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Objective To discuss the application of MRI in making early assessment of the coagulation extent of liver tumor after microwave ablation(MWA).Methods From January 1,2015 to January 31,2016,CT-guided percutaneous MWA was employed in 46 patients with liver tumor.A total of 55 hepatic lesions were detected in the 46 patients,the mean diameter of the lesion was (26.0±5.3) mm.On the second day after MWA,MRI was performed to evaluate the ablation effect,the ablated extent (long axis×short axis) was calculated,the results were compared with the referential data provided by manufacturer.The MWA-related complications,including inadequate ablation and excessive ablation,were recorded and analyzed.Results MRI performed on the second day after MWA showed that successful MWA treatment was obtained in all the 55 hepatic lesions,and no serious complications occurred immediately after ablation.The used parameter settings of microwave energy included 60 W-5 min (n=4),60 W-8 min (n=4),60 W-10 min (n=14),70 W-8 min (n=40),70 W-10 min (n=11) and 80 W-10 min (n=18);the corresponding ablated extents produced by the above parameter settings were 41.3 mm×31.2 mm,52.0 mm×36.3 mm,51.5 mm×34.3 mm,52.9 mm×35.5 mm,56.8 mm×36.1 mm and 64.0 min×44.0 mm respectively;all the above actual ablated values were larger than the referential data provided by manufacturer,and among them the real ablated extent of 80 W-10 min group carried the biggest difference with that provided by manufacturer (64.0 mm×44.0 mm vs.54.0 mm×37.0 mm,P＜0.01).No inadequate ablation of lesion was observed,and excessive ablation was seen in 12 lesions,presenting as the involvement of the hepatic capsule or even the subcutaneous muscle layer.Conclusion Early MRI examination after MWA can precisely evaluate the ablation extent.The results of this study indicate that the actual ablated value is bigger than the referential value provided by manufacturer.Accurate prediction of ablation range before MWA is helpful in ensuring a complete ablation as well as in improving the safety of MWA.
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Objective To explore early prognostic value of quantitative detection of paraquat (PQ) plasma concentration and urine sodium dithionite assay for prognosis in patients with acute PQ poisoning. Methods A prospective study was conducted. The patients with acute PQ poisoning admitted to Department of Emergency of First Hospital of China Medical University from August 2013 to December 2015 were enrolled. At admission, blood samples and urine samples were collected. The PQ plasma concentration was determined by high-performance liquid chromatography (HPLC), and the PQ urine concentration was determined by sodium dithionite, meanwhile the biochemical parameters were determined to carry out sequential organ failure assessment (SOFA) score. According to the prognosis of 90-day follow-up, the patients were divided into survival group and death group. Logistic regression analysis was used to analyze the relationship between the prognosis and the indexes, and the receiver operating characteristic curve (ROC) was drawn to evaluate the prognosis. Results There were 148 patients with acute PQ poisoning, with 43 alive and 105 dead, and the 90-day mortality rate was 70.9%. The ingestion volume (mL: 22.69±18.57 vs. 9.91±4.61), plasma concentration of PQ (mg/L: 2.28±1.52 vs. 0.91±0.38) and positive rate of urine sodium dithionite (87.6% vs. 14.0%) in death group were significantly higher than those of survived group (all P 0.05). It was shown by logistic regression analysis that the key factors affecting the prognosis of patients with PQ poisoning were urine sodium dithionite assay [odds ratio (OR) = 8.731, 95% confidence interval (95%CI) = 2.828-26.954, P = 0.000], PQ plasma concentration (OR = 2.082, 95%CI = 1.204-3.603, P = 0.009) and ingestion volume (OR = 1.175, 95%CI = 1.048-1.318, P = 0.006) respectively. It was shown by ROC curve that the area under ROC curve (AUC) of plasma PQ concentration, urine sodium dithionite assay, poisoning dose and SOFA score for predicting the prognosis in patients with acute PQ poisoning was 0.866, 0.857, 0.826, and 0.631 respectively (all P < 0.05). The sensitivity of urine sodium dithionite assay for predicting the prognosis was 87.6%, and the specificity was 83.7%. Conclusions Early plasma PQ concentrations can objectively reflect the body absorbed toxicant doses and actual situation after poisoning, and help to judge the early evaluation of prognosis. The accuracy of urine sodium dithionite assay in judging the prognosis of PQ poisoning is high. Because of its simplicity and availability, it was easier to be performed in the primary hospital.