Virtual Monochromatic Dual-Energy Aortoiliac CT Angiography With Reduced Iodine Dose: A Prospective Randomized Study.

Area of Science:

• Radiology
• Medical Imaging
• Cardiovascular Imaging

Background:

• Abdominopelvic aortoiliac CT angiography (CTA) is crucial for evaluating aneurysms.
• Optimizing contrast dose while maintaining image quality is an ongoing challenge.
• Dual-energy CT (DECT) offers potential for improved image quality and reduced contrast administration.

Purpose of the Study:

• To assess the feasibility of abdominopelvic aortoiliac CT angiography (CTA) using reduced iodine contrast medium.
• To evaluate low-energy virtual monochromatic (VMC) images from rapid-kilovoltage-switching dual-energy CT (DECT).
• To compare image quality and diagnostic performance against standard-dose single-energy CTA (SECTA).

Main Methods:

• 52 adults with abdominal aortoiliac aneurysm underwent DECTA with ~50% reduced iodine dose (16.0 or 16.2 g).
• Low-energy VMC images (40 and 50 keV) were acquired using rapid-kilovoltage-switching DECT.
• Image quality was assessed by two readers; intravascular attenuation and endoleak detection were evaluated.
• Radiation dose parameters were compared between DECTA and SECTA.

Main Results:

• DECTA examinations were diagnostic with image quality comparable to SECTA.
• Intravascular attenuation was significantly higher on 40- and 50-keV VMC images compared to SECTA (p < 0.01).
• Sensitivity and specificity for endoleak detection were high (78.9-94.7% and 100%, respectively).
• Total dose-length product was lower for DECTA than for SECTA.

Conclusions:

• Low-energy VMC DECTA with reduced iodine dose provides adequate intravascular attenuation.
• Diagnostic quality for aortoiliac evaluation is achieved with approximately 50% less iodine.
• This approach demonstrates feasibility and potential for dose reduction in abdominopelvic CTA.