Deep learning reconstruction for turbo spin echo to prospectively accelerate ankle MRI: A multi-reader study.

PURPOSE: To evaluate a deep learning reconstruction for turbo spin echo (DLR-TSE) sequence of ankle magnetic resonance imaging (MRI) in terms of acquisition time, image quality, and lesion detectability by comparing with conventional TSE. METHODS: Between March 2023 and May 2023, patients with an indication for ankle MRI were prospectively enrolled. Each patient underwent a conventional TSE protocol and a prospectively undersampled DLR-TSE protocol. Four experienced radiologists independently assessed image quality using a 5-point scale and reviewed structural abnormalities. Image quality assessment included overall image quality, differentiation of anatomic details, diagnostic confidence, artifacts, and noise. Interchangeability analysis was performed to evaluate the equivalence of DLR-TSE relative to conventional TSE for detection of structural pathologies. RESULTS: In total, 56 patients were included (mean age, 32.6 ± 10.6 years; 35 men). The DLR-TSE (233 s) protocol enabled a 57.4 % reduction in total acquisition time, compared with the conventional TSE protocol (547 s). DLR-TSE images had superior overall image quality, fewer artifacts, and less noise (all P < 0.05), compared with conventional TSE images, according to mean ratings by the four readers. Differentiation of anatomic details, diagnostic confidence, and assessments of structural abnormalities showed no differences between the two techniques (P > 0.05). Furthermore, DLR-TSE demonstrated diagnostic equivalence with conventional TSE, based on interchangeability analysis involving all analyzed structural abnormalities. CONCLUSION: DLR can prospectively accelerate conventional TSE to a level comparable with a 4-minute comprehensive examination of the ankle, while providing superior image quality and similar lesion detectability in clinical practice.

A Real-Time Monitoring Method for Droplet Transfer Frequency in Wire-Filled GTAW Based on Arc Sensing.

Droplet transfer frequency is a decisive factor in welding quality and efficiency in gas tungsten arc welding (GTAW). However, there still needs to be a monitoring method for droplet transfer frequency with high precision and good real-time performance. Therefore, a real-time monitoring method for droplet transfer frequency in wire-filled GTAW using arc sensing is proposed in this paper. An arc signal acquisition system is developed, and the wavelet filtering method filters out noise from the arc signal. An arc signal segmentation method-based on the OTSU algorithm and a feature extraction method for droplet transition based on density-based spatial clustering of applications with noise (DBSCAN)-is proposed to extract the feature signal of the droplet transition. A new conception of droplet transition uniformity is proposed, and it can be used to monitor the weld bead width uniformity. Numerous experiments for monitoring droplet transfer frequency in real time are conducted with typical welding parameters. This method enables the real-time observation of droplet transfer frequency, and the result shows that the average monitoring error is less than 0.05 Hz.

Evaluation of Open Versus Arthroscopic Anterior Talofibular Ligament Reconstruction for Chronic Lateral Ankle Instability With Talar and Subtalar Cartilage MRI T2 Mapping: A 3-Year Prospective Study.

BACKGROUND: Previous studies have examined patients with chronic lateral ankle instability (CLAI) undergoing open and arthroscopic anterior talofibular ligament (ATFL) reconstruction, reporting equivalent clinical results between the 2 procedures. However, data on the magnetic resonance imaging (MRI) outcomes on cartilage health after the 2 procedures are limited. PURPOSE: To compare the cartilage MRI T2 values of the talar and subtalar joints between patients with CLAI undergoing open and arthroscopic ATFL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A prospective study was conducted on patients who underwent open or arthroscopic ATFL reconstruction between January 2018 and December 2019, with a mean follow-up duration of 3 years. MRI scans and American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner score estimations were completed by patients ≤1 week before surgery, as a baseline measurement, and at a 3-year follow-up. A total of 21 healthy volunteers were included who underwent MRI at baseline. Cartilage health was evaluated using MRI T2 mapping. The talar and subtalar cartilage regions were segmented into 14 subregions. RESULTS: At baseline, patients with CLAI had substantially higher T2 values in the medial anterior, medial center, medial posterior, and lateral center regions on the talus compared with the healthy controls (P = .009, .003, .001, and .025, respectively). Remarkable increases in T2 values in the lateral posterior region on the talus were observed from baseline to follow-up in the open group (P = .007). Furthermore, T2 values were considerably higher in the medial center, medial posterior, lateral posterior, and lateral posterior calcaneal facets of the posterior subtalar joint at follow-up in the arthroscopic group compared with the baseline values (P = .025, .002, .006, and .044, respectively). No obvious differences in ΔT2 values were noted between the 2 groups at follow-up. The AOFAS and Tegner scores remarkably improved from baseline to follow-up for the 2 groups (open: 3.25 ± 0.58 vs 5.13 ± 0.81, P < .001; arthroscopic: 3.11 ± 0.90 vs 5.11 ± 1.08, P < .001), with no considerable difference between them. CONCLUSION: The elevated T2 values of cartilage could not be fully recovered after open or arthroscopic ATFL reconstruction. Both arthroscopic and open ATFL reconstruction displayed similar effects on cartilage health concerning ΔT2, but the arthroscopic group demonstrated more degenerative cartilage subregions than the open group.

Prospective Comparison of Standard and Deep Learning-reconstructed Turbo Spin-Echo MRI of the Shoulder.

Background Deep learning (DL)-based MRI reconstructions can reduce imaging times for turbo spin-echo (TSE) examinations. However, studies that prospectively use DL-based reconstructions of rapidly acquired, undersampled MRI in the shoulder are lacking. Purpose To compare the acquisition time, image quality, and diagnostic confidence of DL-reconstructed TSE (TSEDL) with standard TSE in patients indicated for shoulder MRI. Materials and Methods This prospective single-center study included consecutive adult patients with various shoulder abnormalities who were clinically referred for shoulder MRI between February and March 2023. Each participant underwent standard TSE MRI (proton density- and T1-weighted imaging; conventional TSE sequence was used as reference for comparison), followed by a prospectively undersampled accelerated TSEDL examination. Six musculoskeletal radiologists evaluated images using a four-point Likert scale (1, poor; 4, excellent) for overall image quality, perceived signal-to-noise ratio, sharpness, artifacts, and diagnostic confidence. The frequency of major pathologic features and acquisition times were also compared between the acquisition protocols. The intergroup comparisons were performed using the Wilcoxon signed rank test. Results Overall, 135 shoulders in 133 participants were evaluated (mean age, 47.9 years ± 17.1 [SD]; 73 female participants). The median acquisition time of the TSEDL protocol was lower than that of the standard TSE protocol (288 seconds [IQR, 288-288 seconds] vs 926 seconds [IQR, 926-950 seconds], respectively; P < .001), achieving a 69% lower acquisition time. TSEDL images were given higher scores for overall image quality, perceived signal-to-noise ratio, and artifacts (all P < .001). Similar frequency of pathologic features (P = .48 to > .99), sharpness (P = .06), or diagnostic confidence (P = .05) were noted between images from the two protocols. Conclusion In a clinical setting, TSEDL led to reduced examination time and higher image quality with similar diagnostic confidence compared with standard TSE MRI in the shoulder. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Chang and Chow in this issue.

Characterization and evaluation of Bletilla striata polysaccharide/konjac glucomannan blend hydrogel for wound healing.

Bletilla striata polysaccharide (BSP) is effective for wound healing and has important applications in health care. A series of blend hydrogels was designed with BSP and konjac glucomannan (KGM) in this study to overcome the deficient mechanical performance caused by the excessive dissolution of BSP without affecting its physiological activity. The interplay between them, as well as the effects of KGM concentration on the physical properties and microstructures of hydrogels, were also explored. It was proved that the frame of the hydrogel was primarily formed by KGM. BSP was dispersed uniformly and linked to KGM through hydrogen bonding, which effectively improved the physical properties, such as increasing the water-holding capacity, improving the swelling degree, and enhancing the mechanical properties. Blend hydrogel BK2-2 (containing 1.0% BSP and 1.0% KGM, w/v) was found to be the optimal formulation based on the thermal stability and microstructure, which was used for further research. In vitro experiments revealed the L929 cell proliferative effects of the blend hydrogel, and no difference was found with BSP sponge extract after 72 h of exposure. In vivo animal studies indicated that the BK2-2 accelerated wound healing compared with the control group; however, no difference was found with dressings only made of BSP. These results demonstrated that KGM improved the physical properties of BSP-based material without negatively affecting its physiological properties. Also, the BSP/KGM blend hydrogel had good comprehensive properties and is expected to be used as a wound healing material in the future.

T2*-corrected Q-Dixon and reduced-FOV diffusion kurtosis imaging (DKI) parameters: correlation with QCT-derived bone mineral density (BMD) and ability to identify abnormal BMD and osteoporosis in postmenopausal women.

Background: Bone marrow fat increases when the bone volume decreases. The composition of the bone marrow microenvironment can also become altered. Assessments of bone marrow fat and bone marrow structural heterogeneity have the potential to predict abnormal bone mineral density (BMD) and osteoporosis. This study aimed to investigate the diagnostic performance of T2*-corrected Q-Dixon and reduced-field-of-view (FOV) diffusion kurtosis imaging (DKI) parameters in determining abnormal BMD and osteoporosis in postmenopausal women. Methods: In this prospective study, the individuals who were eligible for inclusion included postmenopausal women (over 50-year-old) with suspected osteoporosis based on experiencing low back pain. This mono-center study was conducted in tertiary care in China. All of the patients were recruited by using the consecutive sampling method. Subjects who underwent T2*-corrected Q-Dixon and reduced-FOV DKI sequences were enrolled. Fat fraction (FF), T2*, mean kurtosis (MK), and mean diffusivity (MD) values were measured on L1, L2, and L3 vertebral bodies. Quantitative computed tomography (QCT) examinations served as the reference standard. All of the subjects were divided into three groups: normal (BMD >120 mg/cm3), osteopenia (BMD 80-120 mg/cm3), and osteoporosis (BMD <80 mg/cm3). One-way analysis of variance, correlation coefficient analysis, and receiver operating characteristic curve analysis were performed. Results: Among all of the enrolled subjects, 52 were in the normal group, 51 were in the osteopenia group, and 52 were in the osteoporosis group. There were significant differences in FF, T2*, MK, and MD values between the three groups (P<0.001, P<0.001, P<0.001, and P=0.003, respectively). FF, T2*, and MK values exhibited significant negative correlations with BMD values (r=-0.739, P<0.001; r=-0,676, P<0.001; and r=-0.626, P<0.001, respectively). Excellent discriminatory capacity was observed in the Q-Dixon [area under the curve (AUC): 0.976, 95% confidence interval (CI): 0.955-0.997] differentiation between normal and abnormal BMD subjects. It was significantly better than the DKI (AUC: 0.812, 95% CI: 0.741-0.882) parameter combination (P<0.001), whereas the DKI model (AUC: 0.825, 95% CI: 0.739-0.910) performed comparably to the Q-Dixon model (AUC: 0.798, 95% CI: 0.710-0.886) for screening osteoporosis (P=0.57). Conclusions: FF and T2* values measured by using T2*-corrected Q-Dixon, as well as MK and MD values measured by using reduced-FOV DKI, may serve as potential imaging biomarkers in assessing abnormal BMD and osteoporosis in postmenopausal women.

Correlation between IVIM parameters and microvessel architecture: direct comparison of MRI images and pathological slices in an orthotopic murine model of rhabdomyosarcoma.

OBJECTIVE: This study aimed to explore the correlation between intravoxel incoherent motion (IVIM) parameters and microvessel architecture (microvessel density (MVD), vasculogenic mimicry (VM), and pericyte coverage index (PCI)) in an orthotopic murine model of rhabdomyosarcoma. METHODS: The murine model was established by injecting rhabdomyosarcoma-derived (RD) cells into the muscle. Nude mice underwent routine magnetic resonance imaging (MRI) and IVIM examinations with ten b values (0, 50, 100, 150, 200, 400, 600, 800, 1000, and 2000 s/mm2). D, D*, and f values were calculated with the ADW4.7 workstation. MRI images and pathological slices were directly compared to ensure that radiology parameters accurately reflect pathology. MVD, VM, PCI, and cellularity were obtained by histological analysis. The correlations were assessed between IVIM parameters (D, D*, f, and fD* values) and pathological markers (MVD, VM, PCI, and cellularity). RESULTS: The average of D, D*, f, and fD* values were 0.55 ± 0.07 × 10-3 mm2/s, 5.25 ± 0.73 × 10-3 mm2/s, 13.39 ± 7.68%, and 0.73 ± 0.49 × 10-3 mm2/s, respectively. The average of MVD, VM, PCI, and cellularity were 41.91 ± 10.98, 1.16 ± 0.83, 0.49 ± 0.18, and 39.15 ± 9.00%. D*, f, and fD* values showed a positive correlation with MVD separately, while the D value did not correlate with MVD. D value negatively correlated to VM moderately, and other parameters did not associate with VM. D* and fD* values were positively correlated with PCI, but no correlation was observed between other parameters and PCI. CONCLUSIONS: IVIM may evaluate the tumor microvessel architecture. D*, f, and fD* may reflect the endothelial lining blood vessel; D could indirectly reflect the VM; D* and fD* could reflect PCI(the normal degree of the tumor blood vessel). CLINICAL RELEVANCE STATEMENT: An intravoxel incoherent motion may be useful in assessing rhabdomyosarcoma microvessel structure to predict the target and effectiveness of anti-angiogenic therapy. KEY POINTS: • IVIM may be used to evaluate the tumor microvessel architecture in the mouse rhabdomyosarcoma model. • The MRI-pathology control method achieves correspondence between MRI slices and pathology slices, which ensures the consistency of the ROI of MRI and the pathology observation region.

Pericoronary adipose tissue differences among plaque types: a retrospective assessment.

PURPOSE: To assess differences in pericoronary adipose tissue (PCAT) in patients with different plaque types by using several quantitative parameters of PCAT and investigate the relationship between PCAT and different plaque types. MATERIALS AND METHODS: We retrospectively recruited 488 patients diagnosed with stable coronary artery disease (CAD) via coronary computed tomographic angiography, including 279 with calcified plaques (CP), 153 with non-calcified plaques (NCP), and 56 with mixed plaques (MP). Volume, fat attenuation index (FAI), and 10th percentile, 90th percentile, median, and minimum Hounsfield unit (HU) values of PCAT surrounding plaques were quantified. Clinical features and quantitative PCAT parameters were compared between different plaque types. RESULTS: No intergroup differences were observed for age, sex, body mass index, risk factors, and plaque location. Length and PCAT volume in the NCP group were lower than those of the CP and MP groups (P < 0.001), whereas there were no significant differences between the CP and MP groups (P > 0.05). Patients with NCP and MP had a higher FAI and 10th percentile, 90th percentile, median, and minimum HU values of PCAT than CP (P < 0.001); however these values were not significantly different between the NCP and MP groups (P > 0.05). CONCLUSION: The quantitative parameters of PCAT, as a biosensor for CAD, vary among the different plaque types.

Quantitative Magnetic Resonance Imaging-Based Tendon Healing of Different Regions of the Shoulder: Comparison Between the Suture-Bridge and Single-Row Techniques.

Background: Rotator cuff retears occur more often at the proximal region with the suture-bridge (SB) technique than at the typical footprint region with the single-row (SR) technique. Few longitudinal clinical trials have focused on the postoperative tendon quality of the repaired rotator cuff at different regions between the 2 techniques. Purpose: To compare tendon healing of the proximal and distal regions between the SB and SR techniques. Study Design: Cohort study; Level of evidence, 3. Methods: Included were consecutive patients who underwent arthroscopic rotator cuff repair and undertook clinical and magnetic resonance imaging (MRI) examinations at 3, 6, and 12 months postoperatively between 2016 and 2017. These patients were divided into the SB and SR groups according to the technique used. The repaired tendon was segmented into distal and proximal regions on ultrashort echo time-T2* mapping images. Clinical outcomes (Constant score, American Shoulder and Elbow Surgeons score, Fudan University Shoulder Score, and visual analog scale for pain) and MRI-based tendon healing (T2* values) of different regions were compared between the 2 groups. The differences in T2* values and clinical scores were determined by 1-way analysis of variance for repeated measurements. Results: A total of 31 patients (17 in SB group and 14 in SR group) were included. At 12-month follow-up, significant improvements from preoperatively were achieved for all patients in all clinical scores (P < .001 for all). No significant between-group differences were found in T2* values of the distal region at any time point; however, the mean T2* value of the proximal region at 3 months was significantly higher in the SB group compared with the SR group (P = .03). This difference became nonsignificant at subsequent follow-up time points. Conclusion: Significant clinical improvements over time can be expected in the first year after arthroscopic rotator cuff repair. In the early postoperative period, higher T2* values in the proximal region of the repaired tendon (representing inferior tendon quality) were seen with the SB technique compared with the SR technique; however, this phenomenon was resolved over time.

Soft tissue sarcoma: intravoxel incoherent motion and diffusion kurtosis imaging parameters correlate with the histological grade and Ki-67 expression.

BACKGROUND: Accurate prediction of the histological grade and Ki-67 expression of soft tissue sarcoma (STS) before surgery is essential for the subsequent diagnosis, treatment, and prognostic evaluation of patients. PURPOSE: To evaluate intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in predicting the histological grade and Ki-67 expression of STS. MATERIAL AND METHODS: A total of 40 patients underwent 3-T MRI, including conventional sequences; IVIM and DKI parameters were obtained. All patients were divided into a low-grade (grade 1 and grade 2) group and a high-grade (grade 3) group through pathological analysis. Ki-67 expression of each lesion was calculated. Chi-square test, independent sample t-test, Mann-Whitney U test, Pearson, Spearman, and receiver operating characteristic curve analysis were performed. RESULTS: There were 17 patients in the low-grade group and 23 in the high-grade group. Ki-67 expression was in the range of 10%-80%. D value was inversely correlated with Ki-67 expression. MK value showed a moderate positive correlation with Ki-67 expression. Regarding histological grading, only the peritumoral enhancement was statistically different between low- and high-grade STS on conventional MRI (P=0.024). The high-grade group had significantly higher MK value and lower D and MD value than the low-grade group. MK value showed the best diagnostic performance. The combination of MK and MD yielded the highest specificity (88.24%), and the combination of D, MK, and MD yielded the best area under the curve value (0.841) and sensitivity (95.65%). CONCLUSION: IVIM and DKI parameters were correlated with Ki-67 expression and could help differentiate between low- and high-grade STS.

Whole-tumor histogram analysis of diffusion-weighted imaging and dynamic contrast-enhanced MRI for soft tissue sarcoma: correlation with HIF-1alpha expression.

OBJECTIVE: To investigate the correlation of histogram metrics from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with HIF-1alpha expression in soft tissue sarcoma (STS). METHODS: We enrolled 71 patients with STS who underwent 3.0-T MRI, including conventional MRI, DWI, and DCE-MRI sequences. Location, maximum tumor diameter, envelope, T2-weighted tumor heterogeneity, peritumoral edema, peritumoral enhancement, necrosis, tail-like pattern, bone invasion, and vessel/nerve invasion and/or encasement were determined using conventional MRI images. The whole-tumor histogram metrics were calculated on the apparent diffusion coefficient (ADC), Ktrans, Kep, and Ve maps. Independent-samples t test and one-way ANOVA were used for testing the differences between normally distributed categorical data with HIF-1alpha expression. Pearson and Spearman correlations and multiple linear regression analyses were performed to determine the correlations between histogram metrics and HIF-1alpha expression. Survival curves were plotted using the Kaplan-Meier method. RESULTS: Regarding conventional MRI features, only highly heterogeneous on T2-weighted images (55.6 ± 19.9% vs. 45.4 ± 20.5%, p = 0.041) and more than 50% necrotic area (57.3 ± 20.4% vs. 43.9 ± 19.7%, p = 0.002) were prone to indicate STS with higher HIF-1alpha expression. Histogram metrics obtained from ADC (mean, median, 10th, and 25th percentile values), Ktrans (mean, median, 75th, and 90th percentile values), and Kep (90th percentile values) were significantly correlated with HIF-1alpha expression. Multiple linear regression analysis demonstrated that more than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression. CONCLUSION: DWI and DCE-MRI histogram parameters were significantly correlated with HIF-1alpha expression in STS. KEY POINTS: • DWI and DCE-MRI histogram parameters are correlated with HIF-1alpha expression in STS. • More than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression in STS.

Using Radiomics to Detect Subtle Architecture Changes of Cartilage and Subchondral Bone in Chronic Lateral Ankle Instability Patients Based on MRI PD-FS Images.

RATIONALE AND OBJECTIVES: To use radiomics to detect the subtle changes of cartilage and subchondral bone in chronic lateral ankle instability (CLAI) patients based on MRI PD-FS images. MATERIALS AND METHODS: A total of 215 CLAI patients and 186 healthy controls were included and randomly split into a training set (n=281, patients/controls=151/130) and an independent test set (n=120, patients/controls=64/56). They underwent ankle MRI examinations. On sagittal PD-FS images, eight cartilage regions and their corresponding subchondral bone regions were drawn. Radiomics models of cartilage, subchondral bone and combined cartilage and subchondral bone were built to differentiate CLAI patients from controls. A receiver operating characteristic curve (ROC) was used to assess the model's performance. RESULTS: In the test dataset, the cartilage model yielded an area under the curve (AUC) of 0.0.912 (95% confidence interval (CI): 0.858-0.965, p<0.001), a sensitivity of 0.859, a specificity of 0.893, a negative predictive value (NPV) of 0.848, and a positive predictive value (PPV) of 0.902. The subchondral bone model yielded an AUC of 0.837 (95% CI: 0.766-0.907, p<0.001), a sensitivity of 0.875, a specificity of 0.714, an NPV of 0.833, and a PPV of 0.778. For the combined model, the AUC was 0.921 (95% CI: 0.863-0.972, p<0.001), sensitivity was 0.844, specificity was 0.911, NPV was 0.836, and PPV was 0.915, whose AUC was higher than those of both the cartilage model and the subchondral bone model. CONCLUSION: The combined radiomics model achieved satisfying performance in detecting potential early architectural changes in cartilage and subchondral bone for CLAI patients.

Soft tissue sarcoma: correlation of dynamic contrast-enhanced magnetic resonance imaging features with HIF-1α expression and patient outcomes.

Background: To investigate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features for predicting hypoxia-inducible factor 1-alpha (HIF-1α) expression and patient outcomes in soft tissue sarcoma (STS). Methods: We enrolled 71 patients with STS who underwent 3.0 Tesla (3.0T) MRI, including conventional MRI and DCE-MRI sequencing. The location, maximum tumor diameter, envelope, T2-weighted tumor heterogeneity, peritumoral edema, peritumoral enhancement, necrosis, configuration, tail-like pattern, bone invasion, and vessel/nerve invasion and/or encasement of the STSs were determined using conventional MRI images. The DCE-MRI parameters, including the volume transfer constant (Ktrans ), reflux rate (Kep ), volume fraction of extravascular extracellular matrix (Ve ), and time-signal intensity curve (TIC) type, of each lesion were independently analyzed by two observers. Independent samples t-test, chi-square test, and Mann-Whitney U-test were performed to evaluate the differences in the MRI features between the two groups. The relationships between the DCE-MRI parameters and HIF-1α expression were analyzed using Spearman's correlation analysis. The Cox proportional hazards model and Kaplan-Meier method were used for survival analysis. Results: Of the conventional MRI features, high heterogeneity, peritumoral enhancement, necrosis, and multilobulation of the T2-weighted tumor were prone to occur in the high-expression group. Of the DCE-MRI parameters, the high-expression group showed significantly higher Ktrans (0.311±0.091 vs. 0.210±0.058 min-1), and Kep values (0.896±0.656 vs. 0.444±0.300 min-1) than the low-expression group. No significant differences in TIC types and Ve values were observed between the low- and high-expression groups (P>0.05). There were positive correlations between Ktrans and Kep values with HIF-1α expression (r=0.705, P<0.001; r=0.123, P<0.001, respectively). Receiver operating characteristic (ROC) analysis indicated high specificity (93.9%) of the Ktrans value for predicting high expression of HIF-1α. The Kep value provided the best performance in diagnostic sensitivity (84.2%). Survival analyses revealed that more than 50% necrosis, multilobulation, and Ktrans values greater than 0.262 min-1 were strongly associated with a higher risk of death. Conclusions: Conventional MRI features and DCE-MRI parameters were significantly helpful in determining HIF-1α expression levels and predicting the overall survival (OS) of patients with STS.

Duck hepatitis A virus prevalence in mainland China between 2009 and 2021: A systematic review and meta-analysis.

Duck hepatitis A virus (DHAV) is a single-strand positive-sense small RNA virus that causes high mortality in ducklings. In recent years, the incidence of DHAV-3 subtype has been increasing in China, leading to great economic losses to the duck-breeding industry. We investigated the incidence and mortality rates of DHAV in ducks and analysed the seroprevalence of DHAV in mainland China, by meta-analysis. Twenty-six studies published between 2009 and 2021 were retrieved, with a total of 689,549 cases from 14 provinces. Using the DerSimonian-Laird model, DHAV prevalence was estimated with the variance-stabilizing double arcsine transformation. The incidence of DHAV in mainland China was 12 % (95 % confidence interval [CI]: 3-20 %), and the mortality rate was 11 % (95 % CI: 2-19 %), suggesting that the virus was highly virulent and mortality was high. Time analysis showed that DHAV incidence decreased over time. The typing survey showed that strains of DHAV-1 serotype accounted for 38 % (95 % CI: 21-56 %) and strains of DHAV-3 serotype accounted for 49 % (95 % CI: 31-68%) of the tested samples. The decline in the detection rate of DHAV-1 may be due to the widespread use of the DHAV-1 vaccine, which has effectively controlled the DHAV-1 serotype virus. The DHAV-3 vaccine has been on the market for a short time and has no cross protection with DHAV-1, so DHAV-3 accounted for a high proportion of the tested samples. Subgroup analysis of the detection methods showed little difference between PCR and other detection methods.

Correlations between DWI, IVIM, and HIF-1α expression based on MRI and pathology in a murine model of rhabdomyosarcoma.

PURPOSE: To investigate the correlation between DWI, intravoxel incoherent motion (IVIM), and hypoxia-inducible factor 1-alpha (HIF-1α) expression in a nude mouse model of rhabdomyosarcoma based on imaging and pathological comparisons. METHODS: Human rhabdomyosarcoma-derived (RD) cells were inoculated into the right thigh muscle of 20 BALB/c female nude mice. Mice were imaged using 3.0 Tesla MRI system. T1 -weighted imaging, T2 -weighted imaging, DWI, and IVIM images were obtained. ADW4.7 (GE Healthcare, ChicagoAQ34, IL, USA) was used for image processing of ADC, Dslow , Dfast , and f values. All parameter values were independently analyzed by 2 observers. Immunohistochemistry of HIF-1α was performed. We used a specific image-pathology comparison method to ensure correct overlap between the image plane and the pathological section. Mann-Whitney U test or independent sample t test, Pearson or Spearman correlation test, the intragroup correlation coefficient, Kolmogorov-Smirnov test, and receiver operating characteristic curve were used. The correlation between DWI and intravoxel incoherent motion parameter values and HIF-1α expression was determined. RESULTS: There were 10 mice in the low-expression group and 7 in the high-expression group. The ADC and Dslow values were negatively correlated with HIF-1α with correlation coefficients of -0.491 and - 0.702 (P = 0.045 and 0.002). The f value positively correlated with HIF-1α expression (r = 0.485, P = 0.048). ADC, Dslow , and f were significantly different between the high-HIF-1α expression tumors and the low-HIF-1α expression tumors. ADC showed the best predictive performance among all parameters (area under the curve = 0.652, sensitivity = 83.3%, specificity = 63.6%). CONCLUSION: The parameter values of DWI and intravoxel incoherent motion can be used to evaluate the expression of HIF-1α in rhabdomyosarcoma. ADC, Dslow , and f value showed correlation with the expression of HIF-1α.

Relationship between oseteoporosis with fatty infiltration of paraspinal muscles based on QCT examination.

INTRODUCTION: To investigate the correlation between paraspinal muscles features and osteoporosis in lumbar spine. MATERIALS AND METHODS: A total of 367 subjects who underwent quantitative computed tomography (QCT) examination were enrolled in this study. QCT pro workstation was used to obtain the mean bone mineral density (BMD) of the lower lumbar spine. Fat fraction (FF) and cross-section area (CSA) of the paraspinal muscles at the corresponding levels were measured. All participants were divided into normal, osteopenia, and osteoporosis groups. One-way ANOVA and independent samples t tests were performed to compare differences between groups. Pearson and Spearman correlation coefficients and partial correlation analysis after controlling for confounding factors were used to analyze the correlation between BMD and paraspinal muscles measurements. RESULTS: Among the 367 participants included, 116 were in the normal group, 130 in the osteopenia group and 121 in the osteoporosis group. There were significant differences among the three groups for the mean and multifidus FF. BMD showed negative correlations with the FF of the paraspinal muscles. Multifidus and mean FF showed the best correlation (r = - 0.654, - 0.777). There were also significant differences in the mean and multifidus FF between different age groups, while after controlling for confounding factors, there was no correlation between age and FF of the paraspinal muscles. CONCLUSION: This preliminary study demonstrated the association of BMD with fatty infiltration of paraspinal muscles. Different muscles might have specific effects in different sex and age groups.

Effect of ACE, ACE2 and CYP11B2 gene polymorphisms and noise on essential hypertension among steelworkers in China: a case-control study.

BACKGROUND: Previous studies on the relationship between ACE I/D, ACE2 G8790A and CYP11B2-344T/C gene polymorphisms and essential hypertension (EH) were inconsistent. Moreover, few studies have reported the combined effect of these gene polymorphisms and noise exposure on EH. The purpose of this study was to explore the combined and separate effects of ACE I/D, ACE2 G8790A and CYP11B2-344T/C gene polymorphisms and noise on EH among steelworkers. METHODS: A case-control study was conducted on 725 male workers between March 2014 and July 2014 in the Tangsteel Company, China. The noise exposure of the workers were measured. Logistic regression and crossover analysis were used to analyse the effects of the interactions on the EH among steelworkers. GMDR was used to determine the best combination model of gene-noise interactions. RESULTS: Multivariate logistic regression showed that noise exposure increased the odds of EH, and the OR is 1.52 (95% CI 1.04-2.22). The risk of having EH for ACE I/D DD genotype carriers was 1.99 times that for II genotype carriers (95% CI 1.14-3.51). There was a negative additive interaction between ACE2 G8790A and CYP11B2-344T/C on EH (U3 = - 2.221, P = 0.026, and S = 0.128) and a positive multiplicative interaction between ACE I/D and CYP11B2-344T/C on essential hypertension (P = 0.041). In addition, there was no significant gene-noise interaction model through the GMDR method after adjusting the confounders. CONCLUSIONS: The ACE DD genotype may make men susceptible to EH. Simultaneously carrying the DD genotype of ACE I/D and the TC genotype of CYP11B2-344T/C increased the risk of EH.

Identification of abnormal BMD and osteoporosis in postmenopausal women with T2*-corrected Q-Dixon and reduced-FOV IVIM: correlation with QCT.

OBJECTIVE: To investigate the predictive value of quantitative Dixon (Q-Dixon) and intravoxel incoherent motion (IVIM) parameters in identifying normal bone mineral density (BMD), osteopenia, and osteoporosis in postmenopausal women. METHODS: We enrolled 105 postmenopausal female subjects who underwent 3 T MRI, including T2*-corrected Q-Dixon and reduced-field-of-view (reduced-FOV) IVIM sequences. The measurement of Q-Dixon and IVIM parameters was performed on the L3 vertebral body. BMD values were obtained using quantitative computed tomography (QCT) examination, which served as the reference standard. The intraclass correlation coefficient (ICC) was used to assess the measurement reproducibility across observers. One-way ANOVA, Spearman analysis, and receiver operating characteristic curve analysis were performed. RESULTS: There were significant differences in FF, T2*, and Dslow values between the three groups (p = 0.011, p = 0.021, p = 0.015). FF and T2* values were negatively correlated with BMD (r = - 0.747, p < 0.001; r = - 0.498, p = 0.007). Dslow and f values were positively correlated with BMD (r = 0.659, p < 0.001; r = 0.472, p = 0.012). Dslow values showed a significant negative correlation with FF values (r = 0.659, p < 0.001). f values showed a moderate negative correlation with FF values (r = - 0.387, p = 0.026). The sensitivity (89.2%), specificity (92.7%), and accuracy (91.4%) of the Q-Dixon model in differentiating normal and abnormal BMD (osteopenia and osteoporosis) were superior to those of the IVIM model. Conversely, the IVIM model outperformed the Q-Dixon model in discriminating osteopenia and osteoporosis; the sensitivity, specificity, and accuracy were 85.4%, 81.5%, and 83.8%, respectively. CONCLUSIONS: T2*-corrected Q-Dixon and reduced-FOV IVIM parameters have the potential to become new biomarkers in the assessment of abnormal BMD and osteoporosis in postmenopausal women. KEY POINTS: • T2*-corrected Q-Dixon and reduced-FOV IVIM parameters are correlated with BMD. • Fat quantification and bone trabecular microstructure information provided by T2*-corrected Q-Dixon outperforms reduced-FOV IVIM in identifying abnormal BMD. • Quantification of bone marrow water molecule diffusion movement and perfusion effects obtained from the reduced-FOV IVIM technique can differentiate osteopenia and osteoporosis more accurately than T2*-corrected Q-Dixon.

Piezoelectric energy harvester with double cantilever beam undergoing coupled bending-torsion vibrations by width-splitting method.

We propose piezoelectric energy harvester (PEH) with double-cantilever-beam (DCB) undergoing coupled bending-torsion vibrations by combining width-splitting method and asymmetric mass, in order that more ambient energy could be harvested from environmental vibration with multiple-frequency excitation. The geometrical dimensions are optimized for PEHDCB, when the maximum of output peak voltages Up-max and resonance frequency difference (Δf0) between the first and second modes are chosen as optimization objectives based on orthogonal test method. The energy harvesting efficiency is evaluated by the proportion of half-power bandwidth and quality factor, and the experimental and simulation results are compared to verify reliability. The Up-max1 and Pp-max1 are increased 25.2% and 57.3% for PEHDCB under the multi-frequency excitation, when the split-width method is applied into PEH with single-cantilever-beam (SCB) undergoing coupled bending-torsion vibrations. The deviations of Up-max1 and f0 are at the ranges of 4.9-14.2% and 2.2-2.5% for PEHDCB under the different mass ratios, and the measurement reliability is acceptable considering incomplete clamping, damping and inevitable assembly effects. The energy harvesting efficiency of PEHDCB presented is much higher than that of the conventional PEHSCB from environmental vibration with multiple-frequency excitation.