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

Area of Science:

• Radiology and Imaging Science
• Medical Physics
• Computed Tomography (CT) Technology

Background:

• Spectral detector computed tomography (SDCT) enables advanced image reconstruction techniques.
• Virtual monoenergetic images (VMI) and virtual non-contrast (VNC) images can be derived from a single contrast-enhanced acquisition.
• Evaluating the diagnostic utility of these derived images for abdominal vessel assessment is crucial for optimizing CT protocols.

Purpose of the Study:

• To compare the diagnostic accuracy of VMI_40keV and VNC images with conventional arterial and true non-contrast (TNC) images.
• To assess abdominal and pelvic vessel visualization using images reconstructed from the venous phase of SDCT acquisitions.
• To determine if a single venous-phase SDCT acquisition can replace triphasic protocols for vessel assessment.

Main Methods:

• Triphasic abdominal SDCT was performed in 25 patients, including true non-contrast (TNC), arterial, and venous phases.
• Virtual monoenergetic images at 40 keV (VMI_40keV) and virtual non-contrast (VNC) images were reconstructed from the venous phase.
• Quantitative (region-of-interest measurements) and qualitative assessments compared VMI_40keV and VNC with conventional arterial (CI_art) and venous (CI_ven) phase images.

Main Results:

• No significant attenuation differences were observed between TNC and VNC in most arterial vessels, except the renal artery.
• VMI_40keV demonstrated equivalent arterial enhancement and contrast-to-noise ratio compared to conventional arterial phase images (CI_art).
• Qualitative assessment showed VMI_40keV provided similar arterial enhancement as CI_art, and VNC images were comparable to TNC.

Conclusions:

• Virtual non-contrast (VNC) and VMI_40keV derived from a single venous-phase SDCT acquisition offer comparable major abdominal vessel assessment.
• These derived images can potentially replace routine triphasic examinations when dynamic contrast information is not required.
• This simplification may lead to reduced radiation dose and contrast agent administration.