title: Whole-brain adaptive 70-kVp perfusion imaging with variable and extended sampling improves quality and consistency while reducing dose.
abstract: OBJECTIVE
  Despite common use of CTP to assess cerebral hemodynamics in the setting of ischemia, concerns over radiation exposure remain. Our aim was to evaluate the efficacy of an adaptive 70-kVp (peak) whole-brain CTP protocol with variable sampling intervals and extended duration against an established fixed-sampling, limited-period protocol at 80 kVp.
  
  
  METHODS
  A retrospective analysis of 37 patients with stroke scanned with conventional (n = 17) and variant-protocol (n = 20) whole-brain CTP was performed. We compared radiation dose, parametric map quality, and consistency of full-contrast circulation capture between a modified 70-kVp protocol, with 20 whole-brain passes at variable sampling intervals over an extended sampling period, and a conventional 80-kVp CTP examination with 24 passes at fixed-sampling intervals and a more limited scanning window. Mann-Whitney U test analysis was used to compare both protocols.
  
  
  RESULTS
  The 70-kVp CTP scan provided superior image quality at a 45% lower CT dose index volume and 13% lower dose-length product/effective dose compared with the conventional 80-kVp scan. With respect to the consistency of contrast-passage capture, 95% of the adaptive, extended protocol continued through the venous return to baseline, compared with only 47% by using the conventional limited-length protocol. Rapid sampling during the critical arterial arrival and washout period was accomplished in nearly 95% with both the variable and fixed-sampling-interval protocols.
  
  
  CONCLUSIONS
  Seventy-kilovolt (peak) CTP with variable and extended sampling produces improved image quality at lower radiation doses with greater consistency of full contrast passage capture.
authors.affiliation: From the Department of Neuroradiology, Mount Sinai Medical Center, One Gustave L. Levy Place, New York, New York.
authors.forename: I
authors.initials: I
authors.lastname: Corcuera-Solano
authors.affiliation: From the Department of Neuroradiology, Mount Sinai Medical Center, One Gustave L. Levy Place, New York, New York.
authors.forename: A M
authors.initials: AM
authors.lastname: McLellan
authors.affiliation: From the Department of Neuroradiology, Mount Sinai Medical Center, One Gustave L. Levy Place, New York, New York.
authors.forename: A H
authors.initials: AH
authors.lastname: Doshi
authors.affiliation: From the Department of Neuroradiology, Mount Sinai Medical Center, One Gustave L. Levy Place, New York, New York.
authors.forename: P S
authors.initials: PS
authors.lastname: Pawha
authors.affiliation: From the Department of Neuroradiology, Mount Sinai Medical Center, One Gustave L. Levy Place, New York, New York. nuromri@gmail.com.
authors.forename: L N
authors.initials: LN
authors.lastname: Tanenbaum
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging*