Objective To investigate the correlativity between elasticity modulus and pathological severity in chronic pancreatitis (CP).Methods Twenty-one pigs were divided randomly into experimental group (n=18) and control group (n=3) using random number method.The main pancreatic duct (MPD) was incompletely ligated to establish the CP model.In control group, MPD was not ligated.The animals were killed in batches at 4th, 8th and 12th week after surgery.The pancreatic tissue was taken for elasticity modulus test and pathological examination, and the pigs were classified into control, mild, moderate and severe groups based on the severity of fibrosis.Cell density, fat infiltration and extracellular edema were observed and classified into mild and severe.The difference of elasticity modulus among different groups were compared by Variance analysis, the correlation between pancreatic fibrosis and elastic modulus was analyzed with Spearman correlation analysis, and ROC curve was used to evaluate its efficacy of diagnosing CP.Results Sixteen CP models were established successfully expected for 2 deaths (mild, n=7;moderate, n=2 and severe, n=7).All of the control group (n=3) showed normal pancreas.The elasticity modulus of control, mild and moderate to severe group were 0.4268±0.0566, 0.3203±0.0518 and 0.2235±0.0685, respectively.The difference between the groups was statistically significant (F=13.658,P<0.01), and the elastic modulus and pathological grade had a negative correlation (r=0.969, P<0.01).AUC of elasticity modulus for differentiating normal and mild CP was 1.000, the best critical value was 0.3807, and both the sensitivity and specificity of the diagnosis were 100%.AUC for differentiating mild and moderate to severe CP was 0.8730, the best critical value was 0.2646, and the sensitivity and specificity of the diagnosis were 85.7% and 77.8%, respectively.The pancreatic elasticity modulus of low parenchymal cell density group and high parenchymal cell density group were 0.1931±0.0373 and 0.3485±0.0655, respectively, which in the high cell density group was significantly higher than that in the low cell density group (t=-5.719, P<0.01).The elasticity modulus of negative infiltration or slight fatty infiltration group and severe fatty infiltration group were 0.3401±0.0697 and 0.1855±0.0344, respectively, which in the negative infiltration or slight infiltration group was significantly higher than that in severe infiltration group (t=5.102, P<0.01).The elasticity modulus of negative or mild cell edema group and moderate to severe cell edema group were 0.2760±0.0825 and 0.3024±0.1056, respectively;there was no statistically significant(t=-0.586, P >0.05).Conclusions The elasticity modulus can be used to detect the pathological changes of CP, and evaluate the CP pathologic grades.

Objective To investigate the correlativity between secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP) findings and pathological severity in a swine chronic
pancreatitis (CP) model. Methods Thirty-nine swine were divided randomly into control group (n=12) and experimental group (n= 27). In experimental group, the main pancreatic duct (MPD) was incompletely ligated to establish the model of obstructive CP. In control group, laparotomy was performed but without ligating the MPD. At the 4th, 8th and 12th week after modeling, one third swine of each group were undergone a series of dynamic sMRCP scans before (0 min) and at 1, 3, 5, 7, 9, 11 min after administration of secretin (0.6 μg/kg). And the MPD diameter and duodenum filling (DF) degree were measured. All survivals were sacrificed to pathological examination including HE and Van Gieson staining for histopathological grading. According to pathological severity, swine were divided into normal group, mild CP group and moderate to severe CP group. MRI features and indexes, including baselined diameter (BD), end diameter (ED), maximum diameter (MD), the largest expansion rate (LER), time to peak (Tpeak) and end change rate of pancreatic duct and duodenal filling (DF) scores were measured. The relationships between pathological grading and sMPCP indexes were analysed. The comparison of sMRCP data among the 3 groups were used ariance analysis, χ2 test and U test. Correlations between sMPCP indexes and pathological severity were tested using Spearman rank correlation coefficients. The diagnostic efficiency of sMRCP indexes were evaluated by ROC method. Results (1) In experimental group, 22 CP models were established and 19 CP swine (mild CP, n= 8; moderate and severe CP, n=11) were performed sMRCP successfully. Eleven swine in normal group were obtained satisfactory MRCP images. (2) sMRCP results:BD of 3 groups were (1.56 ± 0.46),(2.95 ± 1.17),(7.41 ± 1.91) mm, respectively. ED were (1.49 ± 0.31),(2.96 ± 1.17) and (7.37±1.90) mm, respectively. MD were (2.39±0.43),(3.91±1.27) and (7.86±1.87)mm, respectively. The median of LER were 42.10%, 34.85% and 6.58%, respectively. The median of DF scores were 3, 3, 2, respectively. The differences of above indexes have statistically significance (P values were all<0.01). There were correlation between sMRCP indexes (BD, ED, MD, LER and DFscores) and pathological severity (r values were 0.89, 0.92, 0.90,-0.85,-0.66, respectively and P values were all<0.01). Tpeak and end change rate of pancreatic duct had no significant differences (P values were>0.05),and no correlation with pathological severity(P values were all>0.05).For differential diagnosis between normal and mild CP, the area under ROC of BD, ED, MD, LER and DFscores were 0.915, 0.977, 0.926, 0.778 and 0.472, respectively and differential diagnosis between mild CP and moderate to severe CP group, the area under ROC were 0.966,0.966,0.960,1.000 and 0.915, respectively. Conclusions sMRCP findings of CP have characteristics and could be used for in vivo evaluation on the CP pathologic grades.

Objective To evaluate 99mTc-ciprofloxacin (Infecton) scintigraphy as a method for detecting secondary infections associated with ANP in swine,in comparison with CT.MethodsTwenty-eight healthy swine were randomly assigned to control group (n =6),non-infected ANP (n =6) and infected ANP group( n =16).ANP model was induced by retrograde injection of sodium taurocholate and pancreatic protease mixture into the biliary and pancreatic duct.Two days after ANP induction,swine in infected ANP group were injected with 3 x 108 E.coli into pancreatic tissue,while swine in non-infected ANP group were injected with inactivated E.coli.At 7 d after inoculation,at 0.5,1,2,3,4,and 6 h after intravenous administration of 370 MBq of Infecton,SPECT scan was performed.Then 64-slice spiral CT scan was performed.Then swine were sacrificed,and histopathology examination and bacterial culture of pancreatic tissue were performed.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of the two methods to detect secondary infections were determined.ResultsThere were no abnormality in the normal pancreas and the bacterial culture was negative.There were pancreatic necrosis in the non-infected ANP group,but the bacterial culture was negative.There were pancreatic necrosis and infection in the infected ANP group and the bacterial culture was positive.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of the Infecton method were 93.8％ ( 15/16 ),91.7％ ( 11/12 ),92.9％ ( 26/28 ),93.8 ％(15/16) and 91.7％ ( 11/12),whereas these values for CT were 12.5％ (2/16),100.0％ ( 12/12),50.0％(14/28),100.0％ (2/2) and 46.2％ (12/26),respectively.The sensitivity,accuracy,and negative predictive value of the Infecton method were significantly higher than those in CT group (P ＜0.01 ).ConclusionsInfecton scintigraphy may be a better procedure for detecting ANP secondary infections than CT.

Objective:To explore the predictive value of 18F-FDG PET/CT metabolic parameters combined with inflammatory markers for the medium-term efficacy of chemotherapy in patients with primary gastrointestinal diffuse large B cell lymphoma (PGI-DLBCL). Methods:From April 2011 to May 2020, 67 patients (37 males, 30 females, age: 28-85 years) with PGI-DLBCL examined by 18F-FDG PET/CT before chemotherapy in Changhai Hospital, Navy Medical University were retrospectively analyzed. All patients were treated with cyclophosphamide+ doxorubicin+ vincristine+ prednisone (CHOP) or rituximab+ CHOP (R-CHOP) regimens, and the medium-term efficacy was evaluated after 2-4 cycles of chemotherapy. The effect outcome was divided into complete remission (CR) group and non-CR (NCR) group based on the Lugano lymphoma response evaluation criteria. Mann-Whitney U test was used to compare the differences of SUV max, peak of SUV (SUV peak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio (NLR) between two groups. The independent risk factors of NCR were analyzed by multivariate logistic regression and the binary logistic regression model was established according to the results. The model was tested with external validation data ( n=15). Results:Of 67 PGI-DLBCL patients, 28(41.8%) were CR and 39(58.2%) were NCR. SUV peak, MTV, TLG, PLR and NLR in NCR group (17.3(12.3, 28.1), 73.8(42.9, 141.7) cm 3, 887.5(300.9, 2 075.3) g, 203.9(155.7, 297.1), 3.9(3.0, 4.9)) were significantly higher than those in CR group (9.5(6.2, 15.2), 11.3(4.7, 23.2) cm 3, 85.2(35.5, 214.6) g, 149.3(102.8, 173.1), 2.2(1.8, 4.6); z values: from -6.41 to -2.33, all P<0.05). The logistic regression model was as follows: P=1/(1+ e - x), x=0.100×MTV+ 0.024×PLR-8.064. The prediction accuracy for NCR risk was 86.57%(58/67), with the accuracy of 13/15 tested by external validation data. Conclusion:MTV combined with PLR has a good predictive value for medium-term efficacy of CHOP/R-CHOP chemotherapy in patients with PGI-DLBCL.

Objective:To optimize the preparation conditions and methods of Al 18F-prostate specific membrane antigen (PSMA)-11 and evaluate the feasibility of clinical transformation. Methods:PSMA- N, N′-bis(2-hydroxy-5-(carboxyethy)benzyl)ethylenediamine- N, N′-diacetic acid (HBED-CC) dissolved in CH 3COONH 4 buffer (pH=4.8) was reacted with AlCl 3·3H 2O dissolved in pure water at a molar ratio of 1∶1 (60 ℃, 10 min), and then purified by tC18 column and freeze-dried to obtain [Al]-PSMA-11. [Al]-PSMA-11 was labeled by 18F - and the effects of reaction temperature and pH value on the labeling rate were investigated. The labeled products were purified by tC18 column and filtered through sterile filter to obtain Al 18F-PSMA-11. The comparison of biodistribution between Al 18F-PSMA-11 and 68Ga-PSMA-11 was analyzed on 5 healthy volunteers (age (56±8) years). The differences of SUV max between two groups were analyzed by independent-sample t test. Besides, the early and delayed imaging of Al 18F-PSMA-11 PET/CT were performed on a patient (70 years old) with recurrent prostate cancer for assessment of its potential for prostate cancer recurrence monitoring. Results:The labeling rate was (42.3±3.2)% reacting in aqueous phase (60 ℃, pH=4.8) for 15 min. After being purified with tC18 cartridge, the radiochemical purity of the product was still more than 95% after placement at room temperature for 3 h. Preliminary application demonstrated that there was no significant difference in the biodistribution of Al 18F-PSMA-11 and 68Ga-PSMA-11 among lacrimal gland, parotid gland, submandibular gland, liver, spleen, kidney, bladder and part of intestine and SUV max of targeted organs were also not different ( t values: 0.19-1.95, all P>0.05) between two groups. Multiple bone metastases were observed by Al 18F-PSMA-11 PET/CT delayed imaging (3 h) in a patient with recurrent prostate cancer. Conclusion:Al 18F-PSMA-11 produced with pre-conjugated [Al]-PSMA-11 meets the requirement of the PET imaging application, and it has good potential of localization and imaging for prostate cancer metastatic lesions.