title: Detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase: effect of a low-tube-voltage, high-tube-current CT technique--preliminary results.
abstract: OBJECTIVE
  To intraindividually compare a low-tube-voltage (80 kVp), high-tube-current (675 mA) computed tomographic (CT) technique with a high-tube-voltage (140 kVp) CT protocol for the detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase.
  
  
  METHODS
  This prospective, single-center, HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained. Twenty-seven patients (nine men, 18 women; mean age, 64 years) with 23 solitary pancreatic tumors underwent dual-energy CT. Two imaging protocols were used: 140 kVp and 385 mA (protocol A) and 80 kVp and 675 mA (protocol B). For both protocols, the following variables were compared during the pancreatic parenchymal phase: contrast enhancement for the aorta, the pancreas, and the portal vein; pancreas-to-tumor contrast-to-noise ratio (CNR); noise; and effective dose. Two blinded, independent readers qualitatively scored the two data sets for tumor detection and image quality. Random-effect analysis of variance tests were used to compare differences between the two protocols.
  
  
  RESULTS
  Compared with protocol A, protocol B yielded significantly higher contrast enhancement for the aorta (508.6 HU vs 221.5 HU, respectively), pancreas (151.2 HU vs 67.0 HU), and portal vein (189.7 HU vs 87.3 HU), along with a greater pancreas-to-tumor CNR (8.1 vs 5.9) (P < .001 for all comparisons). No statistically significant difference in tumor detection was observed between the two protocols. Although standard deviation of image noise increased with protocol B (11.5 HU vs 18.6 HU), this protocol significantly reduced the effective dose (from 18.5 to 5.1 mSv; P < .001).
  
  
  CONCLUSIONS
  A low-tube-voltage, high-tube-current CT technique has the potential to improve the enhancement of the pancreas and peripancreatic vasculature, improve tumor conspicuity, and reduce patient radiation dose during the pancreatic parenchymal phase.
authors.affiliation: Department of Radiology, Duke University Medical Center, Erwin Rd, Durham, NC 27710, USA.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
authors.forename: Rendon C
authors.initials: RC
authors.lastname: Nelson
authors.forename: Huiman
authors.initials: H
authors.lastname: Barnhart
authors.forename: Sebastian T
authors.initials: ST
authors.lastname: Schindera
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Ho
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Jaffe
authors.forename: Terry T
authors.initials: TT
authors.lastname: Yoshizumi
authors.forename: Richard
authors.initials: R
authors.lastname: Youngblood
authors.forename: Ehsan
authors.initials: E
authors.lastname: Samei
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001822:Body Burden; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*