Influence of selective photon shield combined with sinogram-affirmed iterative reconstruction on image quality and radiation dose during dual-energy CT angiography-mediated diagnosis of intracranial aneurysms

Abstract

Objective: To investigate the influence of a selective photon shield (SPS) combined with sinogram-affirmed iterative reconstruction (SAFIRE) on image quality and radiation dose during application of dual-energy CT angiography (CTA) for diagnosis of intracranial aneurysms. Methods: We retrospectively reviewed clinical data for 80 patients with diagnoses of spontaneous subarachnoid hemorrhage. All patients underwent three-dimensional digital subtraction angiography scans within 1 week after CTA. Data for patients in the conventional method group were subjected to filtered-back-projection reconstruction, while data for patients in the experimental method group were subjected to SAFIRE reconstruction. Image quality and scanning radiation dose were evaluated. Results: Background noise was significantly lower in the experimental method group than in the conventional method group, while the mean CT value did not differ between the groups. Signal-to-noise ratios were significantly higher in the experimental method group than in the conventional method group. However, the average CT value, contrast-to-noise ratio, and image quality scores did not differ between groups. All scores indicated acceptability for clinical diagnosis. The dose index of volume and effective dose were significantly lower in the experimental method group than in the conventional method group. Surgical verification showed that the detection rates in the experimental and conventional method groups were 100% (29/29) and 96% (25/26), respectively. Conclusions: SPS combined with SAFIRE applied for analysis of dual-energy CTA data improved the quality of CT images, reduced the radiation dosage, and increased diagnostic accuracy. Advances in knowledge: SPS combined with SAFIRE may improve the accuracy of diagnosis of intracranial aneurysms.

KEYWORDS:

• intracranial aneurysm
• tomography
• X-ray computed tomography
• radiation
• dosage
• image quality