Calcium scoring

A new method using ultrarapid computed tomography (spiral CT, ultrafast CT, electron-beam CT) minimizes artifact owing to motion of the heart during contraction and relaxation and provides a semiquan-titative assessment of calcium content in coronary arteries. Calcium scores greater than 150 provide a sensitivity of 74% and specificity of 89%, and this method may be cost-effective compared with ETT. 

Patients in this category include diose widi a 10-year risk of 10%-20% and one of the following (a) age >60 years (b) three or more risk factors (c) a severe risk factor (d) triglycerides >200 mg/dL and HDL-C <40 mg/dL (e) metabolic syndrome (f) highly sensitive C-reactive protein (CRP) >3 mg/L (g) coronary calcium score (age/gender adjusted) >75th percentile. 

Other CAD applications include calcium scoring, used to detect and quantify calcified coronary and aorta plaques, analysis of retinal fundus images for leaking blood vessels as an early indicator for diabetes, and the inspection of skin spots for melanoma (of particular attention in Australia), Burroni 2004. 

Becker CR, Knez A, Jakobs TF et al (1999) Detection and quantification of coronary artery calcification with electron-beam and conventional CT. Eur Radiol 9 620-624 Callister TQ, Cooil B, Raya SP, Lippolis NJ, Russo DJ, Raggi P (1998) Coronary artery disease improved reproducibility of calcium scoring with an electron-beam CT volumetric method. Radiology 208 807-814 Fleischmann D, Hallett RL, Rubin GD (2006) CT angiography of peripheral arterial disease. J Vase Interv Radiol 17 3-26... 

Ulzheimer S, Kalender WA (2003) Assessment of calcium scoring performance in cardiac computed tomography. Eur Radiol 13 484-497... 

All mentioned radiation dose estimates in this article refer to the coronary angiography part of the examination of the heart. However, in many cases a calcium scoring scan precedes CTCA. The scan can be executed with prospective gating the dose ranges between 0.5 and 1.8 mSv (Flohr et al. 2003 Trabold et al. 2003 Poll et al. 2002). Of note, in case of severe coronary... 

One of the easiest ways to reduce radiation dose is correct planning of the examination. In 64-slice cardiac CT, for example, 1 cm of scan length equals between 0.5 to 1 mSv of effective dose for the patient. A typical scan should start at the tracheal bifurcation and end beneath the heart. Anatomical information from the calcium scoring scan prior to the CTCA examination can be used to increase the exactitude of the scan (Fig. 6.1). Scan lengths in cardiac CT may range from 8-14 cm, but can ascend to more than 20 cm in patients with coronary bypass grafts. 

Screening for Diseases 84 Lung Cancer Screening 86 Colorectal Cancer Screening 86 Calcium Scoring 87 Whole-Body Screening 87... 

Calcium scoring at intervals of 4 years from age 50 to 66 years (i.e., five CT examinations). Scan parameters scan length 12 cm current time product 37 mAs pitch 0.37 coUimation 4 2.5 mm 120 kV CTDfyoi 9 mGy. 

Leschka S, Scheffel H, Desbiolles L etal. (2007) Combining Dual-Source Computed Tomography Coronary Angiography and Calcium Scoring Added Value for the Assessment of Coronary Artery Disease. Heart doi 10.1136/ hrt.2007.124800... 

Combining CT with SPECT 288 Combination of CT Calcium Scoring and Myocardial Perfusion SPECT Clinical Results 288 Patient Screening 288 Symptomatic Patients 290 Combination of Coronary CTA and Myocardial Perfusion SPECT Clinical Results 290 Image Fusion 293... 

Combination of CT Calcium Scoring and Myocardial Perfusion SPECT ... 

CT calcium scoring is mainly used for screening asymptomatic patients who are at least at intermediate risk for coronary atherosclerosis. Although myocardial perfusion SPECT can also predict outcome in asymptomatic subjects, CT is able to detect coronary atherosclerosis at earlier stages. Additionally, due to the simplicity and... 

Fig. 3. Electron Beam Computed Tomography (EBCT) coronary diagram of a 68-year-old asymptomatic male with an ABI of 0.8 shows extensive calcium deposits totaling 1000, i.e., coronary calcium score 1000. Coronary angiography (luminography) was recommended. 

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