title: Three-dimensional quantification and visualization of aortic calcification by multidetector-row computed tomography: a simple approach using a volume-rendering method.
abstract: OBJECTIVE
  Three-dimensional (3-D) visualization and quantification of vascular calcification (VC) are important to accelerate the multidisciplinary investigation of VC. Agatston scoring is the standard approach for evaluating coronary artery calcification. However, regarding aortic calcification (AC), quantification methods appear to vary among studies. The aim of this study was to introduce a simple technique of simultaneous quantification and 3-D visualization of AC and provide validation data.
  
  
  METHODS
  The main study comprised of 126 patients who underwent the thoracoabdominal plain computed tomography scan as preoperative general evaluation. AC was quantified using a volume-rendering (VR) method (VR AC volume) by extracting the volume with a density ≥130 HU within the total aorta. The concordance and reproducibility of the VR AC volume were validated in comparison with the conventional slice-by-slice voxel-based AC quantification (volumetric AC score) using the Agatston scoring software.
  
  
  RESULTS
  Excellent concordance between the VR AC volume and volumetric AC score was confirmed (Spearman correlation coefficient = 0.9997, mean difference = -0.05 ± 0.23 mL, p <0.0001). Excellent intraobserver and interobserver reliabilities were demonstrated using the Bland-Altman analysis as the mean intraobserver difference was 0.00 mL (p = 0.9863) and the mean interobserver difference was -0.01 mL (p = 0.6612).
  
  
  CONCLUSIONS
  The VR method was validated to be feasible. This simple approach could overcome the limitation of the current method based on slice-by-slice pixel or voxel summation, which lacks 3-D visual information. Accordingly, this approach would be promising for accelerating the investigation of VC.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: shumpei_8@hotmail.com.
authors.forename: Shumpei
authors.initials: S
authors.lastname: Mori
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Takaya
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kinugasa
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ito
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takamine
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Sei
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishii
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Atsushi K
authors.initials: AK
authors.lastname: Kono
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Seimi
authors.initials: S
authors.lastname: Satomi-Kobayashi
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Signal Transduction, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Rikitake
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okita
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000368:Aged; D001018:Aortic Diseases / Q000000981:diagnostic imaging*; D001027:Aortography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012984:Software; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
keywords: Agatston score; Aortic calcification; Multidetector-row computed tomography; Vascular calcification; Volume-rendering method