Skeletal Radiology最新文献

Organizing thrombus is a well described histologic finding involving the reorganizing and recanalization of a healing thrombus. However, it is rarely large enough to be described on imaging. When the thrombus becomes sufficiently large, intravascular papillary endothelial hyperplasia (IPEH) must be considered. IPEH or Masson's tumor is a benign, exuberant form of organizing thrombus that typically occurs in the soft tissues of the head, neck, and distal extremities. It can occur within a vessel, hematoma, or vascular mass and can mimic benign processes or malignant lesions such as angiosarcoma. Histopathological characteristics are needed for final diagnosis. The treatment is typically complete surgical resection with excellent prognosis. We report the case of a patient presenting with swelling in his left forearm in the same site as a previously treated left basilic vein thrombus. Ultrasound demonstrated a noncompressible, heterogeneous intravascular mass with internal vascularity. Subsequent MRI showed an enhancing mass centered in the left basilic vein with a flow void with the differential diagnosis of IPEH versus intravascular neoplasm. Percutaneous biopsy was performed with histology consistent with reactive vascular proliferation and organizing thrombus. The papillary architecture diagnostic of IPEH was absent. Regardless of final specific terminology, this case presents exuberant organizing thrombus as a benign cause of an enhancing intravascular mass. This patient was treated conservatively with no further intervention.

Epiphyseal and metaphyseal bone lesions in pediatric patients are uncommon, and lesions that cross an open physis are even rarer. The differential diagnosis for such lesions consists of infection, giant cell tumor, and chondroblastoma. We describe a 4-year-old male patient who presented with a bone tumor originating in the proximal tibial metaphysis that extended across the physis into the epiphysis. Sampling revealed a HMGA2::NCOR2 fusion associated with a recently described subset of giant cell-rich bone and soft tissue tumors. This case expands the differential diagnosis for cross-physeal and epiphyseal bone tumors in pediatric patients and highlights the radiological features of keratin-positive giant cell-rich tumor (KPGCT).

Nerve sheath myxoma (NSM) is a rare benign tumor originating from peripheral nerves. We present a case of NSM in the upper extremity. A 67-year-old female presented with painful nodular bulging in the elbow. Magnetic resonance imaging and ultrasonography revealed diagnostic features. Surgical excision was performed and histopathological examination confirmed the diagnosis. Our case contributes to the understanding of NSM's clinical presentation, imaging characteristics, and management strategies of NSM.

Objective: This study aims to provide normative data on normal linear measurements of the lateral calcaneus surface in pediatric subjects aged 2 and 18 years, analyzing variations across age groups and genders using lateral foot radiographs to aid in assessing calcaneal disorders.

Methods: A total of 716 lateral foot radiographs (381 males and 335 females) with a mean age of 8.99 years (range, 2-17) were included. Subjects were divided into five age groups (2-4, 5-7, 8-10, 11-13, and 14-17) to assess calcaneal morphometric changes with growth. Pediatric patients aged 2-18 years with healthy, weight-bearing lateral foot radiographs were included. Exclusion criteria were hindfoot surgery, calcaneal fractures, foot deformities, and poor image quality. Six linear calcaneal measurements (maximum length (MAXL), maximum height (MAXH), minimum height (MINH), load arm length (LAL), body height (BH), and cuboidal facet height (CFH)) were obtained from the radiographs for analysis.

Results: Males showed larger calcaneal measurements than females after the age of 7, with significant differences between age groups (p < 0.001). The highest mean values were observed in the 14-17 age group, while the lowest were in the 2-4 age group. Statistically significant gender-related size differences were found for most parameters, with notable differences in CFH, LAL, and MAXL measurements.

Conclusions: This study provides the largest pediatric sample to date on calcaneal morphometric variations, showing significant age- and sex-related differences in calcaneal dimensions. Notably, after the age of 10, male subjects exhibited significantly greater calcaneal length and height compared to females.

Objective: To assess whether accelerated knee MRI protocols using simultaneous multi-slice (SMS) and deep learning reconstruction (DLR) are non-inferior to a conventional parallel imaging protocol for detecting internal derangement injuries.

Methods: This retrospective cohort study included 1055 patients who underwent knee MRI followed by arthroscopy within 180 days. Patients were scanned using either a conventional protocol (n = 226), an accelerated SMS protocol (n = 406), or a SMS with DLR protocol (n = 423). Each group included consecutive exams. Imaging was performed on 3 T MRI using five standardized two-dimensional turbo spin echo sequences. Radiology interpretations were compared with arthroscopy (reference standard) for anterior cruciate ligament (ACL), medial meniscus (MM), and lateral meniscus (LM) tears. Sensitivity and specificity were calculated with 95% confidence intervals using non-parametric bootstrapping. Non-inferiority was concluded if the upper bound of the 95% confidence interval for the difference in sensitivity and specificity was ≤ 0.05.

Results: Among all patients, 666 had MM tears, 417 had LM tears, and 220 had ACL tears. Sensitivity for ACL tears was higher with accelerated protocols (0.96 and 0.98) than the conventional (0.85), with non-inferiority confirmed. Specificity was ≥ 0.98 across all protocols. MM sensitivity (0.94-0.95) met non-inferiority criteria. MM specificity (0.88-0.91) and LM sensitivity (0.63-0.68) were not statistically different across protocols but did not meet the non-inferiority margin. LM specificity (0.94) met non-inferiority criteria.

Conclusion: Accelerated MRI protocols using SMS and DLR demonstrated comparable diagnostic performance to the reference protocol. Although not all metrics met the strict non-inferiority margin, none showed statistically significant reductions in sensitivity or specificity. These findings support the clinical adoption of accelerated protocols for faster, high-throughput knee imaging.

Objective: The clinical use of magnetic resonance imaging-based volumetric measurement for osteonecrosis of the femoral head (ONFH) is restricted by its complexity. This study aimed to identify a practical computed tomography-based imaging parameter as a reliable alternative to necrotic volume and to evaluate its ability to predict femoral head collapse.

Materials and methods: This retrospective study included 125 hips from 90 patients with ONFH and initial collapse of < 3 mm. Four-dimensional ratios were examined for their association with necrotic volume using generalized estimating equation models. The parameter showing the strongest association was determined by comparing models with the Quasi-likelihood Information Criterion (QIC). Receiver operating characteristic curve analysis was then used to establish a cutoff value for predicting a necrotic volume of ≥ 30%, the threshold defined as severe in the Steinberg classification. This prognostic value of this cutoff for collapse (> 3 mm) was tested with a robust Cox proportional hazards model.

Results: The coronal vertical diameter ratio (CVDR) showed the strongest association with necrotic volume, yielding the lowest QIC. A CVDR cutoff of 51% predicted a large necrotic volume (AUC 0.931). Hips with a CVDR ≥ 51% had a significantly higher risk of collapse compared with those with a CVDR < 51% (HR, 6.07; 95% CI, 3.25-11.34; P < 0.001). This predictive value was consistent across all Japanese Investigation Committee type subgroups.

Conclusion: The CVDR represents a simple and reliable alternative to volumetric assessment. A cutoff of approximately 51% provides clinically useful risk stratification, and incorporating lesion location may further enhance predictive accuracy.

Objective: To compare the qualitative diagnostic performance of conventional computed tomography (CT) alone with that of dual-energy computed tomography (DECT) virtual non-calcium (VNCa) imaging for detecting spinal metastases, and evaluate the diagnostic utility of DECT-derived quantitative material parameters in this retrospective diagnostic accuracy study.

Materials and methods: Consecutive patients (August 2019-January 2024) underwent DECT at a single center. Two board-certified radiologists scored vertebrae on conventional CT and CT + VNCa using a 5-point scale (positive for scores 4-5). The reference standard was a consensus MRI within 3 months, supplemented by PET/CT and/or bone scintigraphy when available. We estimated sensitivity, specificity, and AUC with 95% CIs. Quantitative parameters including 70-keV CT attenuation (HU), water-calcium, water-hydroxyapatite, and Z_eff were compared between metastatic and normal vertebrae using the Wilcoxon rank-sum test.

Results: We included 117 patients, comprising 1416 vertebrae; 24.2% had metastases. For conventional CT, sensitivity was 0.70/0.71 (95% CI 0.664-0.738/0.677-0.750) and specificity, 0.97/0.97 (95% CI 0.939-1.000/0.935-1.000). CT + VNCa sensitivity increased to 0.94/0.93 (95% CI 0.906-0.980/0.890-0.964; p < 0.001) and AUC improved to 0.97/0.96 (both p < 0.001, specificity, 0.99/0.98). Quantitative analysis showed significantly higher values of water-calcium (1133.8 vs. 1007.6 mg/cm³), water-hydroxyapatite (991.5 vs. 971.0 mg/cm³), and effective atomic number (10.5 vs. 8.3) in osteoblastic metastases compared with those in normal vertebrae (all p < 0.05).

Conclusion: CT + VNCa significantly improves the detection of spinal metastases compared with conventional CT alone. Quantitative parameters from material decomposition analysis provide additional diagnostic value.

Objectives: To evaluate the diagnostic accuracy of artificial intelligence-assisted opportunistic chest CT for osteoporosis/osteopenia screening in a Chinese population.

Methods: This retrospective study included 1306 adults (≥ 55 years) undergoing concurrent chest CT and DXA during physical examinations (Apr 2015 to May 2024). Exclusion criteria comprised vertebral fractures, spinal surgery, or contrast-enhanced CT. DXA T-scores (lumbar spine) defined osteoporosis, osteopenia, and normal BMD. The AI system automatically quantified volumetric BMD (AI-BMD) at vertebrae T10-L1. Diagnostic performance was assessed using ROC curves.

Results: Mean age was 63.96 years (36.98% male). Osteoporosis prevalence was 36.45% (n = 476/1306), significantly higher in women (P < 0.01). AI-BMD values decreased significantly from T10 to L1 (P < 0.05). For osteoporosis detection, AI-BMD demonstrated excellent diagnostic accuracy: AUC was 0.84 (95% CI: 0.81-0.87) at T10, 0.83 (95% CI: 0.80-0.86) at T11, 0.81 (95% CI: 0.79-0.84) at T12, and 0.83 (95% CI: 0.80-0.87) at L1. Performance for osteopenia diagnosis was moderate, with AUCs ranging from 0.72 to 0.75.

Conclusion: The combination of opportunistic chest CT and AI shows promise for accurate osteoporosis screening (AUCs 0.81-0.84), albeit with moderate performance in detecting osteopenia (AUCs 0.72-0.75). The retrospective, single-center design of this study suggests that future multi-center validation is warranted to confirm the generalizability of these findings.

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.