Objective To evaluate the imaging feature of microcarcinoma of thyroid with CT.Methods CT findings of 50 lesions in 47 patients with microcarcinoma of thyroid ( dimeter,0.5 to 1.0 cm) were retrospectively analyzed.All of the patients had pathological diagnosis.Results Of the 50 lesions,38 lesions showed homogeneous low density on non-enhanced CT and various degree of enhancement on postcontrast CT. Thirty-three lesions showed discontinuous edge of the thyroids on non-enhanced CT. The boundary of 30 lesions became unclear on post-contrast CT relative to non-enhanced CT and the extension of low density of lesions decreased. Theshape of 31 lesions were irregular. Fifteen lesions showed calcifications,with granular calcifications in 13 lesions.Ten lesions were complicated with thyroiditis.Conclusions Irregular shape,discontinuous edge of the thyroids,the shrinkage of low density of lesions on post-contrast CT relative to non-enhanced CT,granular calcifications and multiple small lymph node around lesions indicate the diagnosis of microcarcinoma of the thyroid.It should be noted that thyroiditis can cover up microcarcinoma of thyroid.

Objective To evaluate the value of annular calcification in CT in the diagnosis and differential diagnosis for benign and malignant thyroid nodules.Methods CT findings of 67 nodules in 67 patients pathologically diagnosed with annular calcifications were retrospectively analyzed to identify 49 benign nodules and 18 malignant nodules.The interior or boundaries of annular calcification before and after contrast-enhancement were compared,and the degree of enhancements of both interior annular calcification and thyroid tissues were observed.After contrast-enhancement,the numbers of lesions showing clearer boundaries and higher degree of enhancement were summarized.Statistic analysis was conducted by using x2 test.Results Among 67 nodules with annular calcifications,clearer boundaries after contrast-enhancement were observed in 61.2％ (30/49) benign nodules and 16.7％ (3/18) malignant nodules,showing significant statistical difference (x2 =10.457,P ＜ 0.05).The sensitivity and specificity of clearer edge after contrast-enhancement for benign nodules were 61.2％ (30/49) and 83.3％ (15/18) respectively.Higher degree of enhancement were observed in 16.3％ (8/49) in benign nodules and 0(0/18) malignant nodules,showing no significant statistical difference (x2 =3.337,P ＞ 0.05).The sensitivity and specificity of higher degree of enhancement for benign nodules were 16.3％ (8/49) and 100.0％ (18/18) respectively.The combination of clearer boundaries and higher degree of enhancement after contrast-enhancement was observed in 77.6％ (38/49) benign nodules and 16.7％ (3/18) malignant nodules,showing significant statistical difference (x2 =20.549,P ＜ 0.05).Meanwhile,the sensitivity and specificity of such combination for benign nodules were 77.6％ (38/49) and 83.3％ (15/18) respectively.Conclusions CT is important in the diagnosis of thyroid nodules with annular calcification.Clearer boundary after contrast-enhancement and its combination with higher degree of enhancement are helpful for the diagnosis of benign nodules.Boundaries that similar to or more obscure than that of plain scan indicate malignant nodules.

Objective To assess the value of CT hyperenhancement sign in diagnosis and differential diagnosis of benign and malignant thyroid nodules.Methods CT findings of 2926 nodules in 1676 patients were retrospectively analyzed,among which 2174 nodules were benign and 752 nodules were malignant.All the patients had pathological diagnosis.The degrees of enhancement were divided into hyperenhancement and iso/hypoenhancement.The distribution of hyperenhancement in benign and malignant nodules were summarized.The sensitivity,specificity,positive and negative predictive value and accuracy of hyperenhancement for benign nodules and adenomatoid nodules were observed.Results Hyperenhancement was more common in benign nodules than in malignant nodules (10.3％ vs 0.7％,x2 =70.259,P ＜ 0.05),and its sensitivity,specificity,positive and negative predictive value and accuracy was 9.8％,99.5％,98.2％,27.6％ and 32.8％,respectively.Hyperenhancement was more common in adenomatoid nodules than in nonadenomatoid benign nodules (67.4％ vs 6.1％,x2 =525.025,P ＜ 0.05),and its sensitivity,specificity,positive and negative predictive value and accuracy was 67.4％,93.9％,41.6％,97.8％ and 92.3％,respectively.Conclusion Hyperenhancement sign is an important sign which can effectively differentiate benign nodules from malignant nodules,and adenomatoid nodules from nonadenomatoid benign nodules,and it is helpful for diagnosis of benign nodules and adenomatoid nodules.

Objective To investigate the diagnostic value of CT signs of ipsilateral central lymph node metastasis (ICLNM) in single papillary thyroid carcinoma (PTC) by multivariate regression analysis.Methods The CT data of 302 single PTC with diameter ＞1.0 cm confirmed by operation and pathology were retrospectively analyzed.The optimal thresholds of lymph node metastasis diameter were obtained by receiver operating characteristic (ROC) curve analysis.And multivariate regression analysis was used to analyze the relation between lymph node size,degree of enhancement,calcification or cystic degeneration,central turbidity,positive lateral cervical lymph nodes and the ICLNM positivity.Results In 302 PTC,the proportion of ICLNM positive and negative was 63.6％ (192/302) and 36.4％ (110/302),respectively.According to the ROC curve,with the increase of lymph node diameter,the sensitivity of diagnosing lymph node metastasis decreased and the specificity increased.When the threshold was 0.4 cm,Youden index was the largest (0.358),and the sensitivity and specificity was 50.5％ and 80.3％,respectively.Multivariate analysis showed that the diameter≥0.4 cm,high enhancement,central turbidity and lateral cervical lymph nodes positivity were the independent risk factors of ICLNM,and the OR values were 4.189[95％ CI (2.037-8.617)],3.875 [(95％ CI (1.561-9.617)],4.054[(95％CI (2.230-7.371)] and 8.735 [(95％ CI (1.093-69.831)],respectively.Calcification or cystic degeneration was not statistically significant in ICLNM.Conclusions The diameter ≥0.4 cm,high enhancement,central turbidity and lateral cervical lymph nodes positivity are the independent risk factors of ICLNM.Although calcification or cystic degeneration is not the independent risk factor,it has high accuracy for ICLNM positivity.The accurate identification of these signs can help surgeons to take a more thorough surgical treatment and has great significance to reduce postoperative recurrence.

ObjectiveTo explore the related factors of troublemaking behaviors among patients with mental disorders induced by amphetamine-type stimulants （ATS）， and to provide references for the formulation of relevant intervention measures for ATS-induced mental disorders. MethodsA total of 105 patients who met the diagnostic criteria of International Classification of Diseases， tenth edition （ICD-10） for ATS-induced mental disorders were included， and classified into troublemaking group and non-troublemaking group. The general demographic data and clinical data of the selected individuals were collected， and all patients were assessed using Social Support Rating Scale （SSRS）. Then univariate analysis and multivariate Logistic regression model were used to screen the related factors of troublemaking behaviors. ResultsThe scores of SSRS， objective support dimension and social support utilization dimension were significantly lower in troublemaking group than those in non-troublemaking group， with statistical differences ［（24.10±6.59） vs. （28.94±5.59）， t=3.364， P=0.001； （5.50±1.96） vs. （8.20±2.13）， t=5.183， P<0.01； （4.60±2.26） vs. （6.28±1.90）， t=3.435， P=0.001］. Multivariate Logistic regression analysis showed that male （OR=6.061， P=0.014） was a risk factor， while high social support level （OR=0.873， P=0.018） was the protective factor for troublemaking behaviors among patients with ATS-induced mental disorders. ConclusionPatients with ATS-induced mental disorders of the males and with low social support level are at high risk of troublemaking behaviors.

Objective To elucidate the causal relationship between high-density lipoprotein cholesterol (HDL-C) and colorectal cancer (CRC) through Mendelian randomization. Methods Mendelian randomization analysis was conducted using genetic instrumental variables selected from a genome-wide association study dataset. The main methods included inverse variance weighted, MR-Egger, weighted median, simple mode, and weighted mode method; among which, inverse variance weighted method served as the primary analytical approach. Sensitivity analyses were performed to verify the robustness of results. Results A total of 41 genetic instrumental variables associated with HDL-C were identified. Inverse variance weighted method (OR=0.84, 95%CI: 0.73-0.96, P=0.01) and weighted median method (OR=0.82, 95%CI: 0.67-0.99, P=0.04) indicated a negative correlation between genetically-determined HDL-C and CRC risk. Sensitivity analyses confirmed the absence of heterogeneity and horizontal pleiotropy (P>0.05). Conclusion A causal relationship exists between HDL-C and CRC risk, with rs1077834 as a potential key determinant in the influence of HDL-C on CRC risk.