Normalized glandular dose coefficients for digital breast tomosynthesis using detailed Chinese breast models

The rise in breast cancer diagnoses among Chinese women has necessitated the use of X-ray breast screening,which carries a radiation risk.This study aimed to provide a dosimetry protocol for the Chinese female population to replace the traditional standard that utilizes simplified breast models,for the accurate estimation of the mean glandular dose of a patient undergoing digital breast tomosynthesis(DBT).The first set of detailed Chinese female breast models and representative breast parameters was constructed.Considering backscatter radiation and computational efficiency,we improved the combination of these models and the Chinese reference adult female whole-body voxel phantom.Image acquisition for four commercial DBT systems that are widely employed in China was simulated using the Monte Carlo method to obtain the normalized glandular dose coefficients of DBT(D_(gN)^(DBT))and the glandular depth dose(D_(g)^(dep)(z))for different breast characteristics and X-ray spectra.We calculated a series of D_(gN)^(DBT) values for breasts with different percentage mass glandularities(5%,25%,50%,75%,and 100%)and compressed breast thicknesses(2,3,4,5,6,and 7 cm)at various tube potentials(25,28,30,32,35,and 49 kV)and target/filter combinations(W/Rh,W/Al,Mo/Mo,Rh/Rh,and Rh/Ag).The parameter dependence of the breast characteristics and beam conditions on D_(gN)^(DBT) in detailed breast models was investigated.The D_(gN)^(DBT) results were 14.6-51.0%lower than those of the traditional dosimetry standard in China.The difference in D_(gN)^(DBT) was mainly due to a decrease in the depth of the main energy deposition area caused by the glandular distribution along the depth direction.The results obtained in this study may be used to improve breast dosimetry in China and provide more detailed information on risk assessment during DBT.

DTS在胫骨骨折内固定术后的应用价值

目的探讨数字断层融合摄影(DTS)在胫骨骨折内固定术后复查中的应用价值。方法回顾性分析2020年10月至2023年10月在我院行胫骨骨折内固定术后的患者120例,于术后3个月及6个月时行数字化X线摄影(DR)及DTS检查,比较两种影像学方法的图像质量和骨折愈合显示情况,并对2名医师的图像质量评分结果进行一致性分析。结果2名医师在DTS及DR的图像质量评分结果上均有较好的一致性。术后3个月时,DTS图像质量评分为(3.658±1.170)分,DR图像质量评分为(2.750±1.176)分,两组差异有统计学意义(P<0.05)。DTS图像骨折愈合情况显示率为91.67%(110/120),DR图像骨折愈合情况显示率为72.50%(87/120),差异有统计学意义(P<0.05)。术后6个月时,DTS图像质量评分为(3.692±1.165)分,DR图像质量评分为(2.792±1.187)分,两组差异有统计学意义(P<0.05)。DTS图像骨折愈合情况显示率为93.33%(112/120),DR图像骨折愈合情况显示率为75.83%(91/120),差异有统计学意义(P<0.05)。结论在胫骨骨折内固定术后复查中,DTS图像质量优于DR,能更加清晰地显示术区骨质结构及骨折愈合情况,有助于临床医师更准确地评估内固定术后恢复情况,具有较好的临床应用价值。

Efficacy of digital breast tomosynthesis combined with magnetic resonance imaging in the diagnosis of early breast cancer

BACKGROUND The incidence and mortality rate of breast cancer in China rank 120th and 163rd,worldwide,respectively.The incidence of breast cancer is on the rise;the risk increases with age but is slightly reduced after menopause.Early screening,diagnosis,and timely determination of the best treatment plan can ensure clinical efficacy and prognosis.AIM To evaluate the clinical value of magnetic resonance imaging(MRI) combined with digital breast tomosynthesis(DBT) in diagnosing early breast cancer and the effect of breast-conserving surgery by arc incision.METHODS This study was divided into two parts.Firstly,110 patients with early breast cancer confirmed by pathological examination and 110 with benign breast diseases diagnosed simultaneously in Changzhi People’s Hospital of Shanxi Province and Shanxi Dayi Hospital from May 2019 to September 2020 were included in the breast cancer group and the benign group,respectively.Both groups underwent DBT and MRI examination,and the pathological results were used as the gold standard to evaluate the effectiveness of the combined application of DBT and MRI in the diagnosis of early breast cancer.Secondly,according to the operation method,110 patients with breast cancer were divided into either a breast-conserving group(69 patients) or a modified radical mastectomy group(41 patients).The surgical effect,cosmetic effect,and quality of life of the two groups were compared.RESULTS Among the 110 cases of breast cancer,66 were of invasive ductal carcinoma(60.00%),and 22 were of ductal carcinoma in situ(20.00%).Among the 110 cases of benign breast tumors,55 were of breast fibromas(50.00%),and 27 were of breast adenosis(24.55%).The sensitivity,specificity,and area under the curve(AUC) of DBT in the differential diagnosis of benign and malignant breast tumors were 73.64%,84.55%,and 0.791,respectively.The sensitivity,specificity,and AUC of MRI in the differential diagnosis of benign and malignant breast tumors were 84.55%,85.45%,and 0.850,respectively.The sensitivity,specificity,and AUC of DBT combined with MRI in the differential diagnosis of benign and malignant breast tumors were 97.27%,93.64%,and 0.955,respectively.The blood loss,operation time and hospitalization time of the breast-conserving group were significantly lower than those of the modified radical treatment group,and the difference was statistically significant(P < 0.05).After 3 mo of observation,the breast cosmetic effect of the breast-conserving group was better than that of the modified radical group,and the difference was statistically significant(P < 0.05).Before surgery,the quality-of-life scores of the breast-conserving and modified radical mastectomy groups did not differ(P > 0.05).Three months after surgery,the quality-of-life scores in both groups were higher than those before surgery(P < 0.05),and the quality-of-life score of the breast-conserving group was higher than that of the modified radical group(P < 0.05).In the observation of tumor recurrence rate two years after the operation,four patients in the breast-conserving group and one in the modified radical treatment group had a postoperative recurrence.There was no significant difference in the recurrence rate between the two groups(χ2 = 0.668,P = 0.414 > 0.05).CONCLUSION MRI combined with DBT in diagnosing early breast cancer can significantly improve the diagnostic efficacy compared with the two alone.Breast-conserving surgery leads to better cosmetic breast effects and reduces the impact of surgery on postoperative quality of life.

Follow-up of endovascular aortic aneurysm repair:Preliminary validation of digital tomosynthesis and contrast enhanced ultrasound in detection of medium- to long-term complications

AIM: To validate the feasibility of digital tomosynthesis of the abdomen(DTA) combined with contrast enhanced ultrasound(CEUS) in assessing complications after endovascular aortic aneurysm repair(EVAR) by using computed tomography angiography(CTA) as the gold standard.METHODS: For this prospective study we enrolled 163 patients(123 men; mean age, 65.7 years) referred for CTA for EVAR follow-up. CTA, DTA and CEUS were performed at 1 and 12 mo in all patients, with a maximum time interval of 2 d.RESULTS: Among 163 patients 33 presented complications at CTA. DTA and CTA correlated for the presence of complications in 32/33(96.96%) patients and for the absence of complications in 127/130(97.69%) patients; the sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) and accuracy of DTA were 97%, 98%, 91%, 99%, and 98%, respectively. CEUS and CTA correlated for the presence of complications in 19/33(57.57%) patients and for the absence of complications in 129/130(99.23%) patients; the sensitivity, specificity, PPV, NPV and accuracy of CEUS were 58%, 99%, 95%, 90%, and 91%, respectively. Sensitivity, specificity and accuracy of combining DTA and CEUS together in detecting EVAR complications were 77%, 98% and 95%, respectively.CONCLUSION: Combining DTA and CEUS in EVAR follow-up has the potential to limit the use of CTA only in doubtful cases.

Comparison between Visualization of Microcalcifications by Digital Breast Tomosynthesis and Full-Field Digital Mammography

Objective: To date, few studies have compared the diagnostic performance and visibility of microcalcifications obtained using digital breast tomosynthesis (DBT) with those obtained from full-field digital mammography (FFDM). The visualization and characterization of microcalcifications with DBT remain controversial. The purpose of this study was to compare the visibility of microcalcifications and determine whether DBT exhibits a diagnostic advantage for visualizing microcalcifications over FFDM. Methods: We retrospectively reviewed 120 cases including DBT and FFDM imaging (60 histologically verified as breast cancers and 60 as benign microcalcifications or normal). DBT images with a wide scan-angle of 50° and FFDM images were obtained using a flat-panel system (MAMMOMAT Inspiration, Siemens). Images were independently reviewed by four board-certified radiologists and evaluated for the presence of microcalcifications, probability of malignancy (BI-RADS classification), and visibility. Results: In predicting the malignancy of detected microcalcifications, no significant difference was found between readers’ areas under the receiver operating characteristic curve for DBT and FFDM (p = 0.068). The visibility scores of detected microcalcifications were 3.74 ± 1.06 for DBT and 3.46 ± 0.93 for FFDM, respectively. The visibility of microcalcifications when using DBT was found to be significantly superior to that of FFDM (p < 0.05). Conclusion: Our results suggest that the image quality of DBT with a wide scan-angle is comparable or superior to that obtained with FFDM in terms of both visibility and assessment of microcalcifications.

Comparison of Different Reconstruction Algorithms for Decreasing the Exposure Dose during Digital Breast Tomosynthesis: A Phantom Study

We compared reconstruction algorithms [filtered back projection (FBP), maximum likelihood expectation maximization (MLEM), and the simultaneous iterative reconstruction technique (SIRT)] in terms of the radiation dose and image quality, for exploring the possibility of decreasing the radiation dose during digital breast tomosynthesis (DBT). The three algorithms were implemented using a DBT system and experimentally evaluated using measurements, such as signal difference-to-noise ratio (SDNR) and intensity profile, on a BR3D phantom (infocus plane image). The possible radiation dose reduction, contrast improvement, and artifact reduction in DBT were evaluated using different exposure levels and the three reconstruction techniques. We performed statistical analysis (one-way analysis of variance) of the SDNR data. The effectiveness of each technique for enhancing the visibility of the BR3D phantom was quantified with regard to SDNR (FBP versus MLEM, P < 0.05;FBP vs. SIRT, P < 0.05;MLEM vs. SIRT, P = 0.945);the artifact reduction was quantified with regard to the intensity profile. MLEM and SIRT produced reconstructed images with SDNR values indicative of low-contrast visibility. The SDNR value for the half-radiation dose MLEM and SIRT images was close to that of the FBP reference radiation dose image. Artifacts were decreased in the MLEM and SIRT images (in the infocus plane) according to the intensity profiles that we obtained. With MLEM and SIRT, the radiation dose may be decreased to half comparison with FBP.

A Comparison of Reconstruction Algorithms Regarding Exposure Dose Reductions during Digital Breast Tomosynthesis

This study compared reconstruction algorithms [filtered back projection (FBP) and simultaneous iterative reconstruction technique (SIRT)] with respect to radiation doses and image quality and suggested the possibility of decreasing the exposure dose in digital breast tomosynthesis (DBT). These two existing algorithms were implemented using a DBT system and experimentally evaluated using contrast-detail (CD) phantom measurements, such as contrast-to-noise ratio (CNR), root mean square error (RMSE), intensity profile, and artifact spread function (ASF), and the results obtained with FBP and SIRT were compared. The potential dose reduction, contrast improvement, quantum noise reduction, and artifact reduction in DBT were evaluated using different exposures and the two reconstruction techniques. The effectiveness of each technique for enhancing the visibility of a CD phantom was quantified with respect to CNR and RMSE, and artifact reduction was quantified with respect to the intensity profile and ASF. SIRT produced reconstructed images with CNR values indicative of high-contrast detection. Image error was smaller in the in-focus plane SIRT images, and artifacts were decreased in these images according to the determined intensity profiles and ASF. These results suggest that when using SIRT, the exposure dose could possibly be decreased to half.

Dual-Energy Subtraction X-Ray Digital Tomosynthesis: Basic Physical Evaluation

The present study was performed to determine the potential of applying dual-energy subtraction (DES) digital tomo-synthesis to basic physical evaluations. Volumetric X-ray DES digital tomosysnthesis was used to obtain an image of a detectability phantom (an artificial lesion). The image quality of DES digital tomosynthesis was compared to that of DES radiography. The purpose of this study was to determine enhanced visibility quantified in terms of the contrast- to-noise ratio, figure-of-merit, and root-mean-square error. In the in-focus plane, the image quality is better by DES digital tomosynthesis than by DES radiography. The potential usefulness of DES digital tomosynthesis for evaluating a detectability phantom was demonstrated. Further studies are required to determine the ability of DES digital tomosyn-thesis to quantify the spatial relationships between the artificial lesion components of these devices, as well as to iden- tify lesions with diagnostic consequences.

Application of X-ray digital tomosynthesis in knee joint trauma examination

Objective: To explore the clinical value of X-ray digital tomosynthesis(DTS)in the diagnosis of knee joint fractures. Methods: A total of 28 cases of thoracic trauma, X-ray film cannot be clearly diagnosed or can confirm the diagnosis but the need for further identification of forensic diagnosis of cases of DTS scan and three-dimensional reconstruction in order to control the study. Results: 1. The reconstructed images after DTS scanning showed that the knee joint fractures were clearly diagnosed, and the detection rate of 28 knee joint fractures was 92.86%. 2. DTS scanning could clearly detect the fresh knee joint fracture's fracture line, corresponding line and broken bones. For the old fracture, DTS scanning could clearly show the condition of the fracture end's healing. Conclusions: The technique is of great value in the diagnosis of knee joint fracture, especially in the examination of complex structure, thick body and review of internal fixation after fracture.

A Dual Closed-Loop Digital Twin Construction Method for Optimizing the Copper Disc Casting Process

The copper disc casting machine is core equipment for producing copper anode plates in the copper metallurgy industry.The copper disc casting machine casting package motion curve(CPMC) is significant for precise casting and efficient production.However,the lack of exact casting modeling and real-time simulation information severely restricts dynamic CPMC optimization.To this end,a liquid copper droplet model describes the casting package copper flow pattern in the casting process.Furthermore,a CPMC optimization model is proposed for the first time.On top of this,a digital twin dual closed-loop self-optimization application framework(DT-DCS) is constructed for optimizing the copper disc casting process to achieve self-optimization of the CPMC and closed-loop feedback of manufacturing information during the casting process.Finally,a case study is carried out based on the proposed methods in the industrial field.

Digital Twin Modeling and Simulation Optimization of Transmission Front and Middle Case Assembly Line

As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing rapidly,the competition is becoming increasingly fierce,and the digital transformation of the production line is imminent.As one of themost important components of heavy vehicles,the transmission front andmiddle case assembly lines have a high degree of automation,which can be used as a pilot for the digital transformation of production.To ensure the visualization of digital twins(DT),consistent control logic,and real-time data interaction,this paper proposes an experimental digital twin modeling method for the transmission front and middle case assembly line.Firstly,theDT-based systemarchitecture is designed,and theDT model is created by constructing the visualization model,logic model,and data model of the assembly line.Then,a simulation experiment is carried out in a virtual space to analyze the existing problems in the current assembly line.Eventually,some improvement strategies are proposed and the effectiveness is verified by a new simulation experiment.

DTS和DR技术在寰枢椎关节检查中的应用对比研究

目的:对比分析数字断层融合(DTS)和数字X线摄影(DR)技术在寰枢椎关节检查中的应用价值。方法:从既往的寰枢椎检查病例中,分别选取50例已行寰枢椎DTS检查和50例行DR寰枢椎张口位检查的患者,调取其影像信息,由两名高年资医师对其进行诊断,并分别对其影像质量进行评分,诊断结果与已明确的临床结果进行对比。结果:DTS组的诊断准确率(96%)明显高于DR组(78%),差异有统计学意义(P<0.05);DTS组的影像质量评分(4.140±1.080)也明显高于DR组(2.800±1.294)。结论:相较于DR技术,DTS技术在寰枢椎的鉴别诊断中具有获取的影像质量高、诊断准确率高、检查过程中对患者的配合度要求低等优势,加之辐射剂量不高、检查费用也未明显增多,因此DTS技术可作为寰枢椎检查的常规技术手段。

DTS技术及其展望

为提高调度员对电力系统正常调度控制以及处理各种突发事件的应变能力 ,调度员培训仿真技术(DTS)在电力系统中得到了广泛的应用。文中对DTS技术的要求、分类以及结构作了详细的介绍。同时通过对DTS发展现状的分析 。

DTS、杜比多声道环绕声技术的发展与应用

随着多声道环绕声技术在电影院、家庭影院、高清电视、环绕声广播、汽车产品以及相关电子产品中得到应用和普及,为了使听众得到更好的环绕声体验,杜比实验室与DTS公司不断对环绕声技术进行研究与探索,针对这两家公司在目前市场上客户应用范围较广、用户使用较多的5.1,6.1,7.1及n.1声道环绕声技术的发展与应用进行了对比与分析。

数字电影院系统DTS技术及应用

DTS(数字电影院系统)是一种电影数字多声道系统,是家庭环绕声技术中出现的一项全新技术,阐述了DTS数字电影院系统的原理、特点,介绍了DTS数字电影院系统所采用的最新技术.

DTS音频文件软件解码的实现

介绍了DTS音频文件的解码标准,给出了软件解码需要的开发环境和解码流程,对3个DTS音频文件的软件解码结果进行了分析,最后列举了在编写DTS音频文件解码软件过程中需要注意的一些问题。

Digital Twins and Cyber Physical Systems toward Smart Manufacturing and Industry 4.0:Correlation and Comparison

State-of-the-art technologies such as the Internet of Things(IoT),cloud computing(CC),big data analytics(BDA),and artificial intelligence(AI)have greatly stimulated the development of smart manufacturing.An important prerequisite for smart manufacturing is cyber-physical integration,which is increasingly being embraced by manufacturers.As the preferred means of such integration,cyber-physical systems(CPS)and digital twins(DTs)have gained extensive attention from researchers and practitioners in industry.With feedback loops in which physical processes affect cyber parts and vice versa,CPS and DTs can endow manufacturing systems with greater efficiency,resilience,and intelligence.CPS and DTs share the same essential concepts of an intensive cyber-physical connection,real-time interaction,organization integration,and in-depth collaboration.However,CPS and DTs are not identical from many perspectives,including their origin,development,engineering practices,cyber-physical mapping,and core elements.In order to highlight the differences and correlation between them,this paper reviews and analyzes CPS and DTs from multiple perspectives.

X线数字断层融合技术(DTS)在诊断儿童寰枢关节半脱位的临床价值研究

目的:评价X线数字断层融合技术(DTS)在诊断儿童寰枢关节半脱位的临床应用价值。方法:对收集的临床症状表现为斜颈、颈部疼痛、颈部选择活动受限的患儿,征得患者及家属同意,均同时进行寰枢关节张口位+侧位常规X线平片及X线数字断层融合成像扫描,评价两种成像方法所获得的寰枢关节图像质量及对患儿寰枢关节半脱位的诊断情况。结果:共收集34例疑似病例,经DTS扫描发现16例患儿寰枢关节半脱位,而常规X线检查仅检出8例寰枢关节半脱位患儿,漏诊8例,误诊5例。DTS图像和常规X线检查的图像优质率分别为76.47%和32.35%,P=0.000。结论:X线数字断层融合技术(DTS)能明显改善常规X线寰枢关节影像的图像质量,尤其在患儿配合不当及骨关节结构复杂的情况下,具有重要的诊断价值及临床意义。

DTS在肘关节骨折复位固定术后随访中的应用价值

目的探讨数字化断层融合技术(digital tomosynthesis,DTS)在肘关节骨折复位固定后随访中的应用价值。方法选取36例肘关节骨折复位固定后的患者,行DR和DTS检查;对比二者图像,评估DTS检查的应用优势。结果 36例患者中断层融合图像质量优良为26例,图像质量一般为9例,图像质量差为1例。DR检查图像质量优良为10例,图像质量一般为16例,图像质量差为10例。DTS组优良图像比例为72.2%,DR组优良图像比例为27.8%;DTS优片率明显高于DR组(P<0.05)。DR组与DTS组图像质量评分比较,差异有统计学意义(P<0.01)。DTS评分明显高于DR,2组图像差异有统计学意义(P<0.05)。结论 DTS检查能更好显示肘关节骨折复位固定后骨折对位及骨痂生长情况;尤其是DTS独有的T-smart技术能有效去除金属内固定物伪影,有助于准确判断金属内固定物的位置和与周围骨质的结合情况;对于判定肘关节骨折复位固定术后的疗效及预后具有很好的应用价值。