Objective To compare the treatment of malignant obstructive jaundice(MOJ)with trocar versus Seldinger technique for percutaneous transhepatic biliary drainage(PTBD).Methods The imaging data of 80 patients with MOJ were analyzed retrospectively and divided into trocar group(30 cases)and Seldinger group(50 cases).The primary outcomes were technical success rate,efficacy and complication.Results The first success rate was higher in the Seldinger group than the trocar group(98％vs 83.3％;P=0.03).The clinical effect was similar.Conclusion Both trocar and Seldinger technique for PTBD are equally effective to relieve obstructive jaundice.Seldinger technique was associated with a high first success rate.

Nail dystrophy is a group of non-specific nail plate diseases with various clinical manifestations caused by multiple factors. Appropriate surgical approaches could be chosen according to different causes of nail dystrophy to improve the nail plate shape and relieve clinical symptoms. This review summarizes the progress in surgical treatment of pachyonychia congenita, congenital malalignment of the great toenail, congenital hypertrophy of the lateral nail folds of the hallux, chronic paronychia and other nail dystrophies, including resection of the nail matrix and nail bed, nail unit rotation surgery combined with wedge-shaped skin flap excision and repair, nail fold reconstruction, Swiss roll technique, etc., in order to provide a reference for clinicians to choose appropriate surgical approaches.

Skin imaging techniques can markedly improve the accuracy of diagnosis of nail diseases, and can be used to evaluate therapeutic effects. This review mainly summarizes the application of reflectance confocal microscopy, optical coherence tomography, high-frequency ultrasound, and nailfold capillaroscopy in nail diseases, and evaluates their advantages and limitations in clinical practice.

Objective:To observe whether hair follicle cells from mice of different species can integrate to generate new pigmented hair follicles, and to explore the role of different melanocyte populations in pigmented hair follicle reconstruction in mice.Methods:The epidermal cell population, hair follicle epithelial cell population and dermal cell population were isolated from the skin of fetal or neonatal C57BL/6J and BALB/C mice, and epidermal melanocytes were obtained by culture and purification of the epidermal cell population. The experiments were divided into 3 parts: (1) hair follicle reconstruction experiment in neonatal C57BL/6J mice, which included 2 groups: epidermal cells + hair follicle epithelial cells group and dermal cells group; (2) chimeric hair follicle reconstruction experiment, which included 4 groups: dermal cells of neonatal C57BL/6J mice group, dermal cells of neonatal BALB/C mice group, dermal cells of neonatal BALB/C mice + dermal cells of neonatal C57BL/6J mice group, and dermal cells of fetal BALB/C mice + dermal cells of fetal C57BL/6J mice group; (3) pigmented hair follicle reconstruction experiment, which included 3 groups: dermal cells of neonatal BALB/C mice + epidermal cells of neonatal C57BL/6J mice group, dermal cells of neonatal BALB/C mice + hair follicle epithelial cells of neonatal C57BL/6J mice group, and dermal cells of neonatal BALB/C mice + cultured C57BL/6J epidermal melanocytes group. Different cells were implanted into dorsal skin fold chambers of the nude mice, and there were 4 mice in each group. At weeks 4 and 8 after inoculation, hair follicle reconstruction was assessed by gross observation, histological examination and immunofluorescence assay.Results:Among the 8 BALB/C nude mice in the 2 groups in the hair follicle reconstruction experiment, 7 survived and 1 died of wound infections on week 4 after inoculation; at weeks 4 and 8 after inoculation, no hair growth was observed in the epidermal cells + hair follicle epithelial cells group (3 mice) , while normal hair grew out in the dermal cells group (4 mice) mixed with epithelial components. Among the 16 BALB/C nude mice in the 4 groups in the chimeric hair follicle reconstruction experiment, 14 survived and 2 died of wound infections on week 4 after inoculation; at weeks 4 and 8 after inoculation, brown-grey hair grew well in the dermal cells of neonatal BALB/C mice + dermal cells of neonatal C57BL/6J mice group (4 mice) , and dermal cells of fetal BALB/C mice + dermal cells of fetal C57BL/6J mice group (3 mice) . Among the 12 BALB/C nude mice in the 3 groups in the pigmented hair follicle reconstruction experiment, 10 survived and 2 died of wound infections on week 4 after inoculation; at weeks 4 and 8 after inoculation, only white hair grew out in the dermal cells of neonatal BALB/C mice + cultured C57BL/6J epidermal melanocytes group (3 mice) , and no hair follicle melanocytes were observed by immunofluorescence assay, while brown-grey hair grew well in the dermal cells of neonatal BALB/C mice + epidermal cells of neonatal C57BL/6J mice group (4 mice) , and dermal cells of neonatal BALB/C mice + hair follicle epithelial cells of neonatal C57BL/6J mice group (3 mice) .Conclusions:The interaction between mesenchymal cells and hair follicle epithelial cells is a necessary condition for hair follicle reconstruction. The hair follicle cells from different species of mice can integrate to generate new pigmented hair follicles. Both hair follicle melanocytes and epidermal melanocytes can participate in the formation of pigmented hair follicles, but differentiated melanocytes have no such ability.

Objective:To assess the shielding requirements of low energy X-ray intraoperative radiotherapy room under the domestic and foreign standards and guidelines, to measure the sured transmission factors for a range of shielding materials, the ambient dose equivalent rate around concerned positions and the shielding effect of protective devices, so as to provide references for shielding design of such radiotherapy units and applications of radiological protection devices.Methods:The required shielding thicknesses for a treatment room with INTRABEAM intraoperative radiotherapy system were calculated under the Chinese national standard GBZ 121, IPEM report No. 75 and NCRP report No. 151, respectively. The transmission factors for a range of shielding materials including solid water slab, shielding sheet and shielding apron were measured. Moreover, the ambient dose equivalent rates were measured under the simulated working conditions and the shielding effectiveness of a lead screen was evaluated.Results:The required lead thicknesses calculated under different standards and guidelines were less than 0.6 mm for all the concerned points, with the differences at sub-millimeter level. The low energy X-rays generated by this equipment attenuated rapidly in the shielding materials. The measured transmission factors of 0.05 mm lead equivalent shielding sheet and 0.25 mm lead equivalent shielding apron were 0.068 and 0.003 8, respectively. When the radiation was delivered using spherical applicator without any attenuation, the ambient dose equivalent rates at 1 m and 2 m from the X-ray source were 10.7 and 2.6 mSv/h, respectively. The corresponding measurement values decreased to 3.8 and 0.9 μSv/h, respectively, when the spherical applicator was inserted into a small water tank. Meanwhile, the ambient dose equivalent rate at 2 m was reduced to the background level when using protective screen.Conclusions:The shielding requirements for a low energy X-ray intraoperative radiotherapy facility are minimal, with low effective energy of X-rays generated by this equipment, but the dose rate close to the unshielded radiation source is high. The shielding scheme of treatment room should be optimized in design and the protective device should be used in a reasonable way.

Objective:To explore the application effect of case-based learning (CBL) combined with problem-based learning (PBL) teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). CBL combined with PBL teaching method was used in the experimental group, and traditional lecture-based learning (LBL) method was used in the control group. The results of attitude evaluation, staged exminations, graduation assessment and operational skill tests were compared between the two groups, and the questionnaire survey was performed to test the affirmation of self-worth of the two groups of interns. SPSS 17.0 was used for chi-square test, independent t test, and Mann-Whitney U test. Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were significantly higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that such 7 aspects as the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference ( P<0.05), while the consolidation of theoretical knowledge of the experimental group was not statistically different from the control group ( P>0.05). Conclusion:The reasonable application of CBL combined with PBL teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge.

In recent years, some progress has been made in the diagnosis and treatment of nail diseases, but there are still many challenges, such as longitudinal melanonychia, rare nail unit-specific tumors and nail dystrophy. Longitudinal melanonychia may develop into melanoma. Besides, biopsy and surgery are triggering factors for acral melanoma, so it is important to decide whether to operate and how to apply operating principles in clinic. In addition, the diagnosis and treatment should be based on patients′ age, clinical evaluation results, dermoscopic findings and pathological examinations, so as to avoid missed diagnosis of malignant melanonychia and deformities from treatment of benign melanonychia as far as possible. There are few summaries of clinical manifestations and pathological features of rare nail unit-specific tumors, and their diagnosis is difficult. In particular, onychocytic carcinoma and onycholemmal carcinoma are malignant tumors with great harm, so this article focuses on the two kinds of tumors to remind clinicians to avoid missed diagnoses. The etiology of nail dystrophy is complex. Nail dystrophy caused by inflammatory diseases can be treated with topical or systemic drugs, while various nail deformities caused by genetic factors, toe deformities, improper walking posture, mechanical injuries, and chronic inflammation of the nail groove are in need of physical or surgical correction. This article gives insight into challenges and strategies for the diagnosis and treatment of the above nail diseases.

Nail unit tumors are a group of rare tumors only occurring in the nail unit, including onychopapilloma, onychomatricoma, onychocytic matricoma, onycholemmal carcinoma, and so on. These tumors have specific clinical manifestations and pathological features due to their special anatomical locations. This review focuses on clinical manifestations, histopathological characteristics and treatment of the above tumors.

Objective:To explore the application effect of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). Case-based learning combined with problem-based learning teaching method was used in the experimental group, and traditional lecture-based learning method was used in the control group. 2 test was used for sex distribution comparisons between the two groups, and independent t test was conducted to compare the differences in age, working years, entrance examination results, attitude rating scores, stage examination scores, completion examination scores, and operational examination scores between the two groups. Mann-Whitney U test was used for comparisons of non-parametric variables between the two groups, such as qualifications, occupation title, and questionnaire results.Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference [4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 3(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, P<0.05], while the consolidation of theoretical knowledge of the experimental group was not different from the control group [3(2, 3) scores vs. 3(2, 3) scores, P>0.05]. Conclusions:The reasonable application of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge, and it also can contribute to affirmation of self-worth.

Objective:To identify the radiomics features related to the occurrence of radiation pneumonitis based on localized CT images of the chest in lung cancer patients, establish a machine learning model and investigate the value of radiomics technology in predicting the incidence of radiation pneumonitis.Methods:Clinical data of 86 patients with stage Ⅲ non-small cell lung cancer who received radical intensity-modulated radiation therapy (IMRT) were retrospectively analyzed. The radiation pneumonitis was graded by follow-up imaging data and clinical information. The planning CT images were collected. The lung was used as the volume of interest for extraction of radiomics features. The radiomics features, clinical and dosimetric parameters associated with the incidence of radiation pneumonitis were analyzed. Using the support vector machine to construct the model, the prediction performance of the model was evaluated by the five-fold verification method.Results:A total of 1029 radiomics features were extracted from CT images and 5 features were selected by ANOVA and LASSO. Two validation sets showed differences between adopting radiomics features alone and incorporating clinical and dosimetric parameters and radiomics features (AUC=0.67 and 0.71, respectively).Conclusions:The radiomics model constructed by planning CT images of lung cancer patients has the potential to predict the occurrence of radiation pneumonitis. Addition of clinical and dosimetric parameters can further improve the prediction performance of the model.