title: Automatic bone and plaque removal using dual energy CT for head and neck angiography: feasibility and initial performance evaluation.
abstract: OBJECTIVE
  We sought to evaluate the feasibility and efficiency of dual energy (DE) bone and plaque removal in head and neck CT angiography.
  
  
  METHODS
  20 patients with suspected carotid stenoses received head and neck DE-CTA as part of their pre-interventional workup. Visual grading using multiplanar reformations (MPR), thick slab maximum intensity projections (MIP) and quantitative vessel analysis (QVA) of stenoses was performed prior and after DE bone removal. Results were evaluated for the detection of relevant stenoses (vessel area reduction >70%). Vessel segmentation errors were analyzed.
  
  
  RESULTS
  Segmentation errors occurred in 19% of all vessel segments. Nevertheless, most post-bone removal artifacts could be recognized using the MPR technique for reading. Compared to MPR reading prior to bone removal, sensitivity, specificity, positive and negative predictive values after bone removal were 100%, 98%, 88% and 100% for MPR reading and 100%, 91%, 63% and 100% for exclusive MIP reading, respectively. There was a good agreement between the QVA results prior and post-DE plaque removal (r(2)=0.8858).
  
  
  CONCLUSIONS
  DE bone and plaque removal for head and neck angiography is feasible and offers a rapid and highly sensitive overview over vascular head and neck studies. Due to a slightly limited specificity of the MIP technique due to segmentation errors, possible stenoses should be verified and graded using MPR techniques.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany. Christoph.thomas@med.uni-tuebingen.de
authors.forename: C
authors.initials: C
authors.lastname: Thomas
authors.forename: A
authors.initials: A
authors.lastname: Korn
authors.forename: B
authors.initials: B
authors.lastname: Krauss
authors.forename: D
authors.initials: D
authors.lastname: Ketelsen
authors.forename: I
authors.initials: I
authors.lastname: Tsiflikas
authors.forename: A
authors.initials: A
authors.lastname: Reimann
authors.forename: H
authors.initials: H
authors.lastname: Brodoefel
authors.forename: C D
authors.initials: CD
authors.lastname: Claussen
authors.forename: A F
authors.initials: AF
authors.lastname: Kopp
authors.forename: U
authors.initials: U
authors.lastname: Ernemann
authors.forename: M
authors.initials: M
authors.lastname: Heuschmid
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D016477:Artifacts; D001842:Bone and Bones / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005240:Feasibility Studies; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D007479:Iopamidol / Q000031:analogs & derivatives; D009333:Neck / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014711:Vertebral Artery / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol