Skeletal Radiology最新文献

Objective: Accurate assessment of foot and ankle alignment through clinical measurements is essential for diagnosing deformities, treatment planning, and monitoring outcomes. The traditional 2D radiographs fail to fully represent the 3D complexity of the foot and ankle. In contrast, weight-bearing CT provides a 3D view of bone alignment under physiological loading. Nevertheless, manual landmark identification on WBCT remains time-intensive and prone to variability. This study presents a novel AI framework automating foot and ankle alignment assessment via deep learning landmark detection.

Materials and methods: By training 3D U-Net models to predict 22 anatomical landmarks directly from weight-bearing CT images, using heatmap predictions, our approach eliminates the need for segmentation and iterative mesh registration methods. A small dataset of 74 orthopedic patients, including foot deformity cases such as pes cavus and planovalgus, was used to develop and evaluate the model in a clinically relevant population. The mean absolute error was assessed for each landmark and each angle using a fivefold cross-validation.

Results: Mean absolute distance errors ranged from 1.00 mm for the proximal head center of the first phalanx to a maximum of 1.88 mm for the lowest point of the calcaneus. Automated clinical measurements derived from these landmarks achieved mean absolute errors between 0.91° for the hindfoot angle and a maximum of 2.90° for the Böhler angle.

Conclusion: The heatmap-based AI approach enables automated foot and ankle alignment assessment from WBCT imaging, achieving accuracies comparable to the manual inter-rater variability reported in previous studies. This novel AI-driven method represents a potentially valuable approach for evaluating foot and ankle morphology. However, this exploratory study requires further evaluation with larger datasets to assess its real clinical applicability.

Objective: The pathophysiologic significance of transphyseal extension of pediatric osteosarcoma is unknown. The physis acts as a relative anatomic barrier to tumor extension and potentially to hematogenous spread. The purpose of this study was to determine whether transphyseal tumor extension on initial magnetic resonance imaging (MRI) correlates with metastatic disease.

Methods: This is a single-institution 13-year retrospective review of 269 patients aged ≤ 18 years diagnosed with long bone osteosarcoma and open physes on pre-operative imaging. MRIs were reviewed to determine the presence of transphyseal tumor extension, skip lesions, pulmonary metastases, recurrence, and disease status at 3 years. Univariable and multivariable analyses were performed.

Results: The final cohort included 109 patients (range 4-18 years). Fifty-nine percent of patients had transphyseal tumor extension. In univariable analysis, pulmonary metastasis on initial chest CT was significantly higher in patients with transphyseal extension (32.8% vs 15.6%, p = .04). There was no evidence of a difference between patients with and without transphyseal extension with regard to skip lesions (15.6% vs 15.7%, p = .99), tumor recurrence (50% vs 44.4%, p = .57) or death alone (40.6% vs 26.7%, p = .13). Multivariable analysis accounting for age, sex, tumor location, and transphyseal extension demonstrated transphyseal extension to be independently associated with active disease or death by 3 years (OR 3.26, p = 0.03).

Conclusion: Transphyseal tumor extension on initial MRI is associated with an increased prevalence of active disease/death at 3 years follow-up. In addition to entire long bone MR imaging, dedicated high-resolution imaging to delineate transphyseal extension is recommended in the diagnostic workup of long bone osteosarcoma.

Objectives: To evaluate the quality and safety of hip aspiration procedures performed by radiology residents on-call compared to those performed by supervised residents or attending radiologists during workday hours. Additionally, to identify potential areas for improving resident procedural exposure.

Materials and methods: A single-center retrospective study evaluating daytime and on-call hip joint aspirations performed on emergency or admitted patients from June 1, 2019, to May 31, 2020. Data collected included patient demographics, procedure times, performing staff, and procedural and surgical outcomes. The Mann-Whitney U-test was used to analyze quantitative data, and Fisher's exact test was used for categorical variables.

Results: Residents performed 19 (100%) of on-call procedures and 12/50 (24%) of daytime aspirations. On-call procedures had shorter median time from order to procedure start (115 compared to 294 min, p = 0.004) but overall longer median procedure durations (52 versus 32 min, p = 0.054). In total, 17/19 (89%) of procedures on-call versus 49/50 (98%) of daytime cases yielded sufficient sample for analysis (p = 0.18). Of these, 5/17 (26%) on-call and 16/49(34%) of daytime aspirates were culture-positive (p = 0.77).

Conclusions: Resident-performed hip aspirations on-call were initiated more promptly but did not significantly differ in rates of aspirate yield or culture positivity. Residents performed only 24% of daytime cases, highlighting the opportunity to increase resident procedural exposure.

Objective: Given the lack of consensus in lumbar spine MRI protocols, this study sought to characterize current practice patterns among musculoskeletal radiologists in the United States.

Materials and methods: An anonymous 13-item web-based survey covering protocol sharing, sequence selection, and advanced techniques was distributed to members of the Society of Skeletal Radiology and the Society of Academic Bone Radiologists from 12/2022 to 2/2023. Frequency counts and proportions were calculated from the collected responses.

Results: One hundred ninety-three musculoskeletal radiologists completed the survey; 171/193 (88.6%) actively interpret lumbar spine MRI, and 137/193 (71%) reported using a shared protocol with neuroradiologists. The most common protocol combines sagittal T1-weighted, T2-weighted, and short tau inversion recovery (STIR) sequences (150/193 (77.7%)). For axial imaging, respondents use a T1- and T2-weighted pair (102/193, 54.5%) or T2-weighted imaging alone (64/193, 34.2%). Fat suppression is applied to postcontrast T1-weighted images more frequently in the sagittal plane (149/193 (77.2%)) than axially (102/193 (52.8%)), with use dictated by indication or subspecialty preference (less frequent in neuroradiologists' protocols). Specialized sequences are uncommon (3D imaging (19/193, 9.8%), diffusion-weighted imaging (4/193, 2.1%), chemical-shift imaging (17/193, 9.7%)) and are typically reserved for specific indications.

Conclusion: Practices in the United States converge on a core lumbar spine MRI protocol-sagittal T1-weighted, T2-weighted, and STIR sequences with axial T2-weighted imaging-yet diverge in optional elements. Musculoskeletal radiologists use fat-suppressed imaging more than neuroradiologists, while specialized techniques are deployed selectively. Recognizing these variations could potentially enhance interpretive consistency, standardize protocols for research, and support rapid protocol development.

Os centrale carpi is an uncommon accessory carpal bone. We report, to the best of our knowledge, the first case of imaging findings of "os centrale carpi bone bruising" simulating an acute scaphoid fracture. The various differential diagnoses of this entity are discussed. A 22-year-old man presented to our hospital with dorsolateral wrist pain following trauma. Radiography revealed a potential fracture line in the distal pole of the scaphoid and a fracture of the base of the ulnar styloid. Magnetic resonance imaging (MRI) revealed bone bruising of the os centrale carpi and a fracture of the ulnar styloid process. The objective of this case report is to present the imaging findings of os centrale carpi bone bruising, an uncommon occurrence in wrist trauma.

Objective: To assess imaging findings and complications after curettage of atypical cartilaginous tumors (ACTs) in long bones.

Materials and methods: This retrospective study included patients with central ACTs of long bones treated with curettage, adjuvants, and cementation or bone grafting, who had clinical and imaging follow-up data available for at least 2 years after surgery. All imaging studies (radiographs, CT, MRI) were independently assessed by three radiologists. Clinical information was collected from the medical records.

Results: Sixty-eight patients were included (median age [interquartile range, IQR], 53 [45-60] years). Bone graft and cement were used in 53 (77.9%) and 15 (22.1%) patients, respectively. Prophylactic internal fixation was performed in 63 (92.7%) patients. The median (IQR) follow-up duration was 42 (30-64) months. Normal imaging findings were identified at follow-up in 45 patients (66.2%). Our reported complications included peri- (2.9%) and post-operative (8.8%) bone fractures, incomplete bone graft integration (24.5%, out of patients treated with bone grafting), cement loosening (26.7%, out of patients treated with cementation), fixation hardware rupture (1.6%) or loosening (6.3%, out of patients treated with internal fixation) and residual disease (1.5%). Incomplete bone graft integration and cement loosening were associated with tumor location in the humerus (p = 0.023). Inter-reader agreement ranged between moderate and excellent (Fleiss's K = 0.522-1).

Conclusion: After curettage of ACTs in long bones, complications are detected on follow-up imaging examinations in one third of patients, mainly including fractures, incomplete bone graft integration and cement loosening.

Objective of the study: To evaluate whether percutaneous cemented screw fixation improves the ability to walk of patients with pathological fractures of the acetabulum roof.

Material and method: In this retrospective single-center study, interventions performed with image-based guidance using either fluoroscopic or Cone Beam Computed Tomography (CBCT) control, or Four-Dimensional Computed Tomography (4DCT) control, to treat pathological fracture of the acetabulum roof with a percutaneous screwing technique were analyzed. Walking was measured on a 4-level scale: not walking, walking with 2 crutches, walking with a crutch, and walking unassisted. Results were analyzed using a non-parametric Wilcoxon test for paired series. Secondary outcomes were also assessed, such as weight-bearing, postoperative complications, and pain.

Results: A total of 19 consecutive patients (mean age 66.8 years, mostly American Society of Anesthesiologists score 3) receiving a percutaneous cemented screw fixation of the roof of the acetabulum intervention between December 2014 and February 2025 were included. The cancers involved were mainly prostate cancer, followed by lung and breast cancer. The study shows a significant improvement in patients' walking ability (p = 0.0029) and weight-bearing capacity (p = 0.039) when comparing patients' situation before and after the intervention. The intervention also improved pain level in 17 out of 19 patients.

Conclusion: Percutaneous fixation of pathological fractures of the acetabulum roof by cemented screws, guided by imaging, is an approach that significantly improves walking.

Objective: The acetabular cup version in patients with total hip arthroplasty (THA) is a key parameter influencing hip stability and functional outcomes. Although CT remains the reference standard for assessing cup orientation, MRI with metal artifact reduction techniques is increasingly used for evaluating postoperative pain. This study compared MRI- and CT-based measurements of acetabular cup version regarding agreement, reproducibility, and reliability.

Material and methods: Patients who underwent THA between 2015 and 2025 with postoperative CT and MRI were retrospectively analyzed. MRI was performed using optimized metal artifact reduction sequences. Acetabular cup version was measured on axial high-bandwidth T1-weighted turbo spin-echo sequences and on corresponding CT scans by two musculoskeletal radiologists. Inter- and intra-reader, as well as inter-modality agreement, were assessed using intraclass correlation coefficients (ICC). Bland-Altman plots evaluated systematic bias.

Results: Thirty patients were included (mean age, 64.1 years; 14 women). Mean acetabular version was 31.2° (standard deviation (SD), 9.4-10.3) for CT and 30.1-30.2° (SD, 8.9-9.3) for MRI for both readers. Inter-reader agreement was almost perfect for CT (ICC, 0.96) and substantial for MRI (ICC, 0.76). Intra-reader agreement was almost perfect for both modalities (ICC, CT, 0.99; MRI, 0.94). Bland-Altman analysis showed no statistically significant differences between CT and MRI measurements with a slight positive bias for MRI (mean pooled difference, 1.1°; p = 0.058; limits of agreement, -4.7 to 6.8°) and almost perfect agreement for both readers (ICC, 0.86-0.90).

Conclusion: MRI measures acetabular cup version with excellent reliability and close agreement with CT, reinforcing MRI's role in postoperative THA evaluation.

Lateral discoid meniscus is the most common meniscal congenital variant. A lateral discoid meniscus manifests with a spectrum of findings, including abnormalities in size and shape, disorganized collagen architecture, and/or hypermobility, predisposing the meniscus to early degeneration and tearing. The purpose of this narrative review is to discuss the anatomy of the lateral discoid meniscus and to highlight MRI findings that should be included in radiology reports to guide management.

Objective: To evaluate whether femoral neck-parallel reconstruction of CT images improves the correlation with dual-energy X-ray absorptiometry for osteoporosis assessment compared with conventional table-parallel reconstruction.

Materials and methods: A retrospective analysis was conducted on 174 patients who underwent hip CT and dual-energy X-ray absorptiometry. Two CT image reconstruction methods were compared: femoral neck-parallel and table-parallel methods. CT values were extracted from cancellous bone regions in the femoral neck corresponding to the area measured by DXA. Correlation coefficients between CT values and dual-energy X-ray absorptiometry-derived bone mineral density and T-scores were calculated. A stratified analysis by femoral neck-to-table angle (< 5° vs. ≥ 5°) was performed. Receiver operating characteristic (ROC) curve analysis was performed to compare the ability of each method to discriminate between patients with and without low bone mass (defined as osteoporosis or osteopenia).

Results: CT values from the femoral neck-parallel method showed significantly stronger correlations with bone mineral density (r = 0.74) and T-score (r = 0.77) than those from the table-parallel method (bone mineral density: r = 0.66, T-score: r = 0.71) (p = 0.001 for both). In patients with ≥ 5° misalignment, the femoral neck-parallel method showed significantly higher correlation coefficients than the table-parallel method (bone mineral density, p < 0.001; T-score, p = 0.005). ROC curve analysis revealed that the area under the curve for detecting low bone mass was higher in the femoral neck-parallel method (0.87) than in the table-parallel method (0.83) (p = 0.012).

Conclusions: Femoral neck-parallel reconstruction significantly improves the correlation between CT values and dual-energy X-ray absorptiometry for low bone mass assessment compared to table-parallel reconstruction.