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.

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.

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.

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.

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.

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.

Correlation Between Bone Mineral Density (BMD) and Paraspinal Muscle Fat Infiltration Based on QCT: A Cross-Sectional Study.

To investigate the correlation between fatty infiltration of the paraspinal muscle and bone mineral density (BMD). In total, 367 subjects (182 men and 185 women) who underwent quantitative computed tomography (QCT) examination were enrolled in this study. A QCT Pro workstation was used to obtain the mean BMD of the lower lumbar spine (L3, L4, L5) and fat fraction (FF) of the paraspinal muscle (psoas and erector spinae) at the corresponding levels. The patient's age, sex, body mass index, number of previous vertebral fractures, physical activity level, and visual analog scale (VAS) score for lower back pain were recorded. For categorical variables, one-way ANOVA and independent-samples t tests were performed. Spearman and Pearson correlation coefficients were used to analyze the correlations among continuous variables. Influential factors were analyzed by multivariate linear regression analysis. Regarding the mean paraspinal muscle FF, there were significant differences between the different vertebral fracture groups (P < 0.05). Age and VAS score showed a positive correlation with the mean paraspinal muscle FF (r = 0.389, 0.454). BMD showed a negative correlation with the mean paraspinal muscle FF (r = - 0.721). The multiple linear regression analysis showed that vertebral fracture (ß = 0.851, P = 0.021) and BMD (ß = - 4.341, P = 0.004) were independent factors of the mean paraspinal muscle FF. This study demonstrated that an advanced age, a greater VAS score, a higher number of vertebral fractures, and a lower BMD may be associated with more severe fatty infiltration of the paraspinal muscle.

Q-Dixon and GRAPPATINI T2 Mapping Parameters: A Whole Spinal Assessment of the Relationship Between Osteoporosis and Intervertebral Disc Degeneration.

BACKGROUND: The relationship between osteoporosis and intervertebral disc (IVD) degeneration remains controversial. Novel quantitative Dixon (Q-Dixon) and GRAPPATINI T2 mapping techniques have shown potential for evaluating the biochemical components of the spine. PURPOSE: To investigate the correlation of osteoporosis with IVD degeneration in postmenopausal women. STUDY TYPE: Prospective. SUBJECTS: A total of 105 postmenopausal females (mean age, 65 years; mean body mass index, 26 kg/m2 ). FIELD STRENGTH/SEQUENCE: 3 T; sagittal; 6-echo Q-Dixon, multiecho spin-echo GRAPPATINI T2 mapping, turbo spin echo (TSE) T1-weighted and TSE T2-weighted sequences. ASSESSMENT: The subjects were divided into normal (N = 47), osteopenia (N = 28), and osteoporosis (N = 30) groups according to quantitative computed tomography examination. The Pfirrmann grade of each IVD was obtained. Region of interest analysis was performed separately by two radiologists (X.L., with 10 years of experience, and S.C., with 20 years of experience) on a fat fraction map and T2 map to calculate the bone marrow fat fraction (BMFF) from the L1 to L5 vertebrae and the T2 values of each adjacent IVD separately. STATISTICAL TESTS: One-way analysis of variance, post-hoc comparisons, and Kruskal-Wallis H tests were performed to evaluate the differences in the magnetic resonance imaging parameters between the groups. The relationships between BMFF and the IVD features were analyzed using the Spearman correlation analysis and linear regression models. RESULTS: There were significant differences in BMFF among the three groups. The osteoporosis group had higher BMFF values (64.5 ± 5.9%). No significant correlation was found between BMFF and Pfirrmann grade (r = 0.251, P = 0.06). BMFF was significantly negatively correlated with the T2 of the adjacent IVD from L1 to L3 (r = -0.731; r = -0.637; r = -0.547), while significant weak correlations were found at the L4 to L5 levels (r = -0.337; r = -0.278). DATA CONCLUSION: This study demonstrated that osteoporosis is associated with IVD degeneration. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 4.

Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2-Mapping: Initial Experience With 3-Year Follow-Up.

BACKGROUND: Anatomic repair is widely accepted as the primary surgical treatment for chronic lateral ankle instability (CLAI). T2-mapping is a powerful tool for quantitative assessment of biochemical changes in cartilage matrix. PURPOSE: To longitudinally evaluate cartilage matrix changes in the hindfoot joints of CLAI patients before and after anatomic repair by using T2-mapping with magnetic resonance imaging (MRI). STUDY TYPE: Prospective. SUBJECTS: Thirty-two CLAI patients (males/females = 20/12) and 21 healthy controls (males/females = 13/7). FIELD STRENGTH/SEQUENCE: 3 T; sagittal multi-echo spin-echo technique (T2-mapping), coronal, sagittal, and axial spin-echo PD-FS, and sagittal T1WI sequences. ASSESSMENT: MRI examinations were performed in CLAI patients at baseline (prior to surgery) and 3 years after anatomic repair and in healthy controls. On T2-maps, the hindfoot joints were segmented into 16 cartilage subregions. The T2 value of each subregion was measured. All patients were evaluated with the American Orthopedic Foot and Ankle Society (AOFAS) scale at baseline and after surgery. STATISTICAL TESTS: Analysis of variance (ANOVA) and Student's t-test were used. The differences corresponding to P < 0.05 were considered statistically significant. RESULTS: At baseline, the T2 values in most cartilage subregions of talar dome and medial posterior subtalar joint (pSTJ) were higher in CLAI patients than in healthy controls. After surgery, only the T2 value of anteriomedial talar dome decreased from that at baseline (31.11 ± 3.88 msec vs. 34.27 ± 5.30 msec). The T2 values of other subregions with elevated T2 values remained higher than healthy controls. There were no significant differences in T2 values in the midtarsal joints between CLAI patients and healthy controls (P = 0.262, 0.104, 0.169, 0.103). Postoperatively, the patients' AOFAS scores improved significantly from 67.81 to 89.13. DATA CONCLUSION: CLAI patients exhibited elevated T2 values in most subregions of talar dome and medial pSTJ. After anatomic repair, although the patients exhibited good clinical outcomes, the elevated T2 values could not be fully recovered. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 4.

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.

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.

The diagnostic accuracy of intravoxel incoherent motion and diffusion kurtosis imaging in the differentiation of malignant and benign soft-tissue masses: which is better?

BACKGROUND: It is difficult for conventional magnetic resonance imaging (MRI) to distinguish benign soft-tissue masses (STMs) from malignant masses. PURPOSE: To quantitatively compare the diagnostic value of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in STMs. MATERIAL AND METHODS: The data from 58 patients with STMs were retrospectively analyzed. The GE Discovery 3.0-T MRI scanner was used to acquire conventional MRI sequences, IVIM, and DKI images. The chi-square test, independent sample t-test, and Mann-Whitney U tests were used to compare the differences between conventional MRI features, IVIM, and DKI parameters (Dslow, Dfast, f, mean kurtosis [MK], and mean diffusivity [MD]) between the benign and malignant groups. Receiver-operating characteristic (ROC) curve analysis was also performed. RESULTS: Tumor size and depth are statistically different in STTs. Dslow, MK, and MD values in the malignant groups are significantly lower than the benign groups (P < 0.05). However, Dfast and f values are not statistically different between the two groups. The area under the curve (AUC) of Dslow value (0.859) is higher than MD (0.765) and MK (0.676) values for identifying benign and malignant STMs. The Dslow value showed the best specificity (82.93%). The sensitivity and specificity of IVIM and DKI parameters are higher than that of conventional MRI sequences. CONCLUSION: IVIM and DKI can be used to distinguish between benign and malignant STMs, with Dslow as the most meaningful parameter.

Soft tissue sarcomas: IVIM and DKI correlate with the expression of HIF-1α on direct comparison of MRI and pathological slices.

OBJECTIVE: To investigate the correlation of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) parameters with the expression of HIF-1α in soft tissue sarcoma (STS). METHODS: This prospective study was approved by the institutional ethics committee. Written informed consent was obtained from all patients. Forty patients with STS who underwent 3.0 T MRI, including IVIM and DKI, were included in the study. Standard apparent diffusion coefficient (ADC), true ADC (Dslow), pseudo ADC (Dfast), perfusion fraction (f), mean kurtosis (MK), and mean diffusivity (MD) of each lesion were independently analyzed by two observers. An MRI-pathology control method was used to ensure correspondence between the MRI slices and the pathological sections. Spearman analysis, independent sample t test, Mann-Whitney U test, chi-squared test, and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: Dslow and MD values showed a negative correlation with HIF-1α expression (r = - 0.469, - 0.588). MK and f values showed a positive correlation with HIF-1α expression (r = 0.779, 0.572). Dslow, MD, MK, and f values showed significant differences between the high- and low-expression groups. The MK value showed the best diagnostic ability. The optimal cut-off MK value of 0.604 was associated with 78.3% sensitivity and 88.2% specificity (area under the curve, 0.867). CONCLUSIONS: This preliminary study demonstrated the association of IVIM and DKI parameters with the expression of HIF-1α in STS. KEY POINTS: • IVIM and DKI parameters are correlated with the expression of HIF-1α in STS. • The MRI-pathology control method can be used in clinical studies to ensure correspondence between MRI slices and pathology sections.

The diagnostic performance of conventional ultrasound and strain elastography in malignant soft tissue tumors.

OBJECTIVE: To investigate the diagnostic value of conventional ultrasound (US) and strain elastography (SE) in malignant soft tissue tumors. METHOD: A total of 83 soft tissue masses were included prospectively. US and SE imaging were performed at the same time. Two observers assessed the B mode, color Doppler, elastic scores (ES), strain ratio (SR), and SE size to B mode size (EI/B) ratio and compared the consistency of the data between the observers. According to the pathological diagnosis of resection, the cases were divided into malignant and nonmalignant groups. The diagnostic value of conventional US and SE in the prediction of malignant soft tissue tumors was assessed. RESULTS: The pathology results divided cases into 36 malignant lesions and 47 nonmalignant lesions. There was no statistically significant difference in gender, location, maximum diameter, echo, tail sign, cystic component, Doppler scores, or SR between the two groups (p > 0.05). However, significant differences between the two groups were found in age, depth, heterogeneity, edge, ES, and EI/B (p < 0.05). The biggest area under the receiver operating characteristics curve (0.934) was the combination model of age, heterogeneity, edge, ES, and EI/B, and the sensitivity and specificity were 0.861 and 0.957, respectively. CONCLUSIONS: Conventional US and SE are significant for the diagnosis of malignant soft tissue tumors, and SE can be used as a complementary technique to the characterization of STTs using conventional US.

Online Extraction of Pose Information of 3D Zigzag-Line Welding Seams for Welding Seam Tracking.

Three-dimensional (3D) zigzag-line welding seams are found extensively in the manufacturing of marine engineering equipment, heavy lifting equipment, and logistics transportation equipment. Currently, due to the large amount of calculation and poor real-time performance of 3D welding seam detection algorithms, real-time tracking of 3D zigzag-line welding seams is still a challenge especially in high-speed welding. For the abovementioned problems, we proposed a method for the extraction of the pose information of 3D zigzag-line welding seams based on laser displacement sensing and density-based clustering point cloud segmentation during robotic welding. after thee point cloud data of the 3D zigzag-line welding seams was obtained online by the laser displacement sensor, it was segmented using theρ-Approximate DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm. In the experiment, high-speed welding was performed on typical low-carbon steel 3D zigzag-line welding seams using gas metal arc welding. The results showed that when the welding velocity was 1000 mm/min, the proposed method obtained a welding seam position detection error of less than 0.35 mm, a welding seam attitude estimation error of less than two degrees, and the running time of the main algorithm was within 120 ms. Thus, the online extraction of the pose information of 3D zigzag-line welding seams was achieved and the requirements of welding seam tracking were met.

Unfavourable treatment outcomes in tuberculosis patients with different vitamin D status and blood glucose levels in a programme setting in China.

OBJECTIVE: Tuberculosis (TB) treatment success rates are high in China, but there are still a considerable number of cases who have unfavourable treatment outcomes (UTO). We aimed to determine the proportion of TB patients with UTO and to assess whether baseline characteristics that included glycaemic status [normal fasting blood glucose (FBG), transient hyperglycaemia and diabetes mellitus (DM)] and vitamin D status were associated with UTO. METHOD: Prospective cohort study conducted between November 2015 and July 2016 at six clinics within routine TB services in Jilin province, where persons with TB were consecutively recruited. Data analysis was performed using the chi-squared test and multivariate logistic regression. RESULTS: Of the 306 recruited TB patients, 96 (31.4%) had smear-positive pulmonary TB, 187 (61.1%) had smear-negative pulmonary TB and 23 (7.5%) had extrapulmonary TB (EPTB). Of these, 95 (31.1%) had normal blood glucose, 83 (27.1%) had transient hyperglycaemia and 128 (41.8%) had DM. 227 (74.2%) patients had vitamin D deficiency/severe deficiency. There were 125 (40.8%) patients with UTO of whom the majority were lost to follow-up (57.6%) or not evaluated (28.8%). UTO was significantly associated with smear-negative pulmonary TB (P = 0.009), EPTB (P < 0.001) and DM (P = 0.007). CONCLUSION: The proportion of TB patients with UTO increased with smear-negative pulmonary TB, EPTB and DM. TB programmes need to pay more attention to these issues and ensure intensive patient support to those at risk and early detection of DM.

OBJECTIF: Les taux de succès du traitement de la tuberculose (TB) sont élevés en Chine, mais il existe encore un nombre considérable de cas avec des résultats de traitement défavorables (RTD). Nous avons cherché à déterminer la proportion de patients TB avec un RTD et d'évaluer si les caractéristiques de base comprenant le statut glycémique [glycémie normale à jeun (GJ), hyperglycémie transitoire et diabète sucré (DS)] et le statut en vitamine D étaient associés à un RTD. MÉTHODE: Etude de cohorte prospective réalisée entre novembre 2015 et juillet 2016 dans six cliniques des services anti-TB de routine de la province de Jilin, où des personnes atteintes de TB ont été recrutées consécutivement. L'analyse des données a été réalisée à l'aide du test du chi carré et de la régression logistique multivariée. RÉSULTATS: Sur 306 patients TB recrutés, 96 (31.4%) avaient une TB pulmonaire à frottis positif, 187 (61.1%) avaient une TB pulmonaire à frottis négatif et 23 (7.5%) avaient une TB extra pulmonaire (TBEP). Parmi ceux-ci, 95 (31.1%) avaient une glycémie normale, 83 (27.1%) avaient une hyperglycémie transitoire et 128 (41.8%) avaient un DS. 227 (74.2%) patients avaient une déficience/déficience sévère en vitamine D. Il y avait 125 (40.8%) patients avec un RTD dont la majorité (57.6%) ont été perdus de vue ou ont été non évalués (28.8%). Le RTD était significativement associé à la TB pulmonaire à frottis négatif (p = 0.009), la TBEP (P < 0.001) et le DS (P = 0.007). CONCLUSION: La proportion de patients TB avec un RTD augmentait avec la TB pulmonaire à frottis négatif, la TBEP et le DS. Les programmes anti-TB devraient accorder plus d'attention à ces problèmes et assurer un soutien intensif au patient pour les personnes à risque et une détection précoce du DS.

Soft tissue sarcoma: can dynamic contrast-enhanced (DCE) MRI be used to predict the histological grade?

OBJECTIVE: To determine if dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters reflect histological grade of soft tissue sarcoma (STS) MATERIALS AND METHODS: The medical records of 50 patients diagnosed with pathologically confirmed STS were retrospectively reviewed. Each STS was assessed with conventional contrast-enhanced MRI and DCE-MRI using a 3.0-T MRI system. The conventional MRI characteristics of low-grade (grade 1) and high-grade (grade 2 and grade 3) tumors were analyzed. Semi-quantitative parameters, including iAUC and TTP, and quantitative parameters, including Ktrans, Kep, and Ve, were derived from DCE-MRI. The diagnostic performances and optimal thresholds of various combinations of DCE-MRI parameters for predicting histological grades of STS were investigated using receiver operator characteristic (ROC) curves. RESULTS: On conventional MRI, high-grade STSs were significantly larger (≥ 5 cm) and more likely to show a heterogeneous signal intensity on T2WI (> 75%), peritumoral hyperintensity on T2WI, or tumor necrosis (> 50%) compared with low-grade STS. On DCE-MRI, iAUC, TTP, Ktrans, and Kep were significant predictors of STS histological grade. Ktrans had a high diagnostic value for differentiating between high-grade and low-grade STSs. The combination of iAUC, TTP, and Ktrans yielded a higher AUC value (0.841) than the other models. CONCLUSION: High-grade STSs were usually larger than low-grade STSs, had unclear boundaries, a heterogeneous signal intensity on T2-weighted image (T2WI), and extensive necrosis. On DCE-MRI, iAUC, TTP, Ktrans, and Kep could differentiate between high-grade and low-grade STSs. The combination of iAUC, TTP, and Ktrans had a high diagnostic performance for differentiating between STS histological grades.

Welding Seam Trajectory Recognition for Automated Skip Welding Guidance of a Spatially Intermittent Welding Seam Based on Laser Vision Sensor.

To solve the problems of low teaching programming efficiency and poor flexibility in robot welding of complex box girder structures, a method of seam trajectory recognition based on laser scanning displacement sensing was proposed for automated guidance of a welding torch in the skip welding of a spatially intermittent welding seam. Firstly, a laser scanning displacement sensing system for measuring angles adaptively is developed to detect corner features of complex structures. Secondly, a weld trajectory recognition algorithm based on Euclidean distance discrimination is proposed. The algorithm extracts the shape features by constructing the characteristic triangle of the weld trajectory, and then processes the set of shape features by discrete Fourier analysis to solve the feature vector used to describe the shape. Finally, based on the Euclidean distance between the feature vector of the test sample and the class matching library, the class to which the sample belongs is identified to distinguish the weld trajectory. The experimental results show that the classification accuracy rate of four typical spatial discontinuous welds in complex box girder structure is 100%. The overall processing time for weld trajectory detection and classification does not exceed 65 ms. Based on this method, the field test was completed in the folding special container production line. The results show that the system proposed in this paper can accurately identify discontinuous welds during high-speed metal active gas arc welding (MAG) welding with a welding speed of 1.2 m/min, and guide the welding torch to automatically complete the skip welding, which greatly improves the welding manufacturing efficiency and quality stability in the processing of complex box girder components. This method does not require a time-consuming pre-welding teaching programming and visual inspection system calibration, and provides a new technical approach for highly efficient and flexible welding manufacturing of discontinuous welding seams of complex structures, which is expected to be applied to the welding manufacturing of core components in heavy and large industries such as port cranes, large logistics transportation equipment, and rail transit.

The role of taurine in improving neural stem cells proliferation and differentiation.

OBJECTIVES: Taurine is one of the most abundant amino acids in the central nervous system and has important functions in the promotion of brain development. This study aimed to determine the mechanistic role of taurine in improving neuronal proliferation, stem cell proliferation, and neural differentiation. METHODS: The data for this review were primarily retrieved from the PubMed database from 1985 to 2015 in English. The search string included the keywords taurine, brain development, neuronal, stem cell, proliferation, differentiation, and others. Relevant publications were identified, retrieved, and reviewed. RESULTS: This review introduces the source, function, and mechanisms of taurine in brain development and provides additional detail regarding the mechanistic role of taurine in improving neuronal proliferation, stem cell proliferation, and neural differentiation. Many studies concerning these aspects are discussed. CONCLUSIONS: Taurine plays an important role in brain development, including neuronal proliferation, stem cell proliferation, and differentiation, via several mechanisms. Taurine can be directly used in clinical applications to improve brain development because it has no toxic effects on humans.