Skeletal Radiology最新文献

The clinical significance of osteoporosis lies in the occurrence of fragility fractures (FFx), and the most relevant fracture site is the hip. The T-score is defined as follows: (BMD_patient–BMD_{young adult mean})/SDy_{oung adult population}, where BMD is bone mineral density and SD is the standard deviation. When the femoral neck (FN) is measured in adult Caucasian women, a cutpoint value of patient BMD of 2.5 SD below the young adult mean BMD results in a prevalence the same as the lifetime risk of hip FFx for Caucasian women. The FN T-score criterion for classifying osteoporosis in older Caucasian men has been provisionally recommended to be − 2.5, but debates remain. Based on a systematic literature review, we noted that older men suffer from hip FFx at a FN T-score approximately 0.5–0.6 higher than older women. While the mean hip FFx FN T-score of around − 2.9 for women lies below − 2.5, the mean hip FF FN T-score of around − 2.33 for men lies above − 2.5. This is likely associated with that older male populations have a higher mean T-score than older female populations. We propose a new category of low BMD status, osteofrailia, for older Caucasian men with T-score ≤ − 2 (T-score ≤ − 2.1 for older Chinese men) who are likely to suffer from hip FFx. The group with T-score ≤ − 2 for older Caucasian men is comparable in prevalence to the group with T-score ≤ − 2.5 for older Caucasian women. However, older men in such category on average have only half the FFx risk as that of older women with osteoporotic T-score.

Background

Evaluation of glenoid bone loss following recurrent anterior shoulder dislocations is normally performed using cross sectional imaging.

Objectives

To assess how anteroposterior (AP) and Bernageau view radiographs compare to computed tomography (CT), magnetic resonance imaging (MRI) and arthroscopy for evaluating glenoid bone loss in patients with recurrent anterior shoulder dislocation.

Materials and methods

A prospective observational study was performed on 32 patients over two years at a tertiary orthopedic center. The loss of sclerotic glenoid rim (LSGL) on AP radiograph and the percentage relative glenoid bone loss on the Bernageau radiograph were assessed. The percentage glenoid bone loss and anterior straight line (ASL) were calculated using a best fit en face circle method using CT and MRI. Percentage glenoid bone loss was also calculated during arthroscopy in multiples of 5%.

Results

In our study, 90.6% (29) patients were males, while only 9.4% (3) were females. This can be attributed to the involvement of the males in outdoor activities and sports. Also, the maximum number of patients were found to belong to 21–30 years of age, with the mean age being 28.66 years. Of the 32 patients, loss of sclerotic glenoid line (LSGL) on AP radiographs correlated with glenoid bone loss on cross-sectional imaging in 27 patients. Three patients had equivocal LSGL and 2 patients with glenoid bone loss on CT did not demonstrate LSGL. The difference between the two modalities was not statistically significant (p value = 0.002). The glenoid bone loss on Bernageau view correlated with glenoid bone loss on cross sectional imaging in all but one patient. The bone loss as evaluated by radiograph Bernageau view was found to have strong correlation (correlation coefficient r = 0.948, p value < 0.0001).

Conclusion

AP and Bernageau radiographic views for anterior shoulder dislocations demonstrate good correlation with glenoid bone loss on cross-sectional imaging. They may also be used as an adjunct to predict overall bone loss on CT and at arthroscopy.

Objective

The impact of time on neuroma growth and morphology on pain intensity is unknown. This study aims to assess magnetic resonance imaging (MRI) differences between symptomatic and non-symptomatic neuromas in oncological amputees, and whether time influences MRI-detected neuroma dimensions and their association with pain.

Material and methods

Oncological patients who underwent traditional extremity amputation were included. Post-amputation MRIs were assessed before decision for neuroma surgery. Chart review was performed for residual limb pain (numeric rating scale, 0–10) and the presence of neuropathic symptoms. Neuromas were classified as symptomatic or non-symptomatic, with neuroma size expressed as radiological neuroma-to-nerve-ratio (NNR).

Results

Among 78 neuromas in 60 patients, the median NNR was 2.0, and 56 neuromas (71.8%) were symptomatic with a median pain score of 3.5. NNR showed no association with symptomatology or pain intensity but correlated with a longer time-to-neuroma-excision interval and a smaller nerve caliber. Symptomatic neuromas were associated with lower extremity amputation, T2 heterogeneity, and the presence of heterotopic ossification. Lower extremity amputation, T2 heterogeneity, perineural edema, and presence of heterotopic ossification were associated with more painful neuromas.

Conclusion

MRI features associated with symptomatic neuromas and pain intensity were identified. Awareness of the potential clinical significance of these imaging features may help in the interpretation of MRI exams and may aid clinicians in patient selection for neuroma surgery in oncological amputees.

Chordomas are rare primary bone tumours that commonly occur in the sacrococcygeal and skull base region and have high rates of local recurrence. They have a locally aggressive course and the most common site of distant metastasis is the lung. The aim of this case report is to present the imaging findings of instance of muscle metastasis, a rare occurrence in cervical chordoma.

Objective

To evaluate clinical and radiological features of extraskeletal myxoid chondrosarcomas (EMC).

Material and Methods

Our pathology database was queried for cases of EMCs. Tumor location, size, imaging appearance, presence of metastases, disease recurrence, and clinical outcome were documented. Imaging studies were evaluated in consensus by a musculoskeletal radiologist and an orthopedic oncologist.

Results

Thirty subjects met the inclusion criteria (mean age 52.7 ± 16.2 years; 19 male, 11 female), 17 (56.7%) of which had pre-operative imaging. Tumors occurred most often in the lower extremities (20/30; 66.7%). All cases presented as a soft-tissue mass without mineralization on XR or CT. On MRI, tumors were typically hyperintense on T2-weighted sequences (14/14; 100%) and had a chondroid matrix appearance (12/14; 85.7%). Tumor invasion was observed in 11 out of 16 (68.9%) patients and necrosis in 2 out of 11 subjects (18.2%). All subjects had their tumors examined by pathology, and 20 (66.7%) subjects also had descriptive information in addition to the diagnosis (tumor invasion, mitotic rate, and necrosis) noted in the pathology reports. The mean duration of follow-up was 9.4 ± 7.5 (1.0 – 29.6) years. At the last follow-up, 14 out of 28 (50%) subjects were disease-free, 6 out of 28 had persistent metastatic disease and 8 out of 28 had died.

Conclusions

EMC is a rare sarcoma that commonly presents as lower extremity soft tissue mass with chondroid appearance on MRI. Unlike conventional chondrosarcomas, EMC do not demonstrate mineralization on XR or CT.

Somatic overgrowth disorders comprise a wide range of rare conditions that present with focal enlargement of one or more tissue types. The PI3K-AKT-mTOR pathway is a signalling pathway that induces angiogenesis and cell proliferation, and is one of the most commonly overactivated signalling pathways in cancer. The PI3K-AKT-mTOR pathway can be up-regulated by genetic variants that code for proteins in this pathway, or down-regulated by proteins that inhibit the pathway. Mosaic genetic variations can result in cells that proliferate excessively in specific anatomical locations. The PIK3CA-related overgrowth spectrum (PROS) disorders include CLOVES syndrome, macrodystrophia lipomatosa, and Klippel-Trenaunay syndrome among many. The neurofibromatosis type 1 (NF1) gene encodes neurofibromin which down-regulates the PI3K-AKT-mTOR pathway. Thousands of pathological variants in the NF1 gene have been described which can result in lower-than-normal levels of neurofibromin and therefore up-regulation of the PI3K-AKT-mTOR pathway promoting cellular overgrowth. Somatic overgrowth is a rare presentation in NF1 with a wide range of clinical and radiological presentations. Hypertrophy of all ectodermal and mesodermal elements has been described in NF1 including bone, muscle, fat, nerve, lymphatics, arteries and veins, and skin. The shared signalling pathway for cellular overgrowth means that these radiological appearances can overlap with other conditions in the PIK3CA-related overgrowth spectrum. The aim of this review is to describe the genetic basis for the radiological features of NF1 and in particular compare the appearances of the somatic overgrowth disorders in NF1 with other conditions in the PIK3CA-related overgrowth spectrum.

Slipped capital femoral epiphysis is a shearing injury through the growth plate of the proximal femur and is the most common hip disorder in adolescence. Delays in diagnosis persist across practice settings despite ongoing innovations in imaging. Recent insights into pathomechanics highlight the importance of femoral head surface morphology and rotational microinstability centered at the epiphyseal tubercle in causing early physeal changes, which can be detected on imaging prior to frank slip. Scrutiny of physeal morphology and comparison to the contralateral hip is critical at all stages of disease progression, and improper technique may result in undue diagnostic delay. Selective use of cross-sectional imaging can be helpful for troubleshooting equivocal early slips and can inform operative technique and adjuvant therapy candidacy in more severe cases. This review provides a comprehensive approach to imaging suspected slipped capital femoral epiphysis, with an emphasis on early detection and potential pitfalls.

Objective: To develop a deep learning algorithm for diagnosing lumbar central canal stenosis (LCCS) using abdominal CT (ACT) and lumbar spine CT (LCT).

Materials and methods: This retrospective study involved 109 patients undergoing LCTs and ACTs between January 2014 and July 2021. The dural sac on CT images was manually segmented and classified as normal or stenosed (dural sac cross-sectional area ≥ 100 mm² or < 100 mm², respectively). A deep learning model based on U-Net architecture was developed to automatically segment the dural sac and classify the central canal stenosis. The classification performance of the model was compared on a testing set (990 images from 9 patients). The accuracy, sensitivity, and specificity of automatic segmentation were quantitatively evaluated by comparing its Dice similarity coefficient (DSC) and intraclass correlation coefficient (ICC) with those of manual segmentation.

Results: In total, 990 CT images from nine patients (mean age ± standard deviation, 77 ± 7 years; six men) were evaluated. The algorithm achieved high segmentation performance with a DSC of 0.85 ± 0.10 and ICC of 0.82 (95% confidence interval [CI]: 0.80,0.85). The ICC between ACTs and LCTs on the deep learning algorithm was 0.89 (95%CI: 0.87,0.91). The accuracy of the algorithm in diagnosing LCCS with dichotomous classification was 84%(95%CI: 0.82,0.86). In dataset analysis, the accuracy of ACTs and LCTs was 85%(95%CI: 0.82,0.88) and 83%(95%CI: 0.79,0.86), respectively. The model showed better accuracy for ACT than LCT.

Conclusion: The deep learning algorithm automatically diagnosed LCCS on LCTs and ACTs. ACT had a diagnostic performance for LCCS comparable to that of LCT.

Objective: Knowledge of footprint anatomy is essential for ankle anterior talofibular ligament repair and reconstruction. We aimed to determine the intra- and inter-rater measurement reliability of the anterior talofibular ligament footprint dimension using three-dimensional MRI.

Methods: MRI images of 20 ankles with intact ligaments, including 11 with a single bundle and nine with double-bundle ligaments, were analyzed. Imaging was performed using a 3.0-Tesla MRI. Isotropic three-dimensional proton density-weighted images with a voxel size of 0.6 mm were obtained. The fibular and talar footprints were manually segmented using image processing software to create three-dimensional ligament footprints. The lengths, widths, and areas of each sample were measured. A certified orthopedic surgeon and a senior orthopedic fellow performed the measurements twice at 6-week intervals. The intra- and inter-rater differences in the measurements were calculated.

Results: The length, width, and area of the single-bundle fibular footprint were 8.7 mm, 5.4 mm, and 37.4 mm², respectively. Those of the talar footprint were 8.4 mm, 4.3 mm, and 30.1 mm², respectively. The inferior bundle of the double-bundle ligament was significantly smaller than the single and superior bundles (p < 0.001). No differences were observed between intra-rater measurements by either rater, with maximum differences of 0.7 mm, 0.5, and 1.7 mm², in length, width, and area, respectively. The maximum inter-rater measurement differences were 1.9 mm, 0.5, and 2.4 mm², respectively.

Conclusion: Measurements of the anterior talofibular ligament dimensions using three-dimensional MRI were sufficiently reliable. This measurement method provides in vivo quantitative data on ligament footprint anatomy.