Objective To propose a CT truncated data reconstruction model(DDTrans)based on projection and image dual-domain Transformer coupled feature learning for reducing truncation artifacts and image structure distortion caused by insufficient field of view(FOV)in CT scanning.Methods Transformer was adopted to build projection domain and image domain restoration models,and the long-range dependency modeling capability of the Transformer attention module was used to capture global structural features to restore the projection data information and enhance the reconstructed images.We constructed a differentiable Radon back-projection operator layer between the projection domain and image domain networks to enable end-to-end training of DDTrans.Projection consistency loss was introduced to constrain the image forward-projection results to further improve the accuracy of image reconstruction.Results The experimental results with Mayo simulation data showed that for both partial truncation and interior scanning data,the proposed DDTrans method showed better performance than the comparison algorithms in removing truncation artifacts at the edges and restoring the external information of the FOV.Conclusion The DDTrans method can effectively remove CT truncation artifacts to ensure accurate reconstruction of the data within the FOV and achieve approximate reconstruction of data outside the FOV.

Objective To propose a CT truncated data reconstruction model(DDTrans)based on projection and image dual-domain Transformer coupled feature learning for reducing truncation artifacts and image structure distortion caused by insufficient field of view(FOV)in CT scanning.Methods Transformer was adopted to build projection domain and image domain restoration models,and the long-range dependency modeling capability of the Transformer attention module was used to capture global structural features to restore the projection data information and enhance the reconstructed images.We constructed a differentiable Radon back-projection operator layer between the projection domain and image domain networks to enable end-to-end training of DDTrans.Projection consistency loss was introduced to constrain the image forward-projection results to further improve the accuracy of image reconstruction.Results The experimental results with Mayo simulation data showed that for both partial truncation and interior scanning data,the proposed DDTrans method showed better performance than the comparison algorithms in removing truncation artifacts at the edges and restoring the external information of the FOV.Conclusion The DDTrans method can effectively remove CT truncation artifacts to ensure accurate reconstruction of the data within the FOV and achieve approximate reconstruction of data outside the FOV.

Urethra stricture is one of the most common diseases of the urinary system. Accurate imaging diagnosis is key to the selection of surgical approach. At present, X-ray urethral imaging can show the form of urethra cavity, but not the tissues around the urethra. Sonourethrography (SUG) can dynamically identify the urethral cavity and the surrounding tissues without radiation exposure. Multi-layer spiral CT urethrography (CTU) has advantages of no need to adjust the position, quick scanning and reconstruction of the three-dimensional image, which can accurately show the location, length and degree of urethral stricture, and the spatial relationship with the surrounding tissues. Magnetic resonance urethrography (MRU) can provide useful information of the urethral stricture and soft tissues around the urethra, especially in urethral strictures caused by pelvic fractures and complex urethral stenosis. The choice of imaging method should be based on the etiology, anatomy, types of urethral injury and the general situation of patients. Appropriate imaging method can improve the diagnostic accuracy.

Bronchiectasis is a complex and heterogeneous group of diseases with their own characteristics in terms of etiology, symptoms, infections and inflammation, among which infections are both the most common cause of bronchiectasis and the most important factor contributing to the progression of the disease and affecting the prognosis. The current paper will focus on the characterization, diagnosis and treatment of pathogenic bacteria in bronchiectasis.

OBJECTIVE: To develop a digital breast tomosynthesis (DBT) imaging system with optimizes imaging chain. METHODS: Based on 3D tomography and DBT imaging scanning, we analyzed the methods for projection data correction, geometric correction, projection enhancement, filter modulation, and image reconstruction, and established a hardware testing platform. In the experiment, the standard ACR phantom and high-resolution phantom were used to evaluate the system stability and noise level. The patient projection data of commercial equipment was used to test the effect of the imaging algorithm. RESULTS: In the high-resolution phantom study, the line pairs were clear without confusing artifacts in the images reconstructed with the geometric correction parameters. In ACR phantom study, the calcified foci, cysts, and fibrous structures were more clearly defined in the reconstructed images after filtering and modulation. The patient data study showed a high contrast between tissues, and the lesions were more clearly displayed in the reconstructed image. CONCLUSIONS This DBT imaging system can be used for mammary tomography with an image quality comparable to that of commercial DBT systems to facilitate imaging diagnosis of breast diseases.
Algorithms ; Artifacts ; Breast ; diagnostic imaging ; Female ; Humans ; Mammography ; methods ; Phantoms, Imaging ; Radiographic Image Enhancement ; methods

OBJECTIVE: To develop a deep features-based model to classify benign and malignant breast lesions on full- filed digital mammography. METHODS: The data of full-filed digital mammography in both craniocaudal view and mediolateral oblique view from 106 patients with breast neoplasms were analyzed. Twenty-three handcrafted features (HCF) were extracted from the images of the breast tumors and a suitable feature set of HCF was selected using -test. The deep features (DF) were extracted from the 3 pre-trained deep learning models, namely AlexNet, VGG16 and GoogLeNet. With abundant breast tumor information from the craniocaudal view and mediolateral oblique view, we combined the two extracted features (DF and HCF) as the two-view features. A multi-classifier model was finally constructed based on the combined HCF and DF sets. The classification ability of different deep learning networks was evaluated. RESULTS: Quantitative evaluation results showed that the proposed HCF+DF model outperformed HCF model, and AlexNet produced the best performances among the 3 deep learning models. CONCLUSIONS The proposed model that combines DF and HCF sets of breast tumors can effectively distinguish benign and malignant breast lesions on full-filed digital mammography.
Breast Neoplasms ; classification ; diagnostic imaging ; Deep Learning ; Diagnosis, Computer-Assisted ; methods ; Female ; Humans ; Mammography ; methods

Objective:To explore the etiology of male urethral stricture,analyze the therapeutic strategies of urethral stricture,and summarize the complicated cases.Methods:The data of 183 patients with urethral stricture were retrospectively analyzed,including etiology,obstruction site,stricture length,therapeutic strategy,and related complications.Results:The mean age was 49.7 years,the average course was 64.7 months,and the constituent ratio of51 to 65 years old patients was 38.8％ (71/183).The traumatic injury of patients accounted for 52.4％ (96/183),in which the pelvic fracture accounted for 35.5％ (65/183) and the straddle injury accounted for 16.9％ (31/183).There were 54 cases of iatrogenic injury (29.5％).The posterior urethral stricture accounted for 45.9％ (84/183),followed by the anterior urethral stricture (44.8％,82/183) and the stenosis (6.6％,12/183).A total of 99 patients (54.1％) received the end to end anastomosis,and 40 (21.9％) were treated with intracavitary surgery,such as endoscopic holmium laser,cold knife incision,endoscopic electroknife scar removal,balloon dilation,and urethral dilation.In the patients over 65-years old,the urethral stricture rate was 14.8％ and the complication rate (70.4％) for transurethral resection of the prostate (TURP) was significantly higher than that of all samples (P＜ 0.01).Conclusion:Both the etiology of male urethral stricture and the treatment strategy have changed and the incidence of traumatic and iatrogenic urethral stricture has increased in recent 3 years.The main treatment of urethral stricture has been transformed from endoscopic surgery into urethroplasty.

OBJECTIVE: To establish a cone beam computed tomography (ECBCT) system for high-resolution imaging of the extremities. METHODS: Based on three-dimensional X-Ray CT imaging and high-resolution flat plate detector technique, we constructed a physical model and a geometric model for ECBCT imaging, optimized the geometric calibration and image reconstruction methods, and established the scanner system. In the experiments, the pencil vase phantom, image quality (IQ) phantom and a swine feet were scanned using this imaging system to evaluate its effectiveness and stability. RESULTS: On the reconstructed image of the pencil vase phantom, the edges were well preserved with geometric calibrated parameters and no aliasing artifacts were observed. The reconstructed images of the IQ phantom showed a uniform distribution of the CT number, and the noise power spectra were stable in multiple scanning under the same condition. The reconstructed images of the swine feet had clearly displayed the bones with a good resolution. CONCLUSIONS The ECBCT system can be used for highresolution imaging of the extremities to provide important imaging information to assist in the diagnosis of bone diseases.
Algorithms ; Animals ; Artifacts ; Calibration ; Cone-Beam Computed Tomography ; instrumentation ; methods ; Equipment Design ; Extremities ; diagnostic imaging ; Image Processing, Computer-Assisted ; methods ; Phantoms, Imaging ; Radiographic Image Enhancement ; instrumentation ; methods ; Swine

OBJECTIVETo analyze the proportion and associated factors of taking subsequent confirmation test among men who have sex with men (MSM) after being tested positive in oral fluid HIV antibody test.

METHODSBy using successive sampling, 1 003 MSM, who were tested positive in oral fluid HIV antibody test in China-Bill & Melinda Gates Foundation AIDS prevention Program (Extension program) in Beijing during May 1 to December 31, 2013, were recruited. The inclusion criteria included: the objects were men who reported having sex with men; the objects aged more than 18 years old; the objects were tested positive in oral fluid HIV antibody test; the objects had not been reported as HIV positives in China Information System for Disease Control and Prevention previously. According to the program strategy, MSM grassroots organizations transferred the respondents to seek subsequent confirmation tests in specific Center for Disease Control and Prevention (CDCs) or hospitals. The subsequent confirmation tests included: fingertip blood HIV antibody rapid test, venous blood Enzyme Linked Immunosorbent Assay (ELISA) HIV antibody test and venous blood Western Blot (WB) HIV antibody test. Chi-square test was adopted to compare the proportion of taking subsequent confirmation tests in different groups. Nonconditional multivaritae binarylogistic regression analysis was taken to identify the associated factors with whether taking subsequent confirmation tests and to calculate the OR (95% CI) values.

RESULTSThe 1 003 respondents were (30.9 ± 9.1) years old. Among all objects, 87.8% (881/1 003) of them took fingertip blood HIV antibody rapid tests and the positive rate was 85.4% (752/881). 98.0% (737/752) of those who were identified as positive in fingertip blood HIV rapid tests took ELISA and WB tests, and the positive rate was 94.4% (696/737). Comparing with those who were expected to seek subsequent confirmation tests in CDCs, the OR (95% CI) value of those who were expected to seek tests in hospitals was 5.10 (1.69-15.36). The OR (95% CI) values of those who used condom sometimes and those who never used condom in anal sex were 5.81 (2.14-15.77) and 3.45 (2.00-5.97) respectively, in comparison with those who reported not having anal sex or using condom consistently in anal sex during the past 6 months. Comparing with the respondents recruited from the internet, the OR (95% CI) values of those recruited in bathrooms, parks/toilets and bars were 0.17 (0.05-0.53), 0.10 (0.04-0.29) and 0.22 (0.06-0.79) respectively. The likelihood of taking subsequent confirmation test decreased with the increase of number of male sexual partners in the past 3 months, and the OR (95% CI) value was 0.92 (0.86-0.99).

CONCLUSIONThe potential HIV positive MSM in the bathroom, park/toilet and bars are less likely to take subsequent confirmation test. Those who do not use condom consistently during anal sex are more likely to seek subsequent confirmation test. Medical organization conducting subsequent confirmation tests is more likely to increase the confirmation test rate of potential HIV positive MSM. The number of male sexual partners has negative correlation with whether to accept the subsequent confirmation test.

Beijing ; Condoms ; HIV Antibodies ; analysis ; HIV Seropositivity ; diagnosis ; Homosexuality, Male ; Humans ; Male ; Mass Screening ; Patient Acceptance of Health Care ; Risk-Taking ; Sexual Behavior ; Sexual Partners ; Surveys and Questionnaires

To investigate effects of verapamil on primary cultured human urethral scar fibroblasts (USFs) and to provide basis for protecting the formation of urethra scar.
 Methods: The cell proliferation was evaluated with the cell counting kit (CCK)-8 method after USFs were incubated various verapamil concentrations (50, 100, 150, 200, or 250 μmol/L) or solvent for 12, 24, or 48 h. The protein level of matrix metalloproteinase (MMP) was evaluated with ELISA after cells were incubated with verapamil (100 μmol/L) or solvent (control cells) for 24 h.
 Results: The proliferation of USFs was obviously suppressed after verapamil treatment, which was in a dose-dependent and time-dependent manner. Meanwhile, the protein levels of MMP-2 and MMP-9 in the verapamil treatment group increased obviously compared with those of the control groups (P<0.05).
 Conclusion: Calcium channel blockers may prevent the excessive formation of urethra scar by inhibiting the proliferation of urethral scar fibroblasts and enhancing the activity of MMP.
Calcium Channel Blockers ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cicatrix ; prevention & control ; Fibroblasts ; drug effects ; Humans ; Matrix Metalloproteinase 2 ; drug effects ; Matrix Metalloproteinase 9 ; drug effects ; Matrix Metalloproteinase Inhibitors ; pharmacology ; Up-Regulation ; drug effects ; Urethra ; cytology ; pathology ; Verapamil ; pharmacology