title: The Utility of Dual-Energy Computed Tomographic Angiography for the Evaluation of Brain Aneurysms After Surgical Clipping: A Prospective Study.
abstract: OBJECTIVE
  The purpose of this prospective study was to compare a novel dual-energy computed tomographic angiography (DECTA) method for postoperative assessment of clipped brain aneurysms to detect aneurysm remnants and parent artery patency, with catheter-based digital subtraction angiography (DSA).
  
  
  METHODS
  Patients who underwent microsurgical cerebral aneurysm repair were prospectively evaluated after surgery by both DECTA and conventional DSA. CTA was performed using a novel dual-energy method with single source and fast kilovoltage switching (Gemstone Spectral Imaging [GSI]). DSA was performed using biplanar cerebral angiography. An experienced neuroradiologist and a neurosurgeon, both blinded to the original radiologic results, reviewed the images.
  
  
  RESULTS
  On DSA, 8 of 15 aneurysms (53%) had a remnant after clipping. All of these remnants were <2 mm except for 1. The only residual aneurysm >2 mm was clearly detected by GSI CTA. Of those 7 DSA-confirmed <2-mm remnants, 5 were detected by GSI CTA. Metal artifacts compromised the image quality in 2 patients. The sensitivity and specificity of GSI CTA for remnant aneurysm <2-mm detection in single clip-treated patients were 100%. In all patients, these were 71.4 % and 100%, respectively. GSI CTA was 100% sensitive and 77% specific to detect parent vessel compromise, with associated positive and negative predictive values of 60% and 100%, respectively.
  
  
  CONCLUSIONS
  DECTA is a promising noninvasive alternative to conventional catheter-based angiography for identification of aneurysm remnants and assessment of adjacent arteries after surgical clipping of brain aneurysms treated by 2 or fewer clips. It allows for a more rapid image acquisition than DSA, is more cost effective, and is widely available at clinical centers.
authors.affiliation: Department of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: pdolati@bidmc.harvard.edu.
authors.forename: Parviz
authors.initials: P
authors.lastname: Dolati
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eichberg
authors.affiliation: Department of Neurosurgery, University of Calgary, Calgary, Alberta, Canada.
authors.forename: John H
authors.initials: JH
authors.lastname: Wong
authors.affiliation: Department of Neurosurgery, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Mayank
authors.initials: M
authors.lastname: Goyal
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction / Q000191:economics / Q000379:methods; D016477:Artifacts; D002533:Cerebral Angiography / Q000191:economics / Q000379:methods*; D002536:Cerebral Arteries / Q000473:pathology / Q000601:surgery; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000191:economics / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000191:economics / Q000379:methods*; D011446:Prospective Studies; D015900:Radiography, Dual-Energy Scanned Projection / Q000191:economics / Q000379:methods*; D012015:Reference Standards
keywords: Aneurysm clipping; Computed tomographic angiography (CTA); Digital subtraction angiography (DSA); Dual energy