Endoleak

Discussion

66-year-old male with history of abdominal aortic aneurysm for which an endograft was placed.

Spectral virtual low and high monoenergetic images enabled better assessment of endoleak and stent graft integrity.

Axial images

Conventional images show area with faintly higher attenuation dorsolateral to anterior graft leg (red arrow, middle panel). Endoleak is uncertain. Spectral virtual monoenergetic image at 48 keV clearly demonstrates contrast extravasation outside the stent graft, confirming the presence of an endoleak (red arrow, left panel). Spectral virtual monoenergetic image at 200 keV demonstrates irregularity in the anterior stent graft leg, suggesting subtle fracture of the graft, with type IV endoleak (white arrow, right panel).

Conventional CTA for endoleak detection commonly consists of both arterial and late phase acquisitions to maximize the sensitivity for endoleak detection. Spectral CT enables detection of endoleak and evaluation of graft integrity with a single phase acquisition, whereby contrast enhancement and depiction of graft structure can be individually optimized.

Transverse slice at level of maximum aortic aneurysm diameter: Spectral virtual monoenergetic image at 48 keV clearly demonstrates endoleak.

Corresponding conventional image: Endoleak is only faintly visible and can easily be overlooked.

Corresponding spectral virtual monoenergetic image at 200 keV: shows subtle distortion of the stent graft.

History

Benefits or pitfalls of dual-energy CT