Reducing contrast dose using virtual monoenergetic imaging for aortic CTA.

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Three-dimensional computed tomographic angiography (3D-CTA) is crucial for preoperative aortic assessment.
• Dual-energy CT (DECT) with virtual monoenergetic imaging (VMI) offers advanced visualization capabilities.

Purpose of the Study:

• To evaluate the potential for contrast dose reduction in preoperative aortic 3D-CTA using VMI.
• To assess image quality and vessel shape accuracy with reduced iodine concentrations.

Main Methods:

• A custom cylinder phantom was used to quantify contrast-to-noise ratio (CNR) and vessel diameter.
• Volume rendering was employed for visual assessment of image quality.
• VMI was applied at various iodine concentrations and compared to conventional 120 kVp imaging.

Main Results:

• VMI at 40 keV consistently improved CNR compared to conventional imaging.
• An iodine content of 9 mgI/mL with VMI achieved image quality comparable to conventional 15 mgI/mL.
• Vessel shape (circularity index) was preserved at iodine levels of 9 mgI/mL and above with VMI.

Conclusions:

• Virtual monoenergetic imaging (VMI) at 40 keV enables significant reduction in contrast iodine content for preoperative aortic 3D-CTA.
• Diagnostic image quality and vessel morphology can be maintained with lower contrast doses, suggesting potential for improved patient outcomes and cost-effectiveness.