André Yui Aihara

Objectives: To evaluate vertebral bone quality (VBQ) and femoral bone quality (FBQ) scores as potential imaging markers of bone mineral density (BMD) for opportunistic osteoporosis screening in at‑risk patients and to assess their correlation with DXA T -scores. Methods: This retrospective cross-sectional study included women ≥ 40 years and men ≥ 50 years who underwent DXA and lumbar spine, hip, or pelvic MRI within 60 days. All MRI examinations were performed at 1.5 T. VBQ and FBQ were obtained using manually placed circular ROIs. FBQ was derived from coronal T1-weighted images using two approaches: femoroacetabular joint fluid (FBQfa) and cerebrospinal fluid (FBQcsf). Interobserver reproducibility was assessed using intraclass correlation coefficient (ICC). Correlations with DXA T -scores and diagnostic performance for osteoporosis were analyzed using Pearson coefficients and ROC curves. Results: Among 248 patients, VBQ demonstrated excellent reproducibility (ICC = 0.922) and a weak-to-moderate negative correlation with DXA T -scores ( r = −0.307; p  < 0.001). VBQ values increased across DXA bone density categories, with an optimal cutoff of 3.61 for osteoporosis (AUC = 0.71). FBQcsf showed high reproducibility (ICC = 0.874) compared with FBQfa (ICC = 0.462) but no evidence of correlation with DXA ( p = 0.151). FBQcsf distinguished normal BMD from osteopenia ( p = 0.002) and, after adjustment for age and sex, also differentiated patients with osteopenia from those with osteoporosis ( p = 0.011). Conclusion: VBQ can serve as an opportunistic exploratory screening marker of low BMD. FBQcsf may complement VBQ by identifying early marrow-related changes, although further validation is required.

Recognition of normal development, anatomic variants, and true pathologic conditions of the pediatric sacroiliac joint is critical to prevent misdiagnosis, avoid unnecessary treatment, and reduce morbidity and long-term complications in the developing skeleton.

A systematic approach to bone marrow MRI, including integrating signal intensity patterns, distribution, enhancement, and chemical shift imaging findings, enables accurate differentiation of normal variants, benign entities, and malignancies.

Sickle cell disease (SCD) is a spectrum of inherited blood disorders, leading to propensity to sickling disruption of red blood cells. Musculoskeletal complications are a common cause of acute and chronic morbidities, related to the main pathophysiological processes: (i) hemolysis and anemia, resulting in marrow hyperplasia and extramedullary hematopoiesis; and (ii) vaso-occlusion, leading to osteonecrosis/bone infarction, myonecrosis, and infection (osteomyelitis and septic arthritis). Knowing the pathophysiology and clinical manifestations is essential for imaging interpretation, but differentiation between acute osteomyelitis and bone infarction remains a clinical and imaging challenge, therefore requiring a multidisciplinary approach. Large subperiosteal fluid collections (≥ 4 mm in depth), in conjunction with elevated inflammatory markers and white blood counts, are more suggestive of osteomyelitis rather than isolated bone infarction. The unenhanced T1-weighted fat-suppressed sequence on MR images was also proposed to aid in this differentiation, but so far with controversial results. Future perspectives of MR imaging include the DIXON technique, which has shown promising results as a biomarker of morbidity of SCD, through evaluation of fat fraction (FF) of bone marrow in a single acquisition and noninvasive way.

Enthesitis-related arthritis (ERA), a distinct subtype of juvenile idiopathic arthritis (JIA) related to HLA-B27 and peripheral and axial involvement, presents with insidious onset of arthritis and/or enthesitis. However, there is a lack of data concerning axial new bone formation in patients transitioning into adulthood. To evaluate the axial radiographic structural damage (axRxSD), encompassing the sacroiliac joints (SIJ), hips, and spine, in ERA patients across various age groups. A cross-sectional cohort study was conducted with patients aged up to 35 years. Specific tools were used for measuring disease activity (BASDAI, ASDAS), function (BASFI, HAQ-S), mobility (BASMI), clinical enthesitis (MASES), ultrasound evaluation (MASEI), and axRxSD, including mSASSS for spine, Kellgren-Lawrence for hips and modified New York criteria for SIJ. A total of 26 patients were included, of whom 76.9% were males, with a mean age at diagnosis and assessment of 11.9 and 19.7 years, respectively. HLA-B27 positivity was found in 58.3%. Current active arthritis and enthesitis were present in 19.2% and 23%, respectively, with mean MASEI score of 12 (IQR 6–17). Peripheral joint limitation was observed in 50%, despite a BASMI score of 2.2 and 16% occurrence of abnormal FABER test. Most patients were in remission or low disease activity [ASDAS-ESR = 1.2 (0.6-2.3); ASDAS-CRP = 1.55 (0.6-2.4)]. Modified New York criteria were fulfilled by 73.1% of patients and 15.4% had radiographic hip involvement. Spine involvement, measured by mSASSS, was low (IQR 0-4.2), with only two patients exhibiting syndesmophytes. There was no statistical association between any imaging methods and clinical, laboratory, and ultrasound variables, including scores for activity, functionality, and mobility. Significant association was found only between axRxSD and BASMI. Our results showed high frequency of SIJ ankylosis alongside lower radiographic involvement in the spine and hips, suggesting a distinct structural damage phenotype. The early recognition of this outcome and the use of immunobiological therapy may mitigate syndesmophyte occurrence over time. Graphical Abstract

No dinâmico campo da radiologia médica, nossa missão vai além da mera identificação de achados anormais. Ela reside em fornecer informações diagnósticas que orientem decisões clínicas e, por fim, aprimorem a qualidade de vida de nossos pacientes.