Objective To describe radiological features of bronchopulmonary dysplasia(BPD) in premature infants,and improve the diagnostic ability of BPD.Methods Eleven Premature infants with BPD underwent series of chest radiographs,X-ray features of BPD were analysed.Results The radiographic findings frequently included diffuse opacities,linear-reticular opacities,sacculiform radiolucent areas and over-inflation of lung.There were 4 cases with two of the radiological abnormalties obove,diffuse opacities and linear-reticular opacities in 2,diffuse opacities and sacculiform radiolucent areas in one and diffuse opacities and over-inflation in one.There were two cases with three kinds of X-ray features,including diffuse opacities,linear-reticular opacities and sacculiform radiolucent areas.There was one case with all of the radiological features noted above.Conclusion The chest radiographs appearance were of characteristics in premature infants with bronchopulmonary dysplasia.

Objective To measure middle cerebral artery (MCA) hemodynamic parameters of chronic cerebral ischemia in middle aged and elderly people with phase contrast magnetic resonance imaging (PCMRI),and to explore cerebral blood flow dynamic pattern in different degrees of chronic cerebral ischemia patients.Methods Middle aged and elderly people underwent conventional MRI scan,and were divided into 12 cases of the normal group,16 cases of mild cerebral ischemia group and 13 cases of obvious cerebral ischemia group.All groups underwent bilateral MCA PCMRI.Bilateral MCA hemodynamic parameters and phase-velocity curve in a heartbeat cycle were obtained by QFLOW analysis software on the workstation for post-processing.Bilateral MCA vascular area,peak velocity (PV),mean velocity (MV) and mean flow (MF) were recorded.The differences of bilateral MCA hemodynamic parameters among the three groups were compared by SPSS17.0 software.Results Bilateral MCA vascular area,MV,MF and right MCA PV among three groups were statistically significant by one-Way ANOVA (P＜0.05).Compared with normal group,systolic peak of bilateral MCA phase-velocity curve was low,dull,widen,and the connection between the diastolic peak and systolic peak became flattened in chronic cerebral ischemia patients.Conclusion PCMRI can reflect the differences of the cerebral blood flow dynamic change pattern between different degrees of chronic cerebral ischemia.

Objective To observe the application value of MRI in diagnosis and clinical management of abdominal pregnancy.Methods MRI and clinical data of 5 patients with abdominal pregnancy proved surgically were analyzed retrospectively.MRI performances were analyzed and compared with findings in operation.Results Prenatal MRI correctly diagnosed abdominal pregnancy in all 5 patients,including 1 case of primary and 4 cases of secondary abdominal pregnancy.The position of uterine rupture was revealed in all 4 cases of secondary abdominal pregnancy.MRI performances of placenta conformed to operative findings in all 5 patients.A lot of fresh intra-abdominal hemorrhage was found in 1 case,oligohydramnion in 2 cases,and abnormalities of placenta and fetus in 2 patients,which were consistent with findings of operation.Conclusion Prenatal MRI offers a high accuracy rate in diagnosis of abdominal pregnancy.MRI can show fetus,placenta and the relationship with surrounding tissue,therefore being helpful to clinical management of abdominal pregnancy.

Purpose: Knowing the distinction between benign and borderline/malignant phyllodes tumors (PTs) can help in the surgical treatment course. Herein, we investigated the value of magnetic resonance imaging-based texture analysis (MRI-TA) in differentiating between benign and borderline/malignant PTs. Methods: Forty-three women with 44 histologically proven PTs underwent breast MRI before surgery and were classified into benign (n = 26) and borderline/malignant groups (n = 18 [15 borderline, 3 malignant]). Clinical and routine MRI parameters (CRMP) and MRI-TA were used to distinguish benign from borderline/malignant PT. In total, 298 texture parameters were extracted from fat-suppression (FS) T2-weighted, FS unenhanced T1-weighted, and FS first-enhanced T1-weighted sequences. To evaluate the diagnostic performance, receiver operating characteristic curve analysis was performed for the K-nearest neighbor classifier trained with significantly different parameters of CRMP, MRI sequence-based TA, and the combination strategy. Results: Compared with benign PTs, borderline/malignant ones presented a higher local recurrence (p = 0.045); larger size (p < 0.001); different time-intensity curve pattern (p = 0.010); and higher frequency of strong lobulation (p = 0.024), septation enhancement (p = 0.048), cystic component (p = 0.023), and irregular cystic wall (p = 0.045). TA of FS T2-weighted images (0.86) showed a significantly higher area under the curve (AUC) than that of FS unenhanced T1-weighted (0.65, p = 0.010) or first-enhanced phase (0.72, p = 0.049) images. The texture parameters of FS T2-weighted sequences tended to have a higher AUC than CRMP (0.79, p = 0.404). Additionally, the combination strategy exhibited a similar AUC (0.89, p = 0.622) in comparison with the texture parameters of FS T2-weighted sequences. Conclusion MRI-TA demonstrated good predictive performance for breast PT pathological grading and could provide surgical planning guidance. Clinical data and routine MRI features were also valuable for grading PTs.

Objective To evaluate the value of MRI texture analysis based on gray level co-occurrence matrix to predict cervical lymph node metastasis in patients with tongue carcinoma. Methods A total of 70 patients with tongue carcinoma confirmed by pathology were analyzed retrospectively. The patients were divided into cervical lymph node (LN) metastasis group (unilateral LN+, n=18;bilateral LN+,n=22) and no cervical lymph node metastasis(LN-,n=30). T1W, T2W and contrast-enhanced T1W images of the largest section of tumor were selected. ROI of the lesion was manually drew and GLCM texture parameters (energy, contrast, correlation, inverse difference and entropy) were extracted. The tumor length, thickness and para-lingual distance between tumor and tongue midline were also measured.Differences of all parameters were compared between LN+ group and LN- group, unilateral and bilateral cervical lymph node metastasis group, the parameters with statistically significant difference in predicting the efficiency of cervical lymph node metastasis were analyzed. The diagnostic efficiency of lymph node metastasis was calculated. Results The correlation, inverse difference and entropy based on T2WI showed significant difference (Zcor elation=2.97, tinverse dif erence=5.14, tentropy=2.41; P<0.05), entropy showed the best diagnostic efficiency, the area under the ROC curve (AUC) was 0.90, the cut off value was 7.19, the sensitivity was 80.0％, specificity was 86.7％. Only entropy showed significant difference between unilateral LN+group and bilateral LN+group (P<0.05), the AUC was 0.82, the cut off value was 7.47, the sensitivity was 90.9％, specificity was 78.8％. The index of tumor length, thickness and para-lingual distance between tumor and tongue midline all showed significant difference between LN+group and LN-group (P<0.05), the thickness showed the best diagnostic efficiency, the AUC value was 0.81, the cut off value was 11.19, the sensitivity was 78.0％, specificity was 81.7％. The index of tumor length, thickness and para-lingual distance between tumor and tongue midline showed no significant difference between unilateral LN+ group and bilateral LN+ group (P>0.05). The diagnostic sensitivity of radiologists was 65.0％ (26/40), the specificity was 80.0％ (24/32) on cervical lymph node metastasis. Conclusion Texture analysis based on T2WI can predict cervical lymph node metastasis in patients with tongue carcinoma. Entropy has certain value in predicting bilateral cervical lymph node metastasis.

Objective To evaluate the effects of problem-based learning (PBL) teaching model in breast cancer medical imaging education based on multidisciplinary treatment (MDT). Methods The PBL teaching practice of breast cancer imaging based on MDT was carried out in the 192 clinical medicine students in Grade 2014 of Guangzhou Medical University. The students were randomly divided into four groups (group A, B, C and D) and each group was further divided into 1 to 5 teams, with 9 to 11 students in each team. The MDT teaching team consisted of clinical physicians in medical imaging, radiation oncology, surgery (specialized in breast tumor), and other disciplines. The formative assessment method was used to evaluate the teaching effects and the problems involved wereanalyzed. Results Firstly, with a full score of 100 points, the quantitative evaluation of each teaching team on the performance of students in PBL were (86.6±7.8), (87.1±8.1), (83.9±6.5), (88.1±4.5), and (85.1±8.2), respectively. No significant difference was found among each tutor team’s quantitative evaluation (F=1.014, P=0.388). Secondly, the whole posi-tive evaluation rate of students for tutors was 96.28%, with the highest and lowest positive rates as 98.36% and 94.08%, respectively. Significant difference was found among parts of the tutors ( χ2=10.554, P=0.032), specifically between team 1 and 5 (Z=2.245,P=0.025), 3 and 4 (Z=2.217,P=0.027) and 3 and 5 (Z=2.761,P=0.006) respectively. Lastly, the positive and negative evaluation rates of student's self-assessment were 87.33% and 12.67% respectively. Conclusion The effects of PBL based on MDT in breast cancer imaging teaching practice is encouraging, and the formative assessment method can objectively and effectively evalu-ate the effects of this kind of teaching model. However, the standards of evaluation still need to be further perfected and improved.