Original Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 14, 2013; 19(30): 4897-4906
Published online Aug 14, 2013. doi: 10.3748/wjg.v19.i30.4897
Infective severe acute pancreatitis: A comparison of 99mTc-ciprofloxacin scintigraphy and computed tomography
Jian-Hua Wang, Gao-Feng Sun, Jian Zhang, Cheng-Wei Shao, Chang-Jing Zuo, Jun Hao, Jian-Ming Zheng, Xiao-Yuan Feng
Jian-Hua Wang, Department of Radiology, the Affiliated Hospital of Medical School of Ningbo University, Ningbo 315020, Zhejiang Province, China
Gao-Feng Sun, Jian Zhang, Chang-Jing Zuo, Department of Nuclear Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Cheng-Wei Shao, Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Jun Hao, Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Jian-Ming Zheng, Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Xiao-Yuan Feng, Department of Radiology, Huashan Hospital, Fudan University, Shanghai 200040, China
Author contributions: Wang JH and Sun GF contributed equally to this work, performed the experiments, and analyzed the data and drafted the paper; Zhang J and Shao CW analyzed images and revised the paper; Zuo CJ designed the study, analyzed the data and revised the paper; Hao J established the animal models; Zheng JM performed pathologic examinations, analyzed the data and revised the paper; Feng XY designed the study and revised the paper.
Supported by The National Natural Science Foundation of China, No. 81170435 and 30570535; Natural Science Foundation of Zhejiang Province, No. LY13H070008; Medicine and Health Science and Technology Project of Zhejiang Province, 2013KYA182 and 2012KYB176; Natural Science Foundation of Ningbo, 2010A610052; the Dawn Program of the Shanghai Education Committee, 06SG41; the Scientific Research Foundation of the Shanghai Municipal Public Health Bureau, 2007JG0069; and China Postdoctoral Science Foundation, 20100480545
Correspondence to: Chang-Jing Zuo, MD, Department of Nuclear Medicine, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433, China. changjing.zuo@gmail.com
Telephone: +86-21-31162238 Fax: + 86-21-31162238
Received: February 17, 2013
Revised: April 12, 2013
Accepted: May 16, 2013
Published online: August 14, 2013

AIM: To evaluate 99mTc-ciprofloxacin scintigraphy compared with computed tomography (CT) for detecting secondary infections associated with severe acute pancreatitis (SAP) in swine.

METHODS: Six healthy swine were assigned to a normal control group (group A, n = 6). SAP was induced in group B (n = 9) and C (n = 18), followed by inoculation of the resulting pancreatic necroses with inactive Escherichia coli (E. coli) (group B) and active E. coli (group C), respectively. At 7 d after inoculation, a CT scan and a series of analyses using infecton imaging (at 0.5, 1, 2, 3, 4 and 6 h after the administration of 370 MBq of intravenous infecton) were performed. The scintigrams were visually evaluated and semi-quantitatively analyzed using region of interest assignments. The differences in infecton uptake and changes in the lesion-background radioactive count ratios (L/B) in the 3 groups were recorded and compared. After imaging detection, histopathology and bacterial examinations were performed, and infected SAP was regarded as positive. The imaging findings were compared with histopathological and bacteriological results.

RESULTS: In group A, 6 animals survived without infection in the pancreas. In group B, 7/9 swine survived and one suffered from infection. In group C, 15/18 animals survived with infection. Hence, the number of normal, non-infected and infected SAP swine was 6, 6 and 16, respectively. 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 changes in L/B for the infected SAP were significantly different from those of the non-infected and normal swine (P < 0.001). The mean L/B of the infectious foci at 0.5, 1, 2, 3, 4 and 6 h was 1.17 ± 0.10, 1.71 ± 0.30, 2.46 ± 0.45, 3.36 ± 0.33, 2.04 ± 0.37 and 1.1988 ± 0.09, respectively. At 3 h, the radioactive counts (2350.25 ± 602.35 k) and the mean L/B of the infectious foci were significantly higher than that at 0.5 h (P = 0.000), 1 h (P = 0.000), 2 h (P = 0.04), 4 h (P = 0.000) and 6 h (P = 0.000).

CONCLUSION: 99mTc-ciprofloxacin scintigraphy may be an effective procedure for detecting SAP secondary infections with higher sensitivity and accuracy than CT.

Keywords: Pancreatitis, Infection, Radionuclide imaging, Ciprofloxacin, X-ray computed tomography

Core tip: We successfully used a specific inflammatory agent, 99mTc-ciprofloxacin, which non-invasively detected secondary infections in an infective severe acute pancreatitis (SAP) model with higher sensitivity and accuracy than computed tomography. This method may be an effective tool for accurately diagnosing and assessing the severity of secondary infections in human SAP patients in the future. To our knowledge, there have been no previous studies that have compared the differential diagnosis of non-infectious and infectious SAP using 99mTc-ciprofloxacin imaging and histopathological and biological methods.