Objective:To investigate the clinical value of magnetic resonance imaging (MRI) in differential diagnosis for benign and malignant lesions of solitary pulmonary nodules (SPN).Methods: 120 patients with SPN were enrolled in the retrospective analysis, and all of them underwent scan of MR including MRI, DCE-MR and diffusion weighted imaging (DWI) before their surgery. All of patients received detection of pathology or histopathological examination after their surgery, and the ADC values under different b values of dispersion sensitivity factor (300 s/mm2, 500 s/mm2 and 800 s/mm2) were compared.Results:Under the conditions both of 300 s/mm2 and 800 s/mm2, the differences of ADC value between benign nodule and malignant nodule were not statistically significant (t=1.195,P>0.05). And under the condition of 500 s/mm2, the ADC value of benign nodule was significantly higher than that of malignant nodule (t=4.313,P<0.05), and at this time, the sensitivity, specificity, rate of missed diagnosis and misdiagnosis rate of the differential diagnosis for benign and malignant lesions of SPN by using MR were 85.71％, 74％, 14.9％ and 26％, respectively.Conclusion: MR examination has higher sensitivity in differential diagnosis for benign and malignant lesions of SPN, and it has a certain clinical value when it is used as early detecting method.

Objective To explore an effective evaluation method for students' self-and peer-assess-ment. Methods The students of 6 groups participating in extracurricular teaching activities were selected as research subject. Traditional method (final score = mean score of group/2 + teacher's score/2) and mean difference method [final score=teacher's score-(mean difference of group-mean difference of all groups)] were used to calculate final score of each group, and effect of two methods were compared. Results Scores of most groups were higher than the teacher's scores, and high scores were given by group 3 in self- and peer-assessment. The final score of all groups were higher than teacher's scores in traditional method. Compared with teacher's scores, final scores increased significantly in group 1, 4, 5 below mean difference, final score decreased significantly in group 2, 3 above mean difference, and final score did not differ in group 6 equal to mean difference in mean difference method. Conclusion The mean difference method can reflect the effect of student's self- and peer-assessment, and guide student to make objective and accurate evaluation. It is a more reasonable and scientific evaluation method for self-and peer-assessment.

A case diagnosed as ossifying fibroma and compound odontoma in the mandible was reported. The clinicopathological features, diagnosis, and treatment were discussed with the literature review.
Fibroma, Ossifying ; Humans ; Mandible ; Mandibular Neoplasms ; Odontoma

Two-dimensional code technology is widely used in daily life,and its application is relatively rare in medical education.Students organized write the Chinese and English slices' information by the way of extracurricular teaching activities,and two-dimensional code transformed from slices' information as label was pasted onto slice to made slice specimen with two-dimensional code.The students can quickly and accurately read the slice information by scanning the two-dimensional code.This practice can stimulate students' interest in learning and creative ability.It not only creates convenient conditions for the opening of the histology experiment and the independent study of the students,but also provides a way of thinking for the information management of the experimental teaching.