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Abstract Background Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) provide accurate vascular imaging information, but their use may be contraindicated. Color Doppler ultrasonography (CDU) provides simple, safe, noninvasive, and reproducible imaging. We therefore investigated the role of preoperative CDU combined with CTA and MRA in the quantification, typing, and diagnosis of carotid body tumors (CBTs). Methods We retrospectively analyzed patients with CBTs categorized into group A (type I [n = 1] and type II [n = 10]) or group B (type III [n = 56]) per the intraoperative Shamblin classification. CDU, CTA, and MRA characteristics of CBTs were observed, surgical results were correlated, and the diagnostic threshold of the CBT classification was calculated. Results CBTs were usually located at the common carotid artery bifurcation, encircling the carotid artery. An increased angle was found between the internal and external carotid arteries. On CDU, CBTs primarily presented as homogeneous hypoechoic masses with clear boundaries, rich flow signals, and a high-speed, low-resistance artery-like flow spectrum. CTA showed uniform or heterogeneous marked enhancement. MRA showed mixed T1 and slightly longer T2 signals and uniform or uneven obvious enhancement. With increases in the lesion size, amount of blood transfused, and operation time, the intraoperative classification level and possibility of skull-base invasion increased. When the maximum diameter of the lesion, the volume of the tumor, the distance between the upper margin of the tumor to the mastoid and the mandibular angle were 3.10 cm, 10.15 cm3, − 3.26 cm, and 0.57 cm, respectively, the largest Youden index was the best diagnostic boundary value for Shamblin type III tumors. Conclusions CDU combined with CTA and MRA can accurately evaluate the size and classification of CBTs.

The ultrasound diagnosis imaging report reflects the sum of a radiologist's synthesis and judgement into a patient's condition. It is also an important product that is generated by radiologists to help the patients. In spite of the importance of clear and effective report writing, radiologists usually receive little or no formal reporting education. There are key principles when reporting the ultrasound findings, impression, and recommendations to promote report quality and reading experience. The findings should emphasize short and factual observations while avoiding redundancy. The impression is the thoughtful synthesis of findings leading to a diagnosis, a differential diagnosis and management recommendations. Improved report writing is achieved only after persistent learning, follow up and summaries.

Peyton's four-step teaching method is widely used in education of clinical skills. At the present study, this method was introduced into musculoskeletal ultrasound training, and the effect of this training strategy was evaluated. Problems which may occur in the process were also searched in order to improve this method. Compared to traditional method, students accepted Peyton's four-step teaching method, namely demonstration, deconstruction, comprehension and performance all achieved better scores in both theory and skill tests. Peyton's four-step teaching method also stimulated students′ learning interest and improved their teaching skill. However, one-to-one teaching is inefficient and few mutual discussion and inspiration among group members. The modified Peyton's four-step method with group teaching will be optimized and applied in future research and application.

Objective To explore the application of a hybrid training mode characterized by “clinical practice + result oriented +humanistic care” for practical training of medical students. Methods The research objects were the graduate students at the department of ultrasound in Peking University Third Hospital, and the subjective evaluation index was the two-way questionnaire completed by teachers and by students. The recognition of teachers and students to the new training mode and its effectiveness as well as suggestions were evaluated. Results It was found that 95.74% of teachers and students acknowledged the new mode and were willing to participate in, 76.7% of them believed that the method helped to solve problems in work and psychology, 6.4% of teachers and students thought that the communication efficiency of new mode was lower than the traditional method. The advantages and disadvantages of the new model, the opportunities and threats of teaching and management were analyzed with SWOT. Conclusions The new hybrid traniniing model has got a high degree of recognition. According to the results of SWOT analysis, we should develop strengths and circumvent weaknesses, creating new opportunities for medical practice and educational model innovation.

Global position systems (GPS) receiver based on least mean square (LMS) could resist the interference by null jamming direction. Considering that the existing band-limited Gaussian noise jamming signals were easily suppressed by LMS-based GPS receivers, a time domain random flicker band-limited Gaussian noise jamming algorithm was proposed to improve its performance. By disturbing the convergence of LMS, it could achieve the purpose of suppressing the LMS-based GPS. Simulation result shows that the proposed algorithm has an average performance gain of 2.7dB~4.6dB under different number of interferences compared with band-limited Gaussian noise.