Lennart Jans

Microscopic gut inflammation in axial spondyloarthritis: a multiparametric predictive model

Objective To assess the rates and explore predictors of microscopic gut inflammation in a cohort of patients with axial and peripheral spondyloarthritis (SpA). Methods Ileocolonoscopy was performed in 65 patients with axial and peripheral SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT. Histopathological analysis and scoring were performed by an experienced pathologist. Results Overall, 46.2% of the patients with SpA showed microscopic gut inflammation. In axial SpA, the following parameters were independently associated with gut involvement: male sex (OR=8.9, p=0.035); high disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (OR=2.05, p=0.032); restricted spinal mobility measured by the Bath Ankylosing Spondylitis Metrology Index (OR=1.94, p=0.009); and younger age (OR=0.85, p=0.013). No clear association was found for human leucocyte antigen-B27 status, presence of peripheral arthritis, enthesitis, uveitis, psoriasis, intake of non-steroidal anti-inflammatory drugs and family history of SpA. The prevalence of gut inflammation in non-radiographic axial SpA and ankylosing spondylitis was comparable. Conclusions The prevalence of microscopic gut inflammation in SpA remains unaltered over time. Younger age (shorter symptom duration), progressive disease, male sex and higher disease activity are independently associated with microscopic gut inflammation in axial SpA.

Value and Limitations of Diffusion-Weighted Imaging in Grading and Diagnosis of Pediatric Posterior Fossa Tumors

SUMMARY: DWI reportedly accurately differentiates pediatric posterior fossa tumors, but anecdotal experience suggests limitations. In 3 years, medulloblastoma and JPA were differentiated by DWI alone in 23/26 cases (88%). Ependymoma (n = 5) could not be reliably differentiated from medulloblastoma or JPA. A trend toward increased diffusion restriction in higher grade tumors (1/14 grade I, 7%; 9/12 grade IV, 75%) had too much overlap to predict the grade of individual cases. The overlap in ADC between tumor types appeared partly due to technical factors (in small, heterogeneous, calcific, or hemorrhagic tumors) but also likely reflected true histologic variability, given that our 3 overlap cases included a desmoplastic medulloblastoma, an anaplastic ependymoma, and a JPA with restricted diffusion in its nodule. Simple structural features (macrocystic tumor, location off midline) aided in distinguishing JPA from the other tumors in these cases.

Degree of bone marrow oedema in sacroiliac joints of patients with axial spondyloarthritis is linked to gut inflammation and male sex: results from the GIANT cohort

Introduction Bone marrow oedema (BMO) of the sacroiliac joints (SIJs) is a hallmark of axial spondyloarthritis (SpA). However, the relationship between the extent of BMO and disease phenotype is poorly understood. Objective To assess the link between BMO of the SIJs and gut inflammation. We have also evaluated the correlation between BMO and established disease activity parameters. Methods Sixty-eight patients with axial SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT underwent ileocolonoscopy and MRI of the SIJs. Histopathological analysis and SPondyloArthritis Research Consortium of Canada (SPARCC) scores were performed. Results A significant higher SPARCC score (median (range)) was observed in axial SpA patients showing chronic gut inflammation (16.9 (3.8–68.3)) compared with axial SpA patients showing normal gut histology (9.8 (0.0–45.0); p<0.05). In a multiple linear regression model, we identified, besides chronic gut inflammation (effect size of 11.3, 95% CI (2.1 to 20.4)), male sex (effect size of 10.5, 95% CI (3.3 to 17.8)) to be independently associated to the extent of BMO. There was a low to moderate correlation between the degree of BMO and C-reactive protein(r=0.39, p=0.002) and Ankylosing Spondylitis Disease Activity Score (r=0.35, p=0.007). Conclusions Higher degrees of BMO were observed in patients showing chronic gut inflammation. These data solidify a link between mucosal inflammation and progressive disease in axial SpA.

Reliability and construct validity of ultrasonography of soft tissue and destructive changes in erosive osteoarthritis of the interphalangeal finger joints: a comparison with MRI

Objectives To study the reliability and construct validity of ultrasound in interphalangeal finger joints affected by erosive osteoarthritis (EOA) and non-EOA with MRI as the reference method. Methods 252 joints were examined by ultrasound, conventional radiography and clinical examination. Ultrasound was performed using a high-frequency linear transducer (12×18 MHz). On the same day, magnetic resonance images of 112 joints were obtained on a 3.0 T magnetic resonance unit. The ultrasound and MRI images were re-read independently by other readers unaware of the diagnosis, clinical and other imaging findings. Interobserver reliability was calculated by the percentage of exact agreement obtained and κ statistics. With MRI as the reference method, the sensitivity and specificity of ultrasound in detecting structural (bone erosions and osteophytes) and soft tissue (effusion and grey-scale synovitis) changes in EOA were calculated. Results Ultrasound and MRI were found to be more sensitive in detecting erosions than conventional radiography in EOA. A high agreement between ultrasound and MRI in the assessment of bone erosions (77.7%), osteophytes (75.9%) and synovitis (86.5%) was present. A high percentage of inflammatory changes was found in EOA, and in smaller amount in non-EOA, both confirmed by MRI. Good interobserver reliability of ultrasound was obtained for all variables (all median κ >0.8). Conclusion Grey-scale ultrasound proved to be a reliable and valid imaging technique to assess erosions and soft tissue changes, compared with MRI as a reference method in EOA.

Imaging and Interpretation of Axial Spondylarthritis: The Radiologist's Perspective—Consensus of the Arthritis Subcommittee of the ESSR

This article reflects the radiologists perspective on the imaging and interpretation of axial spondylarthritis (SpA). The arthritis subcommittee of the European Society of Skeletal Radiology provides a consensus for the following questions: When and how should we image? How should we analyze the images? How should we interpret the imaging findings? To answer these questions, we address the indications in imaging axial SpA and the different imaging techniques, with a special focus on magnetic resonance imaging protocols. The value of different imaging modalities is discussed. For adequate image analysis, knowledge of the anatomy and the pathologic changes in chronic and acute inflammation of the sacroiliac joints and the spine is mandatory. Differential diagnoses of inflammatory lesions of the sacroiliac joints and the spine are addressed due to their importance in image interpretation.

Evolution of Femoral Condylar Ossification at MR Imaging: Frequency and Patient Age Distribution

PURPOSE To determine how the magnetic resonance (MR) signal intensity seen with variability in distal femoral epiphyseal ossification in children varies with (a) age, (b) sex, (c) distribution to the medial or lateral condyles, and (d) residual physeal cartilage. MATERIALS AND METHODS Ethics committee approval was obtained, and informed patient consent was waived. Two pediatric radiologists retrospectively reviewed the consecutive knee MR imaging studies of 910 children (457 boys, 453 girls; age range, 0.7-16.9 years) for variability in ossification and categorized the variability as preossification center, early ossification center, puzzle piece, incomplete puzzle piece, spiculation, or accessory ossification center. Patient age and sex, ossification variability site, residual physeal cartilage, and associated findings were analyzed. Basic descriptive statistical analysis, Student t tests for comparison of continuous variables, and κ statistics analysis of interobserver agreement were performed where appropriate. RESULTS In 202 (22.2%) patients (278 condyles), ossification variability was present. In the 910 patients, early ossification center (n = 172, 18.9%) and spiculated configuration of the secondary ossification center (n = 151, 16.6%) were the most common variants. Preossification center (50 [5.5%] patients), puzzle piece (26 [2.9%] patients), accessory ossification center (nine [1.0%] patients), and incomplete puzzle piece (two [0.2%] patients) were seen less often. Ossification variability was more common in the medial condyles (169 [18.6%] of 910 cases) than in the lateral condyles (109 [12.0%] of 910 cases), nearly always posteriorly located (277 [99.6%] of 278 condyles), and more common in boys (153/457 [33.5%]) than in girls (49/453 [10.8%]). Ossification variability was less common with decreasing residual physeal cartilage. Peak patient age ranges for ossification variability were 2-12 years for boys and 2-10 years for girls. CONCLUSION Ossification variability in the femoral condyles is common in children and should not be confused with abnormal processes.

MRI of the SI joints commonly shows non-inflammatory disease in patients clinically suspected of sacroiliitis.

PURPOSE To determine the prevalence of clinically relevant non-inflammatory disease on MRI of the sacroiliac (SI) joints in patients suspected of sacroiliitis. To assess the added value of axial imaging of the pelvis in these patients. METHODS In a retrospective study of 691 patients undergoing MRI of the SI joints from January 2006 to December 2012 for inflammatory back pain the prevalence of sacroiliitis and non-inflammatory disease was recorded. RESULTS In 285 (41%) patients MRI did not show any abnormal findings. In 36% of patients MRI features of sacroiliitis were present. Spinal degenerative changes were the most common non-inflammatory finding in 305 patients (44.1%) and consisted of disc degeneration in 222 (32%) patients, facet joint arthrosis in 58 (8.4%) patients and disc herniation in 25 (3.6%) patients. Hip joint disease in 44 (6.4%) patients, lumbosacral transitional anomaly in 41 (5.9%) patients, SI joint degenerative changes in 25 (3.6%) patients and diffuse idiopathic skeletal hyperostosis in 24 (3.5%) patients were also common. Osteitis condensans ilii in 17 (2.5%) patients, tumour in 11 (1.6%) patients, fracture in 8 (1.2%) patients, infection in 4 (0.6%) patients and acute spondylolysis in 2 patients (0.3%) were less frequently seen. CONCLUSION Our study shows that non-inflammatory disease is more common than true sacroiliitis on MRI of the SI joints in patients with inflammatory type back pain. Axial pulse sequences may demonstrate unexpected findings that remain undetected if only coronal images are obtained. Clinical relevance statement:, MRI of the SI joints may demonstrate conditions that clinically mimic sacroiliitis. Axial imaging of the pelvis may help detect these unexpected findings.

MR imaging findings and MR criteria for instability in osteochondritis dissecans of the elbow in children

PURPOSE Osteochondritis dissecans (OCD) of the elbow is an uncommon cause of elbow pain in adolescents and occurs at different locations in the elbow joint. Early diagnosis and treatment may prevent surgery. The aim of the study is to describe the MR imaging features of OCD at initial imaging, and to correlate these findings with surgical findings of stability and instability with arthroscopic findings as the reference standard. METHODS Patients were identified through a keyword search of the radiology information system from 2000 to 2009. Twenty-five patients (26 elbows) with OCD of the elbow were identified (age 10.4-18 years, mean age 14 years). MR studies were retrospectively reviewed by two radiologists in consensus to define MR imaging findings and to determine the presence of previously described MR imaging criteria for OCD instability (i.e., high T2 signal rim, surrounding cysts, high T2 signal fracture line, fluid-filled osteochondral defect). Sensitivity of the individual and combined criteria was calculated. RESULTS OCD occurred in the capitellum in 24 patients (92%), in the trochlea in 2 patients (8%) and radial head in 1 patient (4%). Loose bodies were identified in 11 (42%) patients. Eighteen patients demonstrated MRI findings in keeping with unstable lesions. In all 11 patients who had surgery the surgical findings of instability correlated with the MRI findings. When combined, the MR criteria were 100% sensitive for instability of OCD lesions of the elbow. CONCLUSION The vast majority of OCD of the elbow occurs in the capitellum. When used together, the MR criteria for instability were 100% sensitive for evaluation OCD lesions of the elbow.

Ossification variants of the femoral condyles are not associated with osteochondritis dissecans

PURPOSE To determine if ossification variants of the femoral condyles involving the subchondral bone plate are associated with osteochondritis dissecans (OCD). MATERIALS AND METHODS The prevalence of ossification variants of the unaffected femoral condyle in 116 patients (aged 9-14 years) with unicondylar OCD on MRI (magnetic resonance imaging) of the knee was compared to a control group of 579 patients (aged 9-14 years) without OCD. The evolution of the ossification variants in both groups was studied by reviewing follow-up MR imaging side by side with the baseline study. RESULTS The prevalence of ossification variants in the unaffected condyle in patients with OCD (12.9%) and in the control group of patients without OCD (12.6%) was similar (p=0.88). Evolution of ossification variants to OCD was not seen on follow-up MRI examinations. All variants had decreased in size or were no longer visible. CONCLUSION Ossification variants of the femoral condyle that involve the subchondral bone plate are not associated with OCD. CLINICAL RELEVANCE STATEMENT: Ossification variants are not associated with OCD, indicating that routine MRI follow-up in affected children is not mandatory.

Diagnostic value of MRI features of sacroiliitis in juvenile spondyloarthritis.

AIM To determine the diagnostic utility of magnetic resonance imaging (MRI) features of sacroiliitis in juvenile spondyloarthritis (JSpA). MATERIALS AND METHODS This was a prospective study of 80 paediatric patients who underwent MRI of the sacroiliac joints that were clinically suspected to have sacroiliitis. The prevalence of MRI features of active and structural lesions of sacroiliitis was recorded. Patients were classified according to the International League of Association for Rheumatology criteria. The MRI findings were compared to the final clinical diagnosis. RESULTS Sacroiliitis was seen in 25/80 (31%) patients. MRI showed active inflammation in 23 patients (29%): synovial enhancement (28%), high short tau inversion recovery (STIR)-signal in the joint space (29%), bone marrow oedema (BMO; 20%), and capsulitis (8%). Structural changes were present in 14 patients (18%): erosion (14%), fat infiltration (13%), sclerosis (8%), and ankylosis (1%). Of all MRI features, ankylosis (100%), capsulitis (98%), BMO (96%), and erosion (96%) had the highest specificity for JSpA; global diagnostic impression (55%) and synovial enhancement (52%) were the MRI features with the highest sensitivity. The likelihood ratios (LR+) for diagnosis of JSpA were high for BMO (10.5), capsulitis (7.5), global diagnostic impression (6.9), and erosions (6.75), but greater for BMO concomitant with synovial enhancement (LR+ 19.5) and for erosion concomitant with BMO (LR+ 12) or synovial enhancement (LR+ 13.5). CONCLUSION There are multiple features of active inflammation and structural damage visible at MRI of the sacroiliac joints that can provide a specific diagnosis of JSpA when present in children with suspected sacroiliitis. Synovial enhancement is the MRI feature with the highest sensitivity for JSpA. If BMO is seen concomitant with synovial enhancement or erosion, the diagnosis of JSpA is very likely. Ankylosis, capsulitis, bone marrow oedema, and erosion all have a high specificity for JSpA. Absence of MRI findings of sacroiliitis does not exclude the diagnosis of JSpA.