title: Monitoring of balloon test occlusion of the internal carotid artery by parametric color coding and perfusion imaging within the angio suite: first results.
abstract: BACKGROUND
  Temporary balloon test occlusion (BTO) might be performed prior to procedures in which occlusion of the internal carotid artery (ICA) might be necessary. We tested the hypothesis that parametric color coding (PCC) of angiographic series (digital subtraction angiography (DSA)) along with the assessment of cerebral blood volume (CBV) in the angiography suite would simplify and enhance the identification of candidates who are most likely to tolerate occlusion.
  
  
  METHODS
  Fifteen patients underwent angiographic series (DSA) and perfusion imaging before and during BTO. Pre- and postocclusion DSA acquisitions were evaluated for venous delay by conventional methods ("eye balling") and by PCC measurements. Comparison of CBV values between the left and right hemisphere in 6 defined regions was performed.
  
  
  RESULTS
  Values of venous delay by eye balling and PCC showed a high correlation (r = 0.87, p < 0.01). Bland-Altman plot indicated slightly lower values (-0.05 s) by the PCC method. One of the 15 patients developed an asymmetrical CBV map with an increase in CBV of more than one standard deviation in 3 of the 6 regions of interest (ROIs). Acquisition of angiographic series and perfusion imaging did not prolong the test occlusion time.
  
  
  CONCLUSIONS
  PCC and CBV mapping are feasible during BTO. The use of PCC seems to simplify the ability to measure changes in venous filling delay. Perfusion imaging may show an increase in CBV in patients reaching the limits of cerebral autoregulation. These patients may be at risk for delayed infarction, even though they seem to tolerate temporary occlusion, and could be unsuitable candidates for permanent ICA occlusion.
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuermberg, Schwabachanlage 6, 91054, Erlangen, Germany, tobias.struffert@uk-erlangen.de.
authors.forename: T
authors.initials: T
authors.lastname: Struffert
authors.forename: Y
authors.initials: Y
authors.lastname: Deuerling-Zheng
authors.forename: T
authors.initials: T
authors.lastname: Engelhorn
authors.forename: S
authors.initials: S
authors.lastname: Kloska
authors.forename: P
authors.initials: P
authors.lastname: Gölitz
authors.forename: A
authors.initials: A
authors.lastname: Bozzato
authors.forename: M
authors.initials: M
authors.lastname: Kapsreiter
authors.forename: C M
authors.initials: CM
authors.lastname: Strother
authors.forename: A
authors.initials: A
authors.lastname: Doerfler
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D021721:Balloon Occlusion / Q000379:methods*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D002533:Cerebral Angiography / Q000379:methods; D003116:Color; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015641:Radiography, Interventional / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity