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.     

Rheumatoid knee: role of gadopentetate-enhanced MR imaging

Physical examination is often insufficient in distinguishing between joint effusion and inflamed synovium in the knee joints of patients with rheumatoid arthritis. The authors prospectively evaluated the role of intravenously administered gadopentetate dimeglumine in distinguishing between these two conditions. Fourteen patients with classic rheumatoid arthritis were examined first by a rheumatologist and then by means of magnetic resonance (MR) imaging with T1- and T2-weighted sequences. T1-weighted images were also obtained following the intravenous administration of gadopentetate dimeglumine. T1-weighted images obtained prior to contrast material administration demonstrated an identical low-intensity signal from both effusion and inflamed synovium, and T2-weighted images demonstrated increased signal intensity in both cases. Intravenous administration of gadopentetate dimeglumine allowed distinction between effusion and abnormal synovium, with the effusion remaining of low signal intensity and the synovium demonstrating enhancement and increased signal intensity. The authors conclude that the use of gadopentetate allows distinction between synovial thickening and joint effusion in the knee, which may affect treatment decisions.     

Rheumatoid arthritis: Skeletal manifestations observed on portable chest roentgenograms

This report describes the thoracic skeletal radiographic findings of rheumatoid arthritis, observed on portable chest examinations of 21 patients. Their pathophysiology is reviewed and additional examples of a recently described finding are illustrated: erosion of the medial surface of the proximal humerus with subsequent pathologic fracture, associated with superior and medial migration of the humeral head [11]. It has been proposed that erosion of the medial aspect of the proximal humerus is due to impingement wear, and that pathologic fracture results from the fulcrum effect of the inferior lip of the glenoid on the humerus.Rheumatoid arthritis is often diagnosed by the clinician rather than the radiologist. However, in acutely ill patients receiving portable chest radiographs, complete history and laboratory findings are often unavailable. Attention to the thoracic skeleton may clarify pleural and/or parenchymal lung disease in these patients.     

脊索瘤的MRI表现

目的：探讨脊索瘤的MRI表现及其诊断价值。方法：回顾性分析17例经临床病理证实的脊索瘤的MRI表现。结果：颅底脊索瘤8例，骶尾部脊索瘤9例，邻近颅底及椎体骨质均有溶骨性破坏，伴硬膜外及骶前较大软组织肿块。17例中16例信号不均匀，T1WI呈低、等信号，T2WI呈明显高信号，MRI增强扫描后，肿瘤均有轻度或中度不均匀性强化。结论：T2WI显著高信号是脊索瘤的特征性MRI表现，有重要鉴别诊断意义，MRI反映肿瘤的部位、侵犯范围以及显示骨质破坏作用均优于CT。     

MR imaging manifestations of skin tumors

In this study, we evaluated MR imaging findings of skin tumors and categorized them into four types: (1) discrete mass lesions of the dermis and epidermis, (2) mass lesions of the subcutis with or without abutment to the skin, (3) diffuse or localized skin thickening without a true mass, and (4) a skin mass with bone destruction. The categorization of MR images may be useful in the differential diagnosis of skin tumors.     

皮肤肿瘤的MRI表现

本研究旨在对皮肤肿瘤的影像学表现进行评价,并根据肿瘤的影像学特点将其分为4种类型：①表皮与真皮散在的肿块。②与皮肤相连或不相连的皮下组织肿块。③弥漫或局限性的皮肤增厚,没有形成真正的肿块。④皮肤肿块伴有骨骼破坏。MRI影像的分类有助于皮肤肿瘤的鉴别诊断。     

Juvenile rheumatoid arthritis: assessment with MR imaging

Thirty-three joints of the appendicular skeleton in 15 children with juvenile rheumatoid arthritis were examined with magnetic resonance (MR) imaging to determine if it could demonstrate synovial hypertrophy and status of the articular cartilage. Presumed synovial hypertrophy was seen in 13 joints as masses of varying sizes of low to intermediate signal intensity on T1- and T2-weighted images; sometimes foci of increased signal intensity, most likely due to fluid or inflammation, were seen on T2-weighted images. Probable abnormal articular cartilage was detected in ten joints, and MR imaging also demonstrated epiphyseal overgrowth, bone erosions, joint effusions, and joint space narrowing. Because MR imaging appears to provide an objective method of evaluating both synovial hypertrophy and status of articular cartilage, it may prove to be useful in monitoring progression of juvenile rheumatoid arthritis and response to therapy.     

Tuberculous versus pyogenic arthritis: MR imaging evaluation

PURPOSE: To assess magnetic resonance (MR) imaging features in differentiating tuberculous arthritis from pyogenic arthritis. MATERIALS AND METHODS: Findings in 29 patients with tuberculous arthritis were compared with those of 13 patients with pyogenic arthritis. Bone erosion, marrow signal intensity, synovial lesion signal intensity, boundaries (smooth or irregular) for extraarticular extension of infection, and abscess rim enhancement (thin and smooth or thick and irregular) were analyzed. RESULTS: Bone erosion was more common in patients with tuberculous arthritis (24 [83%] of 29) than in those with pyogenic arthritis (six [46%] of 13) (P =.026), while subchondral marrow signal intensity abnormality was seen more frequently in patients with pyogenic arthritis (12 [92%] of 13) than in those with tuberculous arthritis (17 [59%] of 29) (P =.036). On T2-weighted images, there was no significant difference between the synovial lesion signal intensities of tuberculous arthritis and pyogenic arthritis. Lesions in 16 (70%) of 23 patients with tuberculous arthritis and two (17%) of 12 patients with pyogenic arthritis had smooth extraarticular boundaries, while those in seven (30%) of 23 patients with tuberculous arthritis and 10 (83%) of 12 patients with pyogenic arthritis had irregular boundaries (P =.005). Tuberculous abscesses (16 [100%] of 16) had thin and smooth rim enhancement, while most pyogenic abscesses (five [71%] of seven) had thick and irregular rims (P =.001). CONCLUSION: MR imaging of bone abnormalities, extraarticular lesions, and associated abscesses provides useful information in the differentiation of tuberculous arthritis and pyogenic arthritis.     

化脓性关节炎:USPIO增强巨噬细胞MR成像监测

目的前瞻性评价超微超顺磁氧化铁(USPIO)颗粒增强MR巨噬细胞成像对实验性感染性关节炎抗生素治疗的无创性在体监测。材料与方法该实验方案获动物保护委     

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.     

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 of tuberculous arthritis: Clinical and experimental studies

Signal-intensity characteristics of magnetic resonance (MR) images were assessed in five patients and in 10 rabbits with tuberculous arthritis. MR imaging findings were compared with histologic findings in the animal study. In both of clinical and experimental cases, tuberculous lesions showed both intermediate and high signal intensity on T2-weighted images, while they showed heterogeneously intermediate signal intensity on T1-weighted images. As T2-weighted images were compared with pathologic specimens, intermediate signal intensity corresponded to caseous necrosis, whereas high signal intensity related to granulomas or effusion. Postcontrast T1-weighted images showed enhancement at the peripheries rather than the centers of tuberculous lesions. These results indicate that tuberculous arthritis should be included in the differential diagnosis when intra-articular lesions with low or intermediate signal intensity are found on T2-weighted images.