Application of 640-slice CT wide-detector volume scan in low-dose CT pulmonary angiography.

Background: Computed tomography (CT) pulmonary angiography (CTPA) examination has been frequently applied in detecting suspected pulmonary embolism (PE). How to reduce radiation dose to patients is also of concern.

Objective: To assess the value of using 640-slice CT wide-detector volume scan with adaptive statistical iterative reconstruction (ASIR) algorithm in low-dose CTPA.

Methods: Fifty-eight patients who performed with CTPA were divided into two groups randomly. In the first experimental group (n = 30), ASIR combined with volume scan were performed on the patients, while in the second conventional group (n = 28), patients received ASIR combined with conventional spiral scan. General data including age and body mass index, image quality, pulmonary arterial phase, and radiation dose were analyzed by t test in the two groups.

Results: In both groups, all images revealed the 5-order or higher pulmonary arterial branches and fully met the needs for clinical diagnosis. There was no statistical difference in general data between the two groups. In terms of pulmonary phase accuracy, compared with the conventional group, images at pulmonary arterial phase could be captured more accurately in the experimental group. CTDI in the experimental group decreased by 30% compared with that in the conventional group. The actual radiation dose in the experimental group was 1.5 mSv, which is reduced by 53% compared to that in the conventional group.

Conclusions: Compared with the conventional spiral scan, using 640-slice CT volume scan with ASIR in CTPA is more accurate in scanning phase and has lower radiation dose. There is no significant difference in image quality between the two groups.