title: Usefulness of acoustic radiation force impulse elastography in the differential diagnosis of benign and malignant solid pancreatic lesions.
abstract: OBJECTIVE
  The aim of this study was to evaluate the tissue stiffness of solid pancreatic lesions by using acoustic radiation force impulse (ARFI) elastography to differentiate benign from malignant pancreatic lesions.
  
  
  METHODS
  ARFI elastography was performed in 26 patients who had 27 focal solid pancreatic lesions, including 8 benign lesions (mass-forming pancreatitis, 5; autoimmune pancreatitis, 3) and 19 malignant lesions (pancreatic adenocarcinoma, 16; metastasis from colorectal cancer, 2; malignant neuroendocrine tumor, 1). On the elastographic images of virtual touch tissue imaging (VTI), the echogenicity of the mass was categorized on a 5-grade scale. On the elastographic image of virtual touch tissue quantification (VTQ), the shear wave velocities (SWVs) of the lesion and surrounding parenchyma were measured.
  
  
  RESULTS
  On the VTI images, the mean echogenicity score of the malignant lesions (3.7±1.0) was higher than that of the benign lesions (3.1±0.4; P=0.023). On the VTQ images, there were no statistical differences in the mean SWV between the benign (2.4±1.1 m/sec) and malignant (3.3±1.0 m/sec) lesions (P=0.101). However, the mean SWV difference values between the lesion and background parenchyma of the malignant lesions (1.5±0.8 m/sec) were higher than those of the benign lesions (0.4±0.3 m/sec; P=0.011).
  
  
  CONCLUSIONS
  ARFI elastography can determine the relative stiffness between a lesion and the background pancreatic parenchyma using VTI and VTQ, which is helpful in the differentiation between benign and malignant solid pancreatic lesions.
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Min Kyoung
authors.identifier: 0000-0001-6817-2712
authors.initials: MK
authors.lastname: Park
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: JeongHyun
authors.identifier: 0000-0001-6964-5032
authors.initials: J
authors.lastname: Jo
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Heejin
authors.identifier: 0000-0002-2001-953X
authors.initials: H
authors.lastname: Kwon
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Jin Han
authors.identifier: 0000-0002-5929-9399
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Jong Young
authors.identifier: 0000-0001-5215-5387
authors.initials: JY
authors.lastname: Oh
authors.affiliation: Departments of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Myung Hwan
authors.identifier: 0000-0003-3460-2264
authors.initials: MH
authors.lastname: Noh
authors.affiliation: Departments of Radiology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Kyung Jin
authors.identifier: 0000-0001-9447-3033
authors.initials: KJ
authors.lastname: Nam
keywords: Elasticity imaging Techniques; Pancreas; Pancreatic neoplasms; Ultrasonography