PurposeThe restriction of strain ratio (SR) in the diagnosis of thyroid malignant tumor are caused mainly because of disadvantages including low sensitivity, in this research the authors used different calculation methods of strain ratio based on the size of tumors, to explore the clinical application value of them on the differentiation of benign and malignant thyroid nodules.Materials and Methods Data of 336 patients with thyroid nodule (340 nodules) who underwent elasticity imaging and ultrasound-guided fine-needle aspiration were retrospective analyzed, with the pathology combined follow up acted as golden standards, fixed surface area assay and true surface area assay of strain ratio were compared on the differential diagnosis of benign and malignant thyroid nodules with various size.Results Among 340 thyroid nodules, there were 91 small nodules and 249 big nodules. Pathological results showed that 36 of 91 small nodules and 104 of 249 big nodules were malignant, while the others were benign. The true surface area assay was significantly better for the diagnosis of smaller thyroid nodules with longitudinal diameter and transverse diameter<8 mm with higher consistency with pathology (χ2=20.89,P<0.01), and fixed surface area assay is more suitable of thyroid nodules with longitudinal diameter and transverse diameter>8mm (χ2=57.08,P<0.01). The sensitivity, specificity and consistency for the diagnosis of malignant nodules of true surface area assay were 57.10%, 83.00% and 72.30% (Kappa=0.413), which were 73.60%, 85.00% and 72.30% (Kappa=0.590) in the fixed surface area assay, and 85.00%, 85.50% and 85.30% (Kappa=0.699) in the selective usage of two methods according to the tumor size, respectively.Conclusion The sensitivity is highest when using the two methods selectively according to the nodule size, with a better consistence rate with pathological results as well.

ObjectiveTo explore the change of renal cortical perfusion in rabbits by microbubbles-enhanced ultrasound cavitation.MethodsTotally 20 New Zealand rabbits were randomly divided into four groups, 5 rabbits in each group. SonoVue was injected via the ear vein at a dose of 0.1 ml/kg. The renal perfusion imaging 30 s modeling was made. Under the mode of contrast enhancement, the rabbit kidneys irradiated with different mechanical indexs (MI) were 0.6 (MI 0.6 group) , 0.75 (MI 0.75 group) , 1.1 (MI 1.1 group) and 1.3 (MI 1.3 group) for 60 s, 15 min respectively. After the irradiation and conventional ultrasound contrast was made again, the renal perfusion imaging was mad. The time-intensity curves (TIC) were analyzed obtained from the following parameters: the slope rate of ascending curve (A) , the slope rate of descending curve (α) , area under the curve (AUC) , time to peak (TTP) , and derived peak intensity (DPI) . One-way ANOVA and LSD-t were used to analyze all experimental data.ResultsCompared with the MI 0.6 group, the MI 1.1 group and the MI1.3 group, the A, α were less than MI 0.6 group, the AUC, DPI, TTP were greater than MI 0.6 group, and the differences were statistically signiifcant (MI 1.1 groupvs MI 0.6 group:t=3.13, 5.31, 4.25, 4.53, 5.72, allP<0.05; MI 1.3 groupvs MI 0.6 group:t=3.67, 6.23, 4.47, 5.48, 6.86, allP<0.05). Compared with the MI 0.75 group, the MI 1.1 group and the MI 1.3 group, the α were less than MI 0.75 group, the AUC, DPI, TTP were greater than MI 0.75 group, and the differences were statistically signiifcant (MI 1.1 groupvs MI 0.75 group:t=6.02, 4.36, 4.85, 5.83, allP<0.05; MI 1.3 groupvs MI 0.75 group:t=6.19, 4.51, 5.73, 6.97, allP<0.05); the MI 1.1 group and the MI 1.3 group, the A were less than MI 0.75 group, and the difference were not statistically signiifcant. The MI 1.1 group and the MI 1.3 group, the MI 0.6 and the MI 0.75 group, and the difference were not statistically signiifcant.ConclusionsTo the change of hemodynamic of the rabbits renal cortical perfusion in the microbubbles-enhanced ultrasound cavitation contrast agent can be observed. Along with the mechanical index increased renal cortical perfusion flow stasis and the perfusion on of slowed in rabbit, may cause renal damage, the TIC curve displayed further changes.

Objective To explore the value of contrast-enhanced ultrasound(CEUS) in the evaluation of the renal cortical perfusion in rabbits in low temperature conditions.Methods 20 New Zealand rabbits were randomly divided into five groups,4 rabbits in each group:1) with the first group as the control group (under the conditions of room temperature) ; 2)The second group was treated under-15℃--23℃ for 8hours; 3)the third group was treated under-15℃--23℃ for 4 hours; 4)the fourth group was treated under-6℃--14℃ for 8 hours; 5) the fifth group was treated under-6℃--14℃ for 4 hours.SonoVue was injected via the ear vein at a dose of 0.1 ml/kg,the renal perfusion imaging was made,observing the dynamic image of 0-3 min after the injection and analyzing the time-intensity curves(TIC)obtained from the following parameters:the slope rate of ascending curve(A),the slope rate of descending curve(α),area under the curve (AUC),time to peak (TTP),and derived peak intensity(DPI).Results Compared with the control group,the A,α of the second and the fourth group were significantly decreased (P ＜ 0.05),while the AUC was significantly increased (P ＜ 0.05) and the TTP was significantly prolonged(P ＜0.05),for the third and the fifth group,only the A was decreased (P ＜0.05),and the DPI in each group showed no significant difference.Compared with the third and the fourth group,the AUC of the second group was increased and the TTP was prolonged (P ＜0.05).Conclusions Contrast-enhanced ultrasound can reflect the earlier renal cortical hemodynamic changes in rabbits in the low-temperature conditions,and is of great value for the early diagnosis of renal damage caused by low temperature.

Objective To study the application of strain ratio in differentiation of benign and malignant thyroid nodules through analyzing the influencing factors of the elastic strain ratio (SR) of thyroid nodules.Methods There were 468 patients with 476 thyroid nodules in present study, who came from the Nanjing Drum Tower Hospital from January 2012 to February 2014. SR characteristics of thyroid nodules were retrospectively analyzed, and the critical values were found by receiver-operating characteristic (ROC) curve. Then the size, echo, calcification, blood flow and the correlation between SR and pathology were analyzed by Pearson bivariate correlation analysis.Results The ROC curve showed that SR=0.5 was the best threshold value of SR in differential diagnosis of benign and malignant thyroid nodules. The diagnostic sensitivity, specificity, and the area under the curve were 84.8％, 85.9％, and 0.894, respectively. SR was negatively correlated with echo and calcification, while positively correlated with nodule size and blood flow (r=0.158,P=0.001;r=-0.209,P=0.000;r=-0.218,P=0.000;r=0.189,P=0.000;r=-0.519,P=0.000). The pathology of thyroid nodules had no correlation with nodule size and blood flow (r=-0.025,P=0.582;r=-0.070,P=0.126). The pathology was positively correlated with echo and calcification, while negatively correlated with age (r=0.265,P=0.000;r=0.185,P=0.000;r=-0.207,P=0.000;r=-0.519,P=0.000). Conclusion To improve the accuracy of diagnosis, the differential diagnosis of benign and malignant thyroid nodules should be based on two-dimensional ultrasound combined with SR and fine needle aspiration.