Assessment of inflamed synovial membrane in the knee joint by dynamic magnetic resonance imaging

Dynamic magnetic resonance imaging (dynamic MRI) was used to examine the synovial membrane in the knee joints of 15 patients with rheumatoid arthritis (RA) in order to investigate the relationship between pathological and MRI findings. Signal intensities in the regions of interest (ROI), identified as the synovial membrane of the suprapatellar pouch, were measured on MR images. Signal intensities at various times after the injection of contrast medium Gd–diethylenetriaminopentoacetic acid (Gd–DTPA) were normalized relative to the signal intensity at 80s, and designated as the normalized signal intensity (NSI). Pathological findings were quantified, and the types of inflamed synovial membrane were classified as either acute or chronic. A significant difference in NSI was observed between acute and chronic types (P 0.05). Dynamic MRI was capable of classifying acute and chronic RA by measuring NSI 20s after contrast medium injection. Dynamic MRI was therefore shown to be useful for assessing regional synovial inflammation.     

Utility of in-office extremity magnetic resonance imaging in rheumatology

Introductionof magnetic resonance imaging (MRI) in diagnosis and management of inflammatory arthritides has ushered robust changes in patient outcomes. The efficacy of MRI in detecting inflammation and damage together has raised the expectation of imaging in rheumatology. In-office extremity MRI (eMRI) systems, designed to image the peripheral joints of upper and lower extremities, are small enough to be used in clinics, have smaller fringe magnetic field, are less expensive, and reduce patient discomfort, with comparable diagnostic power. Though less sensitive in detecting osteitis, these systems have been shown to be effective in early diagnosis and monitoring of treatment outcome in patients with rheumatoid arthritis. This review focuses on eMRI systems, outlining their principle, utility in different inflammatory arthritides, and shortcomings.     

Efficacy of radiosynovectomy of the knee in rheumatoid arthritis: Evaluation with magnetic resonance imaging

The intra-articular injection of a radiopharmaceutical agent (radiosynovectomy) produces a reduction of the synovial inflammatory process. The inflammed synovial membrane can be identified with magnetic resonance imaging after the intravenous administration of gadolinium (MRI-Gd). A 6-month prospective study was carried out in 10 patients with rheumatoid arthritis after radiosynovectomy of the knee. The efficacy was evaluated with clinical parameters and MRI-Gd. A progressive amelioration of synovial effusion, pain, articular range of mobility, total leucocytes count in synovial fluid and synovial membrane thickness through MRI-Gd was observed. The global efficacy was considered to be good in six patients, fair in three and bad in one. The study shows for the first time that MRI-Gd allows the evaluation of the response of the synovial membrane to radiosynovectomy.     

Dual-input two-compartment pharmacokinetic model of dynamic contrast-enhanced magnetic resonance imaging in hepatocellular carcinoma

AIM: To investigate the feasibility of a dual-input two-compartment tracer kinetic model for evaluating tumorous microvascular properties in advanced hepatocellular carcinoma(HCC). METHODS: From January 2014 to April 2015, we prospectively measured and analyzed pharmacokinetic parameters [transfer constant(K_(trans)), plasma flow(F_p), permeability surface area product(PS), efflux rate constant(k_(ep)), extravascular extracellular space volume ratio(V_e), blood plasma volume ratio(V_p), and hepatic perfusion index(HPI)] using dual-input two-compartment tracer kinetic models [a dual-input extended Tofts model and a dual-input 2-compartment exchange model(2CXM)] in 28 consecutive HCC patients. A well-known consensus that HCC is a hypervascular tumor supplied by the hepatic artery and the portal vein was used as a reference standard. A paired Student's t-test and a nonparametric paired Wilcoxon rank sum test were used to compare the equivalent pharmacokinetic parameters derived from the two models, and Pearson correlation analysis was also applied to observe the correlations among all equivalent parameters. The tumor size and pharmacokinetic parameters were tested by Pearson correlation analysis, while correlations among stage, tumor size and all pharmacokinetic parameters were assessed by Spearman correlation analysis. RESULTS: The F_p value was greater than the PS value(F_P = 1.07 m L/m L per minute, PS = 0.19 m L/m L per minute) in the dual-input 2CXM; HPI was 0.66 and 0.63 in the dual-input extended Tofts model and the dualinput 2CXM, respectively. There were no significant differences in the K_(ep), V_p, or HPI between the dual-input extended Tofts model and the dual-input 2CXM(P = 0.524, 0.569, and 0.622, respectively). All equivalent pharmacokinetic parameters, except for V_e, were correlated in the two dual-input two-compartment pharmacokinetic models; both Fp and PS in the dualinput 2CXM were correlated with K_(trans) derived from the dual-input extended Tofts model(P = 0.002, r = 0.566; P = 0.002, r = 0.570); K_(ep), V_p, and HPI between the two kinetic models were positively correlated(P = 0.001, r = 0.594; P = 0.0001, r = 0.686; P = 0.04, r = 0.391, respectively). In the dual input extended Tofts model, V_e was significantly less than that in the dual input 2CXM(P = 0.004), and no significant correlation was seen between the two tracer kinetic models(P = 0.156, r = 0.276). Neither tumor size nor tumor stage was significantly correlated with any of the pharmacokinetic parameters obtained from the two models(P 0.05).CONCLUSION: A dual-input two-compartment pharmacokinetic model(a dual-input extended Tofts model and a dual-input 2CXM) can be used in assessing the microvascular physiopathological properties before the treatment of advanced HCC. The dual-input extended Tofts model may be more stable in measuring the V_e; however, the dual-input 2CXM may be more detailed and accurate in measuring microvascular permeability.     

Effect of dopamine agonists on prolactinomas and normal pituitary assessed by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI)

Context Dopamine agonists (DA) may act on prolactinoma size and secretion through additional effects on adenoma vascularity that can be visualized using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). Objective We hypothesized that DAs may exert their effect through a change in tumour functional vascularity leading to a reduction of prolactin (PRL) levels and tumour size. Subjects and methods To investigate this, 23 subjects were studied comprising five with macroprolactinomas, 11 with microprolactinomas, seven with non-lesion hyperprolactinemia and 15 normal volunteers (including five females on oral contraceptive pills). Patients with macroprolactinomas were treated with cabergoline 4 mg weekly and microprolactinomas were treated with quinagolide 75 μg daily for the duration of study. DCE-MRI was performed immediately pre-treatment and at 3–4 days, 1 and 3–4 months after treatment. Normal volunteers took three 75 μg quinagolide doses and were scanned pre-treatment and at 3 days. Data were analysed using the Brix model, producing a measure of vascular permeability and leakage space. Results PRL levels were significantly reduced in all patients and volunteers. Vascular parameters decreased significantly for four of five macroprolactinomas and all microprolactinomas which were maintained during the treatment period (p < 0.01). No changes were seen in normal volunteers or non-lesion hyperprolactinemia. One of five macroprolactinomas showed no change in either permeability or tumour size. Conclusion Functional prolactinoma vascularity differs from non-lesion hyperprolactinemic pituitary and normal pituitary, and is responsive to DA therapy. The reduction in vascular parameters precedes shrinkage in macroprolactinomas, and if not seen within days of treatment may indicate DA resistance requiring early surgery.     

Myocardial material property determination in the in vivo heart using magnetic resonance imaging

Objectives: To determine nonlinear material properties of passive, diastolic myocardium using magnetic resonance imaging (MRI) tissue-tagging, finite element analysis (FEA) and nonlinear optimization.Background: Alterations in the diastolic material properties of myocardium may pre-date the onset of or exist exclusive of systolic ventricular dysfunction in disease states such as hypertrophy and heart failure. Accordingly, significant effort has been expended recently to characterize the material properties of myocardium in diastole. The present study defines a new technique for determining material properties of passive myocardium using finite element (FE) models of the heart, MRI tissue-tagging and nonlinear optimization. This material parameter estimation algorithm is employed to estimate nonlinear material parameters in thein vivo canine heart and provides the necessary framework to study the full complexities of myocardial material behavior in health and disease.Methods and results: Material parameters for a proposed exponential strain energy function were determined by minimizing the least squares difference between FE model-predicted and MRI-measured diastolic strains. Six mongrel dogs underwent MRI imaging with radiofrequency (RF) tissue-tagging. Two-dimensional diastolic strains were measured from the deformations of the MRI tag lines. Finite element models were constructed from early diastolic images and were loaded with the mean early to late left ventricular and right ventricular diastolic change in pressure measured at the time of imaging. A nonlinear optimization algorithm was employed to solve the least squares objective function for the material parameters. Average material parameters for the six dogs wereE=28,722 ± 15,984 dynes/cm² andc=0.00182 ± 0.00232 cm²/dyne.Conclusion: This parameter estimation algorithm provides the necessary framework for estimating the nonlinear, anisotropic and non-homogeneous material properties of passive myocardium in health and disease in thein vivo beating heart.     

Assessment of structural damage progression in established rheumatoid arthritis by conventional radiography,computed tomography,and magnetic resonance imaging

Structural damage progression in patients with established rheumatoid arthritis (RA) has traditionally been assessed by conventional radiography (CR), which has proven its value in clinical practice and clinical trials over the past decades. The most prominent abnormalities visualized by CR in RA patients are erosions as a consequence of bone destruction and joint space narrowing (JSN) as a consequence of cartilage damage. Several validated scoring systems to quantify the structural joint damage and progression herein are available. Computed tomography and magnetic resonance imaging are newer, more sensitive methods for detection and monitoring of structural joint damage. A validated scoring system for magnetic resonance imaging of the hands and wrists exists, while no consensus has been reached on a scoring system for computed tomography. Structural damage identified by either CR or magnetic resonance imaging predicts a poorer disease course in patients with both early and established rheumatoid arthritis.     

Assessment of aortic regurgitation severity by magnetic resonance imaging of the thoracic aorta

A new method of assessing the severity of aortic regurgitationseverity by magnetic resonance imaging has been developed. Twogroups were studied: 20 controls (age=58 ± 19 years)without valvular aortic disease, and 24 patients (age=62 ±13 years) with chronic aortic insufficiency evaluated by magneticresonance and aortic root cineangiography within 1 week of eachother. A magnetic resonance sequence (TR=35 mslTE=12 mslflipangle=20°/magnet=1.5 T) was acquired in a plane containingthe thoracic aorta. A transverse saturation band 30 mm widewas positioned 30–40 mm above the aortic valve. Aorticinsufficiency was graded, the importance of end-diastolic retrogrademovement in the saturation band in the descending aorta wasnoted. Magnetic resonance was also compared to Doppler echocardiographyin 20 patients. In the controls, we found that retrograde blood flow was absent(18/20) or mild (2/20). In contrast, the presence of markedretrograde movement in a saturation band across the thoracicaorta was always associated with severe aortic regurgitation(angiographic grade III or IV). This rapid method (imaging time less than 20 min) can be appliedin most patients with aortic regurgitation and is likely tobe helpful when echocardiography is not possible or gives inconclusiveresults.     

Correlation between angiogenesis and islet graft function in diabetic mice: magnetic resonance imaging assessment

Background/purpose

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to evaluate neovascularization after intravenous injection of gadolinium, where contrast leaks out of new vessels and remains within the tissues. We examined the relationship between DCE-MRI and metabolic parameters such as blood glucose, serum insulin and glucose tolerance test (GTT) after intraportal islet transplantation.

Methods

Streptozotocin-induced diabetic BALB/c mice (n = 15) received syngeneic intraportal islet transplantation (500 islet equivalent). Blood glucose, serum insulin and GTT were evaluated till postoperative day (POD) 14. Liver DCE-MRI was performed at POD 3, 7 and 14. Correlations between DCE-MRI and metabolic parameters were examined using regression analysis.

Results

Eight mice achieved normoglycemia after intraportal transplantation. At POD 3 a significant but moderate correlation between DCE-MRI and blood glucose was found. No DCE-MRI or metabolic parameters correlated at POD 7. However, at POD 14 strong or moderate correlations between DCE-MRIs were found: negative correlations with blood glucose (R ² = 0.86) and GTT (R ² = 0.48) but a positive correlation with serum insulin (R ² = 0.32).

Conclusion

We report that DCE-MRI can reflect the metabolic and functional condition of the transplanted islets.     

Synovial membrane enhancement and bone erosion by magnetic resonance imaging for prediction of radiologic progression in patients with early rheumatoid arthritis

Objective The aim of this study was to determine the prognostic factors related to radiographic progression in patients with early rheumatoid arthritis (RA) (less than 1 year after onset) undergoing enhanced MRI at entry.Methods Demographic characteristics, disease duration, and enhanced MRI of the dominant wrists were recorded at entry. Duration of morning stiffness, number of swollen joints, serum rheumatoid factor (RF), erythrocyte sedimentation rate, C-reactive protein (CRP) level, and radiographs of hands and feet (Sharp/van der Heijde score) were assessed at each follow-up. Outcome was defined as damage seen on radiography.Results One hundred fourteen patients were followed up for 10 years. Logistic regression analysis showed that high MRI score, CRP, and RF positivity were associated with radiologic progression. The MRI score at baseline was a better predictor than CRP level and RF positivity at entry.Conclusion The assessment of synovial membrane enhancement and bone erosion by MRI of the wrist in early RA is very helpful to predict erosive outcome.     

Ultrasonographic evaluation of synovial effusion and synovial proliferation pattern in the knee joints of patients with rheumatoid arthritis

In the present study, 49 knee joints of 26 patients with rheumatoid arthritis and 17 knee joints of 17 healthy subjects were ultrasonographically examined. Lateral, superior, and medial aspects of the patella were scanned using an ultrasonograph with a 7.5-MHz annular array transducer to evaluate the thickness of synovial effusion and the synovial proliferation pattern. The overall mean thickness of synovial effusion (mean of all three sites) in the knee joints was 4.9 ± 3.4 mm for rheumatoid arthritis patients and 1.4 ± 0.5 mm for healthy subjects. In rheumatoid arthritis patients, the mean thickness of synovial effusion at the superior aspect of the patella (6.5 ± 4.1 mm) was significantly greater than that at the lateral aspect (4.5 ± 4.8 mm) (P < 0.05) and the medial aspect (4.0 ± 3.1 mm) (P < 0.01). Patients with the villonodular pattern of synovial proliferation had a shorter duration of disease than those with uniform thickening or an overlapping pattern. Received: May 1, 2001 / Accepted: August 6, 2001     

Magnetic resonance imaging versus musculoskeletal ultrasound in the evaluation of temporomandibular joint in rheumatoid arthritis patients

Aim of the work

To evaluate temporomandibular joint (TMJ) affection in rheumatoid arthritis (RA) patients by magnetic resonance imaging (MRI) versus musculoskeletal ultrasound (MSUS) and to correlate the findings with clinical manifestations, disease activity and functional status.

Analysis of subclinical synovitis detected by ultrasonography and low-field magnetic resonance imaging in patients with rheumatoid arthritis

Abstract

Objective To assess the utilities of ultrasonography (US) and low-field magnetic resonance imaging (compacTscan, cMRI) in the diagnosis of subclinical synovitis of hand joints of patients with rheumatoid arthritis (RA).

Methods A total of 1,540 joints of 77 RA patients were examined clinically, using US, using cMRI, and the baseline X-ray examination was performed. Clinical synovitis was defined as joint tenderness or swelling. Subclinical synovitis was diagnosed by US and by cMRI. The incidence of bone erosion and joint space narrowing was assessed by X-ray examination performed at approximately 40 weeks of follow-up.

Results Of the hand joints examined, 294 (19.1 %) were diagnosed with clinical synovitis, and 218 joints (14.1 %) were diagnosed with subclinical synovitis. The remaining 1,028 joints (66.8 %) were synovitis-free on clinical examination and imaging. For the diagnosis of subclinical synovitis, cMRI (11.4 %) was significantly more sensitive than power Doppler signals detected by US (US-PD; 6.8 %) (P < 0.01), and the combination of US-PD and cMRI was more useful (14.1 %) than US-PD or cMRI alone (P < 0.05). Follow-up X-ray examination of 600 joints showed a significantly higher incidence of bone erosion in joints with subclinical synovitis than in synovitis-free joints (P < 0.05).

Conclusion US-PD and cMRI are useful for detecting subclinical synovitis in patients with RA. Subclinical synovitis of the small joints of the hand can progress to bone destruction.     

Hemangioma of the left ventricular cavity: Presumptive diagnosis by magnetic resonance imaging

Summary In a 16-year-old boy, magnetic resonance imaging (MRI) revealed a 1 × 1.5-cm tumor on a stalk attached to the anterior ventricular wall. The tumor showed homogeneous enhancement after the administration of gadorinium(Gd)-DTPA, indicating it was highly vascular. The tumor was excised during surgery and the histological examination led to a diagnosis of juvenile hemangioendothelioma. MRI therefore allowed a definitive diagnosis of cardiac hemangioma to be made preoperatively. This case represents the first reported instance of a benign left ventricular hemangioma diagnosed by MRI.     

Confirmation of effectiveness of tocilizumab by ultrasonography and magnetic resonance imaging in biologic agent-naïve early-stage rheumatoid arthritis patients

Efficacy of tocilizumab in active early-stage RA patients despite methotrexate was evaluated for 12 months. One out of 5 patients was quitted by infusion reaction whereas tocilizumab continued for 12 months in the remaining 4 patients. Power Doppler articular synovitis was reduced in every patient and disappeared in 2 patients. Marked MRI osteitis, found in 1 patient, had disappeared at 12 months. Present results confirm the efficacy of tocilizumab by ultrasonography and MRI.     

Imaging of transplanted islets by positron emission tomography,magnetic resonance imaging,and ultrasonography

While islet transplantation is considered a useful therapeutic option for severe diabetes mellitus (DM), the outcome of this treatment remains unsatisfactory. This is largely due to the damage and loss of islets in the early transplant stage. Thus, it is important to monitor the condition of the transplanted islets, so that a treatment can be selected to rescue the islets from damage if needed. Recently, numerous trials have been performed to investigate the efficacy of different imaging modalities for visualizing transplanted islets. Positron emission tomography (PET) and magnetic resonance imaging (MRI) are the most commonly used imaging modalities for this purpose. Some groups, including ours, have also tried to visualize transplanted islets by ultrasonography (US). In this review article, we discuss the recent progress in islet imaging.     

动态增强磁共振定量参数诊断肝脏占位性病变良恶性效能分析

目的 探讨应用动态增强磁共振(DCE-MRI)扫描定量参数诊断肝脏占位性病变良恶性的效能。方法 2019年2月～2022年2月我院经手术或穿刺活检组织病理学检查证实的88例肝脏良恶性病变患者,其中肝脏良性病变组47例和恶性病变组41例。所有患者均接受DCE-MRI检查,测量病变的平均强化时间(MET)、正性增强积分(PEI)、最大上升斜率(MSI)和最大下降斜率(MSD)。采用荧光定量PCR法检测组织衍生生长因子-1(Cripto-1)、Kruppel样因子(KLF4)、同源盒蛋白A9(HOXA9)和跨膜蛋白3(IFITM3)mRNA水平。绘制受试者工作特征曲线(ROC)分析MR检查测量的MET、PEI、MSI和MSD诊断肝脏占位性病变性质的效能。结果 恶性病变组MET、PEI和MSI分别为(516.5±40.2)s、(32.4±6.3)和(99.6±17.8),显著低于肝脏良性病变组【分别为(574.3±50.9)s、(256.7±22.7)和(271.6±25.3),P<0.05】,而MSD为(114.6±14.2),显著高于肝脏良性病变组【(85.4±10.9),P<...     

Development of large pseudocysts adjacent to the knee joint in rheumatoid arthritis. Assessment of radiological and histopathological approaches

Abstract

?This study examined the pathogenesis of large pseudocysts adjacent to knee joints in rheumatoid arthritis (RA). The radiological and histopathological features of 17 large subarticular pseudocysts in 12 knee joints of 10 patients were analyzed. Nine of the 10 patients were classified as class 2 according to Steinbrocker's functional class. Eight large pseudocysts were located at the lateral femoral condyle, seven were at the proximal part of the tibia, one was at the medial femoral condyle, and one was at the patella. The large pseudocysts were divided into two groups according to whether they did or did not connect with the joint cavity. Serial radiographs revealed that all large pseudocysts in communication with the joint cavity had enlarged gradually over the past several months. They extended from the subarticular area toward the bone marrow. Histopathological findings confirmed that holes allowing communication were located at a transitional zone between the ligament and the hyaline cartilage, and that rheumatoid granulation tissue invaded the large pseudocyst through these holes. The results of this study indicate that large pseudocysts are formed by the extension of articular inflammation. Moreover, repeated extrinsic mechanical stress due to walking and the aggressive inflammatory nature of rheumatoid arthritis play important roles in the formation of large pseudocysts.