title: Quantitative perfusion analysis of transabdominal contrast-enhanced ultrasonography of pancreatic masses and carcinomas.
abstract: OBJECTIVE
  Preoperative differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) and focal masses in patients with chronic pancreatitis (CP) can be challenging. There are fine differences in the vascularization of these lesions; ultrasound contrast agents can aid in their differentiation. We evaluated the value of software-aided quantitative analysis of transabdominal contrast-enhanced ultrasonography for differential diagnosis of PDAC vs focal masses.
  
  
  METHODS
  Sixty patients for whom it was not possible to differentiate between an inflammatory focal lesion of the pancreas and a pancreatic carcinoma underwent contrast-enhanced ultrasonography with a second-generation contrast agent. Time-intensity curves were obtained for all exams in 2 regions of interest within the lesion and within the normal pancreatic tissue. Images were processed using Axius ACQ software; the following parameters were obtained: maximum intensity, arrival time, time-to-peak, and area under the curve. Absolute values and differences between the lesion and the normal tissue were evaluated.
  
  
  RESULTS
  Histology analysis revealed 45 PDACs and 15 inflammatory masses in patients with CP. Time-dependent parameters (arrival time and time to peak) were significantly longer in PDACs compared to focal masses. Although markedly lower than in healthy pancreata, the maximum intensity and area under the curve parameters were not significantly different between PDACs and focal lesions in patients with CP.
  
  
  CONCLUSIONS
  In cases of CP, PDAC and focal masses exhibit different perfusion patterns at a capillary level that can be visualized using the small microbubbles of ultrasound contrast agents. Contrast quantification software supplements a subjective visual assessment with objective criteria to facilitate the differential diagnosis of focal lesions in pancreatic cancer and chronic pancreatitis.
authors.affiliation: Department of General, Thoracic and Vascular Surgery, School of Medicine, Dresden University of Technology, Dresden, Germany. stephan.kersting@uniklinikum-dresden.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Kersting
authors.forename: Ralf
authors.initials: R
authors.lastname: Konopke
authors.forename: Florina
authors.initials: F
authors.lastname: Kersting
authors.forename: Andreas
authors.initials: A
authors.lastname: Volk
authors.forename: Marius
authors.initials: M
authors.lastname: Distler
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bergert
authors.forename: Hans-Detlev
authors.initials: HD
authors.lastname: Saeger
authors.forename: Robert
authors.initials: R
authors.lastname: Grützmann
authors.forename: Alfred
authors.initials: A
authors.lastname: Bunk
mesh_terms: D001783:Blood Flow Velocity; D002196:Capillaries / Q000000981:diagnostic imaging; D021441:Carcinoma, Pancreatic Ductal / Q000098:blood supply / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D003287:Contrast Media; D006104:Granuloma, Plasma Cell / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D045423:Microbubbles; D010179:Pancreas / Q000098:blood supply / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging*; D055420:Perfusion Imaging / Q000379:methods*; D010743:Phospholipids; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D013459:Sulfur Hexafluoride; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride