Objective To explore the clinical value and significance of elastography technique used in the diagnosis of thyroid nodules .Methods The preoperative imaging data of pathologically confirmed 138 patients with thyroid nodules(160 nodules) were retrospectively analyzed .The imaging characteristics of routine preoperative ultra-sound and elastography were compared and the results were compared with the histopathological findings ,thus to eval-uate the clinical value of elastography in the diagnosis of thyroid nodules .Results Of 160 thyroid nodules in 138 pa-tients,129 nodules (80.63%) were histologically confirmed benign ,31 nodules (19.38%) were confirmed malig-nant.According to the elastic graph color grading standards of ultrasound elastography , in 129 benign nodules, 113 nodules (86.82%) were 0~Ⅱ grade,16 nodules(13.18%) wereⅢ~Ⅳ grade.Of 31 malignant nodules,4 nodules (12.90%) were 0~Ⅱgrade,27 nodules (87.10%) wereⅢ~Ⅳgrade.The diagnosis coincidence rate of conventional ultrasound was 66.25%,which was significantly lower than 87.50%of elastosonography (χ2 =20.32, P=0.000).The specificity,sensitivity,positive predictive value and negative predictive value of routine ultrasound were 61.29%,67.44%,87.88%,31.15%,which were significantly lower than those of ultrasound elastography (87.10%,87.60%,96.58%,62.79%)(χ2 =15.04,P=0.000;χ2 =5.39,P=0.022;χ2 =5.92,P=0.019;χ2 =10.24,P=0.001).Conclusion Compared with conventional ultrasound ,ultrasound elastography technique has ob-vious advantages in the differential diagnosis of benign and malignant thyroid nodules ,which has very important clini-cal value and should be popularized and applied in clinical diagnosis .

BACKGROUND:Single photon emission computed tomography (SPECT)measurement is capable of detecting very early cerebral circulatory disorders accurately and assessing the time-window and the possibility of reversible brain function after reperfusion at various post-ischemia time points.OBJECTIVE: To establish the swine model of ischemic stroke, to assess the time-window of reversible ischemia and to evaluate the significance of SPECT cerebral ischemia-perfusion imaging on predicting very early time window.DESIGN: Randomized, controlled and experimental study.SETTING: Neurological department of a municipal hospital.MATERIALS: From January to August 2002, it was completed at the Laboratory Animal Research Center of Qingdao Municipal Hospital. Twelve 4 months old domestic swine (Sus scrofa), males and females and weighing 8-10 kg, were selected and fed with conventional method.INTERVENTIONS: Twelve swine pigs were divided into block group and reperfusion group, 6 in each group. In all the pigs, common carotid artery in one lateral was blocked by a clamp. Animals in block group sacrificed at 2, 4, 5, 6, 8 and 10 hour respectively. In perfusion group, clamps were removed at 2, 4, 5, 6, 8 and 10 hour respectively, and then the animals were killed 24 hours later. Before sacrifice, all the animals underwent SPECT examination, regional cerebral blood flow (rCBF) measurement and CT scan. After sacrifice, 1 mm3 brain tissues were taken from each lobe and were stained by HE staining. Then light microscope and electron microscope were used to study the histological changes.MAIN OUTCOME MEASURES: SPECT and brain CT scan were used to investigate the cytological changes in brain tissues after various length of ischemiaRESULTS: Twelve swine pigs entered the statistical analysis procedure.By using light microscope and electron microscope, it was found that at 5 hour after operation, neurons in operational side were a little swelled, with swelled mitochondria, a mitochondria crests loss and a progressive plasma loss in a few neurons. While in those with clamps removed within 4 hours after turn off, brain tissue structures were mainly restored.CONCLUSION: SPECT is capable of detecting ischemic brain injury immediately. It is proved by histological evidence that a more-than-5-hour ischemia will cause irreversible changes in neurons.

Objective     To explore the correlation between the quantitative and qualitative features of CT images and the invasiveness of pulmonary ground-glass nodules, providing reference value for preoperative planning of patients with ground-glass nodules. Methods    The patients with ground-glass nodules who underwent surgical treatment and were diagnosed with pulmonary adenocarcinoma from September 2020 to July 2022 at the Third Affiliated Hospital of Kunming Medical University were collected. Based on the pathological diagnosis results, they were divided into two groups: a non-invasive adenocarcinoma group with in situ and minimally invasive adenocarcinoma, and an invasive adenocarcinoma group. Imaging features were collected, and a univariate logistic regression analysis was conducted on the clinical and imaging data of the patients. Variables with statistical difference were selected for multivariate logistic regression analysis to establish a predictive model of invasive adenocarcinoma based on independent risk factors. Finally, the sensitivity and specificity were calculated based on the Youden index. Results     A total of 555 patients were collected. The were 310 patients in the non-invasive adenocarcinoma group, including 235 females and 75 males, with a meadian age of 49 (43, 58) years, and 245 patients in the invasive adenocarcinoma group, including 163 females and 82 males, with a meadian age of 53 (46, 61) years. The binary logistic regression analysis showed that the maximum diameter (OR=4.707, 95%CI 2.060 to 10.758), consolidation/tumor ratio (CTR, OR=1.027, 95%CI 1.011 to 1.043), maximum CT value (OR=1.025, 95%CI 1.004 to 1.047), mean CT value (OR=1.035, 95%CI 1.008 to 1.063), spiculation sign (OR=2.055, 95%CI 1.148 to 3.679), and vascular convergence sign (OR=2.508, 95%CI 1.345 to 4.676) were independent risk factors for the occurrence of invasive adenocarcinoma (P<0.05). Based on the independent predictive factors, a predictive model of invasive adenocarcinoma was constructed. The formula for the model prediction was: Logit(P)=–1.293+1.549×maximum diameter of lesion+0.026×CTR+0.025×maximum CT value+0.034×mean CT value+0.72×spiculation sign+0.919×vascular convergence sign. The area under the receiver operating characteristic curve of the model was 0.910 (95%CI 0.885 to 0.934), indicating that the model had good discrimination ability. The calibration curve showed that the predictive model had good calibration, and the decision analysis curve showed that the model had good clinical utility. Conclusion     The predictive model combining quantitative and qualitative features of CT has a good predictive ability for the invasiveness of ground-glass nodules. Its predictive performance is higher than any single indicator.