Complex aortic aneurysm. Assessment and follow-up

"This Mixed mode series (gated and non-gated) set up for arterial assessment before TAVI is fully adapted for complex aortic pathology surveillance and follow-up, it allowed us to visualize the aorta, its valve and its coronary branches, supra aortic and abdominal."

Dr. Marteau

Clinical Case

Patient history

A woman in her 70s was referred for preoperative evaluation, and surveillance following graft replacement of the thoracoabdominal aorta and digestive arterial revascularization, with underlying chronic abdominal aortic dissection extending to the left renal artery and left iliac axis.

Acquisition

  Gated Axial Gated Helical
kV 100 100
mA 100-450 100-480
Pitch 0.16 1.531
BPM 74/56 -
% ASiR-V 50 60
Rot. Time (s) 0.35 0.35
Coverage (mm) 400 400
Slice Thick. (mm)  0.625 0.625
Acq. Time (s)  13.1 2.2
DLP (mGy.cm)  737 190
IV Protocol 80cc (370) @3.5 cc/s -


Results

 

Enabling Technologies

For Revolution EVO, we redesigned the entire imaging chain using the new Clarity detector inherited from the breakthrough technology introduced on Revolution CT. 

ASiR-V comes standard and focuses primarily on more advanced noise and object modeling with added physics modeling to help reduce noise, improve low-contrast detectability, and reduce artifacts

  • Routinely image with up to 82% less dose1,2. Combining the speed of ASiR* with added capabilities from Veo* full model-based iterative reconstruction, the novel ASiR-V* iterative reconstruction algorithm brings low dose and improved quality to routine imaging. 

  • Up to 100% better spatial resolution1. ASiR-V has the capability to improve spatial resolution compared to FBP by allowing the reconstruction of higher-resolution images with no increase in image noise. 

  • Up to 135% improved low-contrast detectability1. ASiR-V improves the detectability of low-contrast objects by up to 135% when compared to corresponding FBP reconstructions at the same dose.

  • Up to 91% less image noise1. Depending upon the scan technique and reconstruction parameters, ASiR-V can significantly reduce electronic image noise compared to FBP at the same dose. 

  • Less streak artifact1. ASiR-V has the capability to reduce low-signal artifact, such as streak artifact, compared to FBP.

Conclusion

The fast switch between gated thoracic acquisition and non-gated helical scanning, enables the whole aorta assessment as well as coronary arteries imaging in one contrast injection and one apnea.


1 Low contrast detectability (LCD), image noise, spatial resolution and artifacts were assessed using reference factory protocols comparing ASiR-V and FBP. The LCD measured in 0.625 mm slices and tested for both head and body modes using the MITA CT IQ Phantom (CCT183, The Phantom Laboratory), using model observer method.

2 Image quality as defined by low contrast detectability. In clinical practice, the use of ASiR-V may reduce CT patient dose depending on the clinical task, patient size, anatomical location,and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task.


Related

About the institution