Quantitative benchmarking of iodine imaging for two CT spectral imaging technologies: a phantom study

Area of Science:

• Medical Imaging
• Radiology
• CT Technology

Background:

• Dual-energy CT (DECT) enables quantitative iodine imaging.
• Benchmarking DECT technologies is crucial for accurate iodine concentration measurements.
• Understanding performance variations across different DECT systems and phantom sizes is essential.

Purpose of the Study:

• To quantitatively benchmark iodine imaging performance across different virtual monoenergetic energy levels, iodine maps, and virtual non-contrast images.
• To compare the accuracy of rapid switching single-source DECT and dual-source DECT technologies.
• To investigate the influence of phantom size and iodine concentration on quantitative DECT imaging.

Main Methods:

• Iodine solutions with varying concentrations were scanned using single-source and dual-source DECT scanners in phantoms simulating different body sizes.
• Datasets were reconstructed at various virtual monoenergetic energy levels, generating virtual non-contrast images and iodine maps.
• Region of interests (ROIs) were used to measure Hounsfield units (HU) and iodine concentrations.

Main Results:

• Single-source DECT accurately reproduced iodine concentrations (1.8-9.0% error), with minor phantom size dependence.
• Dual-source DECT exhibited significant deviations (-33.8% to 12.0% error) at high iodine concentrations.
• Virtual non-contrast images were affected by iodine concentration and phantom size on both vendors' scanners.

Conclusions:

• Quantitative measurements in post-processed DECT images depend on iodine concentration, phantom size, and the specific DECT technology used.
• Iodine maps demonstrate reliability for accurate iodine quantification.
• Differences between DECT technologies necessitate careful consideration for quantitative applications.