Abdominal vessel depiction on virtual triphasic spectral detector CT: initial clinical experience.

PURPOSE

To evaluate vessel assessment in virtual monoenergetic images (VMI) and virtual-non-contrast images (VNC) derived from venous phase spectral detector computed tomography (SDCT) acquisitions in comparison to arterial phase and true non-contrast (TNC) images.

METHODS

Triphasic abdominal SDCT was performed in 25 patients including TNC, arterial and venous phase. VMI and VNC were reconstructed from the venous phase and compared to conventional arterial-phase images (CI), TNC and conventional venous-phase images (CI). Vessel contrast and virtual contrast removal were analyzed with region-of-interest-based measurements and in a qualitative assessment.

RESULTS

Quantitative analysis revealed no significant attenuation differences between TNC and VNC in arterial vessels (p-range 0.07-0.47) except for the renal artery (p = 0.011). For venous vessels, significant differences between TNC and VNC were found for all veins (p < 0.001) except the inferior vena cava (p = 0.26), yet these differences remained within a 10 HU range in most patients. No significant attenuation differences were found between CI/VMI in arterial vessels (p-range 0.06-0.86). Contrast-to-noise ratio provided by VMI and CI was equivalent for all arterial vessels assessed (p-range 0.14-0.91). Qualitatively, VMI showed similar enhancement of abdominal and pelvic arteries as CI and VNC were rated comparable to TNC.

CONCLUSION

Our study suggests that VNC and VMI derived from single venous-phase SDCT offer comparable assessment of major abdominal vessels as provided by routine triphasic examinations, if no dynamic contrast information is required.