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Background: Many adolescents experience knee pain, and only some undergo detailed imaging. In this population, the prevalence of abnormalities and normal variants on magnetic resonance imaging (MRI) scans is unknown., Purpose: To investigate the prevalence of abnormalities and normal variants of the knee on MRI scans and their relationship with participant characteristics in the general young adolescent population., Study Design: Cross-sectional study; Level of evidence, 3., Methods: This study was part of an open population-based cohort study that focuses on health, growth, and development from fetal life until adulthood. Between 2017 and 2020, adolescents aged 12 to 15 years underwent MRI of both knees. These MRI scans were assessed in a standardized way for abnormalities and normal variants to determine their prevalence. Logistic regression was used to analyze the presence of abnormalities and normal variants in relation to sex, height, weight, body mass index-standard deviation (BMI-SD), and ethnicity., Results: A total of 1910 participants (median age, 13.5 years; interquartile range, 13.4-13.7 years; 52% girls) were included in this study. Of them, 370 (19.4%) participants had at least 1 abnormality or normal variant. Bone marrow edema around the knee was the most prevalent finding, affecting 140 (7.3%) participants. In 107 (5.6%) participants, nonossifying fibromas were found. A total of 43 (2.3%) participants had characteristics of Osgood-Schlatter disease, 16 (0.8%) showed characteristics of Sinding-Larsen-Johansson syndrome, and osteochondritis dissecans was found in 13 (0.7%) participants. Variants such as discoid menisci were found in 40 (2.1%) participants and a bipartite patella in 21 (1.1%) participants. There were multiple associations between abnormalities or variants and participant characteristics, including bone marrow edema being more often present in boys (odds ratio [OR], 2.44; 95% CI, 1.69-3.52) and those with a lower BMI-SD (OR, 0.85; 95% CI, 0.73-0.98). Osgood-Schlatter and osteochondritis dissecans were more often present in boys (OR, 4.21 [95% CI, 2.01-8.85] and OR, 13.18 [95% CI, 1.71-101.58], respectively). Discoid menisci were associated with a non-Western ethnicity (OR, 2.06; 95% CI, 1.07-3.96) and higher BMI-SD (OR, 2.34; 95% CI, 1.76-3.11)., Conclusion: Abnormalities and normal variants on MRI scans of the knees are common in adolescents. Physicians who are involved in the treatment of adolescents with knee pain need to be aware of this prevalence so that these children will not be overtreated or misdiagnosed., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: The Generation R Study is made possible by financial support from Erasmus Medical Center, Rotterdam; Erasmus University Rotterdam; ZonMw; the Netherlands Organisation for Scientific Research (NWO); and the Ministry of Health, Welfare and Sport of the Netherlands. The Anna Foundation (Nederlands Orthopedisch Research en Educatie Fonds) supports the work of L.A.M.K. through a research grant. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Objective: We aimed to evaluate the diagnostic performance of dual-energy computed tomography (DECT) in detecting bone marrow edema (BME) in patients with lower limb joint injuries., Methods: A thorough literature search was conducted across the PubMed, Embase, and Web of Science databases to identify relevant studies up to April 2024. Studies examining the diagnostic performance of DECT in detecting BME in lower limb joint injuries patients were included. Sensitivity and specificity were evaluated using the inverse variance method and transformed via the Freeman-Tukey double arcsine transformation. Furthermore, the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was utilized to evaluate the methodological quality of the included studies., Results: This meta-analysis included 17 articles involving 625 patients. The pooled sensitivity, specificity, and AUC for DECT in detecting BME in lower limb joint injuries patients were 0.82 (95 % CI: 0.76-0.87), 0.95 (95 % CI: 0.92-0.97), and 0.95 (95 % CI: 0.93-0.97), respectively. The pooled sensitivity of DECT for detecting BME in knee, hip, and ankle joint injuries was 0.80, 0.84, and 0.80, with no significant difference among these joints (P = 0.55). The pooled specificity for knee, hip, and ankle injuries was 0.95, 0.97, and 0.89. Specificity differed significantly among the joints (P < 0.01), with the highest specificity in hip injuries., Conclusions: Our meta-analysis indicates that DECT demonstrates high diagnostic performance in detecting BME in patients with lower limb joint injuries, with the highest specificity observed in hip joint injuries. To validate these findings, further larger prospective studies are necessary., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Competing Interests: The authors declare that they have no conflict of interest.

Background Bone marrow lesions (BMLs) are a known risk factor for incident knee osteoarthritis (OA), and deep learning (DL) methods can assist in automated segmentation and risk prediction. Purpose To develop and validate a DL model for quantifying tibiofemoral BML volume on MRI scans in knees without radiographic OA and to assess the association between longitudinal BML changes and incident knee OA. Materials and Methods This retrospective study included knee MRI scans from the Osteoarthritis Initiative prospective cohort (February 2004-October 2015). The DL model, developed between August and October 2023, segmented the tibiofemoral joint into 10 subregions and measured BML volume in each subregion. Baseline and 4-year follow-up MRI scans were analyzed. Knees without OA at baseline were categorized into three groups based on 4-year BML volume changes: BML-free, BML regression, and BML progression. The risk of developing radiographic and symptomatic OA over 9 years was compared among these groups. Results Included were 3869 non-OA knees in 2430 participants (mean age, 59.5 years ± 9.0 [SD]; female-to-male ratio, 1.3:1). At 4-year follow-up, 2216 knees remained BML-free, 1106 showed an increase in BML volume, and 547 showed a decrease in BML volume. BML progression was associated with a higher risk of developing radiographic knee OA compared with remaining BML-free (hazard ratio [HR] = 3.0; P < .001) or BML regression (HR = 2.0; P < .001). Knees with BML progression also had a higher risk of developing symptomatic OA compared with BML-free knees (HR = 1.3; P < .001). Larger volume changes in BML progression were associated with a higher risk of developing both radiographic OA (HR = 2.0; P < .001) and symptomatic OA (HR = 1.7; P < .001). In almost all subchondral plates, especially the medial femur and tibia, BML progression was associated with a higher risk of developing both radiographic and symptomatic OA compared with remaining BML-free. Conclusion Knees with BML progression, according to subregion and extent of volume changes, were associated with an increased risk of OA compared with BML-free knees and knees with BML regression, highlighting the potential utility of monitoring BML volume changes in evaluating interventions to prevent OA development. ClinicalTrials.gov Identifier: NCT00080171 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Said and Sakly in this issue.

Rationale and Objectives: To evaluate the value of dual-energy CT (DECT) virtual noncalcium (VNCa) images in the diagnosis of wrist bone marrow edema (BME) in patients with rheumatoid arthritis (RA)., Materials and Methods: 43 patients with wrist involvement in active RA prospectively underwent DECT and MRI. Functional DECT images reconstruction yielded VNCa images. MRI served as the reference standard for diagnosing BME. BME diagnosis differences between VNCa images and MRI were compared. Differences in CT values between BME and normal bone marrow were assessed. The optimal CT value for detecting BME in VNCa images was determined through ROC curve analysis. The correlation between VNCa images scores and RA disease activity was evaluated., Results: There was a high agreement between VNCa images and MRI in diagnosing BME (Kappa=0.831). VNCa images showed a significant difference in CT values between BME and normal bone marrow (P < 0.001). A cut-off value of - 54.8 HU yielded a sensitivity, specificity, and accuracy of 90.72%, 94.30%, and 93.33%, respectively, for detecting BME on VNCa images. The area under the ROC curve was 0.937 for distinguishing BME from normal bone marrow. Conventional CT images showed no statistically significant difference (P = 0.174) in CT values between BME and normal bone marrow. The VNCa images BME scores were positively correlated with RA disease activity (r = 0.399)., Conclusion: The DECT VNCa technique demonstrates its potential for diagnosing wrist BME in patients with RA and provides a valuable tool for assessing disease activity in RA., Important Findings: The DECT VNCa technique has the ability to distinguish between BME and normal bone marrow. The VNCa images BME scores were positively correlated with the disease activity in RA., Competing Interests: Declaration of Competing Interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Purpose: This study proposes a process for detecting slices with bone marrow edema (BME), a typical finding of axSpA, using MRI scans as the input. This process does not require manual input of ROIs and provides the results of the judgment of the presence or absence of BME on a slice and the location of edema as the rationale for the judgment., Methods: First, the signal intensity of the MRI scans of the sacroiliac joint was normalized to reduce the variation in signal values between scans. Next, slices containing synovial joints were extracted using a slice selection network. Finally, the BME slice detection network determines the presence or absence of the BME in each slice and outputs the location of the BME., Results: The proposed method was applied to 86 MRI scans collected from 15 hospitals in Japan. The results showed that the average absolute error of the slice selection process was 1.49 slices for the misalignment between the upper and lower slices of the synovial joint range. The accuracy, sensitivity, and specificity of the BME slice detection network were 0.905, 0.532, and 0.974, respectively., Conclusion: This paper proposes a process to detect the slice with BME and its location as the rationale of the judgment from an MRI scan and shows its effectiveness using 86 MRI scans. In the future, we plan to develop a process for detecting other findings such as bone erosion from MR scans, followed by the development of a diagnostic support system., (© 2024. CARS.)

Purpose: The purpose of this study was to study the effects of the severity of preoperative bone marrow oedema (BME) on the postoperative short-term outcomes following bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLTs) and to propose a new metric that combines volume and signal density to evaluate BME., Methods: Sixty-five patients with symptomatic OLTs (<100 mm 2 ) and preoperative BME, who received BMS in our institution from April 2017 to July 2021 with follow-ups of 3, 6 and 12 months, were analysed retrospectively. The area, volume and signal value of the BME were collected on preoperative magnetic resonance imaging. The enroled patients were divided into two groups according to the BME index (BMEI), which was defined as the product of oedema relative signal intensity and the relation of oedema volume to total talar volume. Visual analogue scale, American Orthopedic Foot and Ankle Society (AOFAS), Tegner, Foot and Ankle Ability Measure (FAAM)-activities of daily living (ADL) and Sports scores were assessed before surgery and at each follow-up. The relationship between the scores and the volume, relative signal intensity and BMEI was explored., Results: Sixty-five patients with preoperative BME were divided into the mild (n = 33) and severe (n = 32) groups based on the BMEI. A significant difference was found for each score with the general linear model for repeated measures through all follow-up time points (p < 0.001). For the preoperative and 12-month postoperative changes of the enroled patients, 53 patients (81.5%) exceeded the minimal clinically important difference of AOFAS and 26 (40.0%) exceeded that of FAAM-sports in this study. The mild group showed significantly more improvement in AOFAS scores at 12 months (89.6 ± 7.0 vs. 86.2 ± 6.2) and FAAM-ADL scores at 6 months (83.6 ± 7.6 vs. 79.7 ± 7.7) and 12 months (88.5 ± 8.5 vs. 84.4 ± 7.7) than the severe group (p < 0.05). No significant difference of all the scores between the groups was found at 3 months. No significant correlation was found in each group between BMEI and clinical outcomes., Conclusion: The severity of the preoperative BME negatively affected short-term clinical outcomes following arthroscopic BMS for OLTs. Worse clinical outcomes were shown at postoperative 6 and 12 months in patients with a high preoperative BMEI, which could be a favourable parameter for assessing the severity of BME and assist in developing personalised rehabilitation plans and determining the approach and timing of surgery., Level of Evidence: Level III., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: To evaluate the presence of host bone marrow edema (BME) surrounding osteochondral allograft (OCA) plugs on routine 6-month postoperative magnetic resonance imaging (MRI) and to determine whether such BME is correlated with subsequent failure., Methods: The present study was approved under our institutional review board-approved database (#2020-2123). We included patients who underwent cartilage repair with OCA for focal chondral and osteochondral defects of the distal femur by 2 senior surgeons between January 2016 and May 2021 with minimum 2-year follow-up. OCA is frequently performed with concomitant procedures, and therefore ligament reconstruction, meniscal surgery, and osteotomy were not exclusion criteria. Failure was defined as (1) poor clinical outcome with graft collapse on follow-up MRI or second-look arthroscopy, (2) primary OCA removal or revision, or (3) conversion to unicompartmental or total knee arthroplasty. Routine MRI scans were performed at 6 ± 2 months postoperatively. All postoperative MRI scans were reviewed from our imaging record by 2 blinded fellowship-trained orthopaedic surgeons. Patients were divided for analyses into 2 groups: BME ≥10 cm 3 versus BME <10 cm 3 ., Results: Of the 85 patients eligible for the study, 56 patients (30 female, mean age 31.69 ± 11.34 years) had a minimum 2-year follow-up. Nonfailure cases had a mean clinical follow-up of 3.13 ± 0.93 years. The mean time from surgery to failure in our cohort was 1.67 ± 0.91 years. There were 12 (21.4%) patients with BME ≥10 cm³ and 44 (78.6%) patients with BME <10 cm³. No statistically significant differences were found between groups when compared for sex, age, body mass index, OCA size, time to MRI, mean follow-up, number of plugs, graft location, diagnosis, previous surgeries, or concomitant procedures. All OCA failures of the study cohort were in the BME ≥10 cm³ group, representing 50% of this group (P < .001). Kaplan-Meier survival analysis with the log-rank test demonstrated significant difference in survival distributions between groups (P < .001). Patients who ultimately failed had a mean BME volume of 18.49 ± 5.82 cm 3 , while the nonfailure group had a mean volume of 4.66 ± 4.97 cm 3 (P < .001). Cutoff values around 10 cm³ in receiver operating characteristic curve analysis demonstrated 100% sensitivity and close to 90% specificity for OCA failure diagnosis., Conclusions: Host BME with a volume greater than 10 cm³ on 6-month postoperative MRI is predictive of an increased subsequent failure rate after OCA transplantation with a failure rate of 50%., Level of Evidence: Level III, cohort study., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: S.M.S. reports personal fees from Smith + Nephew, Organogenesis, Vericel Corporation, and Pacira Therapeutics and holds investments with Engage and Stryker, outside the submitted work. A.G. reports personal fees from Organogenesis, Vericel Corporation, Bioventus, Smith+ Nephew, Moximed, Pacira Therapeutics, and Joint Restoration Foundation and has stock from Engage Uni, LLC, outside the submitted work. All other authors (G.M.P., R.V., C.F., P.H., M.R.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Serous atrophy of bone marrow (SABM) is characterized by focal replacement of bone marrow elements with extracellular gelatinous substances. It has been associated with a wide range of chronic conditions, including anorexia nervosa, malignancy, chronic kidney disease, and certain chronic infections. Previous literature has reported the disorder as primarily diagnosed via bone marrow biopsy and occurring outside of the distal extremities. Herein we describe a case of SABM occurring in the feet diagnosed via magnetic resonance imaging (MRI), a phenomenon that is rarely reported. The patient is a 45-year-old woman with a history of end-stage renal disease, congestive heart failure, type 2 diabetes, and peripheral arterial disease who initially presented with nonhealing, bilateral foot ulcers. She subsequently underwent several podiatric medical surgeries due to persistent foot infections and poor wound healing. During her most recent hospitalization, MRIs of her feet were obtained, and findings of abnormal bone marrow signal were attributed to technical malfunction of the MRI coil or scanner. After troubleshooting sources of malfunction, a repeated MRI of the foot was obtained and again demonstrated the same bone marrow signal abnormalities; at this time, SABM was diagnosed. Knowledge of this condition can prevent the misinterpretation of SABM on MRI and prevent the waste of time and medical resources.

Dual-energy computed tomography (CT) is an excellent substitute for identifying bone marrow edema in magnetic resonance imaging. However, it is rarely used in practice owing to its low contrast. To overcome this problem, we constructed a framework based on deep learning techniques to screen for diseases using axial bone images and to identify the local positions of bone lesions. To address the limited availability of labeled samples, we developed a new generative adversarial network (GAN) that extends expressions beyond conventional augmentation (CA) methods based on geometric transformations. We theoretically and experimentally determined that combining the concepts of data augmentation optimized for GAN training (DAG) and Wasserstein GAN yields a considerably stable generation of synthetic images and effectively aligns their distribution with that of real images, thereby achieving a high degree of similarity. The classification model was trained using real and synthetic samples. Consequently, the GAN technique used in the diagnostic test had an improved F1 score of approximately 7.8% compared with CA. The final F1 score was 80.24%, and the recall and precision were 84.3% and 88.7%, respectively. The results obtained using the augmented samples outperformed those obtained using pure real samples without augmentation. In addition, we adopted explainable AI techniques that leverage a class activation map (CAM) and principal component analysis to facilitate visual analysis of the network's results. The framework was designed to suggest an attention map and scattering plot to visually explain the disease predictions of the network., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Fat quantification methods in magnetic resonance imaging (MRI) have been studied to differentiate bone marrow pathologies in adult patients; however, scarce literature is available in pediatric patients., Purpose: To evaluate the efficacy of the T1 signal intensity value (T1-SIV), out-of-phase/in-phase signal ratio (OP/IP SR), and fat fraction (FF) to differentiate between normal, benign, and malignant pathological processes., Material and Methods: A total of 48 pediatric patients with lumbar and pelvic MRI were classified into three groups according to bone marrow pathology (group 1, normal; group 2, benign pathology/reconversion; group 3, malignant). The efficacy of T1-SIV, OP/IP SR, and FF values in differentiating these pathologies was evaluated using Kruskal-Wallis or analysis of variance and followed by Bonferroni or Dunn-Bonferroni tests. Cutoff values for malignant infiltration were defined using ROC analysis., Results: Although these values were significantly different in all three groups ( P  = 0.001-0.008), this difference was not sufficient to discriminate between all groups. Subgroup analyses showed significant differences in T1-SIV between groups 1-3, in OP/IP SR between groups 1-3, 2-3, and 1-2, in FF between groups 1-2 and 1-3 in various regions ( P  = 0.001-0.049). Cutoff values had a sensitivity and specificity of 90%-100% for OP/IP SR and FF., Conclusion: T1-SIV, OP/IP SR, and FF may potentially distinguish normal from pathological bone marrow. OP/IP SR and FF values detected malignant infiltration with high sensitivity and specificity in this study. However, only OP/IP SR may significantly differentiate benign and malignant bone marrow pathologies which needs to be confirmed in the future study with a larger patient population., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: The study aimed to explore the value of texture analysis of radiomics based on the short tau inversion recovery (STIR) sequence to evaluate the activity of bone marrow oedema of sacroiliac joints in early AS., Methods: 43 patients with early AS whose data were randomly divided into the training cohort (n=116) and verification cohort (n=56) according to the ratio of 7:3. The optimal feature subsets were obtained by Mann-Whitney U-test, the minimum-Redundancy Maximum-Relevancy (mRMR), and then least absolute shrinkage and selection operator (LASSO) using these texture feature parameters, which were used to construct the final prediction model and obtained the Radscore. The ROC curve was performed to evaluate the performance of the model. The Spearman correlation test was used to analyse the correlation of various indicators., Results: In the training cohort, to differentiate early AS sacroiliac joint bone marrow oedema between the active and stable groups, the AUCs of the Radscore, SPARCC and ADC were 0.81, 0.91, 0.78, respectively. In the validation cohort, the AUCs were 0.87, 0.89, 0.85. In the two cohorts, there were no significant differences in AUCs between values of the Radscore and SPARCC, ADC (p>0.05). There was a significant difference in AUC between SPARCC and ADC in the training cohort (p<0.05), with no statistical significance in the validation cohort (p>0.05). The correlations were all low between the Radscore values and the values of ESR, CRP, tI, ASDAS-ESR and ASDAS-CRP (p<0.05)., Conclusions: Radiomics analysis based on STIR texture analysis has a good prediction for the evaluation of bone marrow oedema activity of sacroiliac joints in AS. It can be a new non-invasive and objective evaluation method for AS activity.

The paediatric metaphysis is afflicted by a wide range of pathological processes as it is the most metabolically active and well-vascularised part of the developing skeleton. This review focuses on metaphyseal marrow signal change detected with magnetic resonance imaging, which is most often occult on radiographs. When bilateral, these imaging appearances frequently present a diagnostic quandary. This review assists the radiologist to confidently dismiss physiological signal change and confidently work through the differential diagnosis. This is achieved by illustrating a practical method of classifying signal change into four categories: physiological red marrow, red marrow reconversion, marrow infiltration, and oedema-like marrow signal intensity. In doing so, various pathological entities are reviewed along with imaging pearls and next-step investigations., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To identify bone marrow lesion (BML) trajectories over 4 years and their demographic and structural predictors in middle-aged and older adults with or at increased risk of knee osteoarthritis (OA)., Methods: A total of 614 participants (mean age 61 years, 62% female) from the Osteoarthritis Initiative cohort (OAI) were included. BMLs in 15 anatomical locations of the knee were measured annually from baseline to 4 years using the Magnetic Resonance Imaging Osteoarthritis Knee Score (MOAKS) method. BML trajectories were determined using latent class mixed models (LCMMs). Multinomial logistic regression was used to examine baseline characteristics that predicted BML trajectories., Results: Three distinct BML trajectories were identified: "Mild-stable BMLs" (25.9%), "Moderate-stable BMLs" (66.4%), and "Rapid-rise BMLs" (7.7%). Compared to the "Mild-stable BMLs" trajectory, current smokers were more likely to be in the "Moderate-stable BMLs" (odds ratio [OR] 2.089, P < 0.001) and "Rapid-rise" (OR 2.462, P < 0.001) trajectories. Moreover, female sex and meniscal tears were associated with an increased risk of being in the "Rapid-rise BMLs" trajectory (OR 2.023 to 2.504, P < 0.05). Participants who had higher education levels and drank more alcohol were more likely to be in the "Rapid-rise BMLs" trajectory (OR 1.624 to 3.178, P < 0.05) and less likely to be in the "Moderate-stable BMLs" trajectory (OR 0.668 to 0.674, P < 0.05)., Conclusions: During the 4-year follow-up, most participants had relatively stable BMLs, few had enlarged BMLs, and no trajectory of decreased BMLs was identified. Sociodemographic factors, lifestyle, and knee structural pathology play roles in predicting distinct BML trajectories., (© 2024. The Author(s).)

Objective: Conventional magnetic resonance imaging (MRI) uses T1-weighted and short-tau inversion recovery (STIR) sequences to characterize bone marrow in axial spondyloarthritis. However, quantification is restricted to estimating the extent of lesions because signal intensities are highly variable both within individuals and across patients and MRI scanners. This study evaluates the performance of quantitative T1 mapping for distinguishing different types of bone marrow lesions of the sacroiliac joints., Materials and Methods: In this prospective study, 62 patients underwent computed tomography (CT) and MRI of the sacroiliac joints including T1, STIR, and T1 mapping. Bone marrow lesions were characterized by three readers and assigned to one of four groups: sclerosis, osteitis, fat lesions, and mixed marrow lesions. Relaxation times on T1 maps were compared using generalized estimating equations and receiver operating characteristics (ROC) analysis., Results: A total of 119 lesions were selected (sclerosis: 38, osteitis: 27, fat lesions: 40; mixed lesions: 14). T1 maps showed highly significant differences between the lesions with the lowest values for sclerosis (1516±220 ms), followed by osteitis (1909±75 ms), and fat lesions (2391±200 ms); p<0.001. T1 mapping differentiated lesions with areas under the ROC curve of 99% (sclerosis vs. osteitis) and 100% (other comparisons)., Conclusion: T1 mapping allows accurate characterization of sclerosis, osteitis, and fat lesions at the sacroiliac joint but only for homogeneous, non-mixed lesions. Thus, further sequence development is needed before implementation in clinical routine., (© 2024. The Author(s).)

Background: Bone marrow lesions (BMLs) in knee osteoarthritis (OA) have been assessed histopathologically and by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI); however, a direct comparison of the results has not been reported., Purpose: To evaluate and compare the findings by DCE-MRI and histopathology of subchondral BMLs in knee OA., Material and Methods: In total, 19 patients with medial tibiofemoral knee OA undergoing total knee arthroplasty were analyzed. Preoperative MRI, including a DCE sequence, was performed, and bone biopsies were obtained from the resected specimens corresponding to BML areas. The contrast enhancement by DCE-MRI was analyzed using semi-quantitative (area under the curve [AUC]), peak enhancement [PE]), and quantitative (Ktrans, Kep) methods. Enhancement in the medial OA compartment was compared with similar areas in a normal lateral compartment, and the DCE characteristics of BMLs were correlated with semi-quantitatively graded histopathological features., Results: AUC and PE were significantly higher in medial tibial and femoral BMLs compared with the values in the lateral condyles; Ktrans and Kep were only significantly higher in the tibial plateau. In the tibia, AUC and PE were significantly correlated with the grade of vascular proliferation, and PE also with the degree of marrow fibrosis. There was no significant correlation between AUC/PE and histopathological findings in the femur and no correlation between quantitative DCE parameters and histopathological findings., Conclusion: BML characteristics by semi-quantitative DCE in the form of AUC and PE may be used as parameters for the degree of histopathological vascularization in the bone marrow whereas quantitative DCE data were less conclusive., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: It is beneficial for society to discover the risk factors associated with surgery and to carry out some early interventions for patients with these risk factors. Few studies specifically explored the relationship between bone marrow lesions (BMLs) and long-term incident joint surgery., Objective: To investigate the association between BML severity observed in knee osteoarthritis (OA) patients' first MRI examination and incident knee surgery within 5 years. Additionally, to assess the predictive value of BMLs for the incident knee surgery., Design: Retrospective cohort study., Methods: We identified patients diagnosed with knee OA and treated at our institution between January 2015 and January 2018, and retrieved their baseline clinical data and first MRI examination films from the information system. Next, we proceeded to determine the Max BML grades, BML burden grades and Presence BML grades for the medial, lateral, patellofemoral, and total compartments, respectively. Multi-variable logistic regression models examined the association of the BML grades with 5-year incident knee surgery. Positive and negative predictive values (PPVs and NPVs) were determined for BML grades referring to 5-year incident knee surgery., Results: Totally, 1011 participants (knees) were found eligible to form the study population. Within the 5 years, surgery was performed on 74 knees. Max BML grade 2 and grade 3 of medial, patellofemoral and total compartments were strongly and significantly associated with incident surgery. None of the BML grades from lateral compartment was associated with incident surgery. The PPV was low and NPV was high for BMLs., Conclusions: BMLs found in the first MRI examination were associated with 5-year incident joint surgery, except for those allocated in lateral compartments. The high NPVs imply that patients without BMLs have a low risk of requiring surgery within 5 years., (© 2024. The Author(s).)

Objectives: T2 STIR MRI sequences can detect preclinical changes associated with periodontal inflammation, i.e. intraosseous edema in the tooth-supporting bone. In this study, we assessed whether MRI can be used for monitoring periodontal disease., Material and Methods: In a prospective cohort study, we examined 35 patients with periodontitis between 10/2018 and 04/2019 by using 3D isotropic T2-weighted short tau inversion recovery (STIR) and Fast Field Echo T1-weighted Black bone sequences. All patients received standardized clinical exams before and three months after non-surgical periodontal therapy. Bone marrow edema extent was quantified in the STIR sequence at 922 sites before and after treatment. Results were compared with standard clinical findings. Non-parametric statistical analysis was performed., Results: Non-surgical periodontal treatment caused significant improvement in mean probing depth (p < 0.001) and frequency of bleeding on probing (p < 0.001). The mean depth of osseous edema per site was reduced from a median [IQR] of 2 [1, 3] mm at baseline to 1 [0, 3] mm, (p < 0.001). Periodontal treatment reduced the frequency of sites with edema from 35 to 24% (p < 0.01)., Conclusion: The decrease of periodontal bone marrow edema, as observed with T2 STIR MR imaging, is indicative of successful periodontal healing., Clinical Relevance Statement: T2 STIR hyperintense bone marrow edema in the periodontal bone decreases after treatment and can therefore be used to evaluate treatment success. Furthermore, MRI reveals new options to depict hidden aspects of periodontitis., Key Points: • T2 STIR hyperintense periodontal intraosseous edema was prospectively investigated in 35 patients with periodontitis before and after treatment and compared to clinical outcomes. • The frequency of affected sites was reduced from 35 to 24% (p < 0.001), and mean edema depth was reduced from a median [IQR] of 2 [1, 3] mm at baseline to 1 [0, 3] mm 3 months after treatment. (p < 0.001). • T2 STIR sequences can be used to monitor the posttreatment course of periodontitis., (© 2023. The Author(s).)

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse., (© 2024. The Author(s).)

Objective: To determine the prevalence of sacroiliac joint variants in patients with axial spondyloarthritis (axSpA) using MRI-based synthetic CT images and to evaluate their relationships with the presence of bone marrow edema, as this may potentially complicate diagnosing active sacroiliitis on MRI in patients with suspected axSpA., Methods: 172 patients were retrospectively included. All patients underwent MRI because of clinical suspicion of sacroiliitis. The diagnosis of axSpA was made by a tertiary hospital rheumatologist. Two readers independently determined the presence of bone marrow edema and the presence of one or more of the nine known sacroiliac joint (SIJ) variants., Results: SIJ variants were common in axSpA patients (82.9%) and the non-SpA group (85.4%); there were no significant differences in prevalence. Bone marrow edema was frequently found in axSpA (86.8%) and non-SpA patients (34%). AxSpA patients with SIJ variants (except for accessory joint) demonstrated 4 to 10 times higher odds for bone marrow edema, however not statistically significant. The more variants were present in this group, the higher the chance of bone marrow edema. However, some multicollinearity cannot be excluded, since bone marrow edema is very frequent in the axSpA group by definition., Conclusion: SIJ variants are common in axSpA and non-SpA patients. SIJ variants were associated with higher prevalence of bone marrow edema in axSpA patients, potentially due to altered biomechanics, except for accessory joint which may act as a stabilizer., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Aim: To assess the relationship between anatomical variants of sacroiliac joint (SIJ) and subchondral changes detected in magnetic resonance enterography (MRE) in patients with Crohn's disease (CD)., Methods: This was a retrospective study of 60 CD patients, who were divided into two groups: with (n = 16) and without SIJ (n = 44) involvement, depending on the presence of inflammatory (bone marrow edema) and structural changes (sclerosis and erosions) in MRE. Anatomical variants of SIJ were assessed in CT of the abdomen and/or pelvis, distinguishing typical form with convex iliac surface and atypical forms. Univariate and multivariate analyses were performed to reveal an association between joint changes and forms., Results: Our study included 60 patients (38 males; mean age 38.72 years ± 13.33). Patients with SIJ changes were older (p = .044). No significant differences in CD localization and behavior were found. The most common SIJ lesions were structural changes (in 75% of patients); the main atypical form was the iliosacral complex. The univariate and multivariate analyses showed a significant association of atypical forms with total subchondral changes (odds ratio [OR]: 3.429, 95% confidence interval [CI] 1.043-11.268; p = .042; OR: 5.066, 95% CI: 1.273-20.167; p = .021, respectively), and with structural changes (OR: 4.185, 95% CI: 1.155-15.160; p = .029; OR: 5.986, 95% CI: 1.293-27.700; p = .022, respectively)., Conclusion: Atypical forms of SIJ are a risk factor for the occurrence of structural joint changes in CD patients. An association between bone marrow edema and atypical forms was not found., (© 2024 The Authors. International Journal of Rheumatic Diseases published by Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Objective: To evaluate the value of virtual non-calcium (VNCa) technique of dual-energy CT (DECT) for detecting bone marrow edema (BME) around nontraumatic osteonecrosis of the femoral head (ONFH) using MRI as reference standard. Methods: Nontraumatic ONFH patients were prospectively studied in the Fourth Medical Center of Chinese PLA General Hospital from October 2022 to May 2023, and their MRI and DECT images were analyzed. The diagnostic efficiency of the subjective assessment of BME around ONFH by two radiologists in VNCa color-coded images were calculated using the MRI results as the reference standard. The BME ranges were compared between VNCa images and MRI. Traditional CT values and VNCa CT values were compared between normal bone marrow and BME. The receiver operator characteristic (ROC) curve was established based on the statistically different CT values, and the area under the curve (AUC) was calculated to find the threshold to distinguish normal bone marrow from BME and evaluate the diagnostic efficacy. Results: Thirty patients with ONFH were included, including 24 males and 6 females, aged (39±12) years. There were 18 bilateral hips and 12 unilateral hips, with a total of 48 hips, 34 hips of which showed BME on MRI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of subjective detection of BME on VNCa color coded maps by two physicians were 97.1% (33/34) and 97.1% (33/34), 92.9% (13/14) and 71.4% (10/14), 97.1% (33/34) and 89.2% (33/37), 92.9% (13/14) and 90.9% (10/11), 95.8% (46/48) and 89.6% (43/48), respectively, with no statistical difference (all P> 0.05).There was no statistical difference between VNCa color-coded images and MRI in the BME range ( P =1.160). The traditional CT values measured by the two radiologists were in good agreement with VNCa CT values, with intraclass correlation coefficient (ICC) of 0.948 (95% CI : 0.908-0.971) and 0.982 (95% CI : 0.969-0.990), respectively. The traditional CT value of normal bone marrow was (400.7±82.8) HU, and that of BME was (443.7±65.7) HU, with no statistical difference ( P =0.062). The VNCa CT value of normal bone marrow was (-103.1±27.8) HU, and that of BME was (-32.9±25.7) HU, with statistical difference ( P <0.001). The AUC of distinguishing normal bone marrow from BME based on VNCa CT value was 0.958 (95% CI : 0.857-0.995). The best cut-off value was -74.5 HU, and when the VNCa CT value was higher than -74.5 HU, the sensitivity, specificity, PPV, NPV and accuracy of diagnosing BME were 97.1%, 92.9%, 97.1%, 92.9% and 95.8 %, respectively. Conclusion: The VNCa technique of DECT has high efficiency in detecting BME around ONFH, and can accurately demonstrate the range of BME.

Objectives: To distinguish bone metastases (BMs) from benign red marrow depositions (BRMs) by qualitative and quantitative analyses of T1-weighted imaging and fat-suppressed T2-weighted imaging (T2 FS)., Methods: For 75 lesions including 38 BMs and 37 BRMs, two radiologists independently evaluated magnetic resonance images by qualitative (signal intensity [SI] of lesions compared to that of normal muscle [NM] or normal bone marrow [NBM]) and quantitative (parameters of the region of interests in the lesions, including T1 ratio [T1 SI ratio of lesion and NM], T2FMu ratio [T2 FS SI ratio of lesion and NM], and T2FMa ratio [T2 FS SI ratio of lesion and NBM]) analyses., Results: Hyperintensity relative to NM or NBM on T2 FS was more frequent in BMs than in BRMs (100% vs 59.5%-78.4%, respectively; P ≤ 0.001) but also was present in more than half of BRMs. All quantitative parameters showed a significant difference between BMs and BRMs (T1 ratio, 1.075 vs 1.227 [P = 0.002]; T2FMu ratio, 2.094 vs 1.282 [P < 0.001]; T2FMa ratio, 3.232 vs 1.810 [P < 0.001]). The receiver operating characteristics areas under the curves of T2FMu and T2FMa ratios were clinically useful (0.781 and 0.841, respectively) and did not demonstrate statistically significant differences., Conclusions: The quantitative analysis of T2 FS facilitates distinguishing between BMs and BRMs, regardless of whether the reference was NM or NBM., Advances in Knowledge: Quantitative parameters derived from T2 FS facilitate differentiation of BMs BRMs without additional scans. The role of NBM as an internal standard for T2 FS to differentiate between BMs and BRMs is similar to that of NM., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: For the diagnosis of bone marrow edema (BME), spectral computed tomography (CT) has emerged as a promising technique., Purpose: To study the different performances of spectral CT in the diagnosis of vertebral BME in young and middle-aged versus elderly patients., Material and Methods: Magnetic resonance imaging (MRI) was used as the gold standard. To determine the existence of BME, spectral CT color-coded images of the vertebral bodies of 82 patients with vertebral compression fractures (VCFs) were visually inspected. A quantitative analysis of the spectral CT vertebral water concentration in the diagnosis of BME was performed using a receiver operating characteristic (ROC) curve. Patients were divided into two groups for comparison: the young and middle-aged group; and the elderly group., Results: The sensitivity and specificity for visual assessment were 83.7% and 98.3%, respectively, in the young and middle-aged group and 96.8% and 98.2%, respectively, in the elderly group. The elderly group had a higher sensitivity than the young and middle-aged group ( P  < 0.05). With a threshold of 1046.2 mg/cm 3 , the ROC curve for the young and middle-aged group displayed an area under the curve (AUC) of 0.870, sensitivity of 86.0%, and specificity of 81.4%. The threshold of 1031.4 mg/cm 3 yielded a sensitivity of 95.2% and a specificity of 98.4%, and the AUC of the elderly group was 0.997. The elderly group had a higher level of specificity than the young and middle-aged group ( P  < 0.05)., Conclusion: Spectral CT can reliably diagnose BME in VCFs, and it performs better in elderly people than in young and middle-aged people., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The clinical significance of foot and ankle bone marrow edema (BME) is poorly understood., Methods: Magnetic resonance imaging (MRI) and the visual analog scale (VAS) pain scores were collected for 17 runners who participated in the Twin Cities Marathon, immediately postmarathon and at a 6-week follow-up. Bone marrow edema lesions were classified using lesion frequency, anatomical location, and grading scale change to calculate a BME score for each affected bone. Spearman rank correlation coefficient test was used to identify a possible correlation between VAS and postmarathon BME. A paired Student t test was used to detect differences between total mileage ran 6 weeks postmarathon in participants with or without BME., Results: After completing the marathon, 8 BME lesions were identified in 5 participants (29.4%; 5/17), 3 were men, and 2 were women, with a mean age of 33.8 years (range: 24-52), and BMI of 22.9 ± 4. All lesions were resolved on 6-week follow-up imaging. VAS pain scores did not correlate with postmarathon BME. A significant difference in total miles logged over 6 weeks postmarathon could not be found among participants with and without BME., Conclusion: Foot and ankle BME changes identified by MRI were not correlated to clinical symptoms and may resolve with self-directed activity in less time than other areas of the lower extremity., Level of Evidence: Level II, Prospective Cohort Study., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. ICMJE forms for all authors are available online.

Objective: We aimed to develop and validate a fully automated machine learning (ML) algorithm that predicts bone marrow edema (BME) on a quadrant level in sacroiliac (SI) joint magnetic resonance imaging (MRI)., Methods: A computer vision workflow automatically locates the SI joints, segments regions of interest (ilium and sacrum), performs objective quadrant extraction, and predicts presence of BME, suggestive of inflammatory lesions, on a quadrant level in semicoronal slices of T1/T2-weighted MRI scans. Ground truth was determined by consensus among human readers. The inflammation classifier was trained using a ResNet18 backbone and five-fold cross-validated on scans of patients with spondyloarthritis (SpA) (n = 279), postpartum individuals (n = 71), and healthy subjects (n = 114). Independent SpA patient MRI scans (n = 243) served as test data set. Patient-level predictions were derived from aggregating quadrant-level predictions, ie, at least one positive quadrant., Results: The algorithm automatically detects the SI joints with a precision of 98.4% and segments ilium/sacrum with an intersection over union of 85.6% and 67.9%, respectively. The inflammation classifier performed well in cross-validation: area under the curve (AUC) 94.5%, balanced accuracy (B-ACC) 80.5%, and F1 score 64.1%. In the test data set, AUC was 88.2%, B-ACC 72.1%, and F1 score 50.8%. On a patient level, the model achieved a B-ACC of 81.6% and 81.4% in the cross-validation and test data set, respectively., Conclusion: We propose a fully automated ML pipeline that enables objective and standardized evaluation of BME along the SI joints on MRI. This method has the potential to screen large numbers of patients with (suspected) SpA and is a step closer towards artificial intelligence-assisted diagnosis and follow-up., (© 2023 American College of Rheumatology.)

Background: Knee injuries are prevalent, and early diagnosis is crucial for guiding clinical therapy. MRI is the diagnostic gold standard for bone marrow edema (BME) in patients with acute knee injuries, yet there are still limitations. Dual-energy CT, a possible viable replacement, is being explored (DECT)., Methods: We systematically retrieved studies from EMBASE, Scopus, PUBMED, and the Cochrane Library and collected gray literatures. In accordance with the PRISMA-DTA standards, a systematic review was conducted between the study's initiation and July 31, 2021, utilizing an MRI reference standard and at least 10 adult patients with acute knee injuries to evaluate the diagnostic effectiveness of DECT for diagnosing BME. Two reviewers collected the study's details independently. For the meta-analysis, a bivariate mixed-effects regression model was utilized, and subgroup analysis was employed to determine the sources of variability., Results: The research included nine studies that examined 290 individuals between the ages of 23 and 53 with acute knee injuries who had DECT and MRI. Overall, the sensitivity, specificity, and AUC of the BME were 85% (95% confidence interval [CI]: 77-90%), 96% (95% CI: 93-97%), and 0.97 (95% CI: 0.95-0.98), respectively. To account for the assumed diversity of research, there were no statistically significant differences between the comparison groups in terms of specificity and sensitivity., Conclusion: DECT is a viable alternative to MRI for individuals with acute knee injuries when MRI is inappropriate or unavailable., (© 2023. The Author(s).)

Objective: To assess whether the presence of bone marrow edema (BME) leads to the development of structural lesions at the same anatomical location of the sacroiliac joints (SIJ), and to investigate the association between BME patterns over time and structural lesions in patients with early axial spondyloarthritis (axSpA)., Methods: Patients with axSpA from the DESIR cohort with ≥2 consecutive magnetic resonance imaging (MRI)-SIJ were assessed at baseline, 2 and 5 years. MRI-SIJ images were divided into 8 quadrants. The association between BME and subsequent structural lesions (sclerosis, erosions, fatty lesions, and ankylosis) on MRI in the same quadrant was tested longitudinally. Additionally, patients were grouped according to the pattern of BME evolution across quadrants over time (no BME, sporadic, fluctuating, and persistent). The association between these patterns and 5-year imaging outcomes (eg: ≥5 erosions and/or fatty lesions on MRI-SIJ) was tested., Results: In total, 196 patients were included. BME in each quadrant was associated with sclerosis (OR:1.9 (95%CI: 1.1;3.4)), erosions (1.9 (1.5;2.5)) and fatty lesions (1.9 (1.4;2.6)). Ankylosis was uncommon. There was a gradient between increased level of inflammation and subsequent damage: compared to the 'no BME' pattern, the sporadic (OR (95% CI): 2.1 (1.0;4.5)), fluctuating (OR:5.6(2.2;14.4)) and persistent (OR:7.5(2.8;19.6)) patterns were associated with higher structural damage on MRI-SIJ at 5-years., Conclusions: In early axSpA, inflammation on MRI-SIJ leads to damage at the quadrant level. The higher the exposure to inflammation across quadrants in the SIJs over time the higher the likelihood of subsequent structural damage, suggesting a cumulative effect., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2023. Published by Elsevier Inc.)

Objective: To investigate the relationship between bone marrow edema and pathological changes, symptoms and signs of severe knee osteoarthritis., Methods: From January 2020 to March 2021, 160 patients with severe knee osteoarthritis who underwrent MRI of the knee at the Department of Bone and Joint, Wangjing Hospital, China Academy of Chinese Medical Sciences were included. Eighty patients with bone marrow edema were selected as the case group, including 12 males and 68 females, aged from 51 to 80 years old with an average of (66.58±8.10) years old, the duration of disease 5 to 40 months with an average of (15.61±9.25) months. Eighty patients without bone marrow edema were selected as the control group, including 15 males and 65 females, aged from 50 to 80 years old with an average of (67.82±8.05) years old, the duration of disease 6 to 37 months with an average of (15.75±8.18) months, BMI was (28.26±3.13) kg·m -2 ranged from 21.39 to 34.46 kg·m -2 . The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score (WORMS). The degree of knee osteoarthritis was evaluated by Kellgren- Lawrence(K-L) grade and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). The degree of joint pain was evaluated by visual analogue scale(VAS) and WOMAC pain score, the joint signs were evaluated by tenderness, percussion pain, joint swelling and joint range of motion. To explore the relationship between bone marrow edema and knee osteoarthritis, the prevalence of bone marrow edema and K-L grade were compared between the two groups. Furthermore the WORMS score and WOMAC index, pain-related score, and sign-related score correlation coefficient were analyzed to further explore the relationship between bone marrow edema and knee osteoarthritis index, joint pain symptoms and signs., Results: There was 68.75% (55/80) of the patients in the case group were in K-L grade Ⅳ, and 52.5% (42/80) in the control group, indicating a higher proportion of patients with grade Ⅳ in the case group than the control group ( χ 2 =4.425, P <0.05). In the case group, there was a strong correlation between bone marrow edema WORMS score and knee osteoarthritis WOMAC index. ( r =0.873>0.8, P <0.001), a moderate correlation between WORMS score and VAS score and WOMAC pain score( r =0.752, 0.650>0.5, P <0.001), a moderate correlation between WORMS score and percussion pain score ( r =0.784>0.5, P <0.001), and a weak correlation between WORMS score and VAS and tenderness score, joint swelling score and joint range of motion score ( r =0.194, 0.259, 0.296<0.3, P <0.001)., Conclusion: Our study suggests that severe knee osteoarthritis is associated with an increased risk of bone marrow edema. Bone marrow edema can also lead to knee osteoarthritis joint pain, with percussion pain being a positive sign, but tenderness, joint swelling and limitation of activity are not significantly related to bone marrow edema.

Objectives: To develop an objective and efficient method based on radiomics to evaluate bone marrow edema (BMO) of sacroiliac joints (SIJs) by magnetic resonance imaging (MRI) in patients with axial spondyloarthritis (axSpA) and to compare with the Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system., Methods: From September 2013 to March 2022, patients with axSpA who underwent 3.0T SIJ-MRI were included and were randomly divided into training and validation cohorts at a ratio of 7:3. The optimal radiomics features selected from the SIJ-MRI in the training cohort were included to generate the radiomics model. The performance of the model was evaluated by ROC analysis and decision curve analysis (DCA). Rad scores were calculated using the radiomics model. The responsiveness was compared for Rad scores and SPARCC scores. We also assessed the correlation between the Rad score and SPARCC score., Results: A total of 558 patients were finally included. The radiomics model showed favorable discrimination of a SPARCC score <2 or ≥2 both in the training (AUC, 0.90; 95% CI: 0.87-0.93) and validation cohorts (AUC, 0.90; 95% CI, 0.86-0.95). DCA confirmed that the model was clinically useful. Rad score showed higher responsiveness to treatment-related change than SPARCC score. Furthermore, a significant correlation was noted between the Rad score and SPARCC score when scoring the status of BMO (r s =0.80, P < 0.001), and a strong correlation was noted when scoring the change in BMO (r=0.70, P < 0.001)., Conclusion: The study proposed a radiomics model to accurately quantify the BMO of SIJs in patients with axSpA, providing an alternative to the SPARCC scoring system. Key Points • The Rad score is an index with high validity for the objective and quantitative evaluation of bone marrow edema (BMO) of the sacroiliac joints in axial spondyloarthritis. • The Rad score is a promising tool to monitor the change of BMO upon treatment., (© 2023. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Objectives: Bone marrow edema (BME) from dual-energy CT is useful to direct attention to radiographically occult fractures. The aim was to characterize utility of BME of lower extremity (LE) fractures with the hypothesis that stabilized and post-acute fractures exhibit decreased extent and frequency of BME than non-stabilized and acute fractures, respectively., Methods: An IRB-approved retrospective review of known LE fractures. A total of 141 cases met inclusion criteria, including 82 fractures without splint/cast stabilization, and 59 cases with stabilization. Two readers independently recorded BME, and its multiplicity and area (mm 2 ). A separate reader assessed fracture location, comminution, and chronicity. Wilcoxon rank sum test, multiple regression, intraclass correlation (ICC), kappa statistics, and chi-square tests were used., Results: BME was significantly larger in non-stabilized (859.3 mm 2 (420.6-1451.8)) than stabilized fractures (493.5 mm 2 (288.8-883.2)), p = .011). Comminuted (p = 0.006), non-stabilized (p = 0.0004), and acute fractures (p = 0.036) were all associated with larger BME area. BME presence had excellent results for both stabilized (Cohen's Kappa = 0.81) and non-stabilized fractures (Cohen's Kappa = 0.84). ICC for BME area showed excellent correlation for both stabilized (ICC = 0.78) and non-stabilized groups (ICC = 0.86). BME multiplicity showed excellent agreement for stabilized (ICC = 0.81) and good agreement for non-stabilized (ICC = 0.67) fractures. Lastly, stabilized cases showed increased multiplicity of BME compared to non-stabilized fractures (p < 0.001)., Conclusions: BME evaluation can assist in differentiation of acute versus post-acute fractures. Extent of BME is reduced with splint/cast stabilization, which may limit its accuracy in detection of lower extremity fractures., Key Points: • Evaluation of bone marrow edema on dual-energy CT aids in differentiation of acute versus post-acute fracture. • Bone marrow edema evaluation is limited in the setting of post-acute or stabilized fractures. • There is decreased frequency and extent of bone marrow edema in post-acute, non-comminuted, and stabilized fractures., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Background: Bone marrow edema (BME) and erosion of the sacroiliac joint are both key lesions for diagnosing axial spondyloarthritis (axSpA) on magnetic resonance imaging (MRI)., Purpose: To qualitatively and quantitatively compare intermediate-weighted MRI with fat suppression (IW-FS) with T2-weighted short tau inversion recovery (T2-STIR) in assessment of sacroiliac BME and erosion in axSpA., Material and Methods: Patients aged 18-60 years with axSpA were prospectively enrolled. All patients underwent a 3.0-T MRI examination of the sacroiliac joints. Para-coronal IW-FS, T2-STIR, and T1-weighted (T1W) images were acquired. BME and erosion were scored by two readers in consensus on IW-FS and STIR using a modified Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system. Consensus scores on T1WI were used as the reference for erosion. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for BME., Results: In total, 49 patients (mean age=33.4 ± 7.6 years) were included. More patients were scored as having BME on T2-STIR (36 vs. 29, P  = 0.016). SPARCC-BME score on IW-FS was lower than that acquired on T2-STIR (mean, 11.5 vs. 14.7, P  = 0.002). SNR and CNR of BME were both lower on IW-FS than on T2-STIR (mean SNR, 118 vs. 218, P  < 0.001; mean CNR, 44 vs. 137, P  < 0.001). The sensitivity of erosion detection was higher on IW-FS (83%) than on T2-STIR (54%, P  = 0.006)., Conclusion: IW-FS is not sufficient for BME detection using T2-STIR as the reference standard in patients with axSpA. IW-FS has a much higher sensitivity than T2-STIR for erosion detection in the sacroiliac joint.

Objectives: To evaluate extensor carpi ulnaris (ECU) tendon pathology and ulnar styloid process bone marrow edema (BME) as diagnostic MRI markers for peripheral triangular fibrocartilage complex (TFCC) tears., Methods: One hundred thirty-three patients (age range 21-75, 68 females) with wrist 1.5-T MRI and arthroscopy were included in this retrospective case-control study. The presence of TFCC tears (no tear, central perforation, or peripheral tear), ECU pathology (tenosynovitis, tendinosis, tear or subluxation), and BME at the ulnar styloid process were determined on MRI and correlated with arthroscopy. Cross-tabulation with chi-square tests, binary logistic regression with odds ratios (OR), and sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were used to describe diagnostic efficacy., Results: On arthroscopy, 46 cases with no TFCC tear, 34 cases with central perforations, and 53 cases with peripheral TFCC tears were identified. ECU pathology was seen in 19.6% (9/46) of patients with no TFCC tears, in 11.8% (4/34) with central perforations and in 84.9% (45/53) with peripheral TFCC tears (p < 0.001); the respective numbers for BME were 21.7% (10/46), 23.5% (8/34), and 88.7% (47/53) (p < 0.001). Binary regression analysis showed additional value from ECU pathology and BME in predicting peripheral TFCC tears. The combined approach with direct MRI evaluation and both ECU pathology and BME yielded a 100% positive predictive value for peripheral TFCC tear as compared to 89% with direct evaluation alone., Conclusions: ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to diagnose tears., Key Points: • ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to confirm the presence of TFCC tears. • If there is a peripheral TFCC tear on direct MRI evaluation and in addition both ECU pathology and BME on MRI, the positive predictive value is 100% that there will be a tear on arthroscopy compared to 89% with direct evaluation alone. • If there is no peripheral TFCC tear on direct evaluation and neither ECU pathology nor BME on MRI, the negative predictive value is 98% that there will be no tear on arthroscopy compared to 94% with direct evaluation alone., (© 2023. The Author(s).)

Objective: To explore relationship between bone marrow edema(BME) and osteoporosis in patients with severe knee osteoarthritis., Methods: Unmatched case-control study was conducted. Totally 160 patients with severe knee osteoarthritis who had undergone knee magnetic resonance imaging (MRI) and bone mineral density examination (BMD) from January 2020 to March 2021 were included. Eighty patients complicated with BME were included in BME group, and 80 patients without BME were selected as NBME group. In BME group, there were 12 males and 68 females, aged from 51 to 80 years old with an average of(66.58±8.10) years old;the courses of disease ranged from 5 to 40 months with an average of (15.61±9.25) months;body mass index(BMI) ranged from 21.81 to 34.70 with an average of (27.79±3.00) kg·m -2 ;25 patients classified to grade Ⅲ and 55 patients grade Ⅳ according to Kellgren- Lawrence(K-L). In NBME group, there were 15 males and 65 females, aged from 50 to 80 years old with an average of(67.82±8.05) years old;the course of disease ranged from 6 to 37 months with an average of(15.75±8.18) months;BMI ranged from 21.39 to 34.46 with an average of (28.26±3.13) kg·m -2 ;25 patients were K-L Ⅲ and 55 patients with K-L Ⅳ. The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score(WORMS). Osteoporosis was diagnosed and BMD was evaluated by DXA T value. To explore the relationship between bone marrow edema and osteoporosis by comparing prevalence rate of osteoporosis between two groups, and to further explore relationship between BME and BMD by Spearman correlation analysis of BME WORMS score and DXA T value in BME group., Results: The complete case data were obtained on the first diagnosis, and there was no significant difference in sex, age, courses of disease and BMI between two groups ( P >0.05). The proportion of K-L Ⅳ in BME group was significantly higher than that in NBME ( P <0.05). The prevalence rate of osteoporosis in BME group was significantly higher than in NBME group with the same K-L grade ( P <0.001), and there was a strong negative correlation between BME WORMS score and DXA BMD T value ( r =-0.812, | r |=0.812 >0.8, P <0.001)., Conclusion: Osteoporosis is one of the risk factors of bone marrow edema in patients with severe knee osteoarthritis, and the lower the bone mineral density is, the easier it is to be complicated with bone marrow edema.

This study aimed to investigate the influence of bone marrow edema (BME) for the assessment of the boundaries of necrotic lesions using unenhanced and contrast-enhanced (CE) magnetic resonance (MR) images in patients with osteonecrosis of the femoral head (ONFH). We retrospectively reviewed 72 consecutive hips in 55 patients of ONFH that were Association Research Circulation Osseous (ARCO) stage III or higher and underwent both unenhanced and contrast-enhanced MR imaging between January 2005 and February 2016. The degree of extension of BMEs, and the boundaries of the necrotic lesions were compared using unenhanced and CE MR images on both mid coronal and mid oblique-axial slices. Forty-two percent of the coronal T1 images, 40% of the coronal fat-saturated T2 images, and 48% of the oblique-axial T1 images showed differences in the boundaries of necrotic lesion, by comparison with those of CET1-weighted MR images. The boundaries of necrotic lesions were clearly detected in all hips on CE coronal slices and 97% of all hips on CE oblique-axial slices. The BME grade in the difference group was significantly higher than in the non-difference group on the coronal plane (P = 0.0058). There were significant differences between the BME grade and duration from the onset of hip pain to MR imaging examination. Multivariate analyses revealed that the duration from the onset to MR imaging examination in both coronal (P = 0.0008) and oblique-axial slices (P = 0.0143) were independently associated with differences in the boundary of necrotic lesion between T1 and CET1-weighted MR images. Our findings suggest that unenhanced MR image may be insufficient for a precise assessment of the boundaries of the necrotic lesions for ONFH cases in the early phase of subchondral collapse due to the diffuse BME., (© 2022. The Author(s).)

Background: Diagnosis of osteomyelitis by imaging can be challenging. The feasibility of diffusion-weighted imaging (DWI) as ancillary sequence was evaluated in this study., Purpose: To evaluate DWI for differentiation between osteomyelitis, bone marrow edema, and healthy bone on forefoot magnetic resonance imaging (MRI)., Study Type: Prospective., Subjects: A total of 60 consecutive patients undergoing forefoot MRI divided into three study groups (20 subjects each): osteomyelitis, bone marrow edema, and healthy bone., Field Strength/sequence: A 1.5T and 3T MRI scanners; readout-segmented multishot echo planar DWI., Assessment: Two independent radiologists measured apparent diffusion coefficient (ADC) values within abnormal or healthy bone., Statistical Tests: ADC values were compared between groups (pairwise t-test with Bonferroni-Holm correction for multiple testing). Intraclass correlation coefficient (ICC) was calculated to assess inter-reader agreement. Threshold ADC values were determined as the cutoffs that maximized the sum of sensitivity and specificity. Receiver operating characteristic (ROC) analysis was performed with statistical threshold of P < 0.05., Results: Inter-reader agreement was 0.92 in the healthy bone group and 0.78 in both the edema and osteomyelitis groups. Average ADC values were significantly different between groups: 1432 ± 222 × 10 -6  mm 2 /sec (osteomyelitis), 1071 ± 196 × 10 -6  mm 2 /sec (bone marrow edema), and 277 ± 89 × 10 -6  mm 2 /sec (healthy bone). A threshold ADC value of 534 × 10 -6  mm 2 /sec distinguishes between healthy and abnormal bone with specificity and sensitivity of 100% each. For distinction between osteomyelitis and bone marrow edema, two cutoff values were determined: a 95%-specificity cutoff indicating osteomyelitis (>1320 × 10 -6  mm 2 /sec) and a 95%-sensitivity cutoff indicating bone marrow edema (<1155 × 10 -6  mm 2 /sec). Diagnostic accuracy of 95% was achieved for 73% (29/40) of the subjects., Data Conclusion: DWI with ADC maps distinguishes between healthy and abnormal bone on forefoot MRI. Calculated cutoff values allow confirmation or exclusion of osteomyelitis in a high proportion of subjects., Evidence Level: 2 TECHNICAL EFFICACY: Stage 2., (© 2022 International Society for Magnetic Resonance in Medicine.)

Objective: To investigate whether bone marrow edema (BME) fulfilling the ASAS definition of magnetic resonance imaging (MRI) sacroiliitis is associated with non-inflammatory spine abnormalities in patients with definite mechanical chronic back pain (CBP)., Methods: Patients with definite mechanical CBP, according to the physician, started before the age of 45 and be lasting for more than 3months but less than 3years underwent a protocolized MRI and radiographs of sacroiliac joint (SIJ) and spine. BME and structural changes were scored, by three readers, for SIJ as well as non-inflammatory abnormalities for spine, including degenerative lesions and static disorders. Univariate analysis by Chi 2 test was performed to search a statistical association between BME fulfilling the ASAS definition of MRI sacroiliitis and the presence of at least one non-inflammatory spine abnormality., Results: A total of 94 patients were analyzed, 27 (29%) patients had BME and 16 (17%) patients had BME fulfilling the ASAS definition of MRI sacroiliitis; 86 (91.5%) patients had at least one non-inflammatory spine abnormality which are associated into 3 distinct clusters. BME was slightly more frequent at the lower and posterior part of the SIJ. MRI sacroiliitis was associated with interspinous bursitis, facet joint effusion and lateral spinal deviation and was more likely in patients with at least one non-inflammatory spine abnormality (OR: 4.96, 95% CI [1.47; 16.72])., Conclusions: BME fulfilling the ASAS definition of MRI sacroiliitis is significantly associated with non-inflammatory spine abnormalities in patients with mechanical CBP., (Copyright © 2022 Société française de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.)

Objective: To investigate the feasibility and correlation of sacroiliac joint (SIJ) fat fraction (FF) and R2 ∗ as markers of bone metabolism in patients with ankylosing spondylitis (AS)., Methods: 75 AS patients were classified into an early active group (EA), late active group (LA), and inactive group (IA). Additionally, 54 matched healthy individuals were selected to be part of the normal control group (NC). All participants underwent chemical shift encoded based MRI (IDEAL-IQ) and routine clinical SIJ MRI at 3.0 T. FF and R2 ∗ were measured in subchondral bone, bone marrow edema (BME), and fat metaplasia (FM). Out of the participants, 39 with BME lesions (15 from EA, 16 from LA, 8 from IA) and 39 with FM lesions (9 from EA, 17 from LA, 13 from IA) were included. Differences in FF, R2 ∗ value for subchondral bone of all participants and for BME, FM lesions were evaluated. Subsequently, different stages of BME and FM in patient groups were compared, and the relationship between FF and R2 ∗ was analyzed., Results: A significant difference in FF was demonstrated among the BME, FM and the normal bone marrow ( p < 0.001), meanwhile, the difference of R2 ∗ value in FM was significantly lower (p = 0.034, 0.012) than that of BME and that of normal bone marrow. At lever of different lesions, only the FF for BME was significantly different among 3 patient groups ( p = 0.001), while there was no significantly different FF for FM among 3 patient groups. Unlike in BME lesions, the FF in FM lesions had a negative correlation with R2 ∗ ( p < 0.001, r = -0.488)., Conclusion: FF and R2 ∗ measurements help to quantitatively analyze the bone marrow fat composition and bony trabecular microstructure changes in AS, providing a noninvasive and accurate assessment basis for AS bone metabolism abnormalities., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Li-ping Ma et al.)

Background: Hip labral tear (LT) causes various degrees of hip pain, for which there are few objective measures. Bone marrow oedema (BME), characterized by a diffuse, widely spreading change in the bone marrow, is observed in some patients with LT. However, its pathological role has not been fully understood. The purpose of this study was to investigate the prevalence of BME on hip magnetic resonance imaging (MRI) in patients with LT and to determine whether BME was an objective indicator of hip pain., Methods: In total, 84 patients with LT who underwent MRI scanning under the same conditions were included. We determined the presence or absence of BME and its size on MRI and evaluated the relationships between BME and sex, age, and pain and total scores on the modified Harris hip score (MHHS). In addition, we collected data on surgical treatments such as hip arthroscopy within a one-year follow-up period and examined whether the presence of BME affected the course of therapy., Results: BME was found in 34.5% of patients. MHHS pain and total scores were significantly lower in patients with BME (MHHS pain score: non-BME vs. BME ≤ 1 cm: p = 0.022, non-BME vs. BME > 1 cm: p < 0.001; MHHS total score: non-BME vs. BME ≤ 1 cm: p = 0.131, non-BME vs. BME > 1 cm: p = 0.027). The presence of BME did not differ between patients who did and did not undergo surgery during follow-up (p = 0.563)., Conclusion: BME on MRI in patients with LT might be an indicator of hip pain and hip joint dysfunction., (© 2022. The Author(s).)

Objective: This study evaluated the ability of a custom dual-energy CT (DECT) post-processing material decomposition method to image bone marrow edema after acute knee injury. Using an independent validation cohort, the DECT method was compared to gold-standard, fluid-sensitive MRI. By including both quantitative voxel-by-voxel validation outcomes and semi-quantitative radiologist scoring-based assessment of diagnostic accuracy, we aimed to provide insight into the relationship between quantitative metrics and the clinical utility of imaging methods., Materials and Methods: Images from 35 participants with acute anterior cruciate ligament injuries were analyzed. DECT material composition was applied to identify bone marrow edema, and the DECT result was quantitatively compared to gold-standard, registered fluid-sensitive MRI on a per-voxel basis. In addition, two blinded readers rated edema presence in both DECT and fluid-sensitive MR images for evaluation of diagnostic accuracy., Results: Semi-quantitative assessment indicated sensitivity of 0.67 and 0.74 for the two readers, respectively, at the tibia and 0.55 and 0.57 at the femur, and specificity of 0.87 and 0.89 for the two readers at the tibia and 0.58 and 0.89 at the femur. Quantitative assessment of edema segmentation accuracy demonstrated mean dice coefficients of 0.40 and 0.16 at the tibia and femur, respectively., Conclusion: The custom post-processing-based DECT method showed similar diagnostic accuracy to a previous study that assessed edema associated with ligamentous knee injury using a CT manufacturer-provided, built-in edema imaging application. Quantitative outcome measures were more stringent than semi-quantitative scoring methods, accounting for the low mean dice coefficient scores., (© 2022. ISS.)

Objective: Magnetic resonance imaging (MRI) plays a pivotal role in spondyloarthritis (SpA) diagnosis. However, a detailed description of MRI findings of the sacroiliac (SI) joints and spine in healthy individuals is currently lacking. This study was undertaken to evaluate the occurrence of MRI-detected SI joint and spinal lesions in healthy individuals in relation to age., Methods: Ninety-five healthy subjects (ages 20-49 years) underwent MRI of the SI joints and spine. Bone marrow edema (BME) and structural lesions of the SI joints were scored using the Spondyloarthritis Research Consortium of Canada (SPARCC) method. Spinal inflammatory and structural lesions were evaluated using the SPARCC MRI spine inflammation index and the Canada-Denmark MRI scoring system, respectively. Fulfillment of the Assessment of SpondyloArthritis international Society definition of a positive MRI for sacroiliitis/spondylitis was reviewed. Findings were compared to MRIs of axial SpA patients from the Belgian Inflammatory Arthritis and Spondylitis cohort., Results: Of the subjects ≥30 years old, 17.2% fulfilled the definition of a positive MRI for sacroiliitis, but this occurred rarely in younger subjects. SI joint erosions (20.0%) and fat metaplasia (13.7%) were detected across all age groups. Erosions were more frequently visualized in subjects ages ≥40 years (39.3%). Spinal BME (35.7%) and fat metaplasia (28.6%) were common in subjects older than 40 years. Nonetheless, only 1 subject had ≥3 corner inflammatory lesions. SI joint and spinal SPARCC scores and total structural lesions scores increased progressively with age., Conclusion: Contrary to what is commonly believed, structural MRI-detected SI joint lesions are frequently seen in healthy individuals. Especially in older subjects, the high occurrence of inflammatory and structural MRI-detected lesions impacts their specificity for SpA, which has important implications for the interpretation of MRIs in patients with a clinical suspicion of SpA., (© 2022 American College of Rheumatology.)

Purpose: The purpose of our study was to analyze the change in water and fat density within the bone marrow using the GE Revolution dual-energy computed tomography (DECT) platform using two-material decomposition analyses at extremity, spine, and pelvic fracture sites compared to normal bone marrow at equivalent anatomic sites in adult patients who sustained blunt trauma., Methods: This retrospective study included 26 consecutive adults who sustained blunt torso trauma and an acute fracture of the thoracolumbar vertebral body, pelvis, or upper and lower extremities with a total of 32 fractures evaluated. Two-material decomposition images were analyzed for quantitative analysis. Statistical analysis was performed using the paired t-test and Shapiro-Wilk test for normality., Results: There were statistically significant differences in the water and fat densities in the bone marrow at the site of an extremity, vertebral body, or pelvic fracture when compared to the normal anatomic equivalent (p < 0.01)., Conclusion: In this preliminary study, DECT basis material images, using water (calcium) and fat (calcium) decomposition illustrated significant differences in water and fat content between fracture sites and normal bone in a variety of anatomical sites., (© 2022. The Author(s), under exclusive licence to American Society of Emergency Radiology (ASER).)

Purpose: This meta-analysis aimed to evaluate the diagnostic performance of dual-energy computed tomography (DECT) for detecting bone marrow edema (BME) in non-traumatic patients., Methods: A systematic search of PubMed, EMBASE, and the Cochrane Library databases was performed up to October 1, 2021 for relevant original studies. Study details were extracted by two independent reviewers. A bivariate mixed-effects regression model was used to assess comprehensive diagnostic performance, and a subgroup analysis was performed to evaluate sources of variability. The risk of bias was evaluated with the QUADAS-2 tool., Results: Ten studies involving 2463 regions, including hands, ankles, hips, and sacroiliac joints, were evaluated in this meta-analysis. Summary sensitivity, specificity, and area under the receiver operating characteristic curve values for BME were 88.4% (95% confidence interval (CI) 82.4%-92.5%), 96.1% (95% CI 94.4%-97.3%), and 0.98 (95% CI 96%-99%), respectively. The subgroup analysis showed that studies using a thicker slice (≥1 mm) had a higher sensitivity, and studies with older patients (≥60 years), fewer included patients (<40), and bones other than the pelvis had a higher specificity. Studies presented a generally low or unclear risk for bias and applicability concerns., Conclusions: DECT has an excellent diagnostic performance for detecting BME in non-traumatic patients and may provide an alternative to magnetic resonance imaging (MRI) for the detection of non-traumatic BME in the future, especially when MRI is unavailable or contraindicated., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Demographic change entails an increasing incidence of fragility fractures. Dual-energy CT (DECT) with virtual non-calcium (VNCa) reconstructions has been introduced as a promising diagnostic method for evaluating bone microarchitecture and marrow simultaneously. This study aims to define the most accurate cut-off value in Hounsfield units (HU) for discriminating the presence and absence of bone marrow edema (BME) in sacral fragility fractures., Methods: Forty-six patients (40 women, 6 men; 79.7 ± 9.2 years) with suspected fragility fractures of the sacrum underwent both DECT (90 kVp / 150 kVp with tin prefiltration) and MRI. Nine regions-of-interest were placed in each sacrum on DECT-VNCa images. The resulting 414 HU measurements were stratified into "edema" (n = 80) and "no edema" groups (n = 334) based on reference BME detection in T2-weighted MRI sequences. Area under the receiver operating characteristic curve was calculated to determine the desired cut-off value and an associated conspicuity range for edema detection., Results: The mean density within the "edema" group of measurements (+ 3.1 ± 8.3 HU) was substantially higher compared to the "no edema" group (-51.7 ± 21.8 HU; p < 0.010). Analysis in DECT-VNCa images suggested a cut-off value of -12.9 HU that enabled sensitivity and specificity of 100% for BME detection compared to MRI. A range of HU values between -14.0 and + 20.0 is considered indicative of BME in the sacrum., Conclusions: Quantitative analysis of DECT-VNCa with a cut-off of -12.9 HU allows for excellent diagnostic accuracy in the assessment of sacral fragility fractures with associated BME. A diagnostic "one-stop-shop" approach without additional MRI is feasible., (© 2022. The Author(s).)

Purpose: To compare the diagnostic performance of a deep learning (DL) model with that of musculoskeletal physicians and radiologists for detecting bone marrow edema on dual-energy CT (DECT)., Method: This retrospective study included adult patients underwent hip DECT and MRI within 1 month between April 2018 and December 2020. A total of 8709 DECT images were divided into training/validation (85%, 7412 augmented images) and test (15%, 1297 images) sets. The images were labeled as present/absent bone marrow edema, with MRI as reference standard. We developed and trained a DL model to detect bone marrow edema from DECT images. Thereafter, DL model, two orthopedic surgeons, and three radiologists evaluated the presence of bone marrow edema on every test image. The diagnostic performance of the DL model and readers was compared. Inter-reader agreement was calculated using Fleiss-kappa statistics., Results: A total of 73 patients (mean age, 59 ± 12 years; 38 female) were included. The DL model had a significantly higher area under the curve (AUC, 0.84 vs. 0.61-0.70, p < 0.001) and sensitivity (79% vs. 29-66%) without loss of specificity (90% vs. 74-93%) than the non- or less-experienced readers and similar to the trained reader (AUC, 0.83, p = 0.402; sensitivity, 71%; specificity, 94%). Additionally, AUCs were strongly dependent on the reader's DECT experience. Inter-reader agreement was fair (κ = 0.303)., Conclusion: The DL model showed better diagnostic performance than less-experienced physicians in detecting bone marrow edema on DECT and comparable performance to a trained radiologist., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objectives: To demonstrate a possible basis for a quantitative magnetic resonance imaging (MRI) approach that uses histographic analysis to determine bone marrow oedema (BME) and fat metaplasia at sacroiliac joints (SIJs) level in patients with axial spondyloarthritis (axSpA)., Methods: In this prospective, cross-sectional study, consecutive axSpA patients with inflammatory low back pain underwent 1.5-T MRI. MRI images were scored on a 4-point (0-3) scoring system both for BME and fat metaplasia by two radiologists. A region-of-interest based histographic quantitative analysis was used to assess MRI images. Using the area under the receiver operating characteristic curve (AUC-ROC) approach was tested the diagnostic accuracy of histographic analysis for detecting BME vs. BME and fat metaplasia on MRI images., Results: 17 of the 43 patients (39.5%) included only had a BME lesion, while the remaining 26 patients (60.5%) had both BME and fat metaplasia at the SIJ level. Inter-rater agreement between readers was good (weighted kappa 0.643). On MRI images, BME and BME+fat metaplasia showed significant difference in histographic analysis (p<0.001), with an AUC-ROC of 0.898, and an optimal cut-off point of 311 at histographic analysis in the distinction of BME vs. fat metaplasia., Conclusions: Histographic analysis could represent a method for quantifying BME on MRI images of SIJs in patients with axSpA. This type analysis can provide important prognostic information and guide the choice of treatment in patients with sacroiliitis.

Introduction: Bone marrow edema (BME) is one of the main imaging characteristics of juvenile idiopathic arthritis (JIA) in children and rheumatoid arthritis (RA) in adult. Previous studies have shown that BME occurred in approximately 64% of adults with RA and was a key predictor of poor prognosis. But BME with JIA has not been of great concern. Therefore, we evaluated the prevalence, characteristics, and prognosis of knee joint BME in children with JIA., Methods: In this retrospective study, we included children with JIA and knee joint involvement from January 2017 to December 2019. BME was evaluated according to the Juvenile Arthritis MRI Scoring system. Clinical characteristics were compared between the BME group and the non-BME group. The characteristics and prognosis of the BME were observed., Results: A total of 128 children with 136 knee joint MRI data were identified, with 37 knee joints (27.2%) having BME. BME has positive correlation with synovial hypertrophy (Rs = 0.562, p = 0.019). There were significant differences in age (p = 0.010) and disease duration (p = 0.013) between the BME and non-BME groups. BME was found to be more common in older children and the patients with long duration of disease. Locations with BME were the lateral tibial plateau (17/37, 45.9%), the lateral weight-bearing femur (16/37, 43.2%), the medial tibial plateau and the medial femoral condyle (both with 15/37, 40.5%), and the medial weight-bearing femur (12/37, 32.4%). The lateral femoral condyle and both the lateral and medial sides of the patella were rarely involved. Of the 15 BME joints with the MRI follow-up data (interval 6.5 ± 3.0 months), the lesions disappeared or improved within 12 months after the treatments in 13 (86.7%) joints., Conclusions: The prevalence of knee BME in JIA was 27.2%. There was positive correlation between BME and synovial hypertrophy. Older children and children with long disease duration had a higher risk for BME, which was commonly a late presentation and more likely involved the weight-bearing surfaces of the joint. The overall prognosis was satisfactory after the standard treatments. Key Points • To the best of our knowledge, this paper is the first one to investigate the MRI manifestation in JIA focus on knee BME sign., (© 2022. The Author(s).)

Objectives: Subjective loss of response immediately prior to routine TNFi therapy can occur in axial spondyloarthritis (axSpA). We investigated clinical outcomes in patients taking the first three licenced TNFis and correlated this with recurrence of MRI bone marrow oedema (MRI-BMO)., Methods: Proof-of-concept study including axSpA patients established on etanercept (ETA), adalimumab (ADA) or infliximab (IFX) reporting symptom deterioration prior to next dose. MRI/clinical data were collected prior to scheduled dose (v1), 4 days post-dose (v2) and at the time of patient-reported symptom return (v3). MRI spine/sacroiliac joints utilizing 3 T were scored using the semi-quantitative Leeds MRI scoring system., Results: A total of 113 clinical assessments and MRIs were performed in 38 participants (ADA = 16, ETA = 12, IFX = 10), mean age 42.1 years ± 24.4(2SD, n = 38), 71.1% male (n = 27/38), 69.7% HLA-B27 positive (n = 23/33). At v1, all patients had high disease activity [ASDAS-CRP = 3 (2.7-3.7)] and 57.9% had MRI-BMO (number of MRI-BMO: ETA = 26, ADA = 59, IFX = 28). Improved clinical responses were seen at v2 [ASDAS-CRP -0.41(-0.81 - 0.30), P =0.018; BASDAI -0.58(-2.2 - 0.52), P =0.024]. Despite just a 4-day interval between v1 and v2, a numerical reduction in MRI-BMO lesions between v1/v2 was observed (ETA = -6, ADA = -10, IFX = -3). By v3, comparatively fewer new BMO lesions were detected in the ETA and ADA groups compared with IFX (ETA = -1, ADA = +3, IFX = +8), although the numbers were too small to enable testing for statistical significance., Conclusions: Short-lived fluctuations in MRI-BMO were commoner with longer-acting agents and corresponded with subjective loss of clinical response before next scheduled TNFi dose. Larger studies are needed to confirm the possible pathogenic implications of this phenomenon., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)