title: Proximal arterial diameters on CT angiography and digital subtraction angiography correlate both at admission and in the vasospasm period after aneurysmal subarachnoid hemorrhage.
abstract: BACKGROUND
  Comparison of artery diameters between CT angiography (CTA) and subtraction arteriography (DSA) has the limitation that measurements on DSA are provided as relative units, making a quantitative comparison difficult. On CTA, artery diameters may depend on windowing settings and may lead to false measurements. This study assesses the correlation between CTA and DSA based on measurements in a basic imaging viewer using normalized DSA values, and assesses whether the validity is time dependent.
  
  
  METHODS
  Patients with aneurysmal subarachnoid hemorrhage (aSAH) were included if they underwent both CTA and DSA within 24 h. The analysis was performed using the basic imaging application Centricity Enterprise PACS viewer (GE Healthcare). A total of 15 arterial locations were assessed on CTA and DSA and a specific measurement protocol with normalization of all artery diameters to the cavernous segment of the internal carotid artery was used. Pearson correlation analysis was calculated to access the correlation of normalized arterial diameters measured with both methods at admission and at clinical onset of CVS.
  
  
  RESULTS
  A total of 627 arteries in 38 patients were analyzed in both CTA and DSA. There was a significant correlation coefficient (R = 0.706) of artery diameters between CTA and DSA measures (p < 0.0001). This correlation remained high when comparing CTA and DSA at admission (correlation coefficient: 0.641; p < 0.0001) vs. in the vasospasm period (0.835; p < 0.0001). The correlation was good in all proximal artery segments and lost significance only when distal vessel segments were considered.
  
  
  CONCLUSIONS
  Using basic imaging viewers, mostly accessible for clinicians, CTA is a noninvasive and reliable method to assess proximal arterial diameters of the brain in the management of cerebral vasospasm in the acute phase after aSAH. Significance is reached, independent of whether CTA is obtained in the acute phase or during the period of vasospasm, by normalization of basal cerebral artery diameters to a non-variable anatomic landmark, i.e., the petrous or cavernous internal carotid artery diameter.
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.
authors.forename: Hassen
authors.initials: H
authors.lastname: Kerkeni
authors.forename: Bawarjan
authors.initials: B
authors.lastname: Schatlo
authors.forename: Hiroki
authors.initials: H
authors.lastname: Dan-Ura
authors.forename: Luca
authors.initials: L
authors.lastname: Remonda
authors.forename: Carl
authors.initials: C
authors.lastname: Muroi
authors.forename: Michael
authors.initials: M
authors.lastname: Diepers
authors.forename: Javier
authors.initials: J
authors.lastname: Fandino
authors.forename: Ali-Reza
authors.initials: AR
authors.lastname: Fathi
mesh_terms: D000328:Adult; D015901:Angiography, Digital Subtraction / Q000379:methods; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging* / Q000209:etiology