^99mTc-环丙沙星显像与CT检测急性坏死性胰腺炎继发感染的比较研究

Detection of secondary infections of acute necrotizing pancreatitis： a comparison study of ^99mTc- ciprofloxacin seintigraphy and CT

目的比较新型显像剂^99mTc-环丙沙星显像与CT检测重症胰腺炎继发感染的价值。方法28只健康幼猪按数字表法随机分为正常组（6只）、非感染性急性坏死性胰腺炎（ANP）组（6只）、感染性ANP组（16只）。采用胰管注入牛磺胆酸钠和胰蛋白酶？昆合液的方法制备ANP模型。感染性ANP组于制模后2d向胰腺组织内注射3×10^8个大肠杆菌，非感染性ANP组注射灭活的大肠杆菌。7d后每只幼猪静脉注射370MBq的^99mTc-环丙沙星，给药后0．5、1、2、3、4、6h行SPECT断层显像，0．5h后行64层螺旋CT扫描。检查结束后处死动物，取胰腺组织行病理检查及细菌培养。比较两种影像学方法检测ANP继发感染的敏感性、特异性、准确性、阳性预测值和阴性预测值。结果正常组胰腺未见异常，细菌培养阴性；非感染性ANP组见胰腺坏死，但细菌培养阴性；感染性ANP组见胰腺坏死并感染，感染灶细菌培养均为阳性。^99mTc-环丙沙星显像检测感染的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为93．8％（15／16）、91．7％（11／12）、92．9％（26／28）、93．8％（15／16）和91．7％（11／12）；CT分别为12．5％（2／16）、100．0％（12／12）、50．0％（14／28）、100．0％（2／2）、46．2％（12／26）^99mTe-环丙沙星显像检测感染的敏感性、准确性、阴性预测值均显著高于CT（P值均〈0．05）。结论^99mTc-环丙沙星显像检测ANP继发感染优于64层螺旋CT。

Objective To evaluate ^99mTc-ciprofloxacin （Infecton） scintigraphy as a method for detecting secondary infections associated with ANP in swine, in comparison with CT. Methods Twenty-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 × 10^8 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. Results There 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 ）. Conclusions Infecton scintigraphy may be a better procedure for detecting ANP secondary infections than CT.