Metallic artifact suppression with MAVRIC-SL in magnetic resonance imaging for assessing chronic pain after hip or knee arthroplasty / Supressão do artefato metálico na ressonância magnética com MAVRIC-SL na avaliação da dor crônica em artroplastia de quadril ou joelho

Abstract Objective: To analyze the association between osteolysis at the prosthesis interfaces, as determined by magnetic resonance imaging (MRI) with multiacquisition variable-resonance image combination selective (MAVRIC-SL) sequences, and clinical severity after knee or hip arthroplasty, as well as to assess interobserver and intraobserver agreement on periprosthetic bone resorption. Materials and Methods: This was a cross-sectional study of 47 patients (49 joints) under postoperative follow-up after knee or hip arthroplasty, with chronic pain, between March 2019 and August 2020. All of the patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The component interfaces were evaluated and ordered into two groups: osseointegrated and osteolytic. Nonparametric tests were used. Results: There were significant differences between the two groups in terms of the mean WOMAC scores: total (p = 0.010); stiffness domain (p = 0.047); and function (p = 0.011) domains. There was substantial interobserver and intraobserver agreement for most analyses of the components. Conclusion: Periprosthetic osteolysis appears to be associated with clinical complaints of pain in the post-arthroplasty scenario, and MAVRIC-SL provides reproducible assessments. It could prove to be an important tool for orthopedists to use in the evaluation of challenging cases of chronic pain after arthroplasty.

Resumo Objetivo: Analisar associação entre osteólise nas interfaces protéticas por ressonância magnética com sequências MAVRIC-SL e a gravidade clínica dos pacientes submetidos a artroplastias de joelho ou quadril. Determinar concordância intraobservador e interobservador na reabsorção óssea peri-implante. Materiais e Métodos: Foi realizado estudo transversal entre março de 2019 e agosto de 2020, com 47 pacientes (49 articulações) em seguimento pós-operatório de artroplastias de joelho ou quadril, com dor crônica, que responderam ao questionário WOMAC. As interfaces dos componentes foram avaliadas e definiram dois grupos: osteointegrado e osteólise. Testes não paramétricos foram usados. Resultados: Houve diferença significativa na média do escore WOMAC entre os grupos (p = 0,010), assim como nos domínios rigidez (p = 0,047) e função (p = 0,011). Houve concordância substancial interobservador e intraobservador para a maioria dos componentes analisados. Conclusão: Osteólise periprótese parece estar associada com a queixa clínica de dor pós-artroplastia, com avaliação reprodutível pela MAVRIC-SL. Isto pode ser uma importante ferramenta para o ortopedista na avaliação de casos desafiadores de dor crônica pós-artroplastia.

Metallic artifact suppression with MAVRIC-SL in magnetic resonance imaging for assessing chronic pain after hip or knee arthroplasty.

Objective: To analyze the association between osteolysis at the prosthesis interfaces, as determined by magnetic resonance imaging (MRI) with multiacquisition variable-resonance image combination selective (MAVRIC-SL) sequences, and clinical severity after knee or hip arthroplasty, as well as to assess interobserver and intraobserver agreement on periprosthetic bone resorption. Materials and Methods: This was a cross-sectional study of 47 patients (49 joints) under postoperative follow-up after knee or hip arthroplasty, with chronic pain, between March 2019 and August 2020. All of the patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The component interfaces were evaluated and ordered into two groups: osseointegrated and osteolytic. Nonparametric tests were used. Results: There were significant differences between the two groups in terms of the mean WOMAC scores: total (p = 0.010); stiffness domain (p = 0.047); and function (p = 0.011) domains. There was substantial interobserver and intraobserver agreement for most analyses of the components. Conclusion: Periprosthetic osteolysis appears to be associated with clinical complaints of pain in the post-arthroplasty scenario, and MAVRIC-SL provides reproducible assessments. It could prove to be an important tool for orthopedists to use in the evaluation of challenging cases of chronic pain after arthroplasty.

Objetivo: Analisar associação entre osteólise nas interfaces protéticas por ressonância magnética com sequências MAVRIC-SL e a gravidade clínica dos pacientes submetidos a artroplastias de joelho ou quadril. Determinar concordância intraobservador e interobservador na reabsorção óssea peri-implante. Materiais e Métodos: Foi realizado estudo transversal entre março de 2019 e agosto de 2020, com 47 pacientes (49 articulações) em seguimento pós-operatório de artroplastias de joelho ou quadril, com dor crônica, que responderam ao questionário WOMAC. As interfaces dos componentes foram avaliadas e definiram dois grupos: osteointegrado e osteólise. Testes não paramétricos foram usados. Resultados: Houve diferença significativa na média do escore WOMAC entre os grupos (p = 0,010), assim como nos domínios rigidez (p = 0,047) e função (p = 0,011). Houve concordância substancial interobservador e intraobservador para a maioria dos componentes analisados. Conclusão: Osteólise periprótese parece estar associada com a queixa clínica de dor pós-artroplastia, com avaliação reprodutível pela MAVRIC-SL. Isto pode ser uma importante ferramenta para o ortopedista na avaliação de casos desafiadores de dor crônica pós-artroplastia.

Six-point DIXON and Magnetic Resonance Spectroscopy Techniques in Quantifying Bone Marrow Fat in Sickle Cell Disease.

RATIONALE AND OBJECTIVES: To compare bone marrow fat quantification using magnetic resonance spectroscopy (MRS) and six-point DIXON (6PD) techniques in patients with sickle cell disease (SCD) and healthy subjects. MATERIALS AND METHODS: Prospective study, with 43 SCD patients (24 homozygous [SS], 19 double heterozygous [SC), and 41 healthy subjects paired by age, weight and sex with SCD patients. All participants underwent magnetic resonance imaging with 6PD and single voxel MRS in the L3 vertebral body. Pearson's correlation, ROC curve, and bland-altman analysis were performed, p-values ​​≤0.05 were considered statistically significant for all tests. RESULTS: Significant linear correlation was found between fat fraction (FF) by 6PD and Total Lipids (TL) (r = 0.932; p < 0.001) and Saturated Lipids (SL) (r = 0.934; p < 0.001), in all subjects. Strong correlations were also identified considering subjects of the SS/SC subgroups. Despite high correlations, no significant difference was observed only between FF and SL in the SS subgroup (Bland-Altman analysis), indicating excellent agreement between the fat estimations in this specific situation. Significant differences were observed in all variables (FF, TL, SL) comparing the SCD and healthy subjects. The ROC curve between SCD and healthy subjects showed the following areas under the curve: FF(0.924) > TL(0.883) > SL(0.892). CONCLUSIONS: The comparison between fat quantification by the 6PD with MRS demonstrated an excellent correlation in SCD patients, especially in the SS subgroup, which usually has a higher degree of hemolysis. The diagnostic performance of 6PD and MRS is similar, with advantages of shorter imaging processing time and larger studied area with the 6PD.

Genetic Polymorphisms in Patients With Systemic Lupus Erythematosus and Jaccoud Arthropathy: A Pilot Study.

INTRODUCTION: Jaccoud arthropathy (JA) is a nonerosive and deforming arthropathy experienced frequently by patients with systemic lupus erythematosus (SLE). Although genetic polymorphisms are associated with SLE development, the association between genetic polymorphisms and JA has not been studied to date. The main objective of this study was to evaluate an association between HLA, STAT4, IRF5, and BLK polymorphisms and the presence of JA in Brazilian individuals with SLE. METHODS: Patients were selected from a cohort of individuals with SLE followed at 2 rheumatology reference centers in Salvador, Bahia, Brazil. The JA diagnosis was based on clinical and radiological criteria. The participants were genotyped for rs9271100, rs7574865, rs10488631, and rs13277113 polymorphisms in the HLA, STAT4, IRF5, and BLK genes, respectively, using real-time polymerase chain reaction. The presence of JA was correlated with allele frequencies, and clinical and laboratory data. RESULTS: One hundred forty-four individuals with SLE (38 with JA and 106 with SLE without JA) were studied. The mean age of the patients was 45 ± 12 years; the majority were women and had brown skin. Patients with JA had a longer disease duration than patients without JA. Serositis and neuropsychiatric manifestations were more frequent in the JA population. The A allele of rs13277113 in the BLK gene was associated with the presence of JA. CONCLUSIONS: The rs13277113 polymorphism in the BLK gene was found to be a possible genetic risk for JA development. However, further studies in larger populations should be performed to confirm this finding.

Qualitative and quantitative magnetic resonance imaging evaluation of bone tissue vaso-occlusive events in patients with sickle cell disease.

OBJECTIVE: To evaluate the association between bone changes due to vaso-occlusive events in sickle cell disease (SCD) revealed by conventional MRI sequences and the fat fraction obtained using a 6-point DIXON technique (FFdix), in an attempt to use quantitative data as a biomarker for bone complications. METHODS: Cross-sectional study, with 48 SCD patients, 26-homozygous (HbSS), and 22-compound heterozygous (HbSC). Forty-eight healthy individuals paired by age, weight, and sex with SCD patients. All participants underwent lumbar spine and pelvis MRI. Conventional sequences: bone complications related to vaso-occlusive events-femoral head avascular necrosis, bone infarctions, "H"-shaped vertebrae, bone marrow necrosis. Six-point DIXON technique: quantitative evaluation of the bone marrow at pre-established sites (lumbar vertebrae, sacrum, iliacs, femoral heads, greater femoral trochanters, femoral necks). Pearson's correlation, ROC curve, and binary logistic regression analysis were performed. RESULTS: The most frequent findings in the SCD group included femoral head avascular necrosis (75%), bone infarctions (58.3%), "H"-shaped vertebrae (58.3%), and typical imaging findings of bone marrow necrosis (8.3%). Cortical bone thickness in the proximal femoral diaphysis in patients with SCD was moderately negatively correlated with FFdix in lumbar vertebrae, iliacs, femoral necks, and first sacral vertebrae. The ROC curves and odds ratios demonstrated excellent performance of FFdix in all the evaluated anatomical sites and identified patients having bone complications. CONCLUSIONS: FFdix could serve as a potential biomarker in SCD because of its association with bone complications secondary to vaso-occlusive events in patients with SCD, especially in femoral heads, femoral necks, and iliacs.

Applications of the Dixon technique in the evaluation of the musculoskeletal system.

The acquisition of images with suppression of the fat signal is very useful in clinical practice and can be achieved in a variety of sequences. The Dixon technique, unlike other fat suppression techniques, allows the signal of fat to be suppressed in the postprocessing rather than during acquisition, as well as allowing the visualization of maps showing the distribution of water and fat. This review of the Dixon technique aims to illustrate the basic physical principles, to compare the technique with other magnetic resonance imaging sequences for fat suppression or fat quantification, and to describe its applications in the study of diseases of the musculoskeletal system. Many variants of the Dixon technique have been developed, providing more consistent separation of the fat and water signals, as well as allowing correction for many confounding factors. It allows homogeneous fat suppression, being able to be acquired in combination with several other sequences, as well as with different weightings. The technique also makes it possible to obtain images with and without fat suppression from a single acquisition. In addition, the Dixon technique can be used as a quantitative method, allowing the proportion of tissue fat to be determined, and, in more updated versions, can quantify tissue iron.

A aquisição de imagens com supressão do sinal da gordura é um recurso de grande utilidade diagnóstica, existindo várias sequências capazes de realizá-la. A técnica Dixon, ao contrário de outras técnicas de supressão de gordura, permite suprimir a contribuição do sinal de gordura no pós-processamento e não durante a aquisição, além de permitir a visualização de mapas com a distribuição da água e da gordura. Esta revisão sobre a técnica Dixon almeja ilustrar os princípios físicos básicos, comparar a técnica com outras sequências de ressonância magnética para supressão ou quantificação de gordura, e descrever suas aplicações no estudo de doenças do sistema musculoesquelético. Muitas variantes da técnica Dixon foram desenvolvidas, proporcionando separação mais consistente dos sinais de gordura e água e permitindo correção de muitos fatores de confusão. Permite obter supressão homogênea de gordura, podendo ser adquirida de forma combinada com várias outras sequências, bem como com diferentes ponderações. Esta técnica possibilita também a obtenção de imagens com e sem supressão de gordura a partir de uma única aquisição. Adicionalmente, a técnica Dixon pode ser utilizada como recurso quantitativo, pois permite a mensuração do porcentual de gordura e, em versões mais atualizadas, consegue quantificar ferro tecidual.

Applications of the Dixon technique in the evaluation of the musculoskeletal system / Aplicações da técnica Dixon na prática radiológica do sistema musculoesquelético

Abstract The acquisition of images with suppression of the fat signal is very useful in clinical practice and can be achieved in a variety of sequences. The Dixon technique, unlike other fat suppression techniques, allows the signal of fat to be suppressed in the postprocessing rather than during acquisition, as well as allowing the visualization of maps showing the distribution of water and fat. This review of the Dixon technique aims to illustrate the basic physical principles, to compare the technique with other magnetic resonance imaging sequences for fat suppression or fat quantification, and to describe its applications in the study of diseases of the musculoskeletal system. Many variants of the Dixon technique have been developed, providing more consistent separation of the fat and water signals, as well as allowing correction for many confounding factors. It allows homogeneous fat suppression, being able to be acquired in combination with several other sequences, as well as with different weightings. The technique also makes it possible to obtain images with and without fat suppression from a single acquisition. In addition, the Dixon technique can be used as a quantitative method, allowing the proportion of tissue fat to be determined, and, in more updated versions, can quantify tissue iron.

Resumo A aquisição de imagens com supressão do sinal da gordura é um recurso de grande utilidade diagnóstica, existindo várias sequências capazes de realizá-la. A técnica Dixon, ao contrário de outras técnicas de supressão de gordura, permite suprimir a contribuição do sinal de gordura no pós-processamento e não durante a aquisição, além de permitir a visualização de mapas com a distribuição da água e da gordura. Esta revisão sobre a técnica Dixon almeja ilustrar os princípios físicos básicos, comparar a técnica com outras sequências de ressonância magnética para supressão ou quantificação de gordura, e descrever suas aplicações no estudo de doenças do sistema musculoesquelético. Muitas variantes da técnica Dixon foram desenvolvidas, proporcionando separação mais consistente dos sinais de gordura e água e permitindo correção de muitos fatores de confusão. Permite obter supressão homogênea de gordura, podendo ser adquirida de forma combinada com várias outras sequências, bem como com diferentes ponderações. Esta técnica possibilita também a obtenção de imagens com e sem supressão de gordura a partir de uma única aquisição. Adicionalmente, a técnica Dixon pode ser utilizada como recurso quantitativo, pois permite a mensuração do porcentual de gordura e, em versões mais atualizadas, consegue quantificar ferro tecidual.

Videocapillaroscopic Findings in Patients With Systemic Lupus Erythematosus With or Without Jaccoud Arthropathy.

BACKGROUND/OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune disease that can present changes in blood vessels, which can be evaluated by periungual nailfold videocapillaroscopy (VCP). This technique is important for the diagnosis of systemic sclerosis and to identify individuals with Raynaud phenomenon at higher risk of developing systemic sclerosis. This study aims to describe the videocapillaroscopic profile of a series of SLE patients and to investigate if the VCP pattern is different among those with Jaccoud arthropathy (JA) compared with those without. METHODS: Between September 2014 and March 2015, the patients in this study underwent VCP, clinical evaluation, and laboratory tests. The capillaroscopic patterns were defined as minor, major, and scleroderma (SD). The presence of capillaroscopic findings, such as elongated capillaries, tortuosity, ectasia, prominent venous plexus, neoangiogenesis, hemorrhage, and megacapillaries, were also observed. Associations were calculated using the χ2, Fisher exact, or Student t test. RESULTS: In a population of 113 females with SLE (67 without JA and 46 with JA), at least 1 alteration was observed in VCP in 89.40% of them, among which "nonspecific changes" were the most prevalent. Minor changes were seen in 39 (58.2%) and 26 (56.5%), major changes in 21 (31.3%) and 11 (23.9%), and SD pattern in 2 (3.0%) and 3 (6.5%), in the patients without and with JA, respectively (p > 0.05). CONCLUSIONS: The majority of patients with SLE demonstrated changes in the VCP examination, but this tool did not allow discrimination between those with or without JA.

Sonographic Findings of Hands and Wrists in Systemic Lupus Erythematosus Patients With Jaccoud Arthropathy.

INTRODUCTION: Jaccoud arthropathy (JA) is a deforming nonerosive arthropathy, characterized by the presence of "reversible" joint deformity. The study aims at describing the main musculoskeletal ultrasound (US) findings of a series of systemic lupus erythematosus (SLE) patients with JA. METHODS: Consecutive patients diagnosed as having JA and SLE were included in the study. All patients underwent a whole clinical evaluation and US of the hands and wrists. The US scan evaluated the presence of synovial hypertrophy, tenosynovitis, and bone erosions. RESULTS: Thirty-nine of 40 patients were female. The US examination was performed on 560 joints of the hands and wrists. At least 1 change was observed in the US examination of 20 patients (50.0%), but there was not a statistically significant association with disease activity (P = 0.33). Nineteen patients (47.5%) had synovial hypertrophy, 9 (22.5%) had tenosynovitis, and 7 (17.5%) had both. Isolated small bone erosions were identified in 2 patients (5.0%). CONCLUSIONS: Ultrasound examination is a reliable and noninvasive imaging method for the evaluation of joint involvement in SLE. Half of the patients with JA have ultrasonographic signs of joint inflammation, and these abnormalities may be found even in the absence of disease activity.

Ultrasound Findings on Hands and Wrists of Patients with Systemic Lupus Erythematosus: Relationship with Physical Examination.

Diagnosis of synovitis/tenosynovitis by physical examination can be difficult. Ultrasound (US) can be an effective tool for the evaluation of joint involvement in systemic lupus erythematosus (SLE). This study will describe musculoskeletal findings by US in SLE patients and the evaluation of their correlation with physical examination. SLE patients underwent clinical/sonographic evaluation of hand/wrists. In total, 896 joints were evaluated: at least 1 change on physical examination was found in 136 joints and at least 1 US abnormality was found in 65 of 896 joints. Out of the 65 joints with US changes, only 13 had findings on physical examination. Conversely, 111 joints had tenderness on physical examination with no sonographic abnormalities. Tenosynovitis was statistically significant more frequently with joint edema (41%) (p = 0.0003). US can detect musculoskeletal changes in only a minority of symptomatic SLE patients. Clinical findings may be related to some reasons that cannot be explained using US.

Formato da onda do jato ureteral ao estudo Doppler espectral: comparação interobservadores. Estudo prospectivo em crianças assintomáticas / Ureteric jet Doppler waveform: interobserver agreement. A prospective study with asymptomatic children

OBJETIVO: Diagnóstico precoce de distúrbios miccionais pode diminuir as repercussões sociais e psicológicas e evitar lesões renais. O jato ureteral pode ser avaliado por estudo Doppler, método que apresenta boa associação com dados clínicos dos pacientes no que diz respeito ao diagnóstico de disfunção miccional. O objetivo deste estudo é avaliar a concordância interobservadores entre os tipos de jato ureteral. MATERIAIS E MÉTODOS: Estudo prospectivo de concordância interobservadores. Um total de 41 pacientes foi examinado sequencialmente por dois médicos ultrassonografistas. Para cada paciente, três curvas dopplerfluxométricas foram obtidas de jatos consecutivos de cada ureter. O número de picos em cada curva foi observado e classificado. A velocidade máxima do maior pico de cada onda foi observada. Coeficientes kappa (κ) foram calculados. RESULTADOS: A concordância interobservadores foi moderada (κ = 0,48; intervalo de confiança 95 por cento: 0,36-0,60). O padrão platô foi o mais frequente. As velocidades máximas dos ureteres, medidas pelos dois observadores, foram de 32,37 cm/s e 35,63 cm/s, respectivamente. CONCLUSÃO: O exame das curvas dopplerfluxométricas do jato ureteral é método que demonstrou moderada concordância interobservadores.

OBJECTIVE: Early diagnosis of voiding dysfunction can minimize social and psychological repercussions and avoid renal lesions. The ureteric jet can be evaluated by color Doppler, and a good correlation has been observed between this method and patients' clinical data in the diagnosis of voiding dysfunction. This study was aimed at evaluating the interobserver agreement in the assessment of the ureteral jet in asymptomatic children. MATERIALS AND METHODS: Interobserver agreement was prospectively evaluated. A total of 41 patients were sequentially evaluated by two medical sonographers. For each patient, three consecutive Doppler waveforms were obtained from each of the two ureteral jets. The number of peaks on each wave was observed and classified. The maximum velocity of the highest peak of each waveform was also observed. Kappa coefficients (κ) were calculated. RESULTS: Moderate interobserver agreement was observed (κ = 0.48; 95 percent confidence interval: 0.36-0.60). Most frequently a plateau pattern was observed for the ureteric jet. Maximum velocities measured by the two observers were respectively 32.37 cm/s and 35.63 cm/s. CONCLUSION: Moderate interobserver agreement was observed in the evaluation of the ureteric jet by means of color Doppler.