Quantitative analysis of diffusion-weighted magnetic resonance imaging of the pancreas: usefulness in characterizing solid pancreatic masses.
OBJECTIVE
To evaluate whether measurement of apparent diffusion coefficient (ADC) and pure diffusion coefficient (D) can help to characterize solid pancreatic masses.


METHODS
Diffusion-weighted MR imaging was performed in both a patient group (n = 71; pancreatic cancer [n = 47], mass-forming pancreatitis [n = 13], solid pseudopapillary neoplasm [n = 6], and neuroendocrine tumor [n = 5]) and a normal control group (n = 11) by applying three b-factors of 0, 500, and 1000 sec/mm(2). ADC(500), ADC(1000), D (ADC using b = 500 and 1000 sec/mm(2)), and perfusion fraction (f, 1- exp [-500 sec/mm(2) x (ADC(500) - D)]) of normal pancreas, pancreatic cancer, and mass-forming pancreatitis were compared using the Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance and optimal cutoff value of these parameters in differentiating pancreatic cancer from mass-forming pancreatitis.


RESULTS
Normal pancreas had significantly higher mean ADC(500), ADC(1000), and f than either pancreatic cancer (P < 0.001, < 0.001, and 0.004, respectively) or mass-forming pancreatitis (P < 0.001, < 0.001, and 0.002, respectively). ADC(500), ADC(1000), and D of mass-forming pancreatitis were significantly lower than those of pancreatic cancer (P = 0.002, 0.004, and 0.014, respectively). Sensitivities and specificities in the diagnosis of pancreatic cancer were 72.3% and 76.9% for ADC(500), 87.2% and 69.2% for ADC(1000), 87.2% and 61.5% for D, and 42.6% and 92.3% for f, respectively.


CONCLUSIONS
Measurement of ADC and D may be helpful in differentiating pancreatic cancers from mass-forming pancreatitis.
Lee
Seung Soo
SS
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Byun
Jae Ho
JH
Park
Beom Jin
BJ
Park
Seong Ho
SH
Kim
Namkug
N
Park
Bumwoo
B
Kim
Jeong Kon
JK
Lee
Moon-Gyu
MG
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010195:Pancreatitis / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve