The image quality and diagnostic performance of CT perfusion-derived CT angiography versus that of conventional CT angiography

Background: To assess the image quality and diagnostic accuracy of computed tomography angiography (CTA) images derived from computed tomography perfusion (CTP) data, and to explore the feasibility of replacing conventional CTA.Methods: A total of 31 consecutive patients with suspected acute ischemic stroke were retrospectively analyzed. All patients underwent head and neck CTA and brain CTP examinations. All the CTP images were transmitted to the ShuKun artificial intelligence system, which reconstructs CTA derived from CTP (CTA-DF-CTP). The images were divided into 2 groups, including CTA-DF-CTP (Group A) and conventional CTA (Group B). The CT attenuation values, subjective image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), image quality, CT volume dose index (CTDIvol), dose length product (DLP), and effective radiation dose (ED) were compared between the 2 groups. Moreover, the consistency of vascular stenosis and stenosis degree between the 2 groups were measured and evaluated.Results: There were no significant differences in image noise, SNR, or CNR between Groups A and B (P>0.05). The CT attenuation values of the arteries were higher in Group A than in B [internal carotid artery (ICA) =548 & PLUSMN;112 vs. 454 & PLUSMN;85 Hounsfield units (HU), middle cerebral artery (MCA) =453 & PLUSMN;118 vs. 388 & PLUSMN;70 HU, and basilar artery (BA) =431 & PLUSMN;99 vs. 360 & PLUSMN;83 HU] (P<0.01). The image quality of the 2 groups met the requirement of clinical diagnosis (4.97 & PLUSMN;0.18 vs. 4.94 & PLUSMN;0.25). No significant difference was found in subjective evaluation (P>0.05). In Group A compared with Group B, the following reductions were observed: CTDIvol (10.7%; 100.8 vs. 112.9 mGy), DLP (23.0%; 1,613 & PLUSMN;0 vs. 2,093 & PLUSMN;88 mGy & BULL;cm), and ED (23.0%; 5.00 & PLUSMN;0.00 vs. 6.49 & PLUSMN;0.27 mSv). Conclusions: CTA-DF-CTP data provide diagnostic accuracy and image quality similar to those of conventional CTA of head and neck CTA.

Automated summary

This study aimed to evaluate the image quality and diagnostic accuracy of CTA images derived from CTP data and explore the possibility of replacing conventional CTA. The results showed that CTA-DF-CTP data provided similar diagnostic accuracy and image quality to conventional CTA in head and neck CTA.