Objective To explore the value of high frequency ultrasound in differential diagnosis in dorsal thyroid (including gland dorsal or posterior) nodules.Methods Ultrasonographic features of 101 patients with ultrasonography suspected or misdiagnosed nodules in the dorsal area of the thyroid gland,which were then confirmed by pathology or hyaluronography/gastroscopy,were retrospectively analyzed.Ultrasonographic homogeneity (other nodules with similar ultrasonographic features were found in the ipsilateral gland),parenchyma homology (nodule parenchyma was continuous with glandular parenchyma) and blood homology (blood flow signals in nodules were continuous with those in glandular parenchyma) were applied as indicators for determinng thyroid nodules.Double-line sign or vascular arch sign at the edge of nodules served as an indicator for determining parathyroid nodules.Results Of the 101 cases,there were 46 thyroid nodules,35 parathyroid nodules,7 enlarged lymph nodes;6 esophageal diverticulum,6 esophageal cancer,1 cleft cyst.The determination of thyroid nodules by at least one of ultrasonographic homogeneity,parenchyma homology and blood homology showed sensitivity of 73.5 ％,specificity of 96.5 ％ and accuracy of 85.8％.In the determination of parathyroid nodules by double-line sign or vascular arch sign at the edge of nodules,sensitivity,specificity and accuracy was 54.1％,85.5 ％ and 74.5 ％,respectively.Conclusions Nodules in the dorsal area of the thyroid gland have different sources,and the understanding of corresponding characteristic ultrasonographic appearances is helpful for improving the differential diagnosis of these nodules.

Objective: To explore the effect of fine particulate matters (PM_2.5) exposure on emergency visits and outpatient visits of 5 hospitals in Beijing, Shanghai and Guangzhou from 2013 to 2015. Methods: Using convenient sampling method, 5 general hospitals in Beijing, Shanghai and Guangzhou were selected which included Beijing hospital, China-Japan friendship hospital, Xinhua hospital affiliated to Shanghai jiaotong University School of Medicine, the liwan hospital of the third affiliated hospital and the first affiliated hospital of Guangzhou Medical University. The emergency and outpatient data, air pollution monitoring data and meteorological data were collected from January 1, 2013 to December 31, 2015. A generalized additive model was used to analyze the effect of PM_2.5 exposure on daily hospital emergency and outpatient visits, and Meta analysis was used to obtain the combined effect value. Results: The number of emergency and outpatient visits of 5 hospitals was 1 378 501 and 18 139 779 in total, respectively. The mean±SD of PM_2.5 exposures in Beijing hospital, China-Japan friendship hospital, Xinhua hospital affiliated to Shanghai jiaotong University School of Medicine, the liwan hospital of the third affiliated hospital and the first affiliated hospital of Guangzhou Medical University were (81.8±68.7), (83.2±69.7), (54.4±34.1), (43.5±24.8) μg/m³, respectively. Results of single pollutant model analysis showed that 0-1 day lag concentrations of PM_2.5 had the largest effect on emergency visits and outpatient visits. For a 10 μg/m³ increase of PM₂.5 concentration, excess risk (ER) (95%CI) of emergency and outpatient visits was 0.56% (0.14%, 0.99%) and0.63% (0.07%, 1.19%), respectively. After adjusting for O₃, NO₂, SO₂, and CO, for a 10 μg/m³ increase of PM_2.5 concentrations, the ER (95%CI) of emergency visits was 0.50% (0.10%, 0.90%), 0.34% (-0.02%, 0.69%), 0.36% (0.02%, 0.69%) and 0.56% (0.10%, 1.03%), respectively and the ER (95% CI) of outpatient visits was 0.65% (0.08%, 1.21%), 0.29% (-0.17%, 0.75%), 0.48% (-0.06%, 1.03%) and 0.48%(-0.02%, 0.99%), respectively. Conclusion Our results suggested that PM_2.5 exposure can increase emergency and outpatient visits of 5 hospitals in Beijing, Shanghai and Guangzhou.

Objective: To evaluate the value of ultrasound-guided fine needle aspiration(US-FNA) combined with detection of BRAF V600E and thyroid imaging reporting and data system(TI-RADS) in diagnosis of benign and malignant thyroid nodules. Methods: In this study, 123 operative thyroid nodules from 114 patients who underwent US-FNA and detection of BRAF V600E were enrolled. TI-RADS was apply for the classification of each nodule before surgery. Specimens from each nodule were subjected for hematoxylin and eosin (HE) staining and cytological diagnosis and detection of BRAF V600E mutation. Results: ①BRAF V600E mutation was found in 71 (71/123) nodules with histologic confirmation of papillary-thyroid carcinoma, 58 of which were cytologically diagnosed as carcinoma and 13 were indeterminate. Compared with the postoperative pathological results, US-FNA combined with BRAF V600E could improve the sensitivity and accuracy of diagnosis to thyroid nodules compared with individual US-FNA, and the difference was statistically significant(P<0.001). ②The mutation rate of BRAF V600E was associated with thyroid capsular invasion(χ²=8.44, P=0.004), and combined with TI-RADS could indicate the high-risk of this invasion. ③Among 123 operative nodules, 18 nodules were BRAF V600E negative and cytologically diagnosed as indetermination, 10 of which were TI-RADS 3b or above. After thyroidectomy, 6 nodules were confirmed as papillary-thyroid carcinoma, 1 nodule was thyroid follicular carcinoma, and 3 nodules were benign ones. Conclusions US-FNA combined with detection of BRAF V600E and TI-RADS can improve the diagnostic accuracy and decrease the misdiagnosis in indeterminate nodules.

Objective: To explore the role of MRI in the pre-operative diagnosis and classification of oblique vaginal septum syndrome (OVSS) . Methods: A retrospective analysis of the clinical records and pre-operative MRI images of 19 patients with surgery proved OVSS was carried out. Two experienced radiologists reviewed the pre-operative pelvic MRI of the 19 patients in consensus blind to the surgery results. Characteristics including malformations of the uterus, cervix and vagina, the diagnosis of the disorder and classification were evaluated. Pre-operative MRI diagnosis and classification were correlated with surgical findings. Results: Mean age of onset of symptoms for the 19 patients was 15 years (ranged 9-25 years) , and mean age of menarche was 12 years. Ten patients suffered from dysmenorrhea or lower abdominal pain, 5 patients complained of vaginal discharge, 3 patients had a history of irregular menstruation, 1 patient suffered from primary infertility. All 19 patients showed uteri didelphys. Eighteen patients showed vaginal oblique septum.One patient showed cervical atresia.MRI was completely correlated with the surgery in the pre-operative diagnosis of OVSS. MRI classification was in line with surgery in 17 patients, including 9 patients with imperforate septum (typeⅠ) , 6 patients with perforate septum (type Ⅱ) , 1 patient with imperforate septum and cervical fistula (type Ⅲ) , and another one with cervical agenesis (type Ⅳ) . One case of type Ⅱ was misdiagnosed as type Ⅰ, another one of type Ⅰ was misdiagnosed as type Ⅲ. Pre-operative MRI classification was correlated with surgery in 17 out of 19 patients. Conclusion Pre-operative MRI allows excellent manifestation and accurate diagnosis of OVSS, and could also facilitate the evaluation of the classification.