Reduction of the estimated radiation dose and associated patient risk with prospective ECG-gated 256-slice CT coronary angiography

Abstract

Computed tomography (CT) coronary angiography has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but high radiation doses have been reported. Prospective ECG-gating using a 'step-and-shoot' axial scanning protocol has been shown to reduce radiation exposure effectively while maintaining diagnostic accuracy. 256-slice scanners with 80 mm detector coverage have been currently introduced into practice, but their impact on radiation exposure has not been adequately studied. The aim of this study was to assess radiation doses associated with CT coronary angiography using a 256-slice CT scanner. Radiation doses were estimated for 25 patients scanned with either prospective or retrospective ECG-gating. Image quality was assessed objectively in terms of mean CT attenuation at selected regions of interest on axial coronary images and subjectively by coronary segment quality scoring. It was found that radiation doses associated with prospective ECG-gating were significantly lower than retrospective ECG-gating (3.2 +/- 0.6 mSv versus 13.4 +/- 2.7 mSv). Consequently, the radiogenic fatal cancer risk for the patient is much lower with prospective gating (0.0176% versus 0.0737%). No statistically significant differences in image quality were observed between the two scanning protocols for both objective and subjective quality assessments. Therefore, prospective ECG-gating using a 'step-and-shoot' protocol that covers the cardiac anatomy in two axial acquisitions effectively reduces radiation doses in 256-slice CT coronary angiography without compromising image quality.

Effect of heart rate on the diagnostic accuracy of 256-slice computed tomography angiography in the detection of coronary artery stenosis: ROC curve analysis

“…Numerous studies have reported that multi-slice helical CTA has advantages in diagnosing CAD (21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Following the introduction of air-cushion suspension-bearing technology in 256-slice spiral CT, friction and oscillation between objects was dispelled, and this accelerated the rotary speed of the ball tube.…”

Radiation doses, noise properties, and in-plane spatial resolutions for CT coronary angiography using different CT scanners: Phantom study

“…Previous studies reported that SAS acquisition effectively reduced radiation doses in CTCA without compromising image quality [13,14] . However, it can only be used for in patients with stable sinus rhythms and low heart rates [15] .…”

Kardiyak Bilgisayarlı Tomografi (BT)’de Buluşlar: Kesit Mücadelesi, Dual Enerji, Miyokardiyal Perfüzyon Spesifik Kontrast Maddeler

“…İki yüz elli altı dedektörlü BT'de her bir rotasyonda z ekseninde 0,5 mm kesit kalınlığı ile 128 mm'lik alandan 3 boyutlu veriler alına-rak görüntü oluşturulmaktadır. Z ekseninde 8 cm genişlik olan 256 kesit BT'de, ileri tetiklemeli elektrokardiyografik (EKG) ile iki adımda tüm kalp taranabilmektedir (Resim 1a, b) [4]. On altı cm z eksen genişliğine sahip olan 320 dedektör BT'de, EKG tetiklemeli veya tetikleme olmaksızın mükemmel görüntü kalitesi elde etmek mümkündür ve tek aksiyel tarama ile kalbin tamamının görüntülenmesi tamamlanabilir.…”