, tenosynovitis, subchondral cysts, and bone erosions, joint space narrowing, subchondral signal changes, osteolysis, luxation, and sub-luxation were examined. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in none of the patients while frequency of involvement was 92% (24/26) by MR imaging. The most common MR imaging findings were Achilles tendonitis (acute and peritendinitis) (57%), retrocalcaneal bursitis (50%), joint effusion/synovitis (46%), soft-tissue edema (46%), and para-articular enthesophytes (38%). The most commonly involved anatomical region was the hindfoot (73%). CONCLUSION: Our data showed that the incidence of foot involvement was very high in asymptomatic patients with psoriasis on MR imaging. Further MR studies are needed to confirm these data. We conclude that MR imaging may be of importance especially in early diagnosis and treatment of inflammatory changes in the foot.     

MR imaging features of foot involvement in ankylosing spondylitis

OBJECTIVE: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. MATERIALS AND METHOD: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22%). CONCLUSION: In our experience, MR imaging may detect inflammatory and/or erosive bone, soft tissue, cartilage, tendon, and joint abnormalities in AS patients, even if AS patients did not have clinical signs and symptoms of foot involvement. If these data prove to be confirmed in further MR studies, MR imaging may be of importance especially in early diagnosis of inflammatory changes in the foot.     

MR imaging findings in hands in early rheumatoid arthritis: comparison with those in systemic lupus erythematosus and primary Sjögren syndrome

PURPOSE: To evaluate prospectively the use of magnetic resonance (MR) imaging for differentiating true rheumatoid arthritis (RA) from systemic lupus erythematosus (SLE) or primary Sj?gren syndrome in patients who have inflammatory polyarthralgia of the hands but no radiographic evidence of RA. MATERIALS AND METHODS: This study had institutional review board approval, and patient informed consent was obtained. Twenty-eight patients (16 female and 12 male patients; mean age, 42 years) with early RA and 19 patients (18 female and one male patient; mean age, 46 years) with SLE (n = 14) or primary Sj?gren syndrome (n = 5) underwent MR imaging of both hands. All patients had inflammatory polyarthralgia of the hands and no evidence of erosive changes on radiographs. Coronal T2-weighted short inversion time inversion-recovery, transverse T1-weighted spin-echo, transverse fat-suppressed gadolinium-enhanced T1-weighted spin-echo, and transverse gadolinium-enhanced three-dimensional gradient-echo MR images were obtained. The following MR imaging variables were assessed in the wrist and nonthumb metacarpophalangeal joints: synovitis, bone lesions (erosion, defect, and edema), and tenosynovitis. Synovitis and bone lesions were scored with the OMERACT RA-MRI scoring system. Findings in patients with RA and those without RA were compared by means of Mann-Whitney, chi2, and Fisher exact tests. RESULTS: The only significant difference between the two groups in terms of individual scores for synovitis, bone lesions, and tenosynovitis was the more frequent presence of tenosynovitis of the right fourth extensor tendon in patients without RA (P = .04). There were no significant differences between patients with RA and those without RA in terms of global scores for synovitis, bone lesions, and tenosynovitis. However, bone marrow edema in the metacarpophalangeal joints was seen more frequently in patients with RA (P < .001). CONCLUSION: It may be impossible to distinguish between patients with early RA and those without RA (ie, those with SLE or primary Sj?gren syndrome) by means of MR imaging.     

Magnetresonanztomographie der Hand bei rheumatoider Arthritis

Magnetic resonance imaging (MRI) is a sensitive diagnostic modality for the detection of inflammatory changes in peripheral joints. Nevertheless, the widespread clinical use of MRI in assessing patients with early rheumatoid arthritis is still hampered by the technical complexity and higher cost of MRI compared with conventional radiography. This overview summarizes the results of recent research and gives practical tips on how to perform MRI of the hands. The authors present an MR protocol for hand imaging, discuss the pros and cons of low-field MR scanners, and outline pitfalls and artifacts. The MRI changes associated with rheumatoid arthritis such as synovitis, tenosynovitis, erosions, and bone marrow edema are described including their prognostic significance. The proven facts on the validation and grading of MR changes in rheumatoid arthritis are summarized. Finally, the role of MRI in the differential diagnosis of arthritis is critically discussed.     

Magnetic resonance imaging of hindfoot involvement in patients with spondyloarthritides: comparison of low-field and high-field strength units

OBJECTIVE: To compare MRI evaluation of a painful hindfoot of patients with spondyloarthritides (SpA) on low-field (0.2 T) versus high-field (1.5 T) MRI. MATERIALS AND METHODS: Patients with SpA and hindfoot pain were randomly referred to either high-field or low-field MRI. Twenty-seven patients were evaluated (male/female: 17:10; mean age: 39+/-1.4 years). Fifteen patients were examined by low-field and 12 by high-field MRI. Two patients (evaluated by high-field MRI) were excluded. Images were separately read by two radiologists who later reached a consensus. In each patient the prevalence of erosions, fluid, synovitis or bone marrow edema of the hindfoot joints, tendinosis or tenosynovitis of tendons, enthesitis of the plantar fascia and Achilles tendon and retrocalcaneal bursitis were recorded. Clinical and demographic parameters were comparable between both groups. RESULTS: MRI evaluation of joints and tendons of the hindfoot revealed no significant differences in patients with SpA groups for all parameters. Analyzing all joints or tendons together, there was no statistically significant difference between the two groups. CONCLUSION: Low-field and high-field MRI provide comparable information for evaluation of inflammatory hindfoot involvement. Thus, low-field MRI can be considered as a reliable diagnostic tool for the detection of hindfoot abnormalities in SpA patients.     

Magnetic resonance imaging in early detection of rheumatoid arthritis

Magnetic resonance imaging (MRI) is the modality of choice in early diagnosis and management of rheumatoid arthritis (RA). The pathologic processes in RA involve synovitis, joint effusion, proliferation of fibrovascular connective tissue, and the formation of pannus. Other imaging techniques available for imaging of RA include ultrasound, scintigraphy, computed tomography, and plain radiography (PR). MRI provides high sensitivity in detecting inflammatory changes in the joints. Several studies report high intra- and interobserver reliability and low variation for MRI. MRI allows detection and, in some cases, quantification of synovial changes. Dynamic MRI is a new technique that utilizes rate of synovial enhancement in evaluation of inflammatory changes. MRI allows visualization of erosions in three orthogonal planes. MRI has been shown in many studies to have much greater sensitivity than PR in detecting erosions. Use of a contrast agent further increases the sensitivity in detecting erosions and differentiates and outlines synovial proliferation from fluid collection. Other manifestations of RA such as intraosseous cysts, tenosynovitis, bone marrow edema, and carpal tunnel syndrome can also be visualized on magnetic resonance images. Advances in MRI include contrast-enhancement, dynamic, and quantitative techniques. MRI assists in the early detection of RA, which allows earlier initiation of treatment with disease-modifying therapies.     

Rheumatoid arthritis of the hand and wrist: comparison of three imaging techniques

OBJECTIVE: The purpose of this study was to compare the relative results from conventional high-field-strength 1.5-T MRI, 0.2-T low-field-strength dedicated extremity MRI, and radiography to detect and grade bone erosions, joint-space narrowing, and synovitis in the hands and wrists of patients with rheumatoid arthritis. SUBJECTS AND METHODS: Eighteen patients with rheumatoid arthritis underwent conventional high-field-strength MRI, low-field-strength dedicated extremity MRI, and conventional radiography of both hands and wrists. Two independent reviewers searched for the presence and extent of bone erosions, joint-space narrowing, and synovitis. Bone erosions (E scores) and joint-space narrowing (J scores) were evaluated at 14 and 13 sites, respectively, on conventional high-field-strength MRI, low-field-strength dedicated extremity MRI, and radiography, using the Sharp-Genant scoring system. Synovitis (S scores) were evaluated at 13 sites on conventional high-field-strength MRI and low-field-strength dedicated extremity MRI. RESULTS: For the detection of bone erosions, we found no significant difference (p = 0.71) between conventional high-field-strength MRI (mean +/- SD E score, 27.5 +/- 9.8) and low-field-strength dedicated extremity MRI (28.8 +/- 10.0), but a significant difference (p < 0.001) appeared between MRI and radiography (13.1 +/- 8.3). J scores derived from MRI (conventional high-field-strength MRI, 15.2 +/- 8.3; low-field-strength dedicated extremity MRI, 14.5 +/- 10.4) were higher than those derived from radiography (12.7 +/- 9.6), although the difference was not significant (p = 0.70). Conventional high-field-strength MRI (S score, 35.1 +/- 8.6) and low-field-strength dedicated extremity MRI (30.8 +/- 10.2) were equivalent (p = 0.14) for the evaluation of synovitis. The interobserver agreement for MRI scores was good to excellent (intraclass correlation coefficients, 0.83-0.94). CONCLUSION: Conventional high-field-strength MRI and low-field-strength dedicated extremity MRI showed similar results in terms of cross-sectional grading of bone erosions, joint-space narrowing, and synovitis in the hands and wrists of patients with rheumatoid arthritis.     

Magnetic resonance imaging of the wrist in early rheumatoid arthritis: a pictorial essay

This pictorial essay describes the changes seen in the wrist in early rheumatoid arthritis (RA) on MRI. Magnetic resonance imaging can demonstrate bone erosions, bone marrow signal changes, synovitis and tenosynovitis in early rheumatoid arthritis. Magnetic resonance imaging of the wrist can identify erosions in RA earlier than plain radiographs and can detect more erosions. Common sites include the capitate, lunate and scaphoid. Bone marrow signal changes occur frequently and are most common in the capitate, lunate and triquetrum. Synovial thickening and enhancement are clearly demonstrated with MRI and are most commonly seen in the radiocarpal joint (RCJ). Tenosynovitis can be seen in the wrist in more than half of patients presenting with RA. This most commonly involves the extensor carpi ulnaris tendon and is seen as sheath fluid, thickening and enhancement.     

The other arthritides. Roentgenologic features of osteoarthritis, erosive osteoarthritis, ankylosing spondylitis, psoriatic arthritis, Reiter's disease, multicentric reticulohistiocytosis, and progressive systemic sclerosis

Osteoarthritis may be divided into primary generalized and secondary forms. Primary generalized osteoarthritis is characterized by narrowing of cartilage, marginal osteophytes, and absence of erosions. The most common sites of involvement are the distal interphalangeal joints of the fingers and the first carpometacarpal joint. Secondary osteoarthritis also results in narrowing of cartilage in the absence of erosions, but in regions of mechanical stress. Erosive osteoarthritis affects predominantly the proximal and distal interphalangeal joints, and evolves into bony fusion in 12 to 15 per cent of cases, about the same percentage of interphalangeal bony fusion that occurs in psoriatic arthritis. Ankylosing spondylitis predominates in the axial skeleton where it eventually leads to fusion of the vertebrae and sacroiliac joints. Psoriatic arthritis combines many features of rheumatoid arthritis, in which synovial inflammation predominates, and ankylosing spondylitis, in which ligamentous inflammation predominates. The hands and feet are involved to an equal extent, and in 20 per cent of patients the disorder also involves the sacroiliac joints and spine. Reiter's disease, like psoriatic arthritis, differs from ankylosing spondylitis in its inconstant involvement of the spine and greater involvement of peripheral joints. Reiter's disease differs from psoriatic arthritis in its predominant involvement of the lower limbs, particularly the feet, with relative sparing of the hands and wrists. Multicentric reticulohistiocytosis is a rare disorder in which polyarthritis usually precedes the onset of nodular cutaneous eruptions, a fact that emphasizes the importance of early roentgenologic recognition. The interphalangeal joints are the predominant sites of involvement in the hands, but eventually all of the synovium lined joints become affected, with arthritis mutilans the end result in one third of cases. The erosions are strikingly symmetrical and well circumscribed, and accompanying osteoporosis is disproportionately mild. Progressive systemic sclerosis is characterized by atrophy and dystrophic calcifications in the soft tissues, ultimately leading to joint deformities and resorption of the terminal tufts of the phalanges. Resorption of bone occurs at other sites as well, and marginal erosions may develop in the metacarpophalangeal and interphalangeal joints of the hands.     

Magnetic resonance imaging of the wrist in rheumatoid arthritis: demonstration of progression between 1 and 6 years

Objective To describe the changes seen in the wrist in rheumatoid arthritis (RA) on magnetic resonance (MR) imaging obtained at 1 year and 6 years.Design A cohort of patients with RA has been studied prospectively from symptom onset.Patients MR scans of the dominant wrist in 31 patients obtained at 1 year and 6 years were compared for bone erosions, marrow signal change (oedema), synovial thickness and tenosynovitis.Results Twenty-two patients had an increase in erosion score in the interval and three patients showed a decrease in erosion score suggesting erosion healing. Fourteen patients had an increase in oedema score in the interval and eight patients had a decrease in oedema score. Synovial thickness increased in 13 patients and decreased in eight. Tenosynovitis increased in 15 patients and decreased in five. Bone erosions developed immediately adjacent to the tenosynovitis in two patients.Conclusions MR imaging is useful in following the progress of bone erosions, marrow oedema, synovitis and tenosynovitis in RA.     

Bilateral MR Imaging of the Hand and Wrist in Early and Very Early Inflammatory Arthritis: Tenosynovitis Is Associated with Progression to Rheumatoid Arthritis

Purpose: To identify bilateral hand and wrist findings of synovial inflammation associated with progression to rheumatoid arthritis (RA) in very-early-RA cohort (VERA) (duration, <3 months) and early-RA cohort (ERA) (duration, <12 but >3 months), to test tenosynovitis as a magnetic resonance (MR) imaging additional parameter for improving diagnostic accuracy of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) RA classification criteria, and to evaluate the symmetry of joint and tendon involvement. Materials and Methods: With institutional review board approval and informed consent, 32 women and three men (mean age, 45 years) with untreated recent-onset inflammatory arthritis participated in this prospective study and underwent MR imaging of both wrists and hands. After 12-month follow-up, 25 patients fulfilled the criteria for RA (10 VERA and 15 ERA patients). Ten patients did not fulfill the criteria for RA (non-RA [control] group). Possible associations between synovitis for each joint and tendon and RA diagnosis at 12 months were tested (univariate logistic regression analysis). Diagnostic performance of the ACR/EULAR RA classification criteria was evaluated (receiver operating characteristic curve analysis). Asymmetry prevalence (all joints and tendons in the analysis) was calculated. Results: Tenosynovitis of the extensor carpi ulnaris (odds ratio, 3.21) and flexor tendons of the second finger (odds ratio, 14.61) in VERA group and synovitis of the radioulnar joint (odds ratio, 8.79) and tenosynovitis of flexor tendons of the second finger (odds ratio, 9.60) in ERA group were significantly associated with progression to RA (P < .05). Consideration of tenosynovitis improved areas under the receiver operating characteristic curve of ACR/EULAR criteria performance for the diagnosis of RA from 0.942 (P < .0001; sensitivity, 52%; specificity, 100%) to 0.972 (P < .0001; sensitivity, 76%; specificity, 100%), with cutoff score of 6 or greater. Asymmetry was found in 80.0% (62 of 77) (VERA patients) and 69.3% (106 of 153) (ERA patients) of joint or tendon pairs (P < .05). Conclusion: Tenosynovitis is an imaging finding in early RA, and its inclusion as a scoring criterion might contribute for a better diagnostic performance of the 2010 ACR/EULAR classification; early RA is an asymmetric disease. ? RSNA, 2012.     

MR imaging of the type II lunate bone: frequency, extent, and associated findings.

OBJECTIVE: Type II lunate bones have an "extra" facet that articulates with the hamate bone, which frequently leads to arthritis. Because the only prior studies, to our knowledge, on this common and clinically significant variant involved dissection of cadavers, we performed an MR imaging study of the type II lunate. MATERIALS AND METHODS: We retrospectively reviewed MR images obtained at 1.5 T of 186 wrists for frequency of type II lunates, size of the extra facet, amount of hamatolunate apposition, and presence of hamate subchondral edema. Of the 186 wrists, 28 also had correlation with findings on wrist arthroscopy. RESULTS: One hundred seven wrists (57.5%) had type II lunates with an average extra facet size of 4.6 mm (range, 1.2-12.0 mm). Apposition (articulation) of the extra lunate facet with the hamate averaged 77.4% (range, 0-100%). Hamate edema was seen in only nine wrists (4.8%), all of which had type II lunates. Arthroscopic evidence of focal hamate chondromalacia and MR imaging evidence of marrow edema were seen in six of these nine wrists; marrow edema was seen only in wrists with frank cartilage changes on arthroscopy. CONCLUSION: An extra facet (type II lunate) was seen in approximately half of 186 wrists. On MR imaging, type II lunates usually have an innocuous appearance. A large percentage of patients with type II lunates also have chondromalacia, which often is occult on MR imaging. When visible, such chondromalacia is the cause of marrow edema similar to that seen in patients with carpal fractures.     

Three-phase bone studies in hemiplegia with reflex sympathetic dystrophy and the effect of disuse

Eighty-five patients with cerebral vascular accidents were assessed with three-phase bone scintigraphy of the hands and with whole-body delayed bone imaging. Nine patients (10%) had normal three-phase bone images. Fifty-five patients (65%) showed decreased blood flow and blood-pool images of the hands and wrists with normal delayed bone scintigrams, indicating the effect of paralysis or disuse. Twenty-one patients (25%) had diffuse increased uptake with periarticular accentuation, felt to be bone-scintigraphic evidence of reflex sympathetic dystrophy of the hands and wrists; in two patients this occurred before its clinical appearance. Thirteen of the 21 reflex sympathetic dystrophy syndromes (RDS)-involved limbs (62%) had increased blood flow, whereas 8 (38%) had decreased flow. Gross limb blood flow appears to be related to the degree of muscle activity, but flow may be altered by the presence of sympathetic changes. A possible dissociation between whole-limb flow and bone blood flow in paralyzed limbs involved with RDS is discussed. The elbow was involved in only one case, and a true "shoulder-hand" distribution was seen in only 11 of 21 cases (52%). Five patients (6%) had leg involvement on whole-body imaging. Traumatic synovitis of the wrist, and trauma to subluxed shoulders, could be recognized on the delayed study.     

Magnetic resonance imaging and radiographic findings of seal finger

Purpose: To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger.

Material and Methods: The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously.

Results: Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen.

Conclusion: In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography.     

进行性假性类风湿发育不良症的临床分析

目的提高对进行性假性类风湿发育不良症的认识。方法对2例进行性假性类风湿发育不良症进行分析,并通过文献复习对本病的临床表现及影像学改变进行分析总结。结果2例患者均为幼年起病,以双手近端指间关节肿胀为突出表现,逐渐出现外周大小关节进行性受累,并伴有脊柱的异常。结合文献报道的51例分析发现,本病男女患病率相仿,发病年龄多为1～10岁,其中77％为3～5岁。外周大小关节均可受累,依次累及双手小关节、髋、膝、踝、腕、肩等,早发骨关节炎改变是致残的主要原因,38％的患者脊柱受累可出现短躯干畸形。影像学特点均表现为普遍性扁平椎并椎体终板不规则、骨骺增大、继发性退行性变和关节周围骨质疏松。本病临床症状与类风湿关节炎相似,但不同的是无滑膜炎和其他炎性改变、X线无破坏性改变。目前无特异的治疗方法。结论进行性假性类风湿发育不良症是一种少见的常染色体隐性遗传性疾病,临床特点及典型的影像学表现有助于诊断。     

MRI of large intraosseous lesions in patients with inflammatory arthritis

OBJECTIVE: The purpose of our study was to evaluate on MRI the occurrence of large cystlike intraosseous lesions in patients with inflammatory arthritis. SUBJECTS AND METHODS: We prospectively reviewed contrast-enhanced MR images of 128 hands and wrists in 44 patients with clinical presentation of inflammatory arthritis. Large lesions (> or = 1 cm) found on MR images were further evaluated for the presence of a cortical break and intraarticular extension. These data were correlated with clinical and laboratory findings and the duration of arthritis. RESULTS: We found 26 patients with rheumatoid arthritis, seven with psoriatic arthritis, two with systemic lupus erythematosus, one with HIV-associated arthritis, one with mixed connective tissue disorder, one with paraneoplastic-associated arthritis, one with inflammatory bowel disease arthritis, and five patients with early unclassified inflammatory arthritis. Twelve patients had 16 large intraosseous lesions, none of which were detected on available radiographs (availability of radiographs for large erosions was 75%). A cortical break with intraarticular extension of the large lesions was seen in 12 cases. Four lesions were not intraarticular. CONCLUSION: Even large intraosseous lesions may be occult on radiography. MRI is a superior technique for detecting these lesions in the small joints of the hand and wrist in inflammatory arthritis. Although large intraosseous erosions often communicate with joints, we observed four large purely intraosseous enhancing lesions without intraarticular connection. Patients with large erosions have a longer duration of inflammatory arthritis.     

Ultrasound detection of bone erosions in rheumatoid arthritis: a comparison to routine radiographs of the hands and feet

Purpose To determine if ultrasound (US) of selected joints in the hands and feet can detect more erosions than radiography and establish the presence of erosive disease in patients with rheumatoid arthritis (RA).Methods Eighty joints in ten patients with RA and 40 joints in five healthy control subjects, who were age, gender and ethnicity-matched to the patients with arthritis, were prospectively studied with radiographs and sonography. Conventional radiographs of the hands and feet were obtained. US examinations of the 2nd and 5th metacarpal-phalangeal (MCP) joints of the hands, and the 1st and 5th metatarsal-phalangeal (MTP) joints of the feet were performed. Radiographs and US exams were independently graded for the presence of erosions.Results None of the control subjects had erosions. US detected erosions in 17/80, and radiographs detected erosions in 6/80 joints assessed with both modalities. US detected all erosions seen by radiographs in these selected joints. Erosive disease was present in the radiographs of seven of ten RA patients. US established erosive disease in eight of ten RA patients. US determined erosive disease in two of the three patients without radiographic erosions.Conclusions US of the MTP and MCP joints in RA can detect erosions not seen with radiography and may be complementary to radiography in establishing the presence of erosive disease in early RA.