RELEVANCE OF SPECTRAL CT-SCAN IN THE FOLLOW UP OF INTRACRANIAL ANEURYSMS TREATED WITH WEB DEVICES: AN IN VITRO AND IN VIVO EXPERIMENT

Introduction

CTA provides a noninvasive technique in the follow-up of intracranial aneurysm treated with WEB; however, its applications remain limited due to WEB-related artifacts. The objective of this in vitro and in vivo study was to assess the improvement of image quality of WEB-treated aneurysms with spectral technology.

Material and Methods

WEBs were implanted in an aneurysm phantom, in two elastase-induced aneurysms in rabbits and in two patients as part as the aneurysm treatment. Polyenergetic, monoenergetic images from 40 to 140 keV and iodine-specific reconstructions, without and with MAR were acquired with a Revolution spectral CT scan (GE Healthcare); we evaluated the extent of distortions and SNR as well as the subjective image quality by three radiologists using a 4-point Likert scale.

Results

The objective analysis showed that low energy monoenergetic reconstructions (40-60 keV) allow an improved lumen density ratio in vitro and in animal model, neck density ratio in vivo and SNR in animal model compared with high energy reconstructions (120-140 keV), without a statistical difference with polyenergetic reconstructions. The subjective analysis showed that medium energy reconstructions (80-110 keV) allow an improved visual assessability of the lumen and neck. Iodine(water) reconstructions and MAR algorithm showed a reduction in the subjective quality of the images.

Conclusion

Low to medium kiloelectronvolt reconstructions without MAR improved the assessment of the artery lumen and aneurysm neck. There was no significant improvement compared with conventional images.