Objective By studying the variation of individual urinary iodine concentration due to different ways of urine sample collection to optimize it for standard clinical evaluation.Methods Totally 20 healthy adults were recruited and their urine samples were collected as a random urine sample within 1 day,the 24 hour urine and morning urine samples within 5 successive days,respectively.The coefficient of variation in each group was calculated.Paired t test was used to compare the results of 24 hour urine with the results of random urine and that of morning urine samples,respectively.Results The range of individual coefficient of variation for random urine sample within one day was 12.5％-57.4％,while most of the coefficients of variation were around 30.39％.In contrast,the individual coefficients of variation of morning urine sample and 24 hour urine results within 5 days were 5.4％-26.0％ and 3.4％-16.6％ and most of them were at about 11.74％ and 7.91％.The paired t test showed that the results of random urine sample were significantly different compared with that of 24 hour urine (t =-4.231,P ＜ 0.05).On the other hand,there was also significant difference for the results of morning urine compared with that of 24 hour urine (t =3.884,P ＜ 0.05).Conclusion This study suggests that 24 hour urine is the most appropriate way of sample collection for individualized detection of urinary iodine.

Objective To compare the diagnostic value of shear wave elastography and 18F-FDG PET/CT imaging in diagnosis of thyroid microcarcinoma.Methods Shear wave elastography and 18F-FDG PET/CT data of patients with thyroid nodules confirmed by pathology were analyzed retrospectively.The sensitivity,specificity,accuracy,positive and negative predictive value of the two methods in diagnosis of malignant thyroid micronodules were compared.Results In all of the 48 micronodules,37 were malignant,11 were benign.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of shear wave elastography and 18F-FDG PET/CT were 91.89％ (34/37),81.82％ (9/11),89.58％ (43/48),94.44％ (34/36),75.00％ (9/12) and 29.73％ (11/37),72.73％ (8/11),39.58％ (19/48),78.57％ (11/ 14),23.53％ (8/34),respectively.The sensitivity,accuracy and negative predictive value between the two methods had statistical difference (all P＜0.05),and the specificity and positive predictive value between the two methods had no statistical difference (both P＞0.05).Conclusion Compared to 18F FDG PET/CT imaging,the diagnositic value of shear wave elastography in diagnosis of thyroid microcarcinoma has obvious advantages.

Objective To explore the value of Chinese thyroid imaging reporting and data system(C-TIRADS)combined with intranodular and perinodular stiffness for distinguishing benign and malignant thyroid nodules.Methods Data of routine ultrasound and ultrasonic shear wave elastography(SWE)in 117 patients with thyroid nodules confirmed by fine needle aspiration cytology(FNAC)and/or surgical pathology were retrospectively analyzed.The nodules were classified according to C-TIRADS and SWE parameters of nodules and surrounding 2 mm glands measured with SWE technique,including Young's modulus of thyroid nodules(E)and perinodular glandular(Eshell)(the maximum[Emax/Eshellmax],the mean[Emean/Eshellmean]and the minimum[Emin/Eshellmin]as well as standard deviation[ESD/EshellSD]values).Then receiver operating characteristic(ROC)curve was drawn,and area under the curve(AUC)was calculated to assess the efficacy of C-TIRADS,SWE and the combination for differentiating benign and malignant thyroid nodules.Results Totally 117 thyroid nodules of 117 patients were enrolled,including 50 benign and 67 malignant ones.SWE parameters of malignant thyroid nodules were higher than those of benign ones(all P＜0.001).AUC of C-TIRADS for differentiating benign and malignant thyroid nodules was 0.736,with sensitivity of 79.10％,specificity of 68.00％and accuracy of 74.36％.AUC of Emax,Emean,Emin and ESD was 0.816,0.752,0.664 and 0.705,respectively,of Emax was the highest.AUC of Eshellmax,Eshellmean,Eshellmin and EshellSD was 0.834,0.804,0.693 and 0.697,respectively,of Eshellmax was the highest,which was not statistically difference with that of Emax(Z=1.044,P=0.297).AUC of C-TIRADS+Emax and C-TIRADS+Eshellmax was 0.835 and 0.843,respectively,being not significantly different(Z=0.574,P=0.566)but higher than that of C-TIRADS(AUC=0.736,Z=2.510,2.230,both P＜0.05),with diagnostic specificity and accuracy both higher than those of C-TIRADS(all P＜0.05).Conclusion C-TIRADS combined with intranodular and perinodular stiffness could be used to effectively distinguish benign and malignant thyroid nodules,which might improve diagnostic efficiency of C-TIRDAS.

Objective To investigate the value of ultrasound and contrast-enhanced ultrasound (CEUS) in the differential diagnosis of mass-type autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC). Methods A retrospective analysis was performed for the clinical data, ultrasound findings, and CEUS findings of 11 patients with mass-type AIP who were diagnosed in Tangshan Workers' Hospital from January 2015 to December 2020, and their characteristic manifestations were analyzed and compared with the data of 23 patients with PDCA. The chi-square test was used for comparison of categorical data between two groups. Results For the 11 patients with mass-type AIP, CEUS had a diagnostic accuracy of 63.64%, and all of these patients had hypoechoic single lesions; the patients with clear boundaries, regular morphology, pancreatic duct dilatation or cutoff, and blood flow signal accounted for 54.55%, 63.64%, 18.18%, and 36.36%, respectively, while in the PDCA group, such patients accounted for 30.43%, 34.78%, 78.26%, and 21.74%, respectively, and there was a significant difference in the presence or absence of pancreatic duct dilatation or cutoff between the two groups( χ 2 =11.089, P < 0.05), with no significant differences in the other indices (all P > 0.05). For the 11 patients with mass-type AIP, CEUS showed that 7 patients (63.64%) had hyperenhancement and 4 (36.36%) had iso-enhancement in the arterial phase, and 5 patients (45.45%) had hyperenhancement in the arterial phase and 6 (54.55%) had iso-enhancement in the venous phase; for the 23 patients with PDCA, 22 (95.65%) had hypoenhancement of lesions in both arterial and venous phases, and there were significant differences in the enhancement pattern in arterial and venous phases between the two groups ( χ 2 =30.345 and 30.084, both P < 0.05). Conclusion The enhancement pattern of CEUS and the presence or absence of pancreatic duct dilatation or cutoff have a relatively high value in the differential diagnosis of mass-type AIP and PDCA.

Objective To assess the value of 18 F-FDG PET/CT, contrast-enhanced ultrasound, and their combination in the differential diagnosis of benign and malignant pancreatic lesions. Methods A retrospective analysis was performed on patients with pancreatic lesions who underwent 18 F-FDG PET/CT and contrast-enhanced ultrasound who were admitted to Tangshan Gongren Hospital from January 2015 to December 2020. The imaging results were confirmed by pathology examination to evaluate diagnostic sensitivity, specificity, accuracy, positive and negative predictive value. The t -test was used for comparison of continuous data between two groups, and the chi-square test was used for comparison of categorical data between groups. Results There were 83 malignant lesions and 25 benign lesions in 108 patients. The sensitivity, specificity, accuracy, positive and negative predictive value were 86.75%, 80.00%, 85.19%, 93.51% and 64.52% for 18 F-FDG PET/CT; and 69.88%, 76.00%, 71.30%, 90.63% and 43.18% for contrast-enhanced ultrasound, respectively. The two methods differed significantly in sensitivity and accuracy (all P < 0.05), but not in specificity, negative and positive predictive value (all P > 0.05). When combined with the contrast-enhanced ultrasound, 18 F-FDG PET/CT had an increased sensitivity, specificity, accuracy, positive and negative predictive value of 90.36%, 84.00%, 88.89%, 94.94% and 72.41%, respectively, though this was not statistically significant due to the increased signal of blood supply in the lesions. Conclusion 18 F-FDG PET/CT has a better performance than contrast-enhanced ultrasound in the differential diagnosis of benign and malignant pancreatic lesions, and their combination can improve the diagnostic value.