The Clinical Value of Apparent Diffusion Coefficient of Readout Segmentation of Long Variable Echo Trains and Correlation With Ki-67 Expression in Distal Rectal Cancer.

OBJECTIVE: The aim of the study is to explore the clinical value of the apparent diffusion coefficient (ADC) derived from the readout segmentation of long variable echo trains (RESOLVE) technique for identifying clinicopathologic features of distal rectal cancer and correlations between ADC and Ki-67 expression. METHODS: The data of 112 patients with a proven pathology of distal rectal cancer who underwent preoperative magnetic resonance imaging were retrospectively analyzed. The mean ADC value was measured using the "full-layer and center" method. Differences in ADC values and Ki-67 expression in different clinical stages, pathological types, and tumor differentiation were compared using analysis of variance. Correlations between ADC value and clinicopathologic features were assessed using Spearman correlation analysis. RESULTS: Interobserver agreement of confidence levels from 2 radiologists was excellent for ADC measurement ( k =  0.85). Patients with a lower clinical stage, well-differentiated adenocarcinomas, and a higher possibility of mucinous adenocarcinoma exhibited a positive correlation with higher ADC values, but these factors were negatively correlated with Ki-67 expression (all P < 0.05). We found that ADC value was negatively correlated with Ki-67 expression ( r = -0.62, P < 0.001). CONCLUSIONS: The ADC value generated by RESOLVE sequences was significantly associated with clinicopathologic features and Ki-67 expression in patients with distal rectal cancer in this study. Thus, the ADC value could be considered a new noninvasive imaging biomarker that could be helpful in predicting the biological properties of distal rectal cancer.

[RAM study on general standard of maximum residue limits for pollution-free traditional Chinese medicine based on Chinese Pharmacopoeia formula].

The excessive pesticide residues and heavy metals in traditional Chinese medicine seriously endanger human health and the sustainable development of Chinese medicine industry. In order to improve the quality of traditional Chinese medicine and establish a general standard for maximum residue limits(MRL) of pesticides in pollution-free traditional Chinese medicine and decoction pieces, and to ensure the safety of clinical medication from its origin, MRLs were calculated based on the formula(MRL=A×W/100M) from Chinese Pharmacopeia, comparing it with the current Chinese and international standards as well as literature review, the RAND/UCLA appropriateness method(RAM) was applied to determine the categories and MRLs of pesticides in pollution-free traditional Chinese medicine and decoction pieces. Two questionnaires were drafted for expert panel and appropriateness analysis was carried out with the 9-point Likert scale to determine the general standard for MRLs of pollution-free traditional Chinese medicine and decoction pieces. The results showed that a total of nine experts from different fields scored the necessity of standard-setting and 206 pesticide residue limits respectively. The appropriateness scores of 206 pesticides were greater than 7, and appropriateness rate was 100%, which signifies that the expert panel has reached consensus. In summary, based on the RAM, the general standard for maximum residue limits of pesticides in pollution-free Chinese medicines and decoction pieces has reached an expert consensus. Comparing with the MRLs of medicinal plants and plant-sourced food from CAC, Europe Union, the United States, South Korea, Japan, Australia, New Zealand and Canada, 206 MRLs from this general standard share 88.8% in common, 4.4% of which is higher and 6.8% lower than those international standards. This has provided a basis for standardizing the use of pesticides in pollution-free traditional Chinese medicine.