Pancreatic ductal adenocarcinoma and chronic mass-forming pancreatitis: Differentiation with dual-energy MDCT in spectral imaging mode.
OBJECTIVE
To investigate the value of dual-energy MDCT in spectral imaging in the differential diagnosis of chronic mass-forming chronic pancreatitis (CMFP) and pancreatic ductal adenocarcinoma (PDAC) during the arterial phase (AP) and the pancreatic parenchymal phase (PP).


METHODS
Thirty five consecutive patients with CMFP (n=15) or PDAC (n=20) underwent dual-energy MDCT in spectral imaging during AP and PP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PP, contrast-to-noise ratio (CNR) and the slope K of the spectrum curve were calculated.


RESULTS
Normalized iodine concentrations (NICs) in patients with CMFP differed significantly from those in patients with PDAC during two double phases (mean NIC, 0.26±0.04 mg/mL vs. 0.53±0.02 mg/mL, p=0.0001; 0.07±0.02 mg/mL vs. 0.28±0.04 mg/mL, p=0.0002, respectively). There were significant differences in the value of the slope K of the spectrum curve in two groups during AP and PP (K(CMFP)=3.27±0.70 vs. K(PDAC)=1.35±0.41, P=0.001, and K(CMFP)=3.70±0.17 vs. K(PDAC)=2.16±0.70, p=0.003, respectively). CNRs at low energy levels (40-70 keV) were higher than those at high energy levels (80-40 keV).


CONCLUSIONS
Individual patient CNR-optimized energy level images and the NIC can be used to improve the sensitivity and the specificity for differentiating CMFP from PDAC by use of dual-energy MDCT in spectral imaging with fast tube voltage switching.
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China; Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No.197, Ruijin 2nd Road, Shanghai 200025, China. Electronic address: yinqihuaphd@163.com.
Qihua
Q
Yin
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China. Electronic address: Zouxinnong@126.com.
Xinnong
X
Zou
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China. Electronic address: xdzhai3456@sina.com.
Xiaodong
X
Zai
Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No.197, Ruijin 2nd Road, Shanghai 200025, China. Electronic address: wzy11549@rjh.com.cn.
Zhiyuan
Z
Wu
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China. Electronic address: qingyangwumd@163.com.
Qingyang
Q
Wu
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China. Electronic address: zoezoejiang@163.com.
Xingyu
X
Jiang
Department of Radiology, Wuxi People's Hospital, Nanjing Medical University, No. 299, Qingyang Road, Wuxi 214023, Jiangsu Province, China. Electronic address: chw6312@163.com.
Hongwei
H
Chen
Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No.197, Ruijin 2nd Road, Shanghai 200025, China. Electronic address: mf11066@rjh.com.cn.
Fei
F
Miao
D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007455:Iodine; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging*; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media; D007455:Iodine
Chronic mass-forming chronic pancreatitis; Dual-energy MDCT in spectral imaging; Iodine concentration; Material decomposition; Pancreatic ductal adenocarcinoma