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Synovial sarcomas (SS) of the extremities are rare soft tissue sarcomas that are more common in young adults. We deciphered the imaging phenotype of SS with the aim to determine if imaging could provide an incremental value to currently known prognostic factors (PF)-age and histological grade-to predict long-term overall survival (OS).This retrospective multicenter study included consecutive pediatric and adult patients with synovial sarcomas of the extremities from December 2002 to August 2020. Inclusion criteria were (i) a follow-up greater than 5 years and (ii) available pre-therapeutic MRI. A subset analysis included MRI and CT-scan. Clinical, pathological, and imaging variables were collected in all patients. The primary endpoint was to evaluate the association of these variables with OS using univariate and multivariate Cox regressions.Out of 428 patients screened for eligibility, 98 patients (mean age: 37.1 ± 15.2 years) were included (MRI: n = 98/98, CT scan: n = 34/98; 35%). The median OS was 75.25 months (IQR = 55.50-109.12) and thirty-six patients (n = 36/98;37%) died during follow-up. The recurrence rate was 12.2% (n =12/98). SS lesions were mostly grade 2 (57/98; 58%). On MRI, SS had a mean long-axis diameter of 67.5 ± 38.3 mm. On CT scan, 44% (15/34) were calcified. Grade (hazard ratio [HR] = 2.71; 95%CI = 1.30-5.66; p = 0.008), size of the lesions evaluated on MRI (HR = 1.02; 95% CI = 1.01-1.03; p0.001), and calcifications on CT scan (HR = 0.10; 95% CI = 0.02-0.50; p = 0.005) were independent PF of OS.This study demonstrated that imaging biomarkers can be used to predict long-term outcome in patients with SS. Strikingly, the presence of calcifications on CT scan is associated with favorable outcome and provides an incremental value over existing PF such as age, grade, and size.• Beyond its diagnostic value, MRI is a pre-operative prognostic tool in synovial sarcomas of the extremities since the size of the lesion is an important prognostic factor. • Calcifications on CT scans are independently and significantly associated with prolonged overall survival.

Chronic low back pain (CLBP) is one of the most common diagnoses encountered when considering years lived with disability. The degenerative changes of the lumbar spine include a wide spectrum of morphological modifications visible on imaging, some of them often asymptomatic or not consistent with symptoms. Phenotyping by considering both clinical and imaging biomarkers can improve the management of CLBP. Depending on the clinical presentation, imaging helps determine the most likely anatomical nociceptive source, thereby enhancing the therapeutic approach by targeting a specific lesion. Three pathologic conditions with an approach based on our experience can be described: (1) pure painful syndromes related to single nociceptive sources (e.g., disk pain, active disk pain, and facet joint osteoarthritis pain), (2) multifactorial painful syndromes, representing a combination of several nociceptive sources (such as lumbar spinal stenosis pain, foraminal stenosis pain, and instability pain), and (3) nonspecific CLBP, often explained by postural (muscular) syndromes.

International audience; PurposeThe purpose of this study was to develop and evaluate a deep learning model to detect bone marrow edema (BME) in sacroiliac joints and predict the MRI Assessment of SpondyloArthritis International Society (ASAS) definition of active sacroiliitis in patients with chronic inflammatory back pain.Materials and methodsMRI examinations of patients from the French prospective multicenter DESIR cohort (DEvenir des Spondyloarthropathies Indifférenciées Récentes) were used for training, validation and testing. Patients with inflammatory back pain lasting three months to three years were recruited. Test datasets were from MRI follow-ups at five years and ten years. The model was evaluated using an external test dataset from the ASAS cohort. A neuronal network classifier (mask-RCNN) was trained and evaluated for sacroiliac joints detection and BME classification. Diagnostic capabilities of the model to predict ASAS MRI active sacroiliitis (BME in at least two half-slices) were assessed using Matthews correlation coefficient (MCC), sensitivity, specificity, accuracy and AUC. The gold standard was experts' majority decision.ResultsA total of 256 patients with 362 MRI examinations from the DESIR cohort were included, with 27% meeting the ASAS definition for experts. A total of 178 MRI examinations were used for the training set, 25 for the validation set and 159 for the evaluation set. MCCs for DESIR baseline, 5-years, and 10-years follow-up were 0.90 (n = 53), 0.64 (n = 70), and 0.61 (n = 36), respectively. AUCs for predicting ASAS MRI were 0.98 (95% CI: 0.93–1), 0.90 (95% CI: 0.79–1), and 0.80 (95% CI: 0.62–1), respectively. The ASAS external validation cohort included 47 patients (mean age 36 ± 10 [SD] years; women, 51%) with 19% meeting the ASAS definition. MCC was 0.62, sensitivity 56% (95% CI: 42–70), specificity 100% (95% CI: 100–100) and AUC 0.76 (95% CI: 0.57–0.95).ConclusionThe deep learning model achieves performance close to those of experts for BME detection in sacroiliac joints and determination of active sacroiliitis according to the ASAS definition.

International audience; The emergence of massively parallel yet affordable computing devices has been a game changer for research in the field of artificial intelligence (AI). In addition, dramatic investment from the web giants has fostered the development of a high-quality software stack. Going forward, the combination of faster computers with dedicated software libraries and the widespread availability of data has opened the door to more flexibility in the design of AI models. Radiomics is a process used to discover new imaging biomarkers that has multiple applications in radiology and can be used in conjunction with AI. AI can be used throughout the various processes of diagnostic imaging, including data acquisition, reconstruction, analysis and reporting. Today, the concept of "AI-augmented" radiologists is preferred to the theory of the replacement of radiologists by AI in many indications. Current evidence bolsters the assumption that AI-assisted radiologists work better and faster. Interventional radiology becomes a data-rich specialty where the entire procedure is fully recorded in a standardized DICOM format and accessible via standard picture archiving and communication systems. No other interventional specialty can bolster such readiness. In this setting, interventional radiology could lead the development of AI-powered applications in the broader interventional community. This article provides an update on the current status of radiomics and AI research, analyzes upcoming challenges and also discusses the main applications in AI in interventional radiology to help radiologists better understand and criticize articles reporting AI in medical imaging.

Artificial intelligence (AI) is increasingly being studied in musculoskeletal oncology imaging. AI has been applied to both primary and secondary bone tumors and assessed for various predictive tasks that include detection, segmentation, classification, and prognosis. Still, in the field of clinical research, further efforts are needed to improve AI reproducibility and reach an acceptable level of evidence in musculoskeletal oncology. This review describes the basic principles of the most common AI techniques, including machine learning, deep learning and radiomics. Then, recent developments and current results of AI in the field of musculoskeletal oncology are presented. Finally, limitations and future perspectives of AI in this field are discussed.

To evaluate the diagnostic performance and interobserver agreement of a magnetic resonance imaging (MRI) protocol that only includes sagittal T2-weighted Dixon fat and water images as an alternative to a standard protocol that includes both sagittal T1-weighted sequence and T2-weighted Dixon water images as reference standard in lumbar degenerative disc disease with Modic changes. From February 2017 to March 2019, 114 patients who underwent lumbar spine MRI for low back pain were included in this retrospective study. All MRI showed Modic changes at least at one vertebral level. Two radiologists read the standard protocol and 1 month later the alternative protocol. All MRI were assessed for Modic changes (types, location, extension) as well as structural changes (endplate defects, facet arthropathy, spinal stenosis, foraminal stenosis, Schmorl nodes, spondylolisthesis, disc bulges, and degeneration). Interobserver agreement was assessed, as well as diagnostic performance using the standard protocol as reference standard. Interobserver agreement was moderate to excellent (kappa ranging from 0.51 to 0.92). Diagnostic performance of the alternative protocol was good for detection of any Modic change (sensitivity = 100.00% [95% CI, 99.03–100.00]; specificity = 98.89% [95% CI, 98.02–99.44]), as well as for detection of each Modic subtype and structural variables (sensitivity respectively 100% and ranging from 88.43 to 99.75% ; specificity ranging respectively from 97.62 to 100% and 99.58 to 99.91% ). Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images provide good diagnostic performance compared to T1-weighted images in lumbar degenerative disc disease with Modic changes, and could therefore allow for a shortened protocol. • Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images (in comparison to T1-weighted sequence) can provide good diagnostic performance in lumbar degenerative disc disease with Modic changes. • Interobserver agreement of the alternative protocol including sagittal T2-weighted Dixon fat and water images was substantial to excellent for every studied variable except for facet arthropathy. • A shortened MRI protocol including T2-weighted Dixon sequence without T1-weighted sequence could be proposed in this clinical setting.

Hand and wrist soft tissue masses may be classified as pseudotumors, benign neoplasms, or malignant neoplasms. The vast majority of hand lesions are benign. Consideration of the location of the lesion and its imaging characteristics often leads to a specific diagnosis. Pseudotumors discussed in this article are ganglion cysts, accessory muscles, and inflammatory lesions. True tumors are described according to their tissue type: nerve sheath tumors, adipocytic tumors, so-called fibrohistiocytic tumors, pericytic tumors, and vascular lesions. We also outline the imaging features of masses encountered in the hand and wrist.

Clinical diagnosis of community-acquired pneumonia (CAP) is difficult to establish with certainty. Adherence to antibiotic guidelines independently affects the prognosis of CAP patients.We aimed to determine whether guidelines' adherence was related to CAP diagnosis level of certainty and could be reinforced accordingly to diagnosis improvement.Secondary analysis of a prospective, multicenter study, which evaluated the impact of early thoracic CT scan on diagnosis and therapeutic plan in patients with clinically suspected CAP visiting emergency departments.In total 319 patients with clinically suspected CAP were enrolled in four emergency departments, Paris, France, between Nov 2011 and Jan 2013.We evaluated guidelines' adherence before and after CT scan and its relationship with CAP diagnosis level of certainty. Antibiotics were categorized as adherent according to 2010 French guidelines. CAP diagnosis level of certainty was prospectively classified by the emergency physicians based on a Likert scale as excluded, possible, probable or definite before and immediately after the CT scan. These classifications and therapeutic plans were also completed by an independent adjudication committee. Determinants of adherence were assessed using Poisson regression with robust variance.Adherence to guidelines increased from 34.2% before CT scan to 51.3% after CT scan [difference 17.1% (95% CI, 9.5-24.7)], meanwhile CAP diagnosis with high level of certainty (definite and excluded CAP) increased from 46.1 to 79.6% [difference 33.5% (95% CI, 26.5-40.5)]. Diagnosis level of certainty before CT scan was the strongest determinant of adherence in multivariate analysis (RR, 2.63; 95% CI, 1.89-3.67).Antibiotic guidelines' adherence was poor and positively related to CAP diagnosis level of certainty. The results suggest that improvements in CAP diagnosis may increase adherence to antibiotic guidelines. Clinical trial registered with www.clinicaltrials.gov (NCT01574066).

Objectives We aimed to clarify the definition, distribution, clinical association and outcomes of large calcinosis in patients with systemic sclerosis (SSc). Methods We conducted a systematic literature review (SLR) focusing on SSc-related large calcified masses. Upon updating the terminology and definition, all cases of “pseudotumoral” calcinosis seen at the Cochin and Padova University Hospitals were reviewed. Results The SLR yielded 30 SSc cases, with large calcified masses mainly defined as “tumoral” or “pseudotumoral”. Among the 629 SSc cases included in the Cochin and Padova cohorts, 19 (3%) living and 7 deceased patients were affected by pseudotumoral calcinosis; among these, the great majority had a severe vascular phenotype. The mean age in the whole population (56 cases) was 59 ± 11.4 years with a median disease duration at calcinosis onset of 7 (5–10) years. Twenty-five out of 56 patients (44.6%) had the diffuse cutaneous form of SSc. Anti-topisomerase I and anticentromere were found equally. Pseudotumoral calcinosis were commonly symmetrical and the size ranged from 2 to 15.5 cm. Most patients had multiple site involvement: 52% hand/wrist, 29% shoulders and elbows, 20% hips and 25% spinal calcinosis. Fistulization/ulceration and infections were reported in 32% and 23% of cases, respectively; nerve compression was found in 40% of spinal calcinosis and in one patient with limb calcinosis. There was no clear evidence of clinical and radiological improvement with any treatment. A partial improvement was seen in 7 patients that underwent surgery. Conclusion Pseudotumoral calcinosis may occur in about 3% of SSc patients, commonly symmetrical and in multiple sites without differences regarding the cutaneous subtypes but often in those with a severe vascular phenotype. Medical treatment seems ineffective, whereas a surgical approach may be considered.

We aimed to compare the reliability and performance of MRI measures enhanced with intravenous (IV) injection of gadolinium contrast versus non-enhanced MRI measures for the diagnosis of adhesive capsulitis (AC). We also aimed to examine the association between MRI findings and clinical features in patients with AC. MRI of 42 patients with a clinical diagnosis of AC confirmed by arthrography and that of 42 patients in a control group were retrospectively studied by 2 blinded readers. Reliability and performance of MRI findings were compared between IV contrast-enhanced measures and non-enhanced MRI measures in T2-weighted fat-saturated and T1-weighted images. MRI findings were correlated with clinical stage, etiology, and pain. Sensitivity (97.6%) and specificity (97.6%) of axillary-recess capsule signal enhancement for AC diagnosis were significantly superior (p = 0.02) to hyperintense signals on T2-weighted fat-suppressed images (sensitivity 90.5%, specificity 92.7%). Measures of the intensity signal in the area of the rotator interval were less performant for AC diagnosis but could be improved with joint capsule enhancement. Moreover, we found very high specificity (100%) of enhancement of the coracohumeral ligament signal for AC diagnosis. The early stage of adhesive capsulitis was positively correlated with joint capsule enhancement in the rotator interval. Secondary etiology of capsulitis was correlated with joint capsule hyperintensity signals of the rotator interval on T2-weighted fat-suppressed images. IV contrast injection with MRI can be helpful for AC diagnosis in difficult cases. The stage of AC seems related to joint capsule enhancement in the rotator interval. • IV gadolinium-enhanced MRI can improve the analysis of signal changes in the shoulder synovium and capsule of the shoulder that are related to adhesive capsulitis. • As an original finding, we observed that coracohumeral ligament enhancement had a 100% specificity for the diagnosis of adhesive capsulitis. • The intensity of enhanced signals in the rotator interval seems to be related to the early stage of frozen shoulder.

Several interventional treatments have recently been integrated into the therapeutic armamentarium available for the treatment of bone tumors. In some scenarios (e.g., osteoid osteoma), interventional treatments represent the sole and definitive applied treatment. Due to the absence of widely shared protocols and the complex multivariate scenarios underlying the clinical presentation of the remaining bone tumors including metastases, therapeutic strategies derived from a multidisciplinary tumor board are essential to provide effective treatments tailored to each patient. In the present review, we present the multidisciplinary therapeutic strategies commonly adopted for the most frequent bone tumors.

The purpose of this study was to report the effectiveness of preoperative transcatheter arterial embolization (TAE) of musculoskeletal tumors in terms of blood loss and functional outcomes. Patients who underwent preoperative TAE of hypervascular musculoskeletal tumors between January 2018 and December 2021 were retrospectively included. The patients’ characteristics, TAE procedure details, degree of post-TAE devascularization, surgical outcomes in terms of red blood cell transfusion and functional results were collected. The degree of devascularization was compared between patients who had peri-operative transfusion and those who did not. Thirty-one patients were included. The 31 TAE procedures led to complete (58%) or near-complete (42%) tumor devascularization. Twenty-two patients (71%) had no blood transfusion during surgery. Nine patients (29%) had a blood transfusion, with a median number of red blood cell packs of three (q1, 2; q3, 4; range: 1–4). Eight patients (27%) had complete improvement of the initial musculoskeletal symptoms at the end of the follow-up, 15 (50%) had partially satisfying improvement, 4 (13%) had partially unsatisfying improvement and 3 (10%) had no improvement. Our study suggests that preoperative TAE of hypervascular musculoskeletal tumors allowed for bloodless surgery in 71% of patients and minimal transfusion needs for the remaining 29%.

Polyarticular juvenile idiopathic arthritis (pJIA) is a subset of juvenile idiopathic arthritis (JIA), divided into two subtypes according to the presence of rheumatoid factor: pJIA without rheumatoid factor (pJIA RF-) and pJIA with positive rheumatoid factor (pJIA RF+), this latter is characterised with more structural damage. Anti-citrullinated peptide antibodies (ACPA) are often associated with RF. The respective performance of ACPA versus RF in structural outcome in pJIA, and in particular in adulthood pJIA remains unknown. Therefore, the aim of this study was to determine whether ACPA could be of value to assess structural damage in pJIA persisting in adulthood.Patients with pJIA and available data for ACPA, RF and X-ray were included retrospectively. Structural damage was assessed by two independent blinded investigators using Sharp Van Der Heijde scores.56 pJIA adult patients were included: 62% (35/56) had pJIA RF+ and 38% (21/56) pJIA RF-. ACPA positivity in pJIA was significantly associated with presence of RF (96% vs 26%, P0.001). RF positivity was significantly associated with higher Sharp van Der Heijde erosion and total scores (respectively P0.01 and P0.05). There were higher Sharp Van Der Heijde erosion, joint space narrowing and total scores in the pJIA ACPA+ subgroup than in the pJIA ACPA- subgroup, although there was no statistical significance. However, when adjusted on disease duration, pJIA ACPA+ patients had significantly higher erosion and total scores than pJIA ACPA- patients (P0.05), and pJIA ACPA+ patients required more bDMARDs than pJIA ACPA- patients (P0.05). Moreover, pJIA patients with high Sharp van Der Heijde joint space narrowing and total scores had significantly higher ACPA levels (P0.01). A correlation was identified between ACPA levels and Sharp van Der Heijde total score (r=0.54, P0.05). In the pJIA RF+ subgroup the presence of ACPA was associated with additional structural damage compared to no ACPA: sharp Van Der Heijde erosion, joint space narrowing and total scores were higher in the pJIA RF+ ACPA+ subgroup than in the pJIA RF+ ACPA- subgroup although these results did not reach significance.Our results suggest that pJIA RF+ ACPA+ adult patients may have a more severe articular phenotype than pJIA RF+ ACPA- patients. ACPA could bring an additional value to RF for pJIA patients regarding structural damage. Altogether our results show that RF and ACPA are associated with structural damage measured by Sharp Van Der Heijde score in pJIA persisting in adulthood.

Objective To compare the sensitivity to change of different imaging scoring methods in patients with early axial spondyloarthritis (SpA). Methods Patients from the Devenir des Spondylarthropathies Indiffererenciees Recentes (DESIR) cohort fulfilling the Assessment of SpondyloArthritis international Society criteria for axial SpA were included. Radiographs and magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and spine were obtained at baseline, 1, 2, and 5 years. Each image was scored by 2 or 3 readers in 3 separate reading waves. The rate of change of outcomes measuring inflammation of the spine and SI joints (e.g., Spondyloarthritis Research Consortium of Canada [SPARCC] score) and structural damage on MRI (e.g., >= 3 fatty lesions) and radiographs (e.g., modified New York grading) was assessed using multilevel generalized estimating equation models (taking all readers and waves into account). To allow comparisons across outcomes, rates were standardized (difference between the individual's value and the population mean divided by the SD). Results In total, 345 patients were included. Inflammation detected on MRI of the SI joints (MRI-SI joints) (standardized rate range -0.278, -0.441) was more sensitive to change compared to spinal inflammation (range -0.030, -0.055). Structural damage in the SI joints showed a higher standardized rate of change on MRI-SI joints (range 0.015, 0.274) compared to radiography of the SI joints (range 0.043, 0.126). MRI-SI joints damage defined by >= 3 fatty lesions showed the highest sensitivity to change (0.274). Spinal structural damage slowly progressed over time with no meaningful difference between radiographic (range 0.037, 0.043) and MRI structural outcomes (range 0.008, 0.027). Conclusion Structural damage assessed in pelvic radiographs has low sensitivity to change, while fatty lesions detected on MRI-SI joints are a promising alternative. In contrast, MRI of the spine is not better than radiography of the spine in detecting structural changes in patients with early axial SpA.

To appraise the performances of an AI trained to detect and localize skeletal lesions and compare them to the routine radiological interpretation.We retrospectively collected all radiographic examinations with the associated radiologists' reports performed after a traumatic injury of the limbs and pelvis during 3 consecutive months (January to March 2017) in a private imaging group of 14 centers. Each examination was analyzed by an AI (BoneView, Gleamer) and its results were compared to those of the radiologists' reports. In case of discrepancy, the examination was reviewed by a senior skeletal radiologist to settle on the presence of fractures, dislocations, elbow effusions, and focal bone lesions (FBL). The lesion-wise sensitivity of the AI and the radiologists' reports was compared for each lesion type. This study received IRB approval (CRM-2106-177).A total of 4774 exams were included in the study. Lesion-wise sensitivity was 73.7% for the radiologists' reports vs. 98.1% for the AI (+24.4 points) for fracture detection, 63.3% vs. 89.9% (+26.6 points) for dislocation detection, 84.7% vs. 91.5% (+6.8 points) for elbow effusion detection, and 16.1% vs. 98.1% (+82 points) for FBL detection. The specificity of the radiologists' reports was always 100% whereas AI specificity was 88%, 99.1%, 99.8%, 95.6% for fractures, dislocations, elbow effusions, and FBL respectively. The NPV was measured at 99.5% for fractures, 99.8% for dislocations, and 99.9% for elbow effusions and FBL.AI has the potential to prevent diagnosis errors by detecting lesions that were initially missed in the radiologists' reports.

This history page in the series "Leaders in MSK Radiology" is dedicated to the memory and achievements of the French physician Jacques Forestier, whose name is connected with the medical eponym Forestier's disease, later referred to as diffuse idiopathic skeletal hyperostosis.

Objective Osteoporosis is underdiagnosed and undertreated, although severe complications of osteoporotic fractures, including vertebral fractures, are well known. This study sought to assess the feasibility and results of an opportunistic screening of vertebral fractures and osteoporosis in a large database of lumbar or abdominal CT scans. Material and methods Data were analysed from CT scans obtained in 35 hospitals from patients aged 60 years or older and stored in a Picture Archiving and Communication System in Assistance-Publique-Hôpitaux de Paris, from 2007 to 2013. Dedicated software was used to analyse the presence or absence of at least 1 vertebral fracture (VF), and the radiodensity of the lumbar vertebrae was measured Hounsfield Units (HUs). A simulated T-score was calculated. Results Data were analysed from 152 268 patients [mean age (S.D.) = 73.2 (9.07) years]. Success rates for VF assessment and HUs measurements were 82 and 87%, respectively. The prevalence of VFs was 24.5% and increased with age. Areas under the receiver operating characteristic curves for the detection of VFs were 0.61 and 0.62 for the mean HUs of the lumbar vertebrae and the L1 HUs, respectively. In patients without VFs, HUs decreased with age, similarly in males and females. The prevalence of osteoporosis (sT-score ≤ –2.5) was 23.8% and 36.5% in patients without and with VFs, respectively. Conclusion It is feasible on a large scale to screen for VFs and osteoporosis during opportunistic screening in patients 60 years or older having lumbar or abdominal CT.

Failed back surgery syndrome is a challenge. We hypothesized that a multidisciplinary team meeting (MTM) may be useful to select patients who are the most likely to benefit from lumbar surgery. We conducted an observational, prospective, comparative, exploratory study. We aimed to compare core clinical patient-reported outcomes at 2 years after lumbar surgery between patients who attended a MTM and those who did not. Patients who underwent lumbar surgery for a degenerative disease, in a single academic orthopedic department, between January and September 2018, were consecutively screened. Eligible patients were surveyed between April and June 2020. Patient-reported outcomes included lumbar and radicular pain, spine-specific activity limitations and health-related quality of life assessed via self-administered questionnaires. Outcomes were compared between respondents who attended the MTM and those who did not. Overall, 211 patients underwent lumbar surgery, 108 were eligible and 44 included: 11 attended the MTM and 33 did not. Mean participants' age was 57.4 (15.4) years, symptom duration was 14.8 (15.3) months, lumbar pain was 51.3 (18.2) and radicular pain was 53.4 (18.6). At 2 years, we found no evidence that lumbar and radicular pain, activity limitations and health-related quality of life differed between the 2 groups. The decrease was -26.8 (41.1) versus -20.8 (30.4) in lumbar pain and -25.5 (43.0) versus -19.5 (27.5) in radicular pain, in participants who attended the MTM versus those who did not, respectively. We found no evidence that core clinical patient-reported outcomes at 2 years after lumbar surgery differed between participants who attended the MTM and those who did not. However, the exploratory design of our study does not allow concluding that MTMs do not have an impact.

Background The interpretation of radiographs suffers from an ever-increasing workload in emergency and radiology departments, while missed fractures represent up to 80% of diagnostic errors in the emergency department. Purpose To assess the performance of an artificial intelligence (AI) system designed to aid radiologists and emergency physicians in the detection and localization of appendicular skeletal fractures. Materials and Methods The AI system was previously trained on 60 170 radiographs obtained in patients with trauma. The radiographs were randomly split into 70% training, 10% validation, and 20% test sets. Between 2016 and 2018, 600 adult patients in whom multiview radiographs had been obtained after a recent trauma, with or without one or more fractures of shoulder, arm, hand, pelvis, leg, and foot, were retrospectively included from 17 French medical centers. Radiographs with quality precluding human interpretation or containing only obvious fractures were excluded. Six radiologists and six emergency physicians were asked to detect and localize fractures with (

Aggressive vertebral hemangiomas usually exhibit extraosseous expansion that can result in spinal cord or radicular compression.1 In symptomatic cases, treatment by alcohol embolization and percutaneous vertebroplasty has been reported as feasible, safe, and effective with long-term benefits on neurological symptoms.2 Safety rules before vertebral alcohol embolization include preoperative spinal cord vascularization mapping and opacification through bone needles to assess the absence of dangerous intratumoral anastomoses.In video 1 we present a case of a symptomatic T2 aggressive vertebral hemangioma with dangerous anastomoses between the lesion and both supreme intercostal arteries (SIAs). Embolization by the arterial route of both SIAs was performed, which required good anatomic knowledge of the spinal cord vascularization at the cervicothoracic junction3 4 as a cervical radiculomedullary artery arose from the left costocervical trunk which also fed the left SIA. After occlusion of all dangerous arterial anastomoses, we were able to successfully perform T2 alcohol embolization and percutaneous vertebroplasty.Video 1Case presentation

International audience; Purpose: Spinal muscles are a major component of posture in spinal pathologies and changes to the spine with aging. Specifically, spinopelvic muscles may compensate for underlying anomalies such as pelvic retroversion, knee flexion, and cervical or thoracic spinal balance abnormalities. To increase understanding between muscular characteristics and compensatory mechanisms, this study aimed to compare the volume of spinopelvic muscles in adults with a spinal deformity (ASD) to a control group of well-aligned adult subjects.Methods: Twenty-eight lumbar ASD patients [Cobb angle > 20°, > 40 years old (yo)] were prospectively included and compared to 35 normal subjects divided into 2 different groups: one group of young (Y) subjects (n = 23, 40 yo). All subjects had a fat/water separation MRI (from C7 to the knees). Volumetric 3D reconstructions of 30 spinopelvic muscles were performed and muscles volumes were compared.Results: Mean age was 60 ± 16 yo, without significant differences between the ASD and O groups (57 ± 11 yo). Age and BMI were smaller in the young group. Mean Cobb angle of the ASD group was 45 ± 11°. Comparing the ASD and O groups, total muscular volume was similar; however, erector spinae (0.24 ± 0.06 vs 0.68 ± 0.08 dm3, p = 0.001), iliopsoas (0.49 ± 0.09 vs 0.60 ± 0.09 dm3, p = 0.001) and obliquus (0.42 ± 0.08 vs 0.50 ± 0.08 dm3, p = 0.02) were significantly smaller in the ASD group. Comparing the Y and the ASD groups, total muscular volume was higher in the Y group than the ASD group (+ 3.3 dm3, p = 0.003) and erector spinae (0.24 ± 0.06 vs 0.74 ± 0.08, p = 0.0001), gluteus medius (0.51 ± 0.07 vs 0.62 ± 0.13, p = 0.01) and vastus lateralis (1.33 ± 0.21 vs 2.08 ± 0.29, p = 0.001) were significantly bigger in the Y group.Conclusion: This is the first study to compare volume of spinopelvic muscles between ASD patients and a control group without spinal deformity. Our results demonstrate that muscular degeneration has a double origin: aging and deformity. Erector spinae, iliopsoas, and obliquus are the muscles most affected by degeneration.

Introduction: Global alignment analysis is of upmost importance in adult spinal deformity patients (ASD). Numerous parameters exist in the literature to measure global alignment based upon C7 or T1. One common limitation of these parameters is that they neglect the cervical segment which is essential in spinal compensatory mechanisms and in horizontal gaze preservation. A recent stereoradiography analysis of asymptomatic subjects introduced a new 3D parameter (ODHA), defined as the angle between the vertical reference line and the line joining the odontoid tip (OD) to hip axis center (HA). Thus, the goal of this study was to analyze 3D global alignment of ASD patients using the new parameter odontoid hip axis angle and its relationship to other spinal parameters. Methods: In this prospective study, 90 adult patients with lumbar scoliosis (Cobb > 20°) were included. All subjects underwent low dose biplanar X-rays with 3D spinal reconstructions. Based on published normative values of ODHA, we defined abnormally high value as mean ODHA of asymptomatic subject + 2SD (i.e., ODHA > 6.1°). Values of 3D radiographic parameters and ODI were compared between patients with ODHA > 6.1° and

Objective: To assess if an integrated longitudinal analysis using all available imaging data affects the precision of estimates of change in patients with axial spondyloarthritis (axSpA), with completers analysis as reference standard.Methods: Patients from the DESIR cohort fulfilling the ASAS axSpA criteria were included. Radiographs and MRIs of the sacroiliac joints and spine were obtained at baseline, 1, 2 and 5 years. Each image was scored by 2 or 3 readers in 3 'reading-waves' (or campaigns). Each outcome was analyzed: i. According to a 'combination algorithm' (e.g. '2 out of 30 for binary scores); and ii. Per reader. Change over time was analyzed with generalized estimating equations by 3 approaches: (a)'integrated-analysis' (all patients with >1 score from >1 reader from all waves); (b1)Completers-only analysis (patients with 5-year follow-up, using scores from individual readers); (b2)Completers analysis using a 'combination algorithm' (as (b1) but with combined scores). Approaches (b1) and (b2) were considered the 'reference'.Results: In total, 413 patients were included. The 'integrated analysis' was more inclusive with similar levels of precision of the change estimates as compared to both completers analyses. In fact, for low-incident outcomes (e.g.% mNY-positive over 5-years), an increased incidence was 'captured', with more precision, by the 'integrated analysis' compared to the completers analysis with combined scores (% change/year (95%CI): 1.1 (0.7; 1.5) vs 1.2 (0.5; 1.8), respectively).Conclusion: An efficient and entirely assumption-free 'integrated analysis' does not jeopardize precision of the estimates of change in imaging parameters and may yield increased statistical power for detecting changes with low incidence. (C) 2020 The Authors. Published by Elsevier Inc.

Introduction Carney Complex (CNC) is a rare multiple endocrine and nonendocrine neoplasia syndrome. Manifestations and genotype-phenotype correlations have been described by retrospective studies, but no prospective study evaluating the occurrence of the different manifestations has been available so far. Methods This multicenter national prospective study included patients with CNC, primary pigmented nodular adrenal disease (PPNAD), or a pathogenic PRKAR1A mutation; after a full initial workup, participants were followed for 3 years with annual standardized evaluation. Results The cohort included 70 patients (50 female/20 male, mean age 35.4 ± 16.7 years, 81% carrying PRKAR1A mutation). The initial investigations allowed identification of several manifestations. At the end of the 3-year follow-up, the newly diagnosed manifestations of the disease were subclinical acromegaly in 6 patients, bilateral testicular calcifications in 1 patient, and cardiac myxomas in 2 patients. Recurrences of cardiac myxomas were diagnosed in 4 patients during the 3-year follow-up study period. Asymptomatic abnormalities of the corticotroph and somatotroph axis that did not meet criteria of PPNAD and acromegaly were observed in 11.4% and 30% of the patients, respectively. Patients carrying the PRKAR1A c.709-7del6 mutation had a mild phenotype. Conclusion This study underlines the importance of a systematic follow-up of the CNC manifestations, especially a biannual screening for cardiac myxoma. By contrast, regular screening for the other manifestations after a first extensive workup could be spread out, leading to a lighter and more acceptable follow-up schedule for patients. These are important results for recommendations for long-term management of CNC patients.

BackgroundDiagnostic tests for SARS-CoV-2 infection (mostly RT-PCR and Computed Tomography) are not widely available in numerous countries, expensive and with imperfect performanceMethodsThis multicenter retrospective study aimed to determine a pre-test probability score for SARS-CoV-2 infection based on clinical and biological variables. Patients were recruited from emergency and infectious disease departments and were divided into a training and a validation cohort. Demographic characteristics, clinical symptoms, and results of blood tests (complete white blood cell count, serum electrolytes and CRP) were collected. The pre-test probability score was derived from univariate analyses between patients and controls, followed by multivariate binary logistic analysis to determine the independent variables associated with SARS-CoV-2 infection. Points were assigned to each variable to create the PARIS score. ROC curve analysis determined the area under the curve (AUC).FindingsOne hundred subjects with clinical suspicion of SARS-CoV-2 infection were included in the training cohort, and 300 other consecutive individuals were included in the validation cohort. Low lymphocyte (InterpretationThe PARIS score based on complete white blood cell count has a good performance to categorize the pre-test probability of SARS-CoV-2 infection. It could help clinicians avoid diagnostic tests in patients with a low-probability score and conversely keep on testing individuals with high-probability score but negative RT-PCR or CT. It could prove helpful in countries with a low-availability of PCR and/or CT during the current period of pandemic.FundingNonePutting research into contextEvidence before this studyIn numerous countries, large population testing is impossible due to the limited availability and costs of RT-PCR kits and CT-scan. Furthermore, false-negativity of PCR or CT as well as COVID-19 pneumonia mimickers on CT may lead to inaccurate diagnoses. Pre-test probability combining clinical and biological features has proven to be a particularly useful tool, already used in clinical practice for management of patients with a suspicion of pulmonary embolism.Added value of this studyThis retrospective study including 400 patients with clinical suspicion of SARS-CoV-2 infection was composed of a training and a validation cohort. The pre-test probability score (PARIS score) determines 3 levels of probability of SARS-CoV2 infection based on white blood cell count (lymphocyte, eosinophil, basophil and neutrophil cell count).Implications of the available evidenceThis pre-test probability may help to adapt SARS-CoV-2 infection diagnostic tests. The high negative predictive value (99·5%) of the low probability category may help avoid further tests, especially during a pandemic with overwhelmed resources. A high probability score combined with typical CT features can be considered sufficient for diagnosis confirmation.

Parosteal osteosarcomas and well-differentiated liposarcomas are both well-differentiated locally aggressive tumors. They both have simple karyotypes with amplification of the 12q13-15 regions including MDM2 and CDK4 genes. In this report, we describe the case of a parosteal osteosarcoma intertwined with a low-grade component similar to a well-differentiated liposarcoma. The association of a bone component with an adipose component was initially overlooked. We describe the histological, imaging, and molecular characteristics of this tumor stressing the importance of radio-pathological correlation. To our knowledge, this is the second report of a parosteal osteoliposarcoma. Awareness of this rare presentation may allow radiologists and surgeons to recognize the peripheral fatty component as an integral part of the tumor.

We aimed to compare the reliability and performance of MRI measures enhanced with intravenous (IV) injection of gadolinium contrast versus non-enhanced MRI measures for the diagnosis of adhesive capsulitis (AC). We also aimed to examine the association between MRI findings and clinical features in patients with AC.MRI of 42 patients with a clinical diagnosis of AC confirmed by arthrography and that of 42 patients in a control group were retrospectively studied by 2 blinded readers. Reliability and performance of MRI findings were compared between IV contrast-enhanced measures and non-enhanced MRI measures in T2-weighted fat-saturated and T1-weighted images. MRI findings were correlated with clinical stage, etiology, and pain.Sensitivity (97.6%) and specificity (97.6%) of axillary-recess capsule signal enhancement for AC diagnosis were significantly superior (p = 0.02) to hyperintense signals on T2-weighted fat-suppressed images (sensitivity 90.5%, specificity 92.7%). Measures of the intensity signal in the area of the rotator interval were less performant for AC diagnosis but could be improved with joint capsule enhancement. Moreover, we found very high specificity (100%) of enhancement of the coracohumeral ligament signal for AC diagnosis. The early stage of adhesive capsulitis was positively correlated with joint capsule enhancement in the rotator interval. Secondary etiology of capsulitis was correlated with joint capsule hyperintensity signals of the rotator interval on T2-weighted fat-suppressed images.IV contrast injection with MRI can be helpful for AC diagnosis in difficult cases. The stage of AC seems related to joint capsule enhancement in the rotator interval.• IV gadolinium-enhanced MRI can improve the analysis of signal changes in the shoulder synovium and capsule of the shoulder that are related to adhesive capsulitis. • As an original finding, we observed that coracohumeral ligament enhancement had a 100% specificity for the diagnosis of adhesive capsulitis. • The intensity of enhanced signals in the rotator interval seems to be related to the early stage of frozen shoulder.

Objective To describe the magnetic resonance imaging (MRI) findings in diffuse idiopathic skeletal hyperostosis (DISH) patients and to assess the proportion of DISH patients whose MRI findings would fulfill the Assessment of Spondyloarthritis International Society (ASAS) criteria for a positive MRI of axial spondyloarthritis (SpA). Methods This study involved all DISH patients who had a spine or sacroiliac (SI) joint MRI performed between January 2009 and December 2014. Sociodemographic and clinical data were collected. Available radiographs and MRI were analyzed and blindly scored by an experienced reader, using the Spondyloarthritis Research Consortium of Canada (SPARCC) scores for both spine and SI joint MRI. Results A total of 53 symptomatic DISH patients was included in the analysis. The mean ± SD SPARCC score of the spine was 18.3 ± 23.4. Thirty-five patients (67.3%) had at least 1 fatty corner. Thirty patients (57.7%) met the ASAS definition of a spine MRI suggestive of axial SpA, but only 6 patients (15.8%) with an available SI joint MRI had sacroiliitis according to ASAS criteria. Only 1 patient (3.3%) had ≥3 erosions on the SI joint. Conclusion Inflammatory lesions of the spine are common on the MRI of symptomatic DISH patients, and more than half fulfilled the ASAS criteria for a spine MRI suggestive of axial SpA. However, only a few patients met the ASAS definition of active sacroiliitis, suggesting that MRI of the SI joint but not of the spine might allow the differential diagnosis of DISH versus axial SpA in the elderly.

Resume L’imagerie morphologique est essentielle pour le diagnostic initial des metastases osseuses, ainsi que le bilan d’extension, l’evaluation du risque fracturaire et le suivi. Les metastases de l’os medullaire sont bien visibles en IRM, et les techniques actuelles permettent des explorations precises et assez rapides en associant les ponderations T1, STIR, et la diffusion corps entier. Pour l’os cortical et le risque fracturaire, les radiographies restent tres utiles pour les os longs, mais le scanner s’impose pour le squelette axial, rachis et pelvis. L’imagerie du suivi prend une importance croissante car les survies sont prolongees dans de nombreux cancers metastatiques grâce aux traitements efficaces. Les lesions osseuses sont a integrer, qu’elles soient symptomatiques ou non.

Objective To analyze the progression of spinal radiographic damage in patients with early axial spondyloarthritis (SpA). Methods Axial SpA patients from the DESIR (Devenir des Spondylarthropathies Indifferenciees Recentes) cohort with 5-year spinal (cervical and lumbar) radiographs available (n = 549) were included. Two- and 5-year modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) progression and development of new syndesmophytes (net change: the number of patients with positive change minus the number of patients with negative change divided by the total number of patients) were assessed in subgroups defined at baseline according to the Assessment of SpondyloArthritis international Society axial SpA criteria and its arms, modified New York criteria (mNYC) and the presence of syndesmophytes. Results Mean ± SD mSASSS progression was 0.2 ± 0.9 at 2 years and 0.4 ± 1.8 at 5 years. Five-year progression was higher in the imaging arm (mean ± SD 0.6 ± 2.3), magnetic resonance imaging (MRI)+/mNYC+ (mean ± SD 1.3 ± 4.0), than in the clinical arm only (mean ± SD 0.1 ± 0.7), and highest in patients with syndesmophytes (mean ± SD 2.7 ± 5.0). At 5 years, 7% of all patients had a net change of any new syndesmophyte; this value was 10% for the imaging arm (mNYC+/MRI+ with 18%), 17% for mNYC+ patients, and 42% for patients with syndesmophytes. Conclusion Spinal radiographic progression, although limited in early axial SpA, can be captured after 2 years. Inflammation and damage in the sacroiliac joint are associated with higher radiographic progression. The presence of baseline syndesmophytes already strongly predicts the development of further structural damage early in the disease.

International audience; Introduction While the clinical impact of coronal and sagittal alignment in adult spinal deformity (ASD) patients (pts) is established, there is a paucity of data in terms of axial plane deformity and potential association between muscle degenera- tion and 3D deformity. The purpose of this study was to analyze spinopelvic muscles characteristics in association with the 3D deformity of ASD patients. Methods This is a prospective cohort study; primary lumbar scoliosis patients (Cobb > 20°) were enrolled and sustained a low-dose X-rays with 3D spinal reconstructions and a fat/water separation MRI (from C7 to the knee). Volumetric 3D reconstructions and fat infiltration (FI) of 6 muscles groups were performed. Relationships between muscular data, radio- graphic parameters and health-related quality of life were investigated. Patients were stratified and compared based on the SRS classification, the odontoid-hip axis (ODHA) angle (> or < 6.1°) and occurrence of rotatory subluxation. Results and discussion Twenty-eight patients were enrolled with a mean age of 60 ± 16yo and mean body mass index of 26 ± 4 kg/m2 without differences between groups. There were a moderate sagittal malalignment and a Cobb angle of 45 ± 11° (table). Muscular volume was smaller in patients with more severe deformity (p > 0.05). Pts with ODHA > 6.1° or pelvic incidence minus lumbar lordosis > 10° had significantly higher FI for the 6 muscular groups, patients with pelvic tilt > 20° had significantly higher FI for erector spinae, hip flexors and extensors (p < 0.05). SF36-PCS significantly correlated with the muscular volume; SRS and Oswestry disability index correlated with the erectors spinae volume (p < 0.05). Conclusion This study analyzed for the first time the relationship between 3D radiographic parameters and muscular charac- teristics in ASD. Sagittal malalignment is associated with increased FI and decreased muscle volumes with poor outcomes.

Purpose/Introduction: Measurement of trabecular bone score (TBS®) of the lumbar spine on dual energy X-ray absorptiometry (DXA) devices improves fracture risk prediction. We conducted a proof of concept study to assess the feasibility of TBS® measured on the low-dose imaging system EOS®. Methods: TBS was assessed on both DXA and EOS® in 122 patients aged ≥ 50 yr, receiving no anti-osteoporotic treatment. The TBS® was computed on full-body EOS® images, focusing on the lumbar spine region. The patients were also scanned with a DXA bone densitometer (Hologic) and the spine and hip bone mineral density (g/cm²) were computed. Results: TBS® measurement on EOS® was not possible in 34 patients due to technical problems. It could be measured on both DXA and EOS® in 88 patients (28 with severe low-trauma fracture and 60 without fracture). TBS-EOS values were significantly lower in fractured patients compared to nonfractured patients. TBS-EOS was associated with the presence of fractures as reported by an AUC of 0.70. Odds ratio of TBS-EOS for the presence of severe low-trauma fracture was 2.00 [1.24–3.25], p = 0.005. Conclusions: This proof of concept study, based on a prototype version of the TBS-EOS, demonstrated the feasibility of the measurement of TBS® on low-dose EOS® imaging devices. Results show that the TBS-EOS was lower in patients with severe low-trauma fractures compared to nonfractured patients independently from bone mineral density. Some technical issues need to be solved before its eventual use in routine clinical settings. Additional prospective studies are still needed to define the actual contribution of this new technique.

Objective To assess associations of spinal-pelvic orientation with clinical and imaging-study findings suggesting axial SpA (axSpA) in patients with recent-onset inflammatory back pain. Methods Spinal-pelvic orientation was assessed in DESIR cohort patients with recent-onset inflammatory back pain and suspected axSpA, by using lateral lumbar-spine radiographs to categorize sacral horizontal angle ( Results Of 362 patients, 358, 356 and 357 had available sacral horizontal angle, lumbosacral angle and LL values, respectively; means were 39.3°, 14.6° and 53.0°, respectively. The prevalence of sacroiliitis on both radiographs and MRI was higher in the LL < 50° group than in the LL ⩾50° group, but the difference was not statistically significant. Clinical presentation and confidence in a diagnosis of axSpA did not differ across angle groups. No significant differences were identified for degenerative changes according to sacral horizontal angle, lumbosacral angle or LL. Conclusion Spinal-pelvic balance was not statistically associated with the clinical or imaging-study findings suggesting axSpA in patients with recent-onset inflammatory back pain.

Background Intervertebral disc therapies (IDT) for the management of non-specific chronic low back (NScLBP) pain are raising interest (1). Objectives To review evidence on the benefits and harms of IDT in people with NScLBP. Methods We searched 4 databases and conference abstracts, from inception to July 2018, for randomized trials of IDT versus placebo interventions, active comparators or usual care. Two independent investigators extracted data and assessed the risk of bias. The primary outcome was LBP intensity at short, intermediate and long terms (2). Secondary outcomes were LBP-specific activity limitation and safety (3). Our review was registered with the International Prospective Register of Systematic Reviews (CRD42019106336). Results Of 17 eligible trials, 5 trials (436 patients) assessed glucocorticoid (GC) IDT and were included in a quantitative synthesis. Twelve trials assessed IDT of other products including ozone (n=2, 140 patients), methylene blue (n=1, 72 patients), stems cells (n=1, 24 patients), glycerol (n=1, 11 patients), etanercept (n=2, 96 patients), tocilizumab (n=1, 60 patients), platelet-rich plasma (n=1, 47 patients), chymopapaine (n=1, 39 patients) and rhGDF-5 (n=2, 55 patients) and were included in a narrative synthesis. Standardized mean differences (SMD) of GC IDT for LBP intensity and activity limitations were -1.33 (-2.34;-0.32) and -0.76 (-1.85;0.34) at short-term, -2.22 (-5.34;0.90) and -1.60 (-3.51;0.32) at intermediate-term and -1.11 (-2.91;0.70) and -0.63 (-1.68;0.42) at long-term, respectively. OR of GC IDT for serious and minor adverse events were 1.13 (0.20; 4.59) and 0.97 (0.49;1.91). Conclusion GC IDT are associated with a reduction in LBP intensity at short-term in people with NScLBP. Positive effects are not sustained. There is no effect on activity limitations. References [1] Knezevic NN, Mandalia S, Raasch J, Knezevic I, Candido KD. Treatment of chronic low back pain - new approaches on the horizon. J Pain Res. 2017;10:1111-23. [2] Chiarotto A, Boers M, Deyo RA, Buchbinder R, Corbin TP, Costa LOP, et al. Core outcome measurement instruments for clinical trials in nonspecific low back pain. Pain. 2018;159(3):481-95. [3] Team QAaSM. Safety of medicines : a guide to detecting and reporting adverse drug reactions : why health professionals need to take action. In: Organization WH, ed. Geneva; 2002. Disclosure of Interests None declared

Study Design Retrospective cohort. Objective The aim of this study was to describe the various locations of spinal stenosis (LSS) in lumbar scoliosis and its related clinical symptoms. Introduction Adults with lumbar scoliosis often present with pain and disability. Association of scoliosis and stenosis is not rare, but remains sparsely explored. Consequences of scoliosis on stenosis location and treatment remain debatable. Methods Patients operated for symptomatic LSS with lumbar scoliosis (Cobb angle >20°) from 2015 to 2016 were included. All patients completed preoperative clinical and neurologic examination. Coronal and sagittal radiographic parameters, rotatory subluxation (RS), and spondylolisthesis were analyzed on full spine radiographs. Computed tomographic scan multiplanar reconstructions were performed to measure central, foraminal, and lateral recess stenosis, from T10 to the sacrum. Results A total of 76 patients were included (69 ± 9 years old, 77% female). Sixty percent had neurogenic claudication, and L5 was the most common radicular pain (41%). The mean Cobb angle was 33° ± 16°. Overall, 35 (46%) patients had coronal malalignment; in 69%, side of the coronal tilt corresponded to side of the concavity of the lumbosacral curve. Sixty patients had RS (most frequent level L3–L4). In 50% of the cohort, RS was located at the junction between the lumbar and lumbosacral curves. In 70% (n = 53) of the patients, central stenosis occurred at the junction between the lumbar and lumbosacral curves. Foraminal and lateral stenosis were most frequently observed in the concavity of the distal lumbosacral curve. L5 radicular pain was significantly more frequent in case of lumbosacral contra-curve and right coronal malalignment. Conclusion LSS is frequent in lumbar scoliosis. Relationships exist between curve characteristics and symptomatic LSS in lumbar scoliosis; especially, concavity of the lumbosacral contra-curve and the junctional level between the lumbar curve and the lumbosacral contra-curve. Therefore, accurate analysis of stenosis in ASD seems mandatory, to at least perform decompression because perfect planned treatment for stenosis and scoliosis correction might not always be possible because of the patient's general health status. Level of Evidence Level 4.

ObjectiveTo evaluate the prevalence and performance as axial Spondyloarthritis (axSpA) diagnostic feature of radiographic and MRI lesions ‘typical’ of axSpA of the sacroiliac joint (SIJ) and spine in a mechanical chronic back pain (CBP) population and in an axSpA cohort.MethodsCross-sectional multicentre study. Patients: (1) recent onset axSpA (DESIR cohort) and (2) mechanical non-axSpA CBP matched for age and gender (ILOS study). Imaging: radiographs and MR scans were performed identically in both groups. All images were centrally read, blinded for diagnosis and for other imaging findings in the same patient. Statistical analysis: prevalence of lesions ‘typical of axSpA’ were compared in both groups. Sensitivity, specificity and positive likelihood ratios (LR+) of each lesion (and combination of lesions) were calculated.ResultsA total of 98 patients with CBP were included, and compared with 100 patients with recent onset axSpA. SIJ lesions were consistently more frequent in the axSpA group (35.0% vs 11.8% pConclusionOur study confirms that ‘typical’ lesions can also be observed in patients with non-axSpA CBP but that SIJ lesions by all modalities remain the most valuable for diagnosis, including structural lesions of the SIJ. This suggests the potential interest of adding MRI SIJ structural lesions in the definition of MRI abnormalities for axSpA classification.

To determine the prevalence of simple and complex sacral perineural Tarlov cysts (TCs) in a cohort of children and adults.Retrospective observational epidemiological study assessing 1100 consecutive sacral magnetic resonance (MR) studies, including 100 children and adolescents. All patients underwent 1.5T MR imaging with T1 and T2 weighted image acquisitions in sagittal and axial planes. All perineural cysts affecting the sacral nerve roots S1-S4 were quantitatively and qualitatively assessed.Two hundred and sixty-three sacral TCs were found in 132 adult patients (13.2%), with a female predominance (68%). None was found in children. The prevalence of TCs increased with age. The average number of cysts per patient was 2.0±1.2 with a maximum of 6 cysts in a single patient. Most of the cysts (87.5%) showed a homogenous central fluid collection and a parietal course of the nerve fibers. Complex patterns were present in 33 cysts (12.5%) within which 28 cysts showed endocystic crossing of nerve fibers and 5 cysts contained internal septations. Seventy cysts (26.6%) eroded the adjacent bone and 13 cysts (4.9%) extended to the pelvis.The prevalence of sacral TCs in our cohort corresponded to 13%, with a female predominance. Interestingly no TCs were found in children or adolescents (18 years). In relation to the non-negligible percentage of complex cysts with internal septations, or endocystic crossing of nerve fibers, pre-interventional characterization of sacral TCs might help to choose an appropriate procedure in the treatment of rare symptomatic variants.

Imaging of the sacroiliac joints is the key point in diagnosing and classifying spondyloarthritis. Since the integration of MRI criteria to the Assessment of Spondyloarhtitis Society (ASAS) classification in 2009, the attention was focused on the presence of bone marrow edema to characterize sacroiliitis. However, returning to basics and analysing structural signs is of utmost importance to avoid overdiagnosis of spondyloarthritis.