Skeletal Radiology最新文献

Adductor canal (Hunter's canal) pathologies are often underdiagnosed, with the saphenous nerve being the most commonly affected. While uncommon, involvement of the femoral artery and vein can cause severe and irreversible complications if not detected early. Significant attention must be given to adductor canal pathologies because the musculoaponeurotic tunnel is predominantly fibrotic with minimal adipose tissue. As a result, any edema or space-occupying lesion can lead to early compression of the structures within the adductor canal. Incorporating adductor canal syndrome into the imaging differential diagnosis is essential. For diagnosing and sometimes managing these conditions. In this article, we describe the anatomy and spectrum of pathologies involving the Hunter's canal.

Objective: To investigate potential risk factors for osteoporotic vertebral compression re-fractures (OVCRFs) following percutaneous kyphoplasty (PKP).

Materials and methods: Patients who underwent PKP from January 2012 to January 2020 were included in this study within the same institution. Cases were defined as patients who experienced OVCRFs, while controls were matched based on corresponding clinical characteristics from those patients without OVCRFs. The lumbar localized fat distribution parameters, including the fat infiltration ratio (FIR) in muscles [multifidus (MF), erector spinae (ES), paravertebral muscles (PVM), and psoas major (PS)] and subcutaneous fat thickness (SFT), were compared between the two groups through radiological data. And other clinical data that may be relevant were also compared. Independent risk factors for OVCRFs after PKP were identified through a binary logistic regression analysis.

Result: A total of 1391 patients who underwent PKP were included in this study. 51 patients were categorized into the re-fracture group, and 102 patients were selected as matched controls from the remaining cohort. There were statistically significant differences between the two groups in metrics including MF-FIR, ES-FIR, PVM-FIR, PS-FIR, bone mineral density (BMD), body-mass index (BMI), SFT, hemoglobin (Hb), albumin (ALB), alkaline phosphatase (ALP), and triglycerides (TG) (P < 0.05). Binary logistic regression analysis demonstrated that PVM-FIR (P = 0.003), SFT (P < 0.001), BMD (P = 0.011), and ALP (P = 0.005) were independent predictors for the occurrence of OVCRFs.

Conclusion: This study discovered that lumbar localized fat distribution parameters including PVM-FIR and SFT are independent predictors of OVCRFs. Additionally, BMD and ALP were found to be independent predictors of OVCRFs.

Soft tissue tumors, whether benign or malignant, may grow over time or remain stable, but they usually do not spontaneously decrease in size. However, there are exceptions, such as inflammatory conditions, desmoid tumors, or benign cysts. Intramuscular myxomas are benign soft tissue tumors that typically present as a solitary, slow-growing, painless mass. They are generally treated by surgical resection, after which recurrence is rare. Here, we present a brief series of three unusual cases of intramuscular myxomas that spontaneously decreased in size. They were located in the cervical region, the right lower extremity, and the paravertebral lumbar region. Imaging findings and percutaneous biopsies confirmed the diagnosis in all cases. Follow-up imaging showed a spontaneous reduction in lesion volume over time, far exceeding the amount of tissue sample removed during biopsy. This unusual observation of spontaneous shrinkage may call into question the subsequent therapeutic approach to these lesions.

Spinal imaging may support the diagnosis of axial spondyloarthritis when typical findings are recognized in an appropriate clinical context and it can also indicate disease activity. In May 2022, the definitions for inflammatory and structural spinal lesions in axial spondyloarthritis were updated and validated by the Assessment of SpondyloArthritis international Society (ASAS) magnetic resonance imaging (MRI) working group. The aims of this paper are to demonstrate and describe imaging findings of the spine in patients with axial SpA, including the latest updated definitions by the ASAS, and to show complications in patients with long-standing disease.

Objective: To evaluate the reliability and diagnostic performance of dual-energy CT virtual non-calcium imaging in diagnosing bone marrow infiltration in multiple myeloma.

Materials and methods: Seventy-two patients with multiple myeloma and ten controls were recruited. Patients received dual-energy CT and MRI while controls underwent dual-energy CT only, covering the cervical, thoracic, and lumbar spine and the pelvis. Virtual non-calcium images were compared with magnetic resonance images for confirmation and pattern classification. Fleiss Kappa analysis assessed consistency between virtual non-calcium and MRI classifications. Inter-observer agreement for virtual non-calcium and CT attenuation values was evaluated using Bland-Altman analysis. Diagnostic performances across various sites were evaluated using analysis of variance and receiver operating characteristic curve analysis.

Results: Dual-energy CT achieved higher consistency in classifying bone marrow infiltration in multiple myeloma than did MRI (kappa = 0.944). In the overall analysis, the mean virtual non-calcium attenuation values in the bone marrow infiltration group (- 28.3 HU; 95% confidence interval (CI), - 32.1, - 24.6) were higher than those in the non-bone marrow infiltration (- 97.5 HU; 95% CI, - 104.7, - 90.3) and control (- 89.1 HU; 95% CI, - 95.1, - 83.1; F = 172.027, P < 0.001) groups. The optimal cutoff values for virtual non-calcium attenuation varied across the overall (- 42.2 HU), cervical spine (- 21.9 HU), thoracic spine (- 42.8 HU), lumbar spine (- 56.9 HU), and pelvis (- 66.3 HU).

Conclusion: Dual-energy CT virtual non-calcium imaging and MRI exhibited good consistency in categorising bone marrow infiltration patterns in multiple myeloma. Different virtual non-calcium attenuation value cutoffs should be used to diagnose bone marrow infiltration in various body regions.

Synovial chondrosarcoma (CHS) is a rare malignant tumor arising from the synovial tissue and is often associated with synovial chondromatosis. Herein, we present a unique case of primary synovial CHS in the shoulder joint without evidence of synovial chondromatosis. A 60-year-old man presented to our hospital with a complain of left shoulder pain that persisted for 6 years, which was initially misdiagnosed as synovitis. Radiography revealed an osteolytic lesion involving the humerus and the scapula. Histologically, the tumor exhibited features of grade 2 synovial CHS, infiltrating the trabecular bones and intra-articular space. Wide resection led to a 9-year recurrence-free survival. This case underscores the challenges in diagnosing and managing synovial CHS, particularly in cases with atypical presentations lacking synovial chondromatosis, necessitating careful follow-up and adequate surgical intervention.

Objective: This study aims to identify distinguishing MRI features of Lyme arthritis (LA), an increasingly prevalent cause of pediatric infectious arthritis in the USA, to enable rapid discrimination from septic arthritis (SA) and facilitate appropriate management.

Materials and methods: A single-center, retrospective analysis was conducted on a convenience sample of pediatric patients with LA in an endemic area using EPIC electronic health record data between January 2010 and December 2020. Patients with positive serologic testing and concurrent MRI were selected. MRI scans were reviewed by a subspecialty-trained pediatric radiologist. Key MRI features analyzed include joint effusion, synovitis, myositis, soft tissue edema, and osseous edema and erosions. MRI features, demographics, and clinical data were compared using univariable and multivariable analyses.

Results: Fifty cases of knee LA and 13 cases of knee SA were included. Larger joint effusion (p = 0.0055, z =  - 2.779) and abnormally thickened synovium (p = 0.0011, χ² = 10.622) were more associated with LA. In contrast, increased myositis, subcutaneous edema, and osseous changes were more prevalent in SA. Abnormal bone marrow signal (p < 0.0001, χ² = 36.893) and bone erosion (p < 0.0001, χ² = 25.506) were observed in 84.6% (11/13) and 46.2% (6/13) of SA cases, respectively, while no bone erosion was found in LA.

Conclusion: MRI can be a valuable tool in differentiating LA from SA. Abnormal synovium and increasing joint effusion favor LA, while increasing soft tissue edema and osseous changes favor SA. Notably, the presence of bone erosion effectively excluded LA from consideration.

Objectives: Hip microinstability is a clinical entity increasingly recognized and treated but challenging to diagnose with a lack of objective criteria. This study assessed the prevalence and diagnostic accuracy of different imaging findings for hip microinstability on radiograph and MR.

Methods: A retrospective case-control study of 224 hips treated with arthroscopic surgery by a single orthopedic surgeon, 112 hips with clinical microinstability and 112 controls without. Pre-operative radiograph and MRI/MRA imaging were evaluated by two musculoskeletal radiologists to assess morphological parameters and imaging signs reportedly associated with hip microinstability.

Results: Four imaging features reached significance as predictors of microinstability via three-step logistic regression: labral hyperplasia and decreased lateral center edge angle on MR (OR 2.45 and 0.93, respectively) and the absence of positive ischial spine sign and absence of osteophytes on radiographs (OR 0.47 and 0.28, respectively). Increased acetabular anteversion and absence of cam lesions were more likely in the microinstability group (p = 0.02 and 0.04, respectively), but not independent predictors. Labral tears, chondral loss, abnormal ligamentum teres, anterior capsule thinning, iliocapsularis to rectus femoris ratio, posterior crescent sign, cliff sign, and femoro-epiphyseal acetabular roof (FEAR) index were not associated with microinstabillity.

Conclusion: Imaging features may be predictive of hip microinstability in some cases. Decreased LCEA, increased acetabular anteversion, and labral hyperplasia were associated with microinstability in this study, while many other published imaging findings were not. Imaging remains complementary, but not definitive, in the diagnosis of hip microinstability.

Objective: Novel 0.55 MRI scanners have the potential to reduce metal artifacts around orthopedic implants. The purpose of this study was to compare metal artifact size and depiction of anatomy between 0.55 T and 3.0 T MRI in a biophantom.

Materials and methods: Steel and titanium screws were implanted in 12 porcine knee specimens and imaging at 0.55 T and 3 T MRI was performed using the following sequences: turbo spin-echo (TSE), TSE with view angle tilting (VAT), and slice encoding for metal artifact correction (SEMAC) with proton-density (PD) and T2-weighted short-tau inversion-recovery (T2w-STIR) contrasts. Artifacts were measured, and visualization of anatomy (cartilage, bone, growth plates, cruciate ligaments) was assessed and compared between groups.

Results: Metal artifacts were significantly smaller at 0.55 T. The smallest artifact sizes were achieved with SEMAC at 0.55 T for both PD and T2w-STIR sequences; corresponding relative size reductions vs. 3.0 T were 78.7% and 79.4% (stainless steel) and 45.3% and 1.4% (titanium). Depiction of anatomical structures was superior at 0.55 T.

Conclusion: Substantial reduction of artifact size resulting in superior depiction of anatomical structures is possible on novel 0.55 T MRI systems. Further clinical studies are required to elucidate patient-relevant advantages.

Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.