Preliminary study of 80 kVp CT pulmonary angiography with ASIR using 20 ml of contrast agent

Objective To evaluate the feasibility of 80 kVp and 20 ml of contrast agent in CT pulmonary angiography ( CTPA) with spectral CT using ASIR reconstruction .Methods A total of 60 patients with suspected pulmonary embolism ( PE) under-went CTPA.They were randomly divided into 2 groups.Group A received 60 ml (370 mgI/ml) lopamidol at 120 kVp and FBP reconstruction.Group B were scanned with 80 kVp after injecting 20 ml (370 mgI/ml) lopamidol and 50%ASIR reconstruction. Independent t-test was used to compare the CT values , image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), volume CT dose index (CTDIvol), dose length product (DLP) and effective dose (ED).Mann-Whitney U test was used to com-pare the image quality score of the two groups .Results The CT values of pulmonary arteries , SNR, CNR in group B were higher than those of group A (all P 0.05).Conclusion 80 kVp and 20 ml of contrast agent in CTPA with spectral CT using ASIR reconstruction can provide high quality image , which can meet clinical diagnostic need , the radiation dose and contrast medium volume could be decreased .