Objective To evaluate hepatic enhancement technology with MRI and its clinical application.Methods 147 patients underwent enhanced MRI scanning and an automatic injector.Total dose of contrast agent for each patient was 10 to 15ml(0.2mmol/kg)at a rate of 2ml/s,Two-phase enhancement were performed at a delay of 30 and 70 seconds respectively after the initiation of bolus injection.Results Good visualization of two phases for both hepatic artery and portal vein were achieved in 147 patients in addition to branches of abdominal aorta,hepatic artery,splenic artery,portal vein,inferior vena cava and vasculatures in hepatic port.The 4 patients did not have ideal two-phase images for various reasons.Conclusion MRI with bolus injection using an automatic injector can satisfy the diagnosis for hepatic diseases.

Objective:To explore the potential mechanism of PD-1 inhibitor P on RIMI from the perspective of immune microenvironment.Methods:To establish a mouse model of radiation-induced myocardial injury (RIMI), twenty C57BL/6 mice were randomly divided into 4 groups, 5 in each group. Group A was the healthy control group; Group B was the PD-1 inhibitor group; Group C was the simple irradiation group, with a heart irradiation of 15 Gy; Group D was the irradiation+ PD-1 inhibitor group. One month after irradiation, the mice were anesthetized and sacrificed. The morphological changes of myocardial tissues were observed by HE staining. The myocardial fibrosis was assessed by Masson staining. CD 3+ , CD 3+ CD 4+ , CD 3+ CD 8 lymphocyte subsets and cytokines (IL-4, IL-6, IL-17A, TNF-α, TGF-β 1 and INF-γ) levels were determined by flow cytometry. The apoptosis rate of myocardial cells was detected by TUNE. Results:One month after irradiation, there was no obvious myocardial fibrosis in group B, and collagen fibers were distributed in the interstitium of myocardial cells in groups C and D. Semi-quantitative analysis results showed that the myocardial collagen volume fraction (CVF) of groups A, B, C and D were (1.97±0.36)%, (2.83±1.03)%, (5.39±0.77)% and (7.72±1.43)%, respectively. The CVF between group A and group B was similar ( P=0.314), and the differences in CVF between the other groups were statistically significant (all P<0.05). Compared with group A, the absolute value and percentage of CD 3+ T lymphocytes were significantly increased in groups B, C and D (all P<0.01). The values in group D were significantly higher than those in group B and group C (all P<0.01); The absolute value and percentage of CD 3+ CD4 T lymphocytes were similar among four groups (all P>0.05); The absolute value and percentage of CD 3+ CD 8 T lymphocytes in group D were significantly higher than those in groups A, B and C (all P<0.001). The expression levels of IL-6, IL-17A, and TGF-β 1 in group D were significantly higher compared with those in groups A, B and C (all P<0.001). The apoptotic index was gradually increased in four groups, and the differences in apoptotic index among four groups were statistically significant (all P<0.001). Conclusion:PD-1 inhibitors can aggravate RIMI by promoting myocardial immune inflammatory response.