Radiation dose and physical image quality in 128-section dual-source computed tomographic coronary angiography: a phantom study.

One-hundred-and-twenty-eight-section dual X-ray source computed tomography (CT) systems have been introduced into clinical practice and have been shown to increase temporal resolution. Higher temporal resolution allows low-dose spiral mode at a high pitch factor during CT coronary angiography. We evaluated radiation dose and physical image qualities in CT coronary angiography by applying high-pitch spiral, step-and-shoot, and low-pitch spiral modes to determine the optimal acquisition mode for clinical situations.

[Image quality evaluation of new image reconstruction methods applying the iterative reconstruction].

The purpose of this study was to evaluate the image quality of an iterative reconstruction method, the iterative reconstruction in image space (IRIS), which was implemented in a 128-slices multi-detector computed tomography system (MDCT), Siemens Somatom Definition Flash (Definition). We evaluated image noise by standard deviation (SD) as many researchers did before, and in addition, we measured modulation transfer function (MTF), noise power spectrum (NPS), and perceptual low-contrast detectability using a water phantom including a low-contrast object with a 10 Hounsfield unit (HU) contrast, to evaluate whether the noise reduction of IRIS was effective. The SD and NPS were measured from the images of a water phantom.

Assessment of an organ-based tube current modulation in thoracic computed tomography.

Recently, specific computed tomography (CT) scanners have been equipped with organ-based tube current modulation (TCM) technology. It is possible that organ-based TCM will replace the conventional dose-reduction technique of reducing the effective milliampere-second. The aim of this study was to determine if organ-based TCM could reduce radiation exposure to the breasts without compromising the image uniformity and beam hardening effect in thoracic CT examinations.

[Evaluation of an exposed-radiation dose on a dual-source cardiac computed tomography examination with a prospective electrocardiogram-gated fast dual spiral scan].

We evaluated exposed-radiation doses on dual-source cardiac computed tomography (CT) examinations with prospective electrocardiogram (ECG)-gated fast dual spiral scans. After placing dosimeters at locations corresponding to each of the thoracic organs, prospective ECG-gated fast dual spirals and retrospective ECG-gated dual spiral scans were performed to measure the absorbed dose of each organ. In the prospective ECG-gated fast dual spiral scans, the average absorbed doses were 5.