title: Cerebral CT perfusion using an interventional C-arm imaging system: cerebral blood flow measurements.
abstract: OBJECTIVE
  CTP imaging in the interventional suite could reduce delays to the start of image-guided interventions and help determine the treatment progress and end point. However, C-arms rotate slower than clinical CT scanners, making CTP challenging. We developed a cerebral CTP protocol for C-arm CBCT and evaluated it in an animal study.
  
  
  METHODS
  Five anesthetized swine were imaged by using C-arm CBCT and conventional CT. The C-arm rotates in 4.3 seconds plus a 1.25-second turnaround, compared with 0.5 seconds for clinical CT. Each C-arm scan had 6 continuous bidirectional sweeps. Multiple scans each with a different delay to the start of an aortic arch iodinated contrast injection and a novel image reconstruction algorithm were used to increase temporal resolution. Three different scan sets (consisting of 6, 3, or 2 scans) and 3 injection protocols (3-mL/s 100%, 3-mL/s 67%, and 6-mL/s 50% contrast concentration) were studied. CBF maps for each scan set and injection were generated. The concordance and Pearson correlation coefficients (ρ and r) were calculated to determine the injection providing the best match between the following: the left and right hemispheres, and CT and C-arm CBCT.
  
  
  RESULTS
  The highest ρ and r values (both 0.92) for the left and right hemispheres were obtained by using the 6-mL 50% iodinated contrast concentration injection. The same injection gave the best match for CT and C-arm CBCT for the 6-scan set (ρ = 0.77, r = 0.89). Some of the 3-scan and 2-scan protocols provided matches similar to those in CT.
  
  
  CONCLUSIONS
  This study demonstrated that C-arm CBCT can produce CBF maps that correlate well with those from CTP.
authors.affiliation: Department of Radiology, Stanford University, California 94305-5488, USA. aganguly@stanford.edu
authors.forename: A
authors.initials: A
authors.lastname: Ganguly
authors.forename: A
authors.initials: A
authors.lastname: Fieselmann
authors.forename: M
authors.initials: M
authors.lastname: Marks
authors.forename: J
authors.initials: J
authors.lastname: Rosenberg
authors.forename: J
authors.initials: J
authors.lastname: Boese
authors.forename: Y
authors.initials: Y
authors.lastname: Deuerling-Zheng
authors.forename: M
authors.initials: M
authors.lastname: Straka
authors.forename: G
authors.initials: G
authors.lastname: Zaharchuk
authors.forename: R
authors.initials: R
authors.lastname: Bammer
authors.forename: R
authors.initials: R
authors.lastname: Fahrig
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D005260:Female; D012039:Regional Blood Flow; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*