ABSTRACT
Objective:To evaluate the efficacy of T 2* mapping and zoomed imaging with parallel transmission technique (ZOOMit) intravoxel incoherent motion (IVIM) DWI in differentiating benign and malignant thyroid nodules. Methods:The data of 67 patients with thyroid nodules confirmed by surgery and pathology in Ma′anshan People′s Hospital from July 2019 to March 2020 were retrospectively collected. There were a total of 80 nodules, of which 39 were benign nodules and 41 were malignant nodules. All patients underwent MRI including T 2WI, T 2* mapping, and ZOOMit IVIM sequence scans before surgery to measure the T 2*, D, D *, and f values of the nodules. The comparison of the parameters between benign and malignant nodules was evaluated by independent sample t test or Wilcoxon rank sum test. A combined parameter model was established through two-class logistic regression and the predicted probability value was calculated. The ROC curve was used to evaluate the diagnostic efficacy of each parameter and the combined parameter model in differentiating between benign and malignant thyroid nodules. Results:The T 2*, D, f values of benign thyroid nodule group were higher than that in malignant group, and the difference was statistically significant ( P<0.05). The difference of D * value between two groups was not statistically significant ( Z=1.258, P= 0.215). The area under ROC curve (AUC) of T 2*, D, and f values for identifying benign and malignant nodules was 0.703, 0.892, and 0.743, the diagnostic sensitivity was 80.2%, 84.1%, and 80.0%, and the specificity was 65.6%, 81.3%, and 75.0%, respectively. The AUC of T 2*combined with D, T 2*with D * and T 2* with f was 0.925, 0.709, and 0.743, the diagnostic sensitivity was 96.2%, 80.4%, and 80.0%, and the specificity was 81.2%, 65.6%, and 75.0%, respectively. Conclusion:D, f and T 2* derived from ZOOMit IVIM have good value in differentiating between benign and malignant thyroid nodules, and the combination of T 2* and D parameters has the higher diagnostic efficacy.
ABSTRACT
Acetylcholinesterase (AChE) plays a key role in the pesticide determination. However, the extraction of AChE from natural materials has the disadvantages of low yield, complex purification and poor stability. Therefore, the preparation of recombinant AChE with high performance becomes the hot topic of researchers in recent years. In this article we summarize the progress in the expression of recombinant AChE and the improvement of its analytical characteristic. Finally, we point out that the directed evolution strategy combined with surface display technology is the future trend on improving recombinant AChE activity.