title: Benefit of a sharp computed tomography angiography reconstruction kernel for improved characterization of intracranial aneurysms.
abstract: BACKGROUND
  Computed tomography angiography (CTA) is the first-line imaging modality used for cerebral aneurysms because of its speed and sensitivity for detection, although digital subtraction angiography is often required for more detailed aneurysm shape delineation.
  
  
  OBJECTIVE
  To determine whether a sharper CTA reconstruction kernel can better characterize an aneurysm and improve decision-making before intervention.
  
  
  METHODS
  Fifteen patients presenting with aneurysmal subarachnoid hemorrhage underwent 64-row CTA. CTA data were reconstructed using the default H20f smooth kernel and a H60f sharp kernel and compared with contemporaneous catheter 3-dimensional rotational angiography (3DRA). Aneurysm neck, width, and aspect ratio measurements were made using intensity line plots of identical projections on all imaging datasets and compared by matched-pair statistics.
  
  
  RESULTS
  Aneurysm neck measurements from the H20f smooth kernel revealed overestimation compared with both the sharp kernel (greater by 0.64 ± 0.21 mm, P < .01) and 3DRA (greater by 0.68 ± 0.19 mm, P < .01). There was no statistically significant difference between 3DRA and the sharp kernel CTA measurements. Neck measurements correlated well between the H60f kernel and 3DRA but not between the H20f Kernel and 3DRA (R 0.97 vs 0.86).
  
  
  CONCLUSIONS
  H60f sharp CTA kernel reconstruction provides more accurate anatomic characterization of cerebral aneurysms than the H20f smooth kernel at the expense of less visually pleasing reconstructions. Because it does not require additional contrast, radiation, or imaging hardware and is more similar to 3DRA, it may aid in selecting the appropriate treatment strategy before to evaluation by catheter-based angiography.
authors.affiliation: Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center and Tufts University School of Medicine, Boston, Massachusetts.
authors.forename: Brian
authors.initials: B
authors.lastname: Oʼmeara
authors.forename: Jason P
authors.initials: JP
authors.lastname: Rahal
authors.forename: Alexandra
authors.initials: A
authors.lastname: Lauric
authors.forename: Adel M
authors.initials: AM
authors.lastname: Malek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D002533:Cerebral Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012399:Rotation; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*