title: Pancreatic carcinoma coexisting with chronic pancreatitis versus tumor-forming pancreatitis: diagnostic utility of the time-signal intensity curve from dynamic contrast-enhanced MR imaging.
abstract: OBJECTIVE
  To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis.
  
  
  METHODS
  Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n=33), tumor-forming pancreatitis (n=8), and islet cell tumor (n=7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-I, II, III, and IV, respectively, and were then compared to the corresponding histological pancreatic conditions.
  
  
  RESULTS
  Pancreatic carcinomas demonstrated type-III (n=13) or IV (n=20) TIC. Tumor-forming pancreatitis showed type-II (n=5) or III (n=3) TIC. All islet cell tumors revealed type-I. The type-IV TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis.
  
  
  CONCLUSIONS
  Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis.
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. ytajima@net.nagasaki-u.ac.jp
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Tajima
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kuroki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Tsutsumi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Isomoto
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanematsu
mesh_terms: D007516:Adenoma, Islet Cell / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007340:Insulinoma / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000209:etiology* / Q000473:pathology; D012189:Retrospective Studies