Calcium Scoring of Aortic Valve Calcification in Aortic Valve Stenosis with a Multislice Computed Tomography Scanner: Non‐enhanced versus Contrast‐enhanced Studies
Authors: Mühlenbruch, G.; Wildberger, J. E.; Koos, R.; Das, M.; Thomas, C.; Ruhl, K.; Niethammer, M.; Floh, T. G.; Stanzel, S.; Günther, R. W.; Mahnken, A. H.
Source: Acta Radiologica, 1 October 2005, vol. 46, no. 6, pp. 561-566(6)
Abstract:Purpose: 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. Material and 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 non‐enhanced 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. Conclusion: Quantification of AVC from contrast‐enhanced images is not reliable, as contrast material simulates calcification.
Document Type: Research Article
Affiliations: Department of Diagnostic Radiology, Department of Cardiology, Institute of Medical Statistics, University Hospital (RWTH) Aachen, Germany; Siemens Medical Solutions, Computed Tomography, Forchheim, Germany
Publication date: October 1, 2005