Peak SNR in automated coronary calcium scoring: Selecting CT scan parameters and statistically defined scoring thresholdsa)

Medical Physics - Tập 37 Số 7Part1 - Trang 3621-3632 - 2010
Ben Arnold1, Ping Xiang, Song Mao, Matthew J. Budoff
1Image Analysis, 1380 Burkesville Rd. Columbia, Kentucky 42728, USA. [email protected]

Tóm tắt

PurposeDevelopment and verification of peak signal‐to‐noise ratio equations for determining optimum CT scanning and scoring parameters for a new automated coronary calcium scoring program (N‐vivo™). Experimental evaluation of the new program for scoring small calcium hydroxyapatite (CaHA) microspheres with small voxel CT images.MethodsTheoretical equations were developed using measures of noise, resolution, contrast, scatter, and x‐ray photon energy. A coronary calcium scoring test phantom containing very small CaHA microspheres was scanned simultaneously with a calibration phantom at three kVps, three voxel sizes, and three phantom sizes. Agatston and calibrated mass scores, noise standard deviations, peak noise, and peak signal voxel intensities were measured by the N‐vivo method for individual microspheres and in patient CT scans.ResultsThe equation was predictive of the optimum voxel size, kVp, and phantom size, and allowed automated computation of mass scoring thresholds specific to each patient and CT scan. The smallest microcalcification scored in the full sized phantom with the N‐vivo method by calibrated mass score (volume , mass 0.17 mg) was approximately four times smaller than that scored with the Agatston method (, mass 0.63 mg).ConclusionsThe equation can be used to model and optimize calcium scoring and CT scan parameters. The common assumptions that noise is too high in thin slice CT or requires high radiation dose for CAC scoring are shown to be misleading. The N‐vivo method showed higher detection sensitivity for small microspheres and more consistent mass scores at different beam energies than the conventional Agatston method. Advanced calcium scoring methods with higher sensitivity may allow improved monitoring of plaque changes and provide earlier detection of atherosclerosis.

Từ khóa


Tài liệu tham khảo

10.1016/j.jacc.2005.10.058

10.2214/ajr.174.4.1740915

10.1016/j.jacc.2003.10.059

10.1016/j.jacc.2006.01.041

10.1148/radiol.2251010173

10.1148/radiol.2362040513

10.1148/radiology.196.1.7784560

10.1148/radiol.2341040439

10.1148/radiol.2352040515

10.1097/01.RLI.0000073449.90302.75

10.1016/j.ejrad.2005.12.027

10.1148/radiol.2273020369

10.1007/s00330-006-0332-0

10.1016/S0167-5273(00)00449-6

10.1097/01.RLI.0000055289.97726.B1

10.1148/radiology.208.3.9722864

10.2214/ajr.181.3.1810743

10.1148/radiol.2332031470

10.1097/00004424-200302000-00006

10.1148/radiol.2292021305

10.2214/ajr.177.6.1771429

10.1016/S0002-9149(01)01767-2

10.1016/0735-1097(90)90282-T

10.2214/AJR.05.1369

10.1097/01.rli.0000084257.43062.c2

B. A.Arnold “Calibration of tissue densities in computerized tomography ” U.S. Patent No. 7 292 721 (6 November2007).

B. A.Arnold “Hybrid calibration of tissue densities in computerized tomography ” U.S. Patent No. 20 030 095 695 (22 May2003).

B. A.ArnoldandJ.Reed “Automatic detection and quantification of coronary and aortic calcium ” U.S. Patent No. 7 558 611 (7 July2009).

10.1118/1.594773

B. A. Arnold J. Kereiakes S. Thomas C. Orton 1986 Plenum New York PP55 PP81

B. A.Arnold S. S.Mao J.Child andM. J.Budoff “Coronary calcium phantom containing true CaHA microspheres for evaluation of advanced CT calcium scoring methods” (unpublished).

10.1118/1.595111

10.1118/1.1350438

10.1148/radiol.2292021016

10.1097/00004424-199408000-00001

Arnold B. A., 2009, Detection of very small calcifications by automated coronary calcium scoring with patient specific plaque definitions and hybrid phantom calibration, J. Cardiovasc. Comput. Tomogr., 3, 40

Thông tin
Thông tin xuất bản

Medical Physics

Tập 37 Số 7Part1

3621-3632

Thông tin tác giả