title: Calcium scoring of aortic valve calcification in aortic valve stenosis with a multislice computed tomography scanner: non-enhanced versus contrast-enhanced studies.
abstract: OBJECTIVE
  Previous studies have shown a positive correlation between amount of aortic valve calcification (AVC) and degree of aortic valve stenosis (AVS). We have investigated whether calcium scoring of AVC from contrast-enhanced images is reliable.
  
  
  METHODS
  Nineteen patients with suspected AVS underwent retrospectively ECG-gated multislice computed tomography (MSCT). Standardized scan protocols were applied prior to (120 KV, 133 mAseff) and after (120 KV, 500 mAseff) the administration of non-ionic contrast material. Image reconstruction was performed at 60% of the RR interval (slice thickness 3 mm, reconstruction increment 2 mm). AVC was quantified using Agatston score and calcium mass. The number of lesions was calculated. All nonenhanced images were scored using thresholds of 130 HU and 350 HU. Contrast-enhanced images were assessed with a threshold of 350 HU exclusively.
  
  
  RESULTS
  Fifteen patients with AVCs were included in the statistical analysis. The mean Agatston score (calcium mass) in non-enhanced images was 2888.4 +/- 2844.4 (694.2 mg +/- 869.3 mg). Altering the threshold from 130 HU to 350 HU led to a 58.2% (30.5%) decrease in the AVC score (P values < 0.001). Contrast-enhanced images showed an increased Agatston score (calcium mass) of 56.2% (33.5%) compared to non-enhanced images (P values <0.05) with the same threshold of 350 HU.
  
  
  CONCLUSIONS
  Quantification of AVC from contrast-enhanced images is not reliable, as contrast material simulates calcification.
authors.affiliation: Department of Diagnostic Radiology, Department of Cardiology, Institute of Medical Statistics, University Hospital (RWTH) Aachen, Germany. gmuehlen@rad.rwth-aachen.de
authors.forename: G
authors.initials: G
authors.lastname: Mühlenbruch
authors.forename: J E
authors.initials: JE
authors.lastname: Wildberger
authors.forename: R
authors.initials: R
authors.lastname: Koos
authors.forename: M
authors.initials: M
authors.lastname: Das
authors.forename: C
authors.initials: C
authors.lastname: Thomas
authors.forename: K
authors.initials: K
authors.lastname: Ruhl
authors.forename: M
authors.initials: M
authors.lastname: Niethammer
authors.forename: T G
authors.initials: TG
authors.lastname: Floh
authors.forename: S
authors.initials: S
authors.lastname: Stanzel
authors.forename: R W
authors.initials: RW
authors.lastname: Günther
authors.forename: A H
authors.initials: AH
authors.lastname: Mahnken
mesh_terms: D001021:Aortic Valve / Q000000981:diagnostic imaging*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging*; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D004562:Electrocardiography; D005260:Female; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide