title: Cone beam CT paranasal sinuses versus standard multidetector and low dose multidetector CT studies.
abstract: Cone-beam computed tomography (CBCT) is a promising modality for quick outpatient imaging with lower radiation dose and less metal artifact when compared to conventional CT (MDCT) scans. This article will be providing evidence on the diagnostic and treatment-planning applications of CBCT in sinus imaging, mainly, in patients with chronic sinusitis for surgical planning, which retrospectively assessed 21 patients over a period of one year at Queen Elisabeth Hospital, Birmingham, UK. The main objective was to compare the absorbed dose of radiation from CBCT and conventional CT, and to compare the clarity and image quality for important structures in sinus anatomy in patients with sinus disease meriting CT scan imaging. Results of the mean effective dose of twenty-one consecutive CBCTs of paranasal sinuses were 0.27 mSv (range 0.05-0.48 mSv). This dose was approximately 40% lower when compared to a similar cohort of standard MDCT examinations and 30% lower when compared to low dose sinus CT scans. The visualization of high-contrast bone morphology on CBCT was comparable to standard sinus CT, allowing clear delineation of the principal surgically relevant osseous structures. Soft tissue visibility was however limited. We concluded that, CBCT scan provides a fast and efficient alternative to conventional CT with substantial radiation dose reduction and low dose MDCT techniques. However for more advanced sinus disease, conventional CT scan is preferable.
  
  
  OBJECTIVE
  The main objective was to compare the absorbed dose in the cone beam computed tomography (CBCT) and conventional CT and to compare the clarity and image quality for important structures in sinus anatomy.
  
  
  METHODS
  Retrospective scan review.
  
  
  METHODS
  We compared both the image characteristics and the effective dose used in CBCT and conventional MDCT sinus imaging, performed at Queen Elizabeth Hospital Birmingham over a 1 year period.
  
  
  METHODS
  Patient with sinus disease meriting CT scan imaging.
  
  
  METHODS
  Comparison of effective dose exposure and image quality.
  
  
  RESULTS
  The mean effective dose of twenty one consecutive CBCTs of paranasal sinuses performed in our institution over a one year period was 0.27 mSv (range 0.05-0.48 mSv). The dose was approximately 40% lower when compared to a similar cohort of standard MDCT examinations and 30% lower when compared to low dose sinus CT scans. The visualization of high-contrast bone morphology on CBCT was comparable to standard sinus CT, allowing clear delineation of the principal surgically relevant osseous structures. Soft tissue visibility was however limited.
  
  
  CONCLUSIONS
  Cone beam CT scan is a quick and efficient alternative to conventional CT with substantial radiation dose reduction over conventional and low dose MDCT techniques. However for more advanced sinus disease, conventional CT scan is preferable.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Al Nahdha Hospital, Po Box 1556, PC 114, Jibro, Muscat, Oman. Electronic address: Dr_janan_a@yahoo.com.
authors.forename: Janan
authors.initials: J
authors.lastname: Al Abduwani
authors.affiliation: Department of Radiology, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom. Electronic address: Laura.Zilinkiene@uhb.nhs.uk.
authors.forename: Laura
authors.initials: L
authors.lastname: ZilinSkiene
authors.affiliation: Department of Radiology, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom. Electronic address: Steve.Colley@uhb.nhs.uk.
authors.forename: Steve
authors.initials: S
authors.lastname: Colley
authors.affiliation: Department of ENT, Queen Elizabeth Hospital, Birmingham, United Kingdom. Electronic address: shahz.ahmed@nhs.net.
authors.forename: Shahzada
authors.initials: S
authors.lastname: Ahmed
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D061330:Multidetector Computed Tomography; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D012189:Retrospective Studies