Radiation Dose, Image Quality, Stenosis Measurement, and CT Densitometry Using ECG-Triggered Coronary 64-MDCT Angiography: A Phantom Study

Horiguchi, Jun; Kiguchi, Masao; Fujioka, Chikako; Shen, Yun; Arie, Ryuichi; Sunasaka, Kenichi; Ito, Katsuhide

doi:10.2214/ajr.07.2191

Cited by 49 publications

(37 citation statements)

References 44 publications

(20 reference statements)

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“…ECG-gated MDCT provides high resolution images in a near isotropic condition that allows precise 3D measurements. Although MDCT imparts a high dose of ionizing radiation [21], it remains the gold standard for quantitative imaging owing to its high spatial resolution. MDCT allows fast and readily accessible acquisition of volume data that are prone to easy post-processing.…”

Section: Discussionmentioning

confidence: 99%

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

Huber

Rizzo

et al. 2008

Eur Radiol

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Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies Abstract The aim of this study was to provide an insight into normative values of the ascending aorta in regards to novel endovascular procedures using ECG-gated multi-detector CT angiography. Seventy-seven adult patients without ascending aortic abnormalities were evaluated. Measurements at relevant levels of the aortic root and ascending aorta were obtained. Diameter variations of the ascending aorta during cardiac cycle were also considered. Mean diameters (mm) were as follows: LV outflow tract 20.3±3.4, coronary sinus 34.2±4.1, sino-tubular junction 29.7±3.4 and mid ascending aorta 32.7±3.8 with coefficients of variation (CV) ranging from 12 to 17%. Mean distances (mm) were: from the plane passing through the proximal insertions of the aortic valve cusps to the right brachio-cephalic artery (BCA) 92.6±11.8, from the plane passing through the proximal insertions of the aortic valve cusps to the proximal coronary ostium 12.1±3.7, and between both coronary ostia 7.2±3.1, minimal arc of the ascending aorta from left coronary ostium to right BCA 52.9 ±9.5, and the fibrous continuity between the aortic valve and the anterior leaflet of the mitral valve 14.6±3.3, CV 13-43%. Mean aortic valve area was 582.0±131.9 mm 2 . The variation of the antero-posterior and transverse diameters of the ascending aorta during the cardiac cycle were 8.4% and 7.3%, respectively. Results showed large inter-individual variations in diameters and distances but with limited intra-individual variations during the cardiac cycle. A personalized approach for planning endovascular devices must be considered.

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Section: Discussionmentioning

confidence: 99%

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

Huber

Rizzo

et al. 2008

Eur Radiol

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“…Scans were performed with the following parameters: tube potential, 120 kVp; tube current-time product, 350mAs/rotation; detector collimation, 2 9 32 9 0.6 mm; slice acquisition, 2 9 64 9 0.6 mm by means of a z-flying focal spot; gantry rotation time, 330 ms. The scan was performed at a simulated heart rate of 60 bpm with a prospectively electrocardiography (ECG)-gated protocol; the latter being not different from retrospective gating neither in regards to stenosis measurement nor CT numbers [16].…”

Section: Ct Imagingmentioning

confidence: 99%

Systematic analysis on the relationship between luminal enhancement, convolution kernel, plaque density, and luminal diameter of coronary artery stenosis: a CT phantom study

Morsbach

Berger

Desbiolles

et al. 2013

Int J Cardiovasc Imaging

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To systematically investigate into the relationships between luminal enhancement, convolution kernel, plaque density, and stenosis severity in coronary computed tomography (CT) angiography. A coronary phantom including 63 stenoses (stenosis severity, 10-90 %; plaque densities, -100 to 1,000 HU) was loaded with increasing solutions of contrast material (luminal enhancement, 0-700 HU) and scanned in an anthropomorphic chest. CT data was acquired with prospective triggering using 64-section dual-source CT; reconstructions were performed with soft-tissue (B26f) and sharp convolution kernels (B46f). Two blinded and independent readers quantitatively assessed luminal diameter and CT number of plaque using electronic calipers. Measurement bias between phantom dimensions and CT measurements were calculated. Multivariate linear regression models identified predictors of bias. Inter-and intra-reader agreements of luminal diameter and CT number measurements were excellent (ICCs [ 0.91, p \ 0.01, each). Measurement bias of luminal diameter and plaque density was significantly (p \ 0.01, each) lower (-12 % and 58 HU, respectively) with B46f as opposed to B26f, especially in plaque densities [200 HU. Measurement bias was significantly (p \ 0.01, each) correlated (q = 0.37-55 and q = -0.70-85) with the differences between luminal enhancement and plaque density. In multivariate models, bias of luminal diameter assessment with CT was correlated with plaque density (b = 0.09, p \ 0.05). Convolution kernel (b = -0.29 and -0.38), stenosis severity (b = -0.45 and -0.38), and luminal enhancement (b = -0.11 and -0.29) represented independent (p \ 0.05,each) predictors of measurement bias of luminal diameter and plaque number, respectively. Significant independent relationships exist between luminal enhancement, convolution kernel, plaque density, and luminal diameter, which have to be taken into account when performing, evaluating, and interpreting coronary CT angiography.

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“…[6][7][8][9][10][11][12] However, because of the constant beating of the heart, it is a challenge to find a short tranquil phase for prospective ECG gated imaging of the coronary arteries. The application of prospective ECG gating has been mainly based on patients with a low heart rate.…”

Section: Discussionmentioning

confidence: 99%

“…[6][7][8][9][10][11][12] Since the early application of multislice CT in the field of noninvasive coronary angiography, CT has been improved from four detectors to 16,64,128, and 256 detectors. The diagnostic accuracy has also been improved greatly with the increasing width of detector array coverage.…”

mentioning

confidence: 99%

Study of optimal exposure windows using 320-Detector rows dynamic volume CT

Sun¹,

Li²,

Li³

et al. 2010

RMI

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Abstract:The purpose of this study was to determine the optimal electrocardiographic (ECG) pulsing windows and evaluate the effect on reduced dose and accuracy using 320-detector rows dynamic volume computed tomography (DVCT). A total of 170 patients were prospectively studied. The optimal reconstruction windows were analyzed in 76 patients scanned using retrospective ECG gating. Forty-seven patients were scanned by the predicted triggering windows. The optimal positions of exposure intervals according to different heart rates were evaluated. Optimal image quality, radiation dose, and diagnostic accuracy were then investigated by applying optimal triggering windows. The optimal ECG pulsing windows were determined as follows: when heart rate was ,70 beats per minute, the exposure windows should be preset at 60%-80%; for a heart rate 70-90 beats per minute at 70%-90%; and for a heart rate $90 beats per minute at 30%-50%. The radiation dose for patients scanned with prospective ECG gating was significantly lower (5.9 versus 12.9 mSv, P , 0.001). However, because two or three heart beats were needed when heart rate was .70 beats per minute, the radiation dose increased with increasing heart rate for both retrospective and prospective ECG gating (r = 0.64, P , 0.001 and r = 0.59, P , 0.001, respectively). On the basis of a per segment analysis, overall sensitivity was 98.0% (49/50), specificity was 99.2% (602/607), the positive predictive value was 90.7% (49/54), and the negative predictive value was 99.8% (602/603). In conclusion, DVCT has the potential to provide high image quality across a wide range of heart rates using an optimized ECG pulsing window. However, it is recommended to control heart rate below 70 beats per minute, if possible, to decrease the radiation dose.

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Radiation Dose, Image Quality, Stenosis Measurement, and CT Densitometry Using ECG-Triggered Coronary 64-MDCT Angiography: A Phantom Study

Abstract: Prospective ECG-triggered coronary 64-MDCT has the potential to reduce radiation exposure while maintaining the diagnostic performance of retrospective ECG-gated coronary 64-MDCT.

Cited by 49 publications

References 44 publications

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

Systematic analysis on the relationship between luminal enhancement, convolution kernel, plaque density, and luminal diameter of coronary artery stenosis: a CT phantom study

Study of optimal exposure windows using 320-Detector rows dynamic volume CT

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